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  Subjects -> BIOLOGY (Total: 2998 journals)
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    - BIOLOGY (1428 journals)
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BIOLOGY (1428 journals)                  1 2 3 4 5 6 7 8 | Last

Showing 1 - 200 of 1720 Journals sorted alphabetically
AAPS Journal     Hybrid Journal   (Followers: 20)
Achievements in the Life Sciences     Open Access   (Followers: 4)
ACS Synthetic Biology     Full-text available via subscription   (Followers: 23)
Acta Biologica Colombiana     Open Access   (Followers: 7)
Acta Biologica Hungarica     Full-text available via subscription   (Followers: 4)
Acta Biologica Sibirica     Open Access  
Acta Biomaterialia     Hybrid Journal   (Followers: 25)
Acta Biotheoretica     Hybrid Journal   (Followers: 5)
Acta Chiropterologica     Full-text available via subscription   (Followers: 6)
acta ethologica     Hybrid Journal   (Followers: 4)
Acta Limnologica Brasiliensia     Open Access   (Followers: 3)
Acta Médica Costarricense     Open Access   (Followers: 2)
Acta Musei Silesiae, Scientiae Naturales : The Journal of Silesian Museum in Opava     Open Access  
Acta Neurobiologiae Experimentalis     Open Access  
Acta Parasitologica     Hybrid Journal   (Followers: 9)
Acta Scientiarum. Biological Sciences     Open Access   (Followers: 2)
Acta Scientifica Naturalis     Open Access   (Followers: 2)
Actualidades Biológicas     Open Access   (Followers: 1)
Advanced Health Care Technologies     Open Access   (Followers: 4)
Advanced Studies in Biology     Open Access  
Advances in Antiviral Drug Design     Full-text available via subscription   (Followers: 3)
Advances in Bioinformatics     Open Access   (Followers: 19)
Advances in Biological Regulation     Hybrid Journal   (Followers: 4)
Advances in Biosensors and Bioelectronics     Open Access   (Followers: 6)
Advances in Cell Biology     Open Access   (Followers: 24)
Advances in Cellular and Molecular Biology of Membranes and Organelles     Full-text available via subscription   (Followers: 12)
Advances in Developmental Biology     Full-text available via subscription   (Followers: 11)
Advances in DNA Sequence-Specific Agents     Full-text available via subscription   (Followers: 5)
Advances in Ecological Research     Full-text available via subscription   (Followers: 45)
Advances in Environmental Sciences - International Journal of the Bioflux Society     Open Access   (Followers: 21)
Advances in Enzyme Research     Open Access   (Followers: 9)
Advances in Experimental Biology     Full-text available via subscription   (Followers: 7)
Advances in Genome Biology     Full-text available via subscription   (Followers: 12)
Advances in High Energy Physics     Open Access   (Followers: 19)
Advances in Human Biology     Open Access   (Followers: 1)
Advances in Life Science and Technology     Open Access   (Followers: 14)
Advances in Life Sciences     Open Access   (Followers: 5)
Advances in Marine Biology     Full-text available via subscription   (Followers: 16)
Advances in Molecular and Cell Biology     Full-text available via subscription   (Followers: 22)
Advances in Organ Biology     Full-text available via subscription   (Followers: 2)
Advances in Planar Lipid Bilayers and Liposomes     Full-text available via subscription   (Followers: 3)
Advances in Regenerative Biology     Open Access   (Followers: 1)
Advances in Space Biology and Medicine     Full-text available via subscription   (Followers: 5)
Advances in Structural Biology     Full-text available via subscription   (Followers: 8)
Advances in Virus Research     Full-text available via subscription   (Followers: 5)
African Journal of Range & Forage Science     Hybrid Journal   (Followers: 6)
AFRREV STECH : An International Journal of Science and Technology     Open Access   (Followers: 1)
Ageing Research Reviews     Hybrid Journal   (Followers: 8)
Aging Cell     Open Access   (Followers: 11)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Agrokreatif Jurnal Ilmiah Pengabdian kepada Masyarakat     Open Access  
AJP Cell Physiology     Full-text available via subscription   (Followers: 13)
AJP Endocrinology and Metabolism     Full-text available via subscription   (Followers: 23)
AJP Lung Cellular and Molecular Physiology     Full-text available via subscription   (Followers: 3)
Al-Kauniyah : Jurnal Biologi     Open Access  
Alasbimn Journal     Open Access   (Followers: 1)
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Biology Teacher     Full-text available via subscription   (Followers: 13)
American Fern Journal     Full-text available via subscription   (Followers: 1)
American Journal of Agricultural and Biological Sciences     Open Access   (Followers: 10)
American Journal of Bioethics     Hybrid Journal   (Followers: 10)
American Journal of Biostatistics     Open Access   (Followers: 9)
American Journal of Human Biology     Hybrid Journal   (Followers: 12)
American Journal of Medical and Biological Research     Open Access   (Followers: 7)
American Journal of Plant Sciences     Open Access   (Followers: 19)
American Journal of Primatology     Hybrid Journal   (Followers: 15)
American Malacological Bulletin     Full-text available via subscription   (Followers: 3)
American Naturalist     Full-text available via subscription   (Followers: 73)
Amphibia-Reptilia     Hybrid Journal   (Followers: 6)
Anaerobe     Hybrid Journal   (Followers: 4)
Analytical Methods     Full-text available via subscription   (Followers: 10)
Anatomical Science International     Hybrid Journal   (Followers: 2)
Animal Cells and Systems     Hybrid Journal   (Followers: 4)
Annales de Limnologie - International Journal of Limnology     Hybrid Journal   (Followers: 1)
Annales françaises d'Oto-rhino-laryngologie et de Pathologie Cervico-faciale     Full-text available via subscription   (Followers: 3)
Annales Henri Poincaré     Hybrid Journal   (Followers: 3)
Annales UMCS, Biologia     Open Access   (Followers: 1)
Annals of Applied Biology     Hybrid Journal   (Followers: 7)
Annals of Biomedical Engineering     Hybrid Journal   (Followers: 18)
Annals of Human Biology     Hybrid Journal   (Followers: 4)
Annual Review of Biomedical Engineering     Full-text available via subscription   (Followers: 17)
Annual Review of Biophysics     Full-text available via subscription   (Followers: 25)
Annual Review of Cancer Biology     Full-text available via subscription   (Followers: 1)
Annual Review of Cell and Developmental Biology     Full-text available via subscription   (Followers: 39)
Annual Review of Food Science and Technology     Full-text available via subscription   (Followers: 16)
Annual Review of Genomics and Human Genetics     Full-text available via subscription   (Followers: 20)
Annual Review of Phytopathology     Full-text available via subscription   (Followers: 10)
Anthropological Review     Open Access   (Followers: 24)
Anti-Infective Agents     Hybrid Journal   (Followers: 3)
Antibiotics     Open Access   (Followers: 9)
Antioxidants     Open Access   (Followers: 4)
Antioxidants & Redox Signaling     Hybrid Journal   (Followers: 8)
Antonie van Leeuwenhoek     Hybrid Journal   (Followers: 5)
Anzeiger für Schädlingskunde     Hybrid Journal   (Followers: 1)
Apidologie     Hybrid Journal   (Followers: 4)
Apmis     Hybrid Journal   (Followers: 1)
APOPTOSIS     Hybrid Journal   (Followers: 8)
Applied Bionics and Biomechanics     Open Access   (Followers: 8)
Applied Vegetation Science     Full-text available via subscription   (Followers: 9)
Aquaculture Environment Interactions     Open Access   (Followers: 2)
Aquaculture International     Hybrid Journal   (Followers: 22)
Aquaculture Reports     Open Access   (Followers: 3)
Aquaculture, Aquarium, Conservation & Legislation - International Journal of the Bioflux Society     Open Access   (Followers: 6)
Aquatic Biology     Open Access   (Followers: 5)
Aquatic Ecology     Hybrid Journal   (Followers: 32)
Aquatic Ecosystem Health & Management     Hybrid Journal   (Followers: 14)
Aquatic Science and Technology     Open Access   (Followers: 3)
Aquatic Toxicology     Hybrid Journal   (Followers: 20)
Archaea     Open Access   (Followers: 3)
Archiv für Molluskenkunde: International Journal of Malacology     Full-text available via subscription   (Followers: 3)
Archives of Biomedical Sciences     Open Access   (Followers: 7)
Archives of Microbiology     Hybrid Journal   (Followers: 8)
Archives of Natural History     Hybrid Journal   (Followers: 8)
Archives of Oral Biology     Hybrid Journal   (Followers: 2)
Archives of Virology     Hybrid Journal   (Followers: 5)
Archivum Immunologiae et Therapiae Experimentalis     Hybrid Journal   (Followers: 2)
Arid Ecosystems     Hybrid Journal   (Followers: 3)
Arquivos do Instituto Biológico     Open Access   (Followers: 1)
Arquivos do Museu Dinâmico Interdisciplinar     Open Access  
Arthropod Structure & Development     Hybrid Journal   (Followers: 2)
Arthropods     Open Access   (Followers: 1)
Artificial DNA: PNA & XNA     Hybrid Journal   (Followers: 2)
Artificial Photosynthesis     Open Access   (Followers: 1)
Asian Bioethics Review     Full-text available via subscription   (Followers: 2)
Asian Journal of Biodiversity     Open Access   (Followers: 5)
Asian Journal of Biological Sciences     Open Access   (Followers: 3)
Asian Journal of Cell Biology     Open Access   (Followers: 6)
Asian Journal of Developmental Biology     Open Access   (Followers: 2)
Asian Journal of Medical and Biological Research     Open Access   (Followers: 2)
Asian Journal of Nematology     Open Access   (Followers: 3)
Asian Journal of Poultry Science     Open Access   (Followers: 4)
Australian Life Scientist     Full-text available via subscription   (Followers: 2)
Australian Mammalogy     Hybrid Journal   (Followers: 6)
Autophagy     Hybrid Journal   (Followers: 2)
Avian Biology Research     Full-text available via subscription   (Followers: 5)
Avian Conservation and Ecology     Open Access   (Followers: 13)
Bacteriology Journal     Open Access   (Followers: 2)
Bacteriophage     Full-text available via subscription   (Followers: 4)
Bangladesh Journal of Bioethics     Open Access  
Bangladesh Journal of Plant Taxonomy     Open Access  
Bangladesh Journal of Scientific Research     Open Access   (Followers: 2)
Berita Biologi     Open Access   (Followers: 1)
Between the Species     Open Access   (Followers: 1)
Bio Tribune Magazine     Hybrid Journal  
BIO Web of Conferences     Open Access  
BIO-Complexity     Open Access  
Bio-Grafía. Escritos sobre la Biología y su enseñanza     Open Access  
Bioanalytical Reviews     Hybrid Journal   (Followers: 2)
Biocatalysis and Biotransformation     Hybrid Journal   (Followers: 6)
Biochemistry and Cell Biology     Hybrid Journal   (Followers: 14)
Biochimie     Hybrid Journal   (Followers: 7)
BioControl     Hybrid Journal   (Followers: 5)
Biocontrol Science and Technology     Hybrid Journal   (Followers: 5)
Biodemography and Social Biology     Hybrid Journal   (Followers: 1)
BioDiscovery     Open Access   (Followers: 1)
Biodiversity : Research and Conservation     Open Access   (Followers: 28)
Biodiversity and Natural History     Open Access   (Followers: 6)
Biodiversity Data Journal     Open Access   (Followers: 3)
Biodiversity Informatics     Open Access   (Followers: 1)
Biodiversity Information Science and Standards     Open Access  
Bioedukasi : Jurnal Pendidikan Biologi FKIP UM Metro     Open Access  
Bioeksperimen : Jurnal Penelitian Biologi     Open Access  
Bioelectrochemistry     Hybrid Journal   (Followers: 2)
Bioelectromagnetics     Hybrid Journal   (Followers: 1)
Bioenergy Research     Hybrid Journal   (Followers: 2)
Bioengineering and Bioscience     Open Access   (Followers: 1)
BioEssays     Hybrid Journal   (Followers: 10)
Bioethics     Hybrid Journal   (Followers: 14)
BioéthiqueOnline     Open Access  
Biofabrication     Hybrid Journal   (Followers: 3)
Biogeosciences (BG)     Open Access   (Followers: 10)
Biogeosciences Discussions (BGD)     Open Access   (Followers: 1)
Bioinformatics     Hybrid Journal   (Followers: 275)
Bioinformatics and Biology Insights     Open Access   (Followers: 15)
Bioinspiration & Biomimetics     Hybrid Journal   (Followers: 7)
Biointerphases     Open Access   (Followers: 1)
Biojournal of Science and Technology     Open Access  
Biologia     Hybrid Journal  
Biologia on-line : Revista de divulgació de la Facultat de Biologia     Open Access  
Biological Bulletin     Partially Free   (Followers: 5)
Biological Control     Hybrid Journal   (Followers: 4)
Biological Invasions     Hybrid Journal   (Followers: 17)
Biological Journal of the Linnean Society     Hybrid Journal   (Followers: 16)
Biological Letters     Open Access   (Followers: 4)
Biological Procedures Online     Open Access  
Biological Psychiatry     Hybrid Journal   (Followers: 43)
Biological Psychology     Hybrid Journal   (Followers: 6)
Biological Research     Open Access  
Biological Rhythm Research     Hybrid Journal   (Followers: 2)
Biological Theory     Hybrid Journal   (Followers: 2)
Biological Trace Element Research     Hybrid Journal  
Biologicals     Full-text available via subscription   (Followers: 9)
Biologics: Targets & Therapy     Open Access   (Followers: 1)
Biologie Aujourd'hui     Full-text available via subscription  
Biologie in Unserer Zeit (Biuz)     Hybrid Journal   (Followers: 42)
Biologija     Open Access  
Biology     Open Access   (Followers: 5)
Biology and Philosophy     Hybrid Journal   (Followers: 17)
Biology Bulletin     Hybrid Journal   (Followers: 1)

        1 2 3 4 5 6 7 8 | Last

Journal Cover Antioxidants
  [4 followers]  Follow
    
  This is an Open Access Journal Open Access journal
   ISSN (Online) 2076-3921
   Published by MDPI Homepage  [156 journals]
  • Antioxidants, Vol. 6, Pages 73: Modulation of Nrf2 by Olive Oil and Wine
           Polyphenols and Neuroprotection

    • Authors: Miriam Martínez-Huélamo, Jose Rodríguez-Morató, Anna Boronat, Rafael de la Torre
      First page: 73
      Abstract: Strong adherence to a Mediterranean diet is associated with improved cognitive function and a lower prevalence of mild cognitive impairment. Olive oil and red wine are rich sources of polyphenols which are responsible in part for the beneficial effects on cognitive functioning. Polyphenols induce endogenous antioxidant defense mechanisms by modulating transcription factors such as the nuclear factor (erythroid-derived 2)-like 2 (Nrf2). This review discusses the scientific data supporting the modulating effect of olive oil and red wine polyphenols on Nrf2 expression, and the potential health benefits associated with cognitive functioning.
      Citation: Antioxidants
      PubDate: 2017-09-26
      DOI: 10.3390/antiox6040073
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 74: Alpha-Lipoic Acid Downregulates IL-1β and
           IL-6 by DNA Hypermethylation in SK-N-BE Neuroblastoma Cells

    • Authors: Simona Dinicola, Sara Proietti, Alessandra Cucina, Mariano Bizzarri, Andrea Fuso
      First page: 74
      Abstract: Alpha-lipoic acid (ALA) is a pleiotropic molecule with antioxidant and anti-inflammatory properties, of which the effects are exerted through the modulation of NF-kB. This nuclear factor, in fact, modulates different inflammatory cytokines, including IL-1b and IL-6, in different tissues and cell types. We recently showed that IL-1b and IL-6 DNA methylation is modulated in the brain of Alzheimer’s disease patients, and that IL-1b expression is associated to DNA methylation in the brain of patients with tuberous sclerosis complex. These results prompted us to ask whether ALA-induced repression of IL-1b and IL-6 was dependent on DNA methylation. Therefore, we profiled DNA methylation in the 5’-flanking region of the two aforementioned genes in SK-N-BE human neuroblastoma cells cultured in presence of ALA 0.5 mM. Our experimental data pointed out that the two promoters are hypermethylated in cells supplemented with ALA, both at CpG and non-CpG sites. Moreover, the observed hypermethylation is associated with decreased mRNA expression and decreased cytokine release. These results reinforce previous findings indicating that IL-1b and IL-6 undergo DNA methylation-dependent modulation in neural models and pave the road to study the epigenetic mechanisms triggered by ALA.
      Citation: Antioxidants
      PubDate: 2017-09-26
      DOI: 10.3390/antiox6040074
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 75: Chemotherapy-Induced Tissue Injury: An
           Insight into the Role of Extracellular Vesicles-Mediated Oxidative Stress
           Responses

    • Authors: Chontida Yarana, Daret St. Clair
      First page: 75
      Abstract: The short- and long-term side effects of chemotherapy limit the maximum therapeutic dose and impair quality of life of survivors. Injury to normal tissues, especially chemotherapy-induced cardiomyopathy, is an unintended outcome that presents devastating health impacts. Approximately half of the drugs approved by the Food and Drug Administration for cancer treatment are associated with the generation of reactive oxygen species, and Doxorubicin (Dox) is one of them. Dox undergoes redox cycling by involving its quinone structure in the production of superoxide free radicals, which are thought to be instrumental to the role it plays in cardiomyopathy. Dox-induced protein oxidation changes protein function, translocation, and aggregation that are toxic to cells. To maintain cellular homeostasis, oxidized proteins can be degraded intracellularly by ubiquitin-proteasome pathway or by autophagy, depending on the redox status of the cell. Alternatively, the cell can remove oxidized proteins by releasing extracellular vesicles (EVs), which can be transferred to neighboring or distant cells, thereby instigating an intercellular oxidative stress response. In this article, we discuss the role of EVs in oxidative stress response, the potential of EVs as sensitive biomarkers of oxidative stress, and the role of superoxide dismutase in attenuating EV-associated oxidative stress response resulting from chemotherapy.
      Citation: Antioxidants
      PubDate: 2017-09-28
      DOI: 10.3390/antiox6040075
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 76: S-Adenosylmethionine and Superoxide
           Dismutase 1 Synergistically Counteract Alzheimer’s Disease Features
           Progression in TgCRND8 Mice

    • Authors: Rosaria Cavallaro, Vincenzina Nicolia, Maria Fiorenza, Sigfrido Scarpa, Andrea Fuso
      First page: 76
      Abstract: Recent evidence emphasizes the role of dysregulated one-carbon metabolism in Alzheimer’s Disease (AD). Exploiting a nutritional B-vitamin deficiency paradigm, we have previously shown that PSEN1 and BACE1 activity is modulated by one-carbon metabolism, leading to increased amyloid production. We have also demonstrated that S-adenosylmethionine (SAM) supplementation contrasted the AD-like features, induced by B-vitamin deficiency. In the present study, we expanded these observations by investigating the effects of SAM and SOD (Superoxide dismutase) association. TgCRND8 AD mice were fed either with a control or B-vitamin deficient diet, with or without oral supplementation of SAM + SOD. We measured oxidative stress by lipid peroxidation assay, PSEN1 and BACE1 expression by Real-Time Polymerase Chain Reaction (PCR), amyloid deposition by ELISA assays and immunohistochemistry. We found that SAM + SOD supplementation prevents the exacerbation of AD-like features induced by B vitamin deficiency, showing synergistic effects compared to either SAM or SOD alone. SAM + SOD supplementation also contrasts the amyloid deposition typically observed in TgCRND8 mice. Although the mechanisms underlying the beneficial effect of exogenous SOD remain to be elucidated, our findings identify that the combination of SAM + SOD could be carefully considered as co-adjuvant of current AD therapies.
      Citation: Antioxidants
      PubDate: 2017-09-30
      DOI: 10.3390/antiox6040076
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 77: Procyanidin B2 Protects Neurons from
           Oxidative, Nitrosative, and Excitotoxic Stress

    • Authors: Taylor Sutcliffe, Aimee Winter, Noelle Punessen, Daniel Linseman
      First page: 77
      Abstract: The aberrant generation of oxygen and nitrogen free radicals can cause severe damage to key cellular components, resulting in cell apoptosis. Similarly, excitotoxicity leads to protease activation and mitochondrial dysfunction, which subsequently causes cell death. Each of these factors play critical roles in the neuronal cell death underlying various neurodegenerative diseases. Procyanidin B2 (PB2) is a naturally occurring polyphenolic compound found in high concentrations in cocoa, apples, and grapes. Here, we examine the neuroprotective effects of PB2 in primary cultures of rat cerebellar granule neurons (CGNs) exposed to various stressors. CGNs were pre-incubated with PB2 and then neuronal stress was induced as described below. Mitochondrial oxidative stress was triggered with HA14-1, an inhibitor of the pro-survival Bcl-2 protein which induces glutathione-sensitive apoptosis. Glutamate and glycine were used to induce excitotoxicity. Sodium nitroprusside, a nitric oxide generating compound, was used to induce nitrosative stress. We observed significant dose-dependent protection of CGNs with PB2 for all of the above insults, with the greatest neuroprotective effect being observed under conditions of nitrosative stress. Intriguingly, the neuroprotective effect of PB2 against nitric oxide was superoxide-dependent, as we have recently shown for other catechol antioxidants. Finally, we induced neuronal stress through the removal of depolarizing extracellular potassium and serum (5K conditions), which is a classical model of intrinsic apoptosis in CGNs. PB2 did not display any significant protection against 5K-induced apoptosis at any concentration tested. We conclude that PB2 offers neuronal protection principally as an antioxidant by scavenging reactive oxygen and nitrogen species instead of through modulation of pro-survival cell signaling pathways. These findings suggest that PB2 may be an effective neuroprotective agent for the treatment of neurodegenerative disorders.
      Citation: Antioxidants
      PubDate: 2017-10-13
      DOI: 10.3390/antiox6040077
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 78: Total Phenolic and Yellow Pigment Contents
           and Antioxidant Activities of Durum Wheat Milling Fractions

    • Authors: Bin Fu, Constance Chiremba, Curtis Pozniak, Kun Wang, Shin Nam
      First page: 78
      Abstract: The aim of this study was to investigate the distribution of total yellow pigments, total phenolic compounds, and their antioxidant activities in various durum wheat milling fractions. Carotenoid composition of yellow pigment extract was also examined using UPLC. The ABTS radical scavenging activity of the milling fractions decreased in the order of short bran/bran > feed flour > flour/semolina in both total phenolic and total yellow pigment extracts. Yellow pigments extracts from bran, short bran, and feed flour exhibited 5.6–15.4% higher antioxidant activity than those of total phenolic extracts from the corresponding milling fractions. The UPLC results showed a non-carotenoid peak at Rt 0.47 min which was present in fractions of the grain outer layers but absent in semolina and flour. This peak absorbed in the UV range of 271 to 327 nm. These observations suggest that the unknown peak could be composed of phenolic compounds co-extracted in their free form with carotenoids in the polar water-saturated butanol solvent. The compounds in this peak could result in overestimation of carotenoid content and antioxidant activity in bran, short bran and feed flour as the peak contributed to 18.3–26.0% of total carotenoids if it was taken into account.
      Citation: Antioxidants
      PubDate: 2017-10-14
      DOI: 10.3390/antiox6040078
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 79: The Effect of Taurine on the Recovery from
           Eccentric Exercise-Induced Muscle Damage in Males

    • Authors: Yanita McLeay, Stephen Stannard, Matthew Barnes
      First page: 79
      Abstract: Eccentric exercise is known to bring about microstructural damage to muscle, initiating an inflammatory cascade involving various reactive oxygen species. This, in turn, can significantly impair physical performance over subsequent days. Taurine, a powerful endogenous antioxidant, has previously been shown to have a beneficial effect on muscle damage markers and recovery when taken for a few days to several weeks prior to eccentric exercise. However, to date no studies have looked at the effects of supplementing over the days following eccentric exercise on performance recovery. Thus, this study aimed to determine whether supplementing with taurine over three days following eccentric exercise attenuated the rise in serum creatine kinase and improved performance recovery in males. In a blinded, randomized, crossover design, ten recreationally-fit male participants completed 60 eccentric contractions of the biceps brachii muscle at maximal effort. Following this, participants were supplemented with 0.1 g∙kg−1 body weight∙day−1 of either taurine or rice flour in capsules. Over the next three mornings participants underwent blood tests for the analysis of the muscle damage marker creatine kinase and carried out performance measures on the isokinetic dynamometer. They also continued to consume the capsules in the morning and evening. The entire protocol was repeated two weeks later on the alternate arm and supplement. Significant decreases were seen in all performance measures from pre- to 24-h post-eccentric exercise (p < 0.001) for both taurine and placebo, indicating the attainment of muscle damage. Significant treatment effects were observed only for peak eccentric torque (p < 0.05). No significant time × treatment effects were observed (all p > 0.05). Serum creatine kinase levels did not significantly differ over time for either treatments, nor between treatments (p > 0.05). These findings suggest that taurine supplementation taken twice daily for 72 h following eccentric exercise-induced muscle damage may help improve eccentric performance recovery of the biceps brachii.
      Citation: Antioxidants
      PubDate: 2017-10-17
      DOI: 10.3390/antiox6040079
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 80: Photo Protection of Haematococcus
           pluvialis Algae by Astaxanthin: Unique Properties of Astaxanthin Deduced
           by EPR, Optical and Electrochemical Studies

    • Authors: A. Focsan, Nikolay Polyakov, Lowell Kispert
      First page: 80
      Abstract: The antioxidant astaxanthin is known to accumulate in Haematococcus pluvialis algae under unfavorable environmental conditions for normal cell growth. The accumulated astaxanthin functions as a protective agent against oxidative stress damage, and tolerance to excessive reactive oxygen species (ROS) is greater in astaxanthin-rich cells. The detailed mechanisms of protection have remained elusive, however, our Electron Paramagnetic Resonance (EPR), optical and electrochemical studies on carotenoids suggest that astaxanthin’s efficiency as a protective agent could be related to its ability to form chelate complexes with metals and to be esterified, its inability to aggregate in the ester form, its high oxidation potential and the ability to form proton loss neutral radicals under high illumination in the presence of metal ions. The neutral radical species formed by deprotonation of the radical cations can be very effective quenchers of the excited states of chlorophyll under high irradiation.
      Citation: Antioxidants
      PubDate: 2017-10-21
      DOI: 10.3390/antiox6040080
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 81: The Role of Food Antioxidants, Benefits of
           Functional Foods, and Influence of Feeding Habits on the Health of the
           Older Person: An Overview

    • Authors: Douglas Wilson, Paul Nash, Harpal Buttar, Keith Griffiths, Ram Singh, Fabien De Meester, Rie Horiuchi, Toru Takahashi
      First page: 81
      Abstract: This overview was directed towards understanding the relationship of brain functions with dietary choices mainly by older humans. This included food color, flavor, and aroma, as they relate to dietary sufficiency or the association of antioxidants with neurodegenerative diseases such as dementia and Alzheimer’s disease. Impairment of olfactory and gustatory function in relation to these diseases was also explored. The role of functional foods was considered as a potential treatment of dementia and Alzheimer’s disease through inhibition of acetylcholinesterase as well as similar treatments based on herbs, spices and antioxidants therein. The importance of antioxidants for maintaining the physiological functions of liver, kidney, digestive system, and prevention of cardiovascular diseases and cancer has also been highlighted. Detailed discussion was focused on health promotion of the older person through the frequency and patterns of dietary intake, and a human ecology framework to estimate adverse risk factors for health. Finally, the role of the food industry, mass media, and apps were explored for today’s new older person generation.
      Citation: Antioxidants
      PubDate: 2017-10-28
      DOI: 10.3390/antiox6040081
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 82: On the Origin of Superoxide Dismutase: An
           Evolutionary Perspective of Superoxide-Mediated Redox Signaling

    • Authors: Adam Case
      First page: 82
      Abstract: The field of free radical biology originated with the discovery of superoxide dismutase (SOD) in 1969. Over the last 5 decades, a plethora of research has been performed in species ranging from bacteria to mammals that has elucidated the molecular reaction, subcellular location, and specific isoforms of SOD. However, while humans have only begun to study this class of enzymes over the past 50 years, it has been estimated that these enzymes have existed for billions of years, and may be some of the original enzymes found in primitive life. As life evolved over this expanse of time, these enzymes have taken on new and different functional roles potentially in contrast to how they were originally derived. Herein, examination of the evolutionary history of these enzymes provides both an explanation and further inquiries into the modern-day role of SOD in physiology and disease.
      Citation: Antioxidants
      PubDate: 2017-10-30
      DOI: 10.3390/antiox6040082
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 83: Selenium Concentrations for Maximisation
           of Thioredoxin Reductase 2 Activity and Upregulation of Its Gene
           Transcripts in Senescent Human Fibroblasts

    • Authors: Hazem Ghneim
      First page: 83
      Abstract: Thioredoxin reductase 2 (TR2) activity, its gene transcripts, and hydrogen peroxide (H2O2) generation were examined in biochemically identified early-senescent P20 and senescent P30 fibroblasts subcultured in media (MEM2–MEM8) containing Se concentrations at 1.25, 2.5, 3.5, 5.0, 6.0, 7.0, and 8.0 µM, respectively. Although TR2 activity was moderately increased in P20 and P30 cells subcultured in routine growth medium (MEM1), there were progressive significant activity increases in the same cells subcultured in MEM2–MEM8. Such increases were proportional to Se concentration and peaked in P30 cells incubated with MEM7 and MEM8. H2O2 generation underwent progressive increases in MEM1-incubated P20 and P30 cells, peaking in the latter, but was gradually lowered in those incubated with MEM2–MEM8, reaching its lowest values when cells were incubated with MEM7 and MEM8. In parallel, TR2 gene transcripts underwent significant upregulation in P20 cells and higher magnitude upregulation in P30 cells subcultured in MEM2, MEM4, and MEM8 compared to those recorded for P5 pre-senescent cells subcultured in the same media. The computed Km Se values with respect to TR2 activity equaled 3.34 and 4.98 µM for P20 and P30 cells, respectively, with corresponding Vmax activities of 55.9 and 96.2 nmol/min/mg protein. It is concluded that senescent P30 cells utilize more Se and achieve maximal TR2 activity to combat oxidative injury.
      Citation: Antioxidants
      PubDate: 2017-10-30
      DOI: 10.3390/antiox6040083
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 84: Effects of Cocoa Antioxidants in Type 2
           Diabetes Mellitus

    • Authors: Sonia Ramos, María Martín, Luis Goya
      First page: 84
      Abstract: Type 2 Diabetes mellitus (T2D) is the most common form of diabetes and one of the most common chronic diseases. Control of hyperglycaemia by hypoglycaemic drugs is insufficient in for patients and nutritional approaches are currently being explored. Natural dietary compounds such as flavonoids, abundant in fruits and vegetables, have received broad attention because of their potential capacity to act as anti-diabetic agents. Especially cocoa flavonoids have been proved to ameliorate important hallmarks of T2D. In this review, an update of the most relevant reports published during the last decade in cell culture, animal models and human studies is presented. Most results support an anti-diabetic effect of cocoa flavonoids by enhancing insulin secretion, improving insulin sensitivity in peripheral tissues, exerting a lipid-lowering effect and preventing the oxidative and inflammatory damages associated to the disease. While it could be suggested that daily consumption of flavanols from cocoa or dark chocolate would constitute a potential preventive tool useful for the nutritional management of T2D, this recommendation should be cautious since most of commercially available soluble cocoa products or chocolates contain low amount of flavanols and are rich in sugar and calories that may aggravate glycaemic control in T2D patients.
      Citation: Antioxidants
      PubDate: 2017-10-31
      DOI: 10.3390/antiox6040084
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 85: Treatment with a Catalytic Superoxide
           Dismutase (SOD) Mimetic Improves Liver Steatosis, Insulin Sensitivity, and
           Inflammation in Obesity-Induced Type 2 Diabetes

    • Authors: Gina Coudriet, Meghan Delmastro-Greenwood, Dana Previte, Meghan Marré, Erin O’Connor, Elizabeth Novak, Garret Vincent, Kevin Mollen, Sojin Lee, H. Dong, Jon Piganelli
      First page: 85
      Abstract: Oxidative stress and persistent inflammation are exaggerated through chronic over-nutrition and a sedentary lifestyle, resulting in insulin resistance. In type 2 diabetes (T2D), impaired insulin signaling leads to hyperglycemia and long-term complications, including metabolic liver dysfunction, resulting in non-alcoholic fatty liver disease (NAFLD). The manganese metalloporphyrin superoxide dismustase (SOD) mimetic, manganese (III) meso-tetrakis (N-ethylpyridinium-2-yl) porphyrin (MnP), is an oxidoreductase known to scavenge reactive oxygen species (ROS) and decrease pro-inflammatory cytokine production, by inhibiting nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation. We hypothesized that targeting oxidative stress-induced inflammation with MnP would assuage liver complications and enhance insulin sensitivity and glucose tolerance in a high-fat diet (HFD)-induced mouse model of T2D. During 12 weeks of feeding, we saw significant improvements in weight, hepatic steatosis, and biomarkers of liver dysfunction with redox modulation by MnP treatment in HFD-fed mice. Additionally, MnP treatment improved insulin sensitivity and glucose tolerance, while reducing serum insulin and leptin levels. We attribute these effects to redox modulation and inhibition of hepatic NF-κB activation, resulting in diminished ROS and pro-inflammatory cytokine production. This study highlights the importance of controlling oxidative stress and secondary inflammation in obesity-mediated insulin resistance and T2D. Our data confirm the role of NF-κB-mediated inflammation in the development of T2D, and demonstrate the efficacy of MnP in preventing the progression to disease by specifically improving liver pathology and hepatic insulin resistance in obesity.
      Citation: Antioxidants
      PubDate: 2017-11-01
      DOI: 10.3390/antiox6040085
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 86: Insights into the Dichotomous Regulation
           of SOD2 in Cancer

    • Authors: Yeon Kim, Piyushi Gupta Vallur, Rébécca Phaëton, Karthikeyan Mythreye, Nadine Hempel
      First page: 86
      Abstract: While loss of antioxidant expression and the resultant oxidant-dependent damage to cellular macromolecules is key to tumorigenesis, it has become evident that effective oxidant scavenging is conversely necessary for successful metastatic spread. This dichotomous role of antioxidant enzymes in cancer highlights their context-dependent regulation during different stages of tumor development. A prominent example of an antioxidant enzyme with such a dichotomous role and regulation is the mitochondria-localized manganese superoxide dismutase SOD2 (MnSOD). SOD2 has both tumor suppressive and promoting functions, which are primarily related to its role as a mitochondrial superoxide scavenger and H2O2 regulator. However, unlike true tumor suppressor- or onco-genes, the SOD2 gene is not frequently lost, or rarely mutated or amplified in cancer. This allows SOD2 to be either repressed or activated contingent on context-dependent stimuli, leading to its dichotomous function in cancer. Here, we describe some of the mechanisms that underlie SOD2 regulation in tumor cells. While much is known about the transcriptional regulation of the SOD2 gene, including downregulation by epigenetics and activation by stress response transcription factors, further research is required to understand the post-translational modifications that regulate SOD2 activity in cancer cells. Moreover, future work examining the spatio-temporal nature of SOD2 regulation in the context of changing tumor microenvironments is necessary to allows us to better design oxidant- or antioxidant-based therapeutic strategies that target the adaptable antioxidant repertoire of tumor cells.
      Citation: Antioxidants
      PubDate: 2017-11-03
      DOI: 10.3390/antiox6040086
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 87: The SOD Mimic, MnTE-2-PyP, Protects from
           Chronic Fibrosis and Inflammation in Irradiated Normal Pelvic Tissues

    • Authors: Shashank Shrishrimal, Elizabeth Kosmacek, Arpita Chatterjee, McDonald Tyson, Rebecca Oberley-Deegan
      First page: 87
      Abstract: Pelvic radiation for cancer therapy can damage a variety of normal tissues. In this study, we demonstrate that radiation causes acute changes to pelvic fibroblasts such as the transformation to myofibroblasts and the induction of senescence, which persist months after radiation. The addition of the manganese porphyrin, MnTE-2-PyP, resulted in protection of these acute changes in fibroblasts and this protection persisted months following radiation exposure. Specifically, at two months post-radiation, MnTE-2-PyP inhibited the number of α-smooth muscle actin positive fibroblasts induced by radiation and at six months post-radiation, MnTE-2-PyP significantly reduced collagen deposition (fibrosis) in the skin and bladder tissues of irradiated mice. Radiation also resulted in changes to T cells. At two months post-radiation, there was a reduction of Th1-producing splenocytes, which resulted in reduced Th1:Th2 ratios. MnTE-2-PyP maintained Th1:Th2 ratios similar to unirradiated mice. At six months post-radiation, increased T cells were observed in the adipose tissues. MnTE-2-PyP treatment inhibited this increase. Thus, MnTE-2-PyP treatment maintains normal fibroblast function and T cell immunity months after radiation exposure. We believe that one of the reasons MnTE-2-PyP is a potent radioprotector is due to its protection of multiple cell types from radiation damage.
      Citation: Antioxidants
      PubDate: 2017-11-06
      DOI: 10.3390/antiox6040087
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 88: Polyphenols as Promising Drugs against
           Main Breast Cancer Signatures

    • Authors: María Losada-Echeberría, María Herranz-López, Vicente Micol, Enrique Barrajón-Catalán
      First page: 88
      Abstract: Breast cancer is one of the most common neoplasms worldwide, and in spite of clinical and pharmacological advances, it is still a clinical problem, causing morbidity and mortality. On the one hand, breast cancer shares with other neoplasms some molecular signatures such as an imbalanced redox state, cell cycle alterations, increased proliferation and an inflammatory status. On the other hand, breast cancer shows differential molecular subtypes that determine its prognosis and treatment. These are characterized mainly by hormone receptors especially estrogen receptors (ERs) and epidermal growth factor receptor 2 (HER2). Tumors with none of these receptors are classified as triple negative breast cancer (TNBC) and are associated with a worse prognosis. The success of treatments partially depends on their specificity and the adequate molecular classification of tumors. New advances in anticancer drug discovery using natural compounds have been made in the last few decades, and polyphenols have emerged as promising molecules. They may act on various molecular targets because of their promiscuous behavior, presenting several physiological effects, some of which confer antitumor activity. This review analyzes the accumulated evidence of the antitumor effects of plant polyphenols on breast cancer, with special attention to their activity on ERs and HER2 targets and also covering different aspects such as redox balance, uncontrolled proliferation and chronic inflammation.
      Citation: Antioxidants
      PubDate: 2017-11-07
      DOI: 10.3390/antiox6040088
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 89: Trans-Plasma Membrane Electron Transport
           and Ascorbate Efflux by Skeletal Muscle

    • Authors: Amanda Eccardt, Thomas Bell, Lyn Mattathil, Rohan Prasad, Shannon Kelly, Jonathan Fisher
      First page: 89
      Abstract: Trans-plasma membrane electron transport (tPMET) and the antioxidant roles of ascorbate reportedly play a role in protection of cells from damage by reactive oxygen species, which have been implicated in causing metabolic dysfunction such as insulin resistance. Skeletal muscle comprises the largest whole-body organ fraction suggesting a potential role of tPMET and ascorbate export as a major source of extracellular antioxidant. We hypothesized that skeletal muscle is capable of tPMET and ascorbate efflux. To measure these processes, we assayed the ability of cultured muscle cells, satellite cells, and isolated extensor digitorum longus (EDL) and soleus (SOL) to reduce two extracellular electron acceptors, water soluble tetrazolium salt 1 (WST-1), and dichlorophenolindophenol (DPIP). Ascorbate oxidase (AO) was utilized to determine which portion of WST-1 reduction was dependent on ascorbate efflux. We found that muscle cells can reduce extracellular electron acceptors. In C2C12 myotubes and satellite cells, a substantial portion of this reduction was dependent on ascorbate. In myotubes, glucose transporter 1 (GLUT1) inhibitors along with a pan-GLUT inhibitor suppressed tPMET and ascorbate efflux, while a GLUT4 inhibitor had no effect. The adenosine 5′-monophosphate (AMP)-activated protein kinase activator 5-Aminoimidazole-4-carboxamide ribonucleotide (AICAR) suppressed both tPMET and ascorbate efflux by myotubes, while insulin had no effect. Taken together, our data suggest that muscle cells are capable of tPMET and ascorbate efflux supported by GLUT1, thus illustrating a model in which resting muscle exports electrons and antioxidant to the extracellular environment.
      Citation: Antioxidants
      PubDate: 2017-11-09
      DOI: 10.3390/antiox6040089
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 90: Nox, Reactive Oxygen Species and
           Regulation of Vascular Cell Fate

    • Authors: Denise Burtenshaw, Roya Hakimjavadi, Eileen Redmond, Paul Cahill
      First page: 90
      Abstract: The generation of reactive oxygen species (ROS) and an imbalance of antioxidant defence mechanisms can result in oxidative stress. Several pro-atherogenic stimuli that promote intimal-medial thickening (IMT) and early arteriosclerotic disease progression share oxidative stress as a common regulatory pathway dictating vascular cell fate. The major source of ROS generated within the vascular system is the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase family of enzymes (Nox), of which seven members have been characterized. The Nox family are critical determinants of the redox state within the vessel wall that dictate, in part the pathophysiology of several vascular phenotypes. This review highlights the putative role of ROS in controlling vascular fate by promoting endothelial dysfunction, altering vascular smooth muscle phenotype and dictating resident vascular stem cell fate, all of which contribute to intimal medial thickening and vascular disease progression.
      Citation: Antioxidants
      PubDate: 2017-11-14
      DOI: 10.3390/antiox6040090
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 91: Bioactive Components in Moringa Oleifera
           Leaves Protect against Chronic Disease

    • Authors: Marcela Vergara-Jimenez, Manal Almatrafi, Maria Fernandez
      First page: 91
      Abstract: Moringa Oleifera (MO), a plant from the family Moringacea is a major crop in Asia and Africa. MO has been studied for its health properties, attributed to the numerous bioactive components, including vitamins, phenolic acids, flavonoids, isothiocyanates, tannins and saponins, which are present in significant amounts in various components of the plant. Moringa Oleifera leaves are the most widely studied and they have shown to be beneficial in several chronic conditions, including hypercholesterolemia, high blood pressure, diabetes, insulin resistance, non-alcoholic liver disease, cancer and overall inflammation. In this review, we present information on the beneficial results that have been reported on the prevention and alleviation of these chronic conditions in various animal models and in cell studies. The existing limited information on human studies and Moringa Oleifera leaves is also presented. Overall, it has been well documented that Moringa Oleifera leaves are a good strategic for various conditions associated with heart disease, diabetes, cancer and fatty liver.
      Citation: Antioxidants
      PubDate: 2017-11-16
      DOI: 10.3390/antiox6040091
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 92: MnSOD and Cyclin B1 Coordinate a
           Mito-Checkpoint during Cell Cycle Response to Oxidative Stress

    • Authors: Amanda Kalen, Iman Ahmad, Maher Abdalla, Yunxia O’Malley, Prabhat Goswami, Ehab Sarsour
      First page: 92
      Abstract: Communication between the nucleus and mitochondrion could coordinate many cellular processes. While the mechanisms regulating this communication are not completely understood, we hypothesize that cell cycle checkpoint proteins coordinate the cross-talk between nuclear and mitochondrial functions following oxidative stress. Human normal skin fibroblasts, representative of the G2-phase, were irradiated with 6 Gy of ionizing radiation and assayed for cyclin B1 translocation, mitochondrial function, reactive oxygen species (ROS) levels, and cytotoxicity. In un-irradiated controls, cyclin B1 was found primarily in the nucleus of G2-cells. However, following irradiation, cyclin B1 was excluded from the nucleus and translocated to the cytoplasm and mitochondria. These observations were confirmed further by performing transmission electron microscopy and cell fractionation assays. Cyclin B1 was absent in mitochondria isolated from un-irradiated G2-cells and present in irradiated G2-cells. Radiation-induced translocation of cyclin B1 from the nucleus to the mitochondrion preceded changes in the activities of mitochondrial proteins, that included decreases in the activities of aconitase and the mitochondrial antioxidant enzyme, manganese superoxide dismutase (MnSOD), and increases in complex II activity. Changes in the activities of mito-proteins were followed by an increase in dihydroethidium (DHE) oxidation (indicative of increased superoxide levels) and loss of the mitochondrial membrane potential, events that preceded the restart of the stalled cell cycle and subsequently the loss in cell viability. Comparable results were also observed in un-irradiated control cells overexpressing mitochondria-targeted cyclin B1. These results indicate that MnSOD and cyclin B1 coordinate a cross-talk between nuclear and mitochondrial functions, to regulate a mito-checkpoint during the cell cycle response to oxidative stress.
      Citation: Antioxidants
      PubDate: 2017-11-17
      DOI: 10.3390/antiox6040092
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 93: Tocotrienols: A Family of Molecules with
           Specific Biological Activities

    • Authors: Raffaella Comitato, Roberto Ambra, Fabio Virgili
      First page: 93
      Abstract: Vitamin E is a generic term frequently used to group together eight different molecules, namely: α-, β-, γ- and δ-tocopherol and the corresponding tocotrienols. The term tocopherol and eventually Vitamin E and its related activity was originally based on the capacity of countering foetal re-absorption in deficient rodents or the development of encephalomalacia in chickens. In humans, Vitamin E activity is generally considered to be solely related to the antioxidant properties of the tocolic chemical structure. In recent years, several reports have shown that specific activities exist for each different tocotrienol form. In this short review, tocotrienol ability to inhibit cancer cell growth and induce apoptosis thanks to specific mechanisms, not shared by tocopherols, such as the binding to Estrogen Receptor-β (ERβ) and the triggering of endoplasmic reticulum (EndoR) stress will be described. The neuroprotective activity will also be presented and discussed. We propose that available studies strongly indicate that specific forms of tocotrienols have a distinct mechanism and biological activity, significantly different from tocopherol and more specifically from α-tocopherol. We therefore suggest not pooling them together within the broad term “Vitamin E” on solely the basis of their putative antioxidant properties. This option implies obvious consequences in the assessment of dietary Vitamin E adequacy and, probably more importantly, on the possibility of evaluating a separate biological variable, determinant in the relationship between diet and health.
      Citation: Antioxidants
      PubDate: 2017-11-18
      DOI: 10.3390/antiox6040093
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 94: Symposium on Vitamin C, 15th September
           2017; Part of the Linus Pauling Institute’s 9th International Conference
           on Diet and Optimum Health

    • Authors: Anitra Carr
      First page: 94
      Abstract: The Linus Pauling Institute’s 9th International Conference on Diet and Optimum Health took place on 13–15 September 2017 in Corvallis, OR, USA, on the beautiful Oregon State University campus [...]
      Citation: Antioxidants
      PubDate: 2017-11-21
      DOI: 10.3390/antiox6040094
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 95: Vitamin E Bioavailability: Mechanisms of
           Intestinal Absorption in the Spotlight

    • Authors: Emmanuelle Reboul
      First page: 95
      Abstract: Vitamin E is an essential fat-soluble micronutrient whose effects on human health can be attributed to both antioxidant and non-antioxidant properties. A growing number of studies aim to promote vitamin E bioavailability in foods. It is thus of major interest to gain deeper insight into the mechanisms of vitamin E absorption, which remain only partly understood. It was long assumed that vitamin E was absorbed by passive diffusion, but recent data has shown that this process is actually far more complex than previously thought. This review describes the fate of vitamin E in the human gastrointestinal lumen during digestion and focuses on the proteins involved in the intestinal membrane and cellular transport of vitamin E across the enterocyte. Special attention is also given to the factors modulating both vitamin E micellarization and absorption. Although these latest results significantly improve our understanding of vitamin E intestinal absorption, further studies are still needed to decipher the molecular mechanisms driving this multifaceted process.
      Citation: Antioxidants
      PubDate: 2017-11-22
      DOI: 10.3390/antiox6040095
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 96: Carotenoids from Marine Organisms:
           Biological Functions and Industrial Applications

    • Authors: Christian Galasso, Cinzia Corinaldesi, Clementina Sansone
      First page: 96
      Abstract: As is the case for terrestrial organisms, carotenoids represent the most common group of pigments in marine environments. They are generally biosynthesized by all autotrophic marine organisms, such as bacteria and archaea, algae and fungi. Some heterotrophic organisms also contain carotenoids probably accumulated from food or partly modified through metabolic reactions. These natural pigments are divided into two chemical classes: carotenes (such as lycopene and α- and β-carotene) that are composed of hydrogen and carbon; xanthophylls (such as astaxanthin, fucoxanthin and lutein), which are constituted by hydrogen, carbon and oxygen. Carotenoids, as antioxidant compounds, assume a key role in the protection of cells. In fact, quenching of singlet oxygen, light capture and photosynthesis protection are the most relevant biological functions of carotenoids. The present review aims at describing (i) the biological functions of carotenoids and their benefits for human health, (ii) the most common carotenoids from marine organisms and (iii) carotenoids having large success in pharmaceutical, nutraceutical and cosmeceutical industries, highlighting the scientific progress in marine species cultivation for natural pigments production.
      Citation: Antioxidants
      PubDate: 2017-11-23
      DOI: 10.3390/antiox6040096
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 97: The Subcellular Distribution of
           Alpha-Tocopherol in the Adult Primate Brain and Its Relationship with
           Membrane Arachidonic Acid and Its Oxidation Products

    • Authors: Emily Mohn, Matthew Kuchan, John Erdman, Martha Neuringer, Nirupa Matthan, Chung-Yen Chen, Elizabeth Johnson
      First page: 97
      Abstract: The relationship between α-tocopherol, a known antioxidant, and polyunsaturated fatty acid (PUFA) oxidation, has not been directly investigated in the primate brain. This study characterized the membrane distribution of α-tocopherol in brain regions and investigated the association between membrane α-tocopherol and PUFA content, as well as brain PUFA oxidation products. Nuclear, myelin, mitochondrial, and neuronal membranes were isolated using a density gradient from the prefrontal cortex (PFC), cerebellum (CER), striatum (ST), and hippocampus (HC) of adult rhesus monkeys (n = 9), fed a stock diet containing vitamin E (α-, γ-tocopherol intake: ~0.7 µmol/kg body weight/day, ~5 µmol/kg body weight/day, respectively). α-tocopherol, PUFAs, and PUFA oxidation products were measured using high performance liquid chromatography (HPLC), gas chromatography (GC) and liquid chromatography-gas chromatography/mass spectrometry (LC-GC/MS) respectively. α-Tocopherol (ng/mg protein) was highest in nuclear membranes (p < 0.05) for all regions except HC. In PFC and ST, arachidonic acid (AA, µg/mg protein) had a similar membrane distribution to α-tocopherol. Total α-tocopherol concentrations were inversely associated with AA oxidation products (isoprostanes) (p < 0.05), but not docosahexaenoic acid oxidation products (neuroprostanes). This study reports novel data on α-tocopherol accumulation in primate brain regions and membranes and provides evidence that α-tocopherol and AA are similarly distributed in PFC and ST membranes, which may reflect a protective effect of α-tocopherol against AA oxidation.
      Citation: Antioxidants
      PubDate: 2017-11-26
      DOI: 10.3390/antiox6040097
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 98: Differential Effects of Superoxide
           Dismutase Mimetics after Mechanical Overload of Articular Cartilage

    • Authors: Mitchell Coleman, Marc Brouillette, Nicholas Andresen, Rebecca Oberley-Deegan, James Martin
      First page: 98
      Abstract: Post-traumatic osteoarthritis can develop as a result of the initial mechanical impact causing the injury and also as a result of chronic changes in mechanical loading of the joint. Aberrant mechanical loading initiates excessive production of reactive oxygen species, oxidative damage, and stress that appears to damage mitochondria in the surviving chondrocytes. To probe the benefits of increasing superoxide removal with small molecular weight superoxide dismutase mimetics under severe loads, we applied both impact and overload injury scenarios to bovine osteochondral explants using characterized mechanical platforms with and without GC4403, MnTE-2-PyP, and MnTnBuOE-2-PyP. In impact scenarios, each of these mimetics provides some dose-dependent protection from cell death and loss of mitochondrial content while in repeated overloading scenarios only MnTnBuOE-2-PyP provided a clear benefit to chondrocytes. These results support the hypothesis that superoxide is generated in excess after impact injuries and suggest that superoxide production within the lipid compartment may be a critical mediator of responses to chronic overload. This is an important nuance distinguishing roles of superoxide, and thus superoxide dismutases, in mediating damage to cellular machinery in hyper-acute impact scenarios compared to chronic scenarios.
      Citation: Antioxidants
      PubDate: 2017-11-30
      DOI: 10.3390/antiox6040098
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 99: Recent Advances in our Understanding of
           Tocopherol Biosynthesis in Plants: An Overview of Key Genes, Functions,
           and Breeding of Vitamin E Improved Crops

    • Authors: Steffi Fritsche, Xingxing Wang, Christian Jung
      First page: 99
      Abstract: Tocopherols, together with tocotrienols and plastochromanols belong to a group of lipophilic compounds also called tocochromanols or vitamin E. Considered to be one of the most powerful antioxidants, tocochromanols are solely synthesized by photosynthetic organisms including plants, algae, and cyanobacteria and, therefore, are an essential component in the human diet. Tocochromanols potent antioxidative properties are due to their ability to interact with polyunsaturated acyl groups and scavenge lipid peroxyl radicals and quench reactive oxygen species (ROS), thus protecting fatty acids from lipid peroxidation. In the plant model species Arabidopsis thaliana, the required genes for tocopherol biosynthesis and functional roles of tocopherols were elucidated in mutant and transgenic plants. Recent research efforts have led to new outcomes for the vitamin E biosynthetic and related pathways, and new possible alternatives for the biofortification of important crops have been suggested. Here, we review 30 years of research on tocopherols in model and crop species, with emphasis on the improvement of vitamin E content using transgenic approaches and classical breeding. We will discuss future prospects to further improve the nutritional value of our food.
      Citation: Antioxidants
      PubDate: 2017-12-01
      DOI: 10.3390/antiox6040099
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 100: Effects of the Macular Carotenoid Lutein
           in Human Retinal Pigment Epithelial Cells

    • Authors: Xiaoming Gong, Christian Draper, Geoffrey Allison, Raju Marisiddaiah, Lewis Rubin
      First page: 100
      Abstract: Retinal pigment epithelial (RPE) cells are central to retinal health and homoeostasis. Oxidative stress-induced damage to the RPE occurs as part of the pathogenesis of age-related macular degeneration and neovascular retinopathies (e.g., retinopathy of prematurity, diabetic retinopathy). The xanthophyll carotenoids, lutein and zeaxanthin, are selectively taken up by the RPE, preferentially accumulated in the human macula, and transferred to photoreceptors. These macular xanthophylls protect the macula (and the broader retina) via their antioxidant and photo-protective activities. This study was designed to investigate effects of various carotenoids (β-carotene, lycopene, and lutein) on RPE cells subjected to either hypoxia or oxidative stress, in order to determine if there is effect specificity for macular pigment carotenoids. Using human RPE-derived ARPE-19 cells as an in vitro model, we exposed RPE cells to various concentrations of the specific carotenoids, followed by either graded hypoxia or oxidative stress using tert-butyl hydroperoxide (tBHP). The results indicate that lutein and lycopene, but not β-carotene, inhibit cell growth in undifferentiated ARPE-19 cells. Moreover, cell viability was decreased under hypoxic conditions. Pre-incubation of ARPE-19 cells with lutein or lycopene protected against tBHP-induced cell loss and cell co-exposure of lutein or lycopene with tBHP essentially neutralized tBHP-dependent cell death at tBHP concentrations up to 500 μM. Our findings indicate that lutein and lycopene inhibit the growth of human RPE cells and protect the RPE against oxidative stress-induced cell loss. These findings contribute to the understanding of the protective mechanisms attributable to retinal xanthophylls in eye health and retinopathies.
      Citation: Antioxidants
      PubDate: 2017-12-04
      DOI: 10.3390/antiox6040100
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 101: Tempol Supplementation Restores Diaphragm
           Force and Metabolic Enzyme Activities in mdx Mice

    • Authors: David Burns, Izza Ali, Clement Rieux, James Healy, Greg Jasionek, Ken O’Halloran
      First page: 101
      Abstract: Duchenne muscular dystrophy (DMD) is characterized by striated muscle weakness, cardiomyopathy, and respiratory failure. Since oxidative stress is recognized as a secondary pathology in DMD, the efficacy of antioxidant intervention, using the superoxide scavenger tempol, was examined on functional and biochemical status of dystrophin-deficient diaphragm muscle. Diaphragm muscle function was assessed, ex vivo, in adult male wild-type and dystrophin-deficient mdx mice, with and without a 14-day antioxidant intervention. The enzymatic activities of muscle citrate synthase, phosphofructokinase, and lactate dehydrogenase were assessed using spectrophotometric assays. Dystrophic diaphragm displayed mechanical dysfunction and altered biochemical status. Chronic tempol supplementation in the drinking water increased diaphragm functional capacity and citrate synthase and lactate dehydrogenase enzymatic activities, restoring all values to wild-type levels. Chronic supplementation with tempol recovers force-generating capacity and metabolic enzyme activity in mdx diaphragm. These findings may have relevance in the search for therapeutic strategies in neuromuscular disease.
      Citation: Antioxidants
      PubDate: 2017-12-06
      DOI: 10.3390/antiox6040101
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 102: In Vitro and In Vivo Antioxidant and
           Anti-Hyperglycemic Activities of Moroccan Oat Cultivars

    • Authors: Ilias Marmouzi, El Karym, Nezha Saidi, Bouchra Meddah, Mourad Kharbach, Azlarab Masrar, Mounya Bouabdellah, Layachi Chabraoui, Khalid El Allali, Yahia Cherrah, My Faouzi
      First page: 102
      Abstract: Improvement of oat lines via introgression is an important process for food biochemical functionality. This work aims to evaluate the protective effect of phenolic compounds from hybrid Oat line (F11-5) and its parent (Amlal) on hyperglycemia-induced oxidative stress and to establish the possible mechanisms of antidiabetic activity by digestive enzyme inhibition. Eight phenolic acids were quantified in our samples including ferulic, p-hydroxybenzoic, caffeic, salicylic, syringic, sinapic, p-coumaric and chlorogenic acids. The Oat extract (2000 mg/kg) ameliorated the glucose tolerance, decreased Fasting Blood Glucose (FBG) and oxidative stress markers, including Superoxide dismutase (SOD), Catalase (CAT), Glutathione peroxidase (GPx), Glutathione (GSH) and Malondialdehyde (MDA) in rat liver and kidney. Furthermore, Metformin and Oat intake prevented anxiety, hypercholesterolemia and atherosclerosis in diabetic rats. In vivo anti-hyperglycemic effect of Oat extracts has been confirmed by their inhibitory activities on α-amylase (723.91 μg/mL and 1027.14 μg/mL) and α-glucosidase (1548.12 μg/mL & 1803.52 μg/mL) enzymes by mean of a mixed inhibition.
      Citation: Antioxidants
      PubDate: 2017-12-06
      DOI: 10.3390/antiox6040102
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 44: Antifungal and Antiochratoxigenic
           Activities of Essential Oils and Total Phenolic Extracts: A Comparative
           Study

    • Authors: Rachelle EL Khoury, Ali Atoui, Florence Mathieu, Hiba Kawtharani, Anthony EL Khoury, Richard Maroun, Andre EL Khoury
      First page: 44
      Abstract: This study is intended to prevent ochratoxin A (OTA) production by Aspergillus carbonarius S402 using essential oils (EOs) and total phenolic compounds extracted from plants and herbs. The EOs used in this study are the following: bay leaves, cumin, fenugreek, melissa, mint, and sage. As for the phenolic compounds, they were extracted from bay leaves, cumin, fenugreek, melissa, mint, sage, anise, chamomile, fennel, rosemary, and thyme. The experiments were conducted on Synthetic Grape Medium (SGM) medium at 28 °C for 4 days. OTA was extracted from the medium with methanol and quantified using HPLC (High Performance Liquid Chromatography). Results showed that EOs had a greater impact than the total phenolic extracts on the OTA production. Reduction levels ranged between 25% (sage) and 80% (melissa) for the EOs at 5 µL mL−1, and 13% (thyme) and 69% (mint) for the phenolic extracts. Although they did not affect the growth of A. carbonarius, total phenolic extracts and EOs were capable of partially reducing OTA production. Reduction levels depended on the nature of the plants and the concentration of the EOs. Reducing OTA with natural extracts could be a solution to prevent OTA production without altering the fungal growth, thus preserving the natural microbial balance.
      PubDate: 2017-07-09
      DOI: 10.3390/antiox6030044
      Issue No: Vol. 6, No. 3 (2017)
       
  • Antioxidants, Vol. 6, Pages 45: Vitamin E and Alzheimer’s Disease—Is
           It Time for Personalized Medicine'

    • Authors: Breana Cervantes, Lynn Ulatowski
      First page: 45
      Abstract: For the last two decades, it has been hotly debated whether vitamin E—the major lipid-soluble antioxidant, which functions to maintain neurological integrity—is efficacious as a therapy for Alzheimer’s disease. Several factors key to the debate, include (1) which of the eight naturally-occurring vitamin E forms should be used; (2) how combination treatments affect vitamin E efficacy; and (3) safety concerns that most-recently resurfaced after the results of the Selenium and vitamin E Cancer prevention trial SELECT prostate cancer trial. However, with the advent of new genetic technologies and identifications of vitamin E-modulating single nucleotide polymorphisms (SNPs), we propose that clinical trials addressing the question “Is vitamin E an effective treatment for Alzheimer’s disease” should consider a more focused and personalized medicine approach to designing experiments. An individual’s naturally-occurring SNP variants may indeed influence vitamin E’s therapeutic effect on Alzheimer’s disease.
      PubDate: 2017-06-24
      DOI: 10.3390/antiox6030045
      Issue No: Vol. 6, No. 3 (2017)
       
  • Antioxidants, Vol. 6, Pages 46: Evaluating Modern Techniques for the
           Extraction and Characterisation of Sunflower (Hellianthus annus L.) Seeds
           Phenolics

    • Authors: Panagiotis Zoumpoulakis, Vassilia Sinanoglou, Eleni Siapi, George Heropoulos, Charalampos Proestos
      First page: 46
      Abstract: Recently there is a great interest in using high energy techniques (HET) which involve microwave or ultrasound-assisted extraction (MAE and UAE) for isolation of natural bioactive compounds from plant foods. Such bioactive compounds are phenolics which were determined from sunflower (Helianthus annuus L.) kernels and hulls (defatted) utilising two different high energy extraction techniques, ultrasound and microwave assisted solvent extraction. All samples were characterised by ultra-high-performance liquid chromatography-electrospray ionization-mass spectrometry (UHPLC-ESI-MS). The effect of parameters such as the nature of the solvent, volume of solvent, temperature and time is discussed. It is proved that the techniques applied had reduced solvent consumption and shorter extraction times, and extraction yields of the analytes were equal to or to some extent higher than those obtained with conventional techniques. Total Phenolic Composition (TPC) of samples examined was studied by the Folin-Ciocalteu method and results were presented in μg gallic acid equivalents (GAE)/g dry extract. Kernels proved to have the higher amount of TPC while the press residues had shown comparable TPC results. The antioxidant activity of samples was spectrophotometrically determined by 2,2-Diphenyl-1-Picrylhydrazyl (DPPH) assay using Butylated hydroxyl toluene (BHT) as reference compound to compare with samples. Sunflower seeds (kernels) showed again the highest antiradical efficiency (AE) compared to hulls and press-residue extract. Afterwards, ferric reducing ability of plasma (FRAP) and trolox equivalent antioxidant capacity (TEAC) assays were used for measuring the antioxidant capacity of samples. Press residue, a by-product of sunflower oil extraction, contained phenolics as shown by UHPLC-ESI-MS analysis. Hence, later on these compounds can be possibly utilised by food or neutraceutical industries. Phenolic substances characterised in hulls, kernels, and press residue were phenolic acids, mainly chlorogenic, caffeic, cinnamic, 4-hydroxybenzoic and p-coumaric.
      PubDate: 2017-06-24
      DOI: 10.3390/antiox6030046
      Issue No: Vol. 6, No. 3 (2017)
       
  • Antioxidants, Vol. 6, Pages 47: Deletion of TXNIP Mitigates High-Fat
           Diet-Impaired Angiogenesis and Prevents Inflammation in a Mouse Model of
           Critical Limb Ischemia

    • Authors: Sally Elshaer, Islam Mohamed, Maha Coucha, Sara Altantawi, Wael Eldahshan, Megan Bartasi, Ahmed Shanab, Renee Lorys, Azza El-Remessy
      First page: 47
      Abstract: Background: Previous work demonstrated that high-fat diet (HFD) triggered thioredoxin-interacting protein (TXNIP) and that silencing TXNIP prevents diabetes-impaired vascular recovery. Here, we examine the impact of genetic deletion of TXNIP on HFD-impaired vascular recovery using hind limb ischemia model. Methods: Wild type mice (WT, C57Bl/6) and TXNIP knockout mice (TKO) were fed either normal chow diet (WT-ND and TKO-ND) or 60% high-fat diet (WT-HFD and TKO-HFD). After four weeks of HFD, unilateral hind limb ischemia was performed and blood flow was measured using Laser doppler scanner at baseline and then weekly for an additional three weeks. Vascular density, nitrative stress, infiltration of CD68+ macrophages, and expression of inflammasome, vascular endothelial growth factor (VEGF), VEGF receptor-2 were examined by slot blot, Western blot and immunohistochemistry. Results: By week 8, HFD caused similar increases in weight, cholesterol and triglycerides in both WT and TKO. At week 4 and week 8, HFD significantly impaired glucose tolerance in WT and to a lesser extent in TKO. HFD significantly impaired blood flow and vascular density (CD31 labeled) in skeletal muscle of WT mice compared to ND but not in TKO. HFD and ischemia significantly induced tyrosine nitration, and systemic IL-1β and infiltration of CD68+ cells in skeletal muscle from WT but not from TKO. HFD significantly increased cleaved-caspase-1 and IL-1 β compared to ND. Under both ND, ischemia tended to increase VEGF expression and increased VEGFR2 activation in WT only but not TKO. Conclusion: Similar to prior observation in diabetes, HFD-induced obesity can compromise vascular recovery in response to ischemic insult. The mechanism involves increased TXNIP-NLRP3 (nucleotide-binding oligomerization domain-like receptor protein 3) inflammasome activation, nitrative stress and impaired VEGFR2 activation. Deletion of TXNIP restored blood flow, reduced nitrative stress and blunted inflammasome-mediated inflammation; however, it did not impact VEGF/VEGFR2 in HFD. Targeting TXNIP-NLRP3 inflammasome can provide potential therapeutic target in obesity-induced vascular complication.
      PubDate: 2017-06-29
      DOI: 10.3390/antiox6030047
      Issue No: Vol. 6, No. 3 (2017)
       
  • Antioxidants, Vol. 6, Pages 48: Early and Late Induction of KRAS and HRAS
           Proto-Oncogenes by Reactive Oxygen Species in Primary Astrocytes

    • Authors: Samantha Messina, Erika Di Zazzo, Bruno Moncharmont
      First page: 48
      Abstract: Astrocytes, one of the predominant types of glial cells, function as both supportive and metabolic cells for the brain. Among mammalian tissues, the highest levels of p21Ras protein are detected in the brain. Here, we investigated the expression of KRAS and HRAS proto-oncogenes in primary astrocytes following acute oxidative stimulation. Reactive oxygen species (ROS) changed the expression of proto-oncogenes at both transcriptional and translational levels. De novo protein synthesis analysis measured approximate values of proteins half-life, ranging from 1–4 h, of the different H- and K- isoforms by western blot analysis. Quantitative gene expression analysis of KRAS and HRAS revealed an unexpected short-term induction of KRAS mRNA in primary astrocytes in response to acute stimulation. Indeed, cultured astrocytes responded to proteasomal inhibition by preventing the reduction of c-K-Ras. A fraction of K-Ras protein accumulated in the presence of ROS and cycloheximide, while a substantial proportion was continuously synthesized. These data indicate that ROS regulate in a complementary fashion p21Ras isoforms in primary astrocytes: K-Ras is rapidly and transiently induced by post-translational and post-transcriptional mechanisms, while H-Ras is stably induced by mRNA accumulation. We suggest that K-Ras and H-Ras are ROS sensors that adapt cells to metabolic needs and oxidative stress.
      PubDate: 2017-06-29
      DOI: 10.3390/antiox6030048
      Issue No: Vol. 6, No. 3 (2017)
       
  • Antioxidants, Vol. 6, Pages 49: Vitamin C and Microvascular Dysfunction in
           Systemic Inflammation

    • Authors: Karel Tyml
      First page: 49
      Abstract: Sepsis, life-threatening organ dysfunction caused by a dysfunctional host response to infection, is associated with high mortality. A promising strategy to improve the outcome is to inject patients intravenously with ascorbate (vitamin C). In animal models of sepsis, this injection improves survival and, among others, the microvascular function. This review examines our recent work addressing ascorbate’s ability to inhibit arteriolar dysfunction and capillary plugging in sepsis. Arteriolar dysfunction includes impaired vasoconstriction/dilation (previously reviewed) and impaired conduction of vasoconstriction/dilation along the arteriole. We showed that ascorbate injected into septic mice prevents impaired conducted vasoconstriction by inhibiting neuronal nitric oxide synthase-derived NO, leading to restored inter-endothelial electrical coupling through connexin 37-containing gap junctions. Hypoxia/reoxygenation (confounding factor in sepsis) also impairs electrical coupling by protein kinase A (PKA)-dependent connexin 40 dephosphorylation; ascorbate restores PKA activation required for this coupling. Both effects of ascorbate could explain its ability to protect against hypotension in sepsis. Capillary plugging in sepsis involves P-selectin mediated platelet-endothelial adhesion and microthrombi formation. Early injection of ascorbate prevents capillary plugging by inhibiting platelet-endothelial adhesion and endothelial surface P-selectin expression. Ascorbate also prevents thrombin-induced platelet aggregation and platelet surface P-selectin expression, thus preventing microthrombi formation. Delayed ascorbate injection reverses capillary plugging and platelet-endothelial adhesion; it also attenuates sepsis-induced drop in platelet count in systemic blood. Thrombin-induced release of plasminogen-activator-inhibitor-1 from platelets (anti-fibrinolytic event in sepsis) is inhibited by ascorbate pH-dependently. Thus, under acidotic conditions in sepsis, ascorbate promotes dissolving of microthrombi in capillaries. We propose that protected/restored arteriolar conduction and capillary bed perfusion by ascorbate contributes to reduced organ injury and improved survival in sepsis.
      PubDate: 2017-06-29
      DOI: 10.3390/antiox6030049
      Issue No: Vol. 6, No. 3 (2017)
       
  • Antioxidants, Vol. 6, Pages 50: Antioxidant Activity of Yichun Blue
           Honeysuckle (YBHS) Berry Counteracts CCl4-Induced Toxicity in Liver Injury
           Model of Mice

    • Authors: Mian-Ying Wang, Madhuwanti Srinivasan, Subramanyam Dasari, Parnal Narvekar, Angela Samy, Venkata Dontaraju, Lin Peng, Gary Anderson, Gnanasekar Munirathinam
      First page: 50
      Abstract: Yichun Blue Honeysuckle (YBHS) is reported to have a broad range of health benefits including protection against a number of chronic diseases. The objective of our study was to determine whether YBHS exhibits antioxidant activity, and if so, determine how it provides protection against oxidative stress. Eight-week old mice (25 male and 25 female) were randomized into five groups (n = 10 per group). YBHS extract (at 6.25%, 12.5%, or 25%) was administrated via intra-gastric tube to mice at 0.1 mL/10 g body weight once daily for 7 days. On the 8th day, all animals except for the controls received 250 mg/kg of CCl4 through an intra-gastric tube. The animals were sacrificed 6 h after CCl4 administration. Liver samples obtained from these mice were analyzed for the levels of Thiobarbituric Acid Reactive Substances (TBARS) and glutathione and the activities of Superoxide Dismutase (SOD), Catalase (CAT), and Glutathione Peroxidase (GPx), using biochemical assay kits. Our results showed that YBHS indeed reduces lipid peroxidation, suggesting that YBHS decreases the Reactive Oxygen Species (ROS) levels. We also found that YBHS activated the endogenous antioxidant enzymes including superoxide dismutase, catalase, and glutathione peroxidase and its co-enzyme glutathione reductase. In addition, we showed that glutathione levels were increased by YBHS treatment. Furthermore, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay revealed that YBHS has potent free radical scavenging activity. Based on the results from our study, we conclude that YBHS scavenges ROS by enhancing the activity of the endogenous antioxidant defense system activity for conferring liver protective effects.
      PubDate: 2017-06-30
      DOI: 10.3390/antiox6030050
      Issue No: Vol. 6, No. 3 (2017)
       
  • Antioxidants, Vol. 6, Pages 51: Molecular Mechanisms behind Free Radical
           Scavengers Function against Oxidative Stress

    • Authors: Fereshteh Ahmadinejad, Simon Geir Møller, Morteza Hashemzadeh-Chaleshtori, Gholamreza Bidkhori, Mohammad-Saeid Jami
      First page: 51
      Abstract: Accumulating evidence shows that oxidative stress is involved in a wide variety of human diseases: rheumatoid arthritis, Alzheimer’s disease, Parkinson’s disease, cancers, etc. Here, we discuss the significance of oxidative conditions in different disease, with the focus on neurodegenerative disease including Parkinson’s disease, which is mainly caused by oxidative stress. Reactive oxygen and nitrogen species (ROS and RNS, respectively), collectively known as RONS, are produced by cellular enzymes such as myeloperoxidase, NADPH-oxidase (nicotinamide adenine dinucleotide phosphate-oxidase) and nitric oxide synthase (NOS). Natural antioxidant systems are categorized into enzymatic and non-enzymatic antioxidant groups. The former includes a number of enzymes such as catalase and glutathione peroxidase, while the latter contains a number of antioxidants acquired from dietary sources including vitamin C, carotenoids, flavonoids and polyphenols. There are also scavengers used for therapeutic purposes, such as 3,4-dihydroxyphenylalanine (L-DOPA) used routinely in the treatment of Parkinson’s disease (not as a free radical scavenger), and 3-methyl-1-phenyl-2-pyrazolin-5-one (Edaravone) that acts as a free radical detoxifier frequently used in acute ischemic stroke. The cell surviving properties of L-DOPA and Edaravone against oxidative stress conditions rely on the alteration of a number of stress proteins such as Annexin A1, Peroxiredoxin-6 and PARK7/DJ-1 (Parkinson disease protein 7, also known as Protein deglycase DJ-1). Although they share the targets in reversing the cytotoxic effects of H2O2, they seem to have distinct mechanism of function. Exposure to L-DOPA may result in hypoxia condition and further induction of ORP150 (150-kDa oxygen-regulated protein) with its concomitant cytoprotective effects but Edaravone seems to protect cells via direct induction of Peroxiredoxin-2 and inhibition of apoptosis.
      PubDate: 2017-07-10
      DOI: 10.3390/antiox6030051
      Issue No: Vol. 6, No. 3 (2017)
       
  • Antioxidants, Vol. 6, Pages 52: Silencing of NRF2 Reduces the Expression
           of ALDH1A1 and ALDH3A1 and Sensitizes to 5-FU in Pancreatic Cancer Cells

    • Authors: Hong-Quan Duong, Kyu You, Seunghoon Oh, Sahng-June Kwak, Yeon-Sun Seong
      First page: 52
      Abstract: Pancreatic cancer remains an intractable cancer with a poor five-year survival rate, which requires new therapeutic modalities based on the biology of pancreatic oncogenesis. Nuclear factor E2 related factor-2 (NRF2), a key cytoprotective nuclear transcription factor, regulates antioxidant production, reduction, detoxification and drug efflux proteins. It also plays an essential role in cell homeostasis, cell proliferation and resistance to chemotherapy. We aimed to evaluate the possibility that modulation of NRF2 expression could be effective in the treatment of pancreatic cancer cells. We investigated whether the depletion of NRF2 by using small interfering RNAs (siRNAs) is effective in the expression of biomarkers of pancreatic cancer stemness such as aldehyde dehydrogenase 1 family, member A1 (ALDH1A1) and aldehyde dehydrogenase 3 family, member A1 (ALDH3A1). NRF2 knockdown markedly reduced the expression of NRF2 and glutamate-cysteine ligase catalytic subunit (GCLC) in cell lines established from pancreatic cancers. NRF2 silencing also decreased the ALDH1A1 and ALDH3A1 expression. Furthermore, this NRF2 depletion enhanced the antiproliferative effects of the chemotherapeutic agent, 5-fluorouracil (5-FU) in pancreatic cancer cells.
      PubDate: 2017-07-01
      DOI: 10.3390/antiox6030052
      Issue No: Vol. 6, No. 3 (2017)
       
  • Antioxidants, Vol. 6, Pages 53: Possible Reactions of Dietary Phenolic
           Compounds with Salivary Nitrite and Thiocyanate in the Stomach

    • Authors: Umeo Takahama, Sachiko Hirota
      First page: 53
      Abstract: Foods are mixed with saliva in the oral cavity and swallowed. While staying in the stomach, saliva is contentiously provided to mix with the ingested foods. Because a salivary component of nitrite is protonated to produce active nitrous acid at acidic pH, the redox reactions of nitrous acid with phenolic compounds in foods become possible in the stomach. In the reactions, nitrous acid is reduced to nitric oxide (•NO), producing various products from phenolic compounds. In the products, stable hydroxybezoyl benzofuranone derivatives, which are produced from quercetin and its 7-O-glucoside, are included. Caffeic acid, chlorogenic acid, and rutin are oxidized to quinones and the quinones can react with thiocyanic acid derived from saliva, producing stable oxathiolone derivatives. 6,8-Dinitrosocatechis are produced from catechins by the redox reaction, and the dinitrocatechins are oxidized further by nitrous acid producing the quinones, which can make charge transfer complexes with the dinitrosocatechin and can react with thiocyanic acid producing the stable thiocyanate conjugates. In this way, various products can be produced by the reactions of salivary nitrite with dietary phenolic compounds, and reactive and toxic quinones formed by the reactions are postulated to be removed in the stomach by thiocyanic acid derived from saliva.
      PubDate: 2017-07-05
      DOI: 10.3390/antiox6030053
      Issue No: Vol. 6, No. 3 (2017)
       
  • Antioxidants, Vol. 6, Pages 54: Reactive Oxygen and Nitrogen Species in
           the Development of Pulmonary Hypertension

    • Authors: David Fulton, Xueyi Li, Zsuzsanna Bordan, Stephen Haigh, Austin Bentley, Feng Chen, Scott Barman
      First page: 54
      Abstract: Pulmonary arterial hypertension (PAH) is a progressive disease of the lung vasculature that involves the loss of endothelial function together with inappropriate smooth muscle cell growth, inflammation, and fibrosis. These changes underlie a progressive remodeling of blood vessels that alters flow and increases pulmonary blood pressure. Elevated pressures in the pulmonary artery imparts a chronic stress on the right ventricle which undergoes compensatory hypertrophy but eventually fails. How PAH develops remains incompletely understood and evidence for the altered production of reactive oxygen and nitrogen species (ROS, RNS respectively) in the pulmonary circulation has been well documented. There are many different types of ROS and RNS, multiple sources, and collective actions and interactions. This review summarizes past and current knowledge of the sources of ROS and RNS and how they may contribute to the loss of endothelial function and changes in smooth muscle proliferation in the pulmonary circulation.
      PubDate: 2017-07-06
      DOI: 10.3390/antiox6030054
      Issue No: Vol. 6, No. 3 (2017)
       
  • Antioxidants, Vol. 6, Pages 55: Attenuation of Red Blood Cell Storage
           Lesions with Vitamin C

    • Authors: Kimberly Sanford, Bernard Fisher, Evan Fowler, Alpha Fowler, Ramesh Natarajan
      First page: 55
      Abstract: Stored red blood cells (RBCs) undergo oxidative stress that induces deleterious metabolic, structural, biochemical, and molecular changes collectively referred to as “storage lesions”. We hypothesized that vitamin C (VitC, reduced or oxidized) would reduce red cell storage lesions, thus prolonging their storage duration. Whole-blood-derived, leuko-reduced, SAGM (saline-adenine-glucose-mannitol)-preserved RBC concentrates were equally divided into four pediatric storage bags and the following additions made: (1) saline (saline); (2) 0.3 mmol/L reduced VitC (Lo VitC); (3) 3 mmol/L reduced VitC (Hi VitC); or (4) 0.3 mmol/L oxidized VitC (dehydroascorbic acid, DHA) as final concentrations. Biochemical and rheological parameters were serially assessed at baseline (prior to supplementation) and Days 7, 21, 42, and 56 for RBC VitC concentration, pH, osmotic fragility by mechanical fragility index, and percent hemolysis, LDH release, glutathione depletion, RBC membrane integrity by scanning electron microscopy, and Western blot for β-spectrin. VitC exposure (reduced and oxidized) significantly increased RBC antioxidant status with varying dynamics and produced trends in reduction in osmotic fragility and increases in membrane integrity. Conclusion: VitC partially protects RBC from oxidative changes during storage. Combining VitC with other antioxidants has the potential to improve long-term storage of RBC.
      PubDate: 2017-07-12
      DOI: 10.3390/antiox6030055
      Issue No: Vol. 6, No. 3 (2017)
       
  • Antioxidants, Vol. 6, Pages 56: NADPH Oxidases, Angiogenesis, and
           Peripheral Artery Disease

    • Authors: Pradeep Manuneedhi Cholan, Siân Cartland, Mary Kavurma
      First page: 56
      Abstract: Peripheral artery disease (PAD) is caused by narrowing of arteries in the limbs, normally occurring in the lower extremities, with severe cases resulting in amputation of the foot or leg. A potential approach for treatment is to stimulate the formation of new blood vessels to restore blood flow to limb tissues. This is a process called angiogenesis and involves the proliferation, migration, and differentiation of endothelial cells. Angiogenesis can be stimulated by reactive oxygen species (ROS), with NADPH oxidases (NOX) being a major source of ROS in endothelial cells. This review summarizes the recent evidence implicating NOX isoforms in their ability to regulate angiogenesis in vascular endothelial cells in vitro, and in PAD in vivo. Increasing our understanding of the involvement of the NOX isoforms in promoting therapeutic angiogenesis may lead to new treatment options to slow or reverse PAD.
      PubDate: 2017-07-12
      DOI: 10.3390/antiox6030056
      Issue No: Vol. 6, No. 3 (2017)
       
  • Antioxidants, Vol. 6, Pages 57: Chemical Analysis of Astragali Complanati
           Semen and Its Hypocholesterolemic Effect Using Serum Metabolomics Based on
           Gas Chromatography-Mass Spectrometry

    • Authors: Tung Sham, Huan Zhang, Daniel Mok, Shun Chan, Jianhong Wu, Songyun Tang, Chi Chan
      First page: 57
      Abstract: The hypocholesterolemic protective effect of the dried seed of Astragalus complanatus (ACS) was investigated in rats fed with normal diet, high cholesterol diet (HCD), and HCD plus 70% ethanol extract of ACS (600 mg/kg/day) by oral gavage for four weeks. ACS extract was tested to be rich in antioxidants, which may be contributed to its high content of phenolic compounds. Consumption of ACS remarkably suppressed the elevated total cholesterol (p < 0.01) and LDL-C (p < 0.001) induced by HCD. Chemical constituents of ACS extract were analyzed by ultra-performance liquid chromatography coupled with electrospray ionization orbitrap mass spectrometry and the results showed that the ACS extract mainly consisted of phenolic compounds including flavonoids and flavonoid glycosides. In addition, based on the serum fatty acid profiles, elucidated using gas chromatography-mass spectrometry, free and esterified fatty acids including docosapentaenoic acid, adrenic acid, dihomo-γ-linolenic acid and arachidonic acid were regulated in ACS treatment group. Western blot results further indicated the protein expression of peroxisome proliferator-activated receptor alpha (PPARα) (p < 0.05) in liver was upregulated in ACS treatment group. To conclude, our results clearly demonstrated that ACS provides beneficial effect on lowering HCD associated detrimental change.
      Citation: Antioxidants
      PubDate: 2017-07-21
      DOI: 10.3390/antiox6030057
      Issue No: Vol. 6, No. 3 (2017)
       
  • Antioxidants, Vol. 6, Pages 58: High Dose Ascorbate Causes Both Genotoxic
           and Metabolic Stress in Glioma Cells

    • Authors: Maria Castro, Georgia Carson, Melanie McConnell, Patries Herst
      First page: 58
      Abstract: We have previously shown that exposure to high dose ascorbate causes double stranded breaks (DSBs) and a build-up in S-phase in glioblastoma (GBM) cell lines. Here we investigated whether or not this was due to genotoxic stress as well as metabolic stress generated by exposure to high dose ascorbate, radiation, ascorbate plus radiation and H2O2 in established and primary GBM cell lines. Genotoxic stress was measured as phosphorylation of the variant histone protein, H2AX, 8-oxo-7,8-dihydroguanine (8OH-dG) positive cells and cells with comet tails. Metabolic stress was measured as a decrease in NADH flux, mitochondrial membrane potential (by CMXRos), ATP levels (by ATP luminescence) and mitochondrial superoxide production (by mitoSOX). High dose ascorbate, ascorbate plus radiation, and H2O2 treatments induced both genotoxic and metabolic stress. Exposure to high dose ascorbate blocked DNA synthesis in both DNA damaged and undamaged cell of ascorbate sensitive GBM cell lines. H2O2 treatment blocked DNA synthesis in all cell lines with and without DNA damage. DNA synthesis arrest in cells with damaged DNA is likely due to both genotoxic and metabolic stress. However, arrest in DNA synthesis in cells with undamaged DNA is likely due to oxidative damage to components of the mitochondrial energy metabolism pathway.
      Citation: Antioxidants
      PubDate: 2017-07-22
      DOI: 10.3390/antiox6030058
      Issue No: Vol. 6, No. 3 (2017)
       
  • Antioxidants, Vol. 6, Pages 59: Storage of Fruits and Vegetables in
           Refrigerator Increases their Phenolic Acids but Decreases the Total
           Phenolics, Anthocyanins and Vitamin C with Subsequent Loss of their
           Antioxidant Capacity

    • Authors: Joseph H. Y. Galani, Jalpesh S. Patel, Nilesh J. Patel, Jayant G. Talati
      First page: 59
      Abstract: It is of paramount importance for consumers, scientists and industrialists to understand how low-temperature storage of food items affects their bioactive compounds and properties. This study evaluated the effects of cold storage on total phenolics (TP), phenolic acids profile (PA), total anthocyanins (TA), total ascorbic acid (Vit. C) and antioxidant activity (AA) of 19 fruits and vegetables, collected from local Indian markets and stored in refrigerator (4 °C) during 15 days. Content of TP was highest in dill and amaranth and decreased (up to 29.67%) with storage. Leafy vegetables (amaranth, dill, onion, fenugreek and spinach) contained higher amounts of the 12 PA revealed by UPLC-UV; ellagic, gallic, sinapic and vanillic acids levels were the highest; chlorogenic acid (ρ = 0.423), syringic acid (ρ = 0.403) and sinapic acid (ρ = 0.452) mostly correlated with TP; and the PA increased during storage. Highest contents of Vit C estimated by AOAC, DCPIP and DNP methods were found in amaranth, dill and pomegranate, and decreased with storage. Pomegranate showed highest TA levels and low-temperature storage did not significantly increase TA, which was the largest contributor of TP in fruits and vegetables (ρ = 0.661). Storage induced a drastic decrease of AA, which mostly correlated with TP (ρ = 0.808, 0.690 and 0.458 for DPPH, ABTS and FRAP assays, respectively). Spearman’s correlation confirmed by principal component analysis demonstrated that dill, pomegranate and amaranth had the highest overall antioxidant capacity, whereas orange juice and carrot showed the lowest. The results provide support for a key-role of TP, followed by Vit. C and TA in antioxidant capacity of fruits and vegetables, which could be interesting dietary sources of natural antioxidants for prevention of diseases caused by oxidative stress.
      Citation: Antioxidants
      PubDate: 2017-07-24
      DOI: 10.3390/antiox6030059
      Issue No: Vol. 6, No. 3 (2017)
       
  • Antioxidants, Vol. 6, Pages 60: Fractioning of Proanthocyanidins of
           Uncaria tomentosa. Composition and Structure-Bioactivity Relationship

    • Authors: Mirtha Navarro, William Zamora, Silvia Quesada, Gabriela Azofeifa, Diego Alvarado, Maria Monagas
      First page: 60
      Abstract: In a previous study, the detailed low-molecular weight polyphenolic profile of the different plant parts (leaves, stem, bark and wood) of Uncaria tomentosa was reported, the leaves being the plant part with the highest phenolic content and presenting the most heterogenous proanthocyanidin composition. Further, cytotoxicity of leaves extracts in two cancer cell lines was also found to be higher than in the remaining parts of the plant. In the present study, fractioning of U. tomentosa leaves polyphenolic extracts was performed using Diaion® HP-20 resin and a detailed characterization and quantification of fractions (n = 5) was achieved using advanced analytical techniques such as Ultra-Performance Liquid Chromatography coupled with Electrospray Ionization and Triple Quadrupole (TQD) Tandem Mass Spectrometry (UPLC/TQ-ESI-MS) and 13C-NMR. Oxygen Radical Absorbance Capacity (ORAC) and cytotoxicity on gastric adenocarcinoma AGS and colon adenocarcinoma SW20 cell lines were also determined in the different fractions. Results showed selective distribution of 32 non-flavonoid and flavonoid phenolics among the different fractions. ORAC varied between 3.2 and 11.8 μmol TE/mg in the different fractions, whereas IC50 of cytotoxicity on gastric adenocarcinoma AGS and colon adenocarcinoma SW20 cell lines best values were between 71.4 and 75.6 µg/mL. Fractions rich in proanthocyanidins also showed the highest bioactivity. In fact, significant positive correlation was found between total proanthocyanidins (TP) quantified by UPLC-DAD and ORAC (R2 = 0.970), whereas significant negative correlation was found between TP and cytotoxicity towards AGS (R2 = 0.820) and SW620 (R2 = 0.843) adenocarcinoma cell lines. Among proanthocyanidins, propelargonidin dimers were of particular interest, showing significant correlation with cytotoxic selectivity on both gastric AGS (R2 = 0.848) and colon SW620 (R2 = 0.883) adenocarcinoma cell lines. These results show further evidence of the bioactivity of U. tomentosa proanthocyanidin extracts and their potential health effects.
      Citation: Antioxidants
      PubDate: 2017-07-28
      DOI: 10.3390/antiox6030060
      Issue No: Vol. 6, No. 3 (2017)
       
  • Antioxidants, Vol. 6, Pages 61: Fate and Prediction of Phenolic
           Secoiridoid Compounds throughout the Different Stages of the Virgin Olive
           Oil Making Process

    • Authors: Giuseppe Fregapane, M. Salvador
      First page: 61
      Abstract: The evolution of the main phenolic secoiridoid compounds throughout the different stages of the virgin olive oil making process—crushing, malaxation and liquid-solid separation—is studied here, with the goal of making possible the prediction of the partition and transformation that take place in the different steps of the process. The concentration of hydroxytyrosol secoiridoids produced under the different crushing conditions studied are reasonably proportional to the intensity of the milling stage, and strongly depend on the olive variety processed. During malaxation, the content of the main phenolic secoiridoids is reduced, especially in the case of the hydroxytyrosol derivatives, in which a variety-dependent behaviour is observed. The prediction of the concentration of phenolic secoiridoids finally transferred from the kneaded paste to the virgin olive oil is also feasible, and depends on the phenolic content and amount of water in the olive paste. The determination of the phenolic compounds in the olive fruit, olive paste and olive oil has been carried out by LC-MS (Liquid-Chromatography Mass-Spectrometry). This improved knowledge could help in the use of more adequate processing conditions for the production of virgin olive oil with desired properties; for example, higher or lower phenolic content, as the amount of these minor components is directly related to its sensory, antioxidant and healthy properties.
      Citation: Antioxidants
      PubDate: 2017-08-03
      DOI: 10.3390/antiox6030061
      Issue No: Vol. 6, No. 3 (2017)
       
  • Antioxidants, Vol. 6, Pages 62: Cysteine, Glutathione, and Thiol Redox
           Balance in Astrocytes

    • Authors: Gethin McBean
      First page: 62
      Abstract: This review discusses the current understanding of cysteine and glutathione redox balance in astrocytes. Particular emphasis is placed on the impact of oxidative stress and astrocyte activation on pathways that provide cysteine as a precursor for glutathione. The effect of the disruption of thiol-containing amino acid metabolism on the antioxidant capacity of astrocytes is also discussed.
      Citation: Antioxidants
      PubDate: 2017-08-03
      DOI: 10.3390/antiox6030062
      Issue No: Vol. 6, No. 3 (2017)
       
  • Antioxidants, Vol. 6, Pages 63: The Ability of Exercise-Associated
           Oxidative Stress to Trigger Redox-Sensitive Signalling Responses

    • Authors: Richard Webb, Michael Hughes, Andrew Thomas, Keith Morris
      First page: 63
      Abstract: In this review, we discuss exercise as an oxidative stressor, and elucidate the mechanisms and downstream consequences of exercise-induced oxidative stress. Reactive oxygen species (ROS) are generated in the mitochondria of contracting skeletal myocytes; also, their diffusion across the myocyte membrane allows their transport to neighbouring muscle tissue and to other regions of the body. Although very intense exercise can induce oxidative damage within myocytes, the magnitudes of moderate-intensity exercise-associated increases in ROS are quite modest (~two-fold increases in intracellular and extracellular ROS concentrations during exercise), and so the effects of such increases are likely to involve redox-sensitive signalling effects rather than oxidative damage. Therefore, the responses of muscle and non-muscle cells to exercise-associated redox-sensitive signalling effects will be reviewed; for example, transcription factors such as Peroxisome Proliferator Activated Receptor-gamma (PPARγ) and Liver X-Receptor-alpha (LXRα) comprise redox-activable signalling systems, and we and others have reported exercise-associated modulation of PPARγ and/or LXRα-regulated genes in skeletal myocyte and in non-muscle cell-types such as monocyte-macrophages. Finally, the consequences of such responses in the context of management of chronic inflammatory conditions, and also their implications for the design of exercise training programmes (particularly the use of dietary antioxidants alongside exercise), will be discussed.
      Citation: Antioxidants
      PubDate: 2017-08-10
      DOI: 10.3390/antiox6030063
      Issue No: Vol. 6, No. 3 (2017)
       
  • Antioxidants, Vol. 6, Pages 64: Analysis and Comparison of the Antioxidant
           Component of Portulaca Oleracea Leaves Obtained by Different Solid-Liquid
           Extraction Techniques

    • Authors: Monica Gallo, Esterina Conte, Daniele Naviglio
      First page: 64
      Abstract: Portulaca oleracea is a wild plant pest of orchards and gardens, but is also an edible vegetable rich in beneficial nutrients. It possesses many antioxidant properties due to the high content of vitamins, minerals, omega-3 essential fatty acids and other healthful compounds; therefore, the intake of purslane and/or its bioactive compounds could help to improve the health and function of the whole human organism. Accordingly, in this work it was analyzed and compared to the extractive capacity of the antioxidant component of purslane leaves obtained by solid-liquid extraction techniques such as: hot-maceration, maceration with ultrasound, rapid solid-liquid dynamic extraction using the Naviglio extractor, and a combination of two techniques (mix extraction). The chromatographic analysis by High Performance Liquid Chromatography (HPLC) of the methanolic extract of dried purslane leaves allowed the identification of various polyphenolic compounds for comparison with the standards. In addition, the properties of the different extracts were calculated on dry matter and the antioxidant properties of the total polyphenol components analyzed by the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay. The results showed that mix extraction was the most efficient compared to other techniques. In fact, it obtained a quantity of polyphenols amounting to 237.8 mg Gallic Acid Equivalents (GAE)/100 g of fresh weight, while in other techniques, the range varied from 60–160 mg GAE/100 g fresh weight. In addition, a qualitative analysis by Liquid Chromatography-Tandem Mass Spectrometry (LC/MS/MS) of the phenolic compounds present in the purslane leaves examined was carried out. The compounds were identified by comparison of their molecular weight, fragmentation pattern and retention time with those of standards, using the “Multiple Reaction Monitoring” mode (MRM). Therefore, this study allowed the re-evaluation of a little-known plant that possesses as its beneficial properties, a great potential for use in both the food and the nutraceuticals and cosmetic field.
      Citation: Antioxidants
      PubDate: 2017-08-12
      DOI: 10.3390/antiox6030064
      Issue No: Vol. 6, No. 3 (2017)
       
  • Antioxidants, Vol. 6, Pages 65: Are Astrocytes the Predominant Cell Type
           for Activation of Nrf2 in Aging and Neurodegeneration'

    • Authors: Jeffrey Liddell
      First page: 65
      Abstract: Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that regulates hundreds of antioxidant genes, and is activated in response to oxidative stress. Given that many neurodegenerative diseases including Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis, Huntington’s disease and multiple sclerosis are characterised by oxidative stress, Nrf2 is commonly activated in these diseases. Evidence demonstrates that Nrf2 activity is repressed in neurons in vitro, and only cultured astrocytes respond strongly to Nrf2 inducers, leading to the interpretation that Nrf2 signalling is largely restricted to astrocytes. However, Nrf2 activity can be observed in neurons in post-mortem brain tissue and animal models of disease. Thus this interpretation may be false, and a detailed analysis of the cell type expression of Nrf2 in neurodegenerative diseases is required. This review describes the evidence for Nrf2 activation in each cell type in prominent neurodegenerative diseases and normal aging in human brain and animal models of neurodegeneration, the response to pharmacological and genetic modulation of Nrf2, and clinical trials involving Nrf2-modifying drugs.
      Citation: Antioxidants
      PubDate: 2017-08-18
      DOI: 10.3390/antiox6030065
      Issue No: Vol. 6, No. 3 (2017)
       
  • Antioxidants, Vol. 6, Pages 66: Superoxide Dismutases in Pancreatic Cancer

    • Authors: Justin Wilkes, Matthew Alexander, Joseph Cullen
      First page: 66
      Abstract: The incidence of pancreatic cancer is increasing as the population ages but treatment advancements continue to lag far behind. The majority of pancreatic cancer patients have a K-ras oncogene mutation causing a shift in the redox state of the cell, favoring malignant proliferation. This mutation is believed to lead to nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation and superoxide overproduction, generating tumorigenic behavior. Superoxide dismutases (SODs) have been studied for their ability to manage the oxidative state of the cell by dismuting superoxide and inhibiting signals for pancreatic cancer growth. In particular, manganese superoxide dismutase has clearly shown importance in cell cycle regulation and has been found to be abnormally low in pancreatic cancer cells as well as the surrounding stromal tissue. Likewise, extracellular superoxide dismutase expression seems to favor suppression of pancreatic cancer growth. With an increased understanding of the redox behavior of pancreatic cancer and key regulators, new treatments are being developed with specific targets in mind. This review summarizes what is known about superoxide dismutases in pancreatic cancer and the most current treatment strategies to be advanced from this knowledge.
      Citation: Antioxidants
      PubDate: 2017-08-19
      DOI: 10.3390/antiox6030066
      Issue No: Vol. 6, No. 3 (2017)
       
  • Antioxidants, Vol. 6, Pages 67: Development of a Rapid Method for the
           Determination of Caffeine in Coffee Grains by GC-FID—A Fully Validated
           Approach

    • Authors: Ioannis Pasias, I. Kiriakou, Charalampos Proestos
      First page: 67
      Abstract: A simple method for the determination of caffeine in coffee grains by GC-FID (Gas Chromatography-Flame Ionisation Detector) is presented in the current work. The method was fully validated according to ISO (International Organization for Standardization) 17025 requirements and European Commission regulations. The accuracy, as provided by recovery experiments, was higher than 93%, and the precision, as provided by the (%) relative standard deviation under reproducibility conditions, was lower than 5%. A vast number of independent parameters that lead in the increase of uncertainty of methods were investigated. The analysis was performed without use of an internal standard, which was proven to be reliable according to several validation methods. The method was applied in real samples, and possible health claims were investigated.
      Citation: Antioxidants
      PubDate: 2017-08-22
      DOI: 10.3390/antiox6030067
      Issue No: Vol. 6, No. 3 (2017)
       
  • Antioxidants, Vol. 6, Pages 68: Solanum trilobatum L. Ameliorate
           Thioacetamide-Induced Oxidative Stress and Hepatic Damage in Albino Rats

    • Authors: Kumar Ganesan, Kumeshini Sukalingam, Baojun Xu
      First page: 68
      Abstract: Solanum trilobatum L. (Solanaceae) has been well known as nightshade, commonly used by diverse populations to heal several disorders. Earlier studies in Solanum trilobatum were focused on different pharmacological activities and a few were concerned with antioxidant and hepatoprotective effects. Thus, the current study was focused to evaluate the antioxidant potential and hepatoprotective effects of S. trilobatum L. on thioacetamide (TAA) intoxication in Wistar albino rats. The rats were kept into four groups and six animals each. Group A was normal control. Group B was the TAA treated control. Groups C and D were pretreated with the aqueous extract from the leaves of S. trilobatum (100 mg, 200 mg/kg bw p.o.) once daily for 10 consecutive days administration followed by a single dose infusion of TAA (100 mg/kg s.c.). After 10 days, blood and livers were collected. The biochemical assay was carried out in the GSH (reduced glutathione), TBARS(thiobarbituric acid reactive substances), Na+-K+-ATPase, and antioxidant enzymes viz., SOD (superoxide dismutase), CAT (catalase), GPx (glutathione peroxidase), GST (glutathione-S-transferase), and GR (glutathione reductase) were analyzed in samples of blood and liver. Treatment with S. trilobatum reduced blood and liver TBARS, and Na+ K+ ATPase activity in TAA (thioacetamide)-induced hepatotoxicity rats. Furthermore, the above antioxidant enzymes were increased in the pretreatment of S. trilobatum in TAA intoxicated rats. Finally, we concluded that S. Trilobatum displayed potent antioxidant properties and alleviate oxidative stress induced hepatotoxic effects and possible engross mechanisms related to free radical scavenging properties.
      Citation: Antioxidants
      PubDate: 2017-08-22
      DOI: 10.3390/antiox6030068
      Issue No: Vol. 6, No. 3 (2017)
       
  • Antioxidants, Vol. 6, Pages 69: A Possible Indicator of Oxidative Damage
           in Smokers: (13Z)-Lycopene'

    • Authors: Daniel Graham, Mario Lorenz, Andrew Young, Gordon Lowe
      First page: 69
      Abstract: In vitro, the gaseous phase of cigarette smoke is known to induce both isomerization and degradation of dietary carotenoids, such as β-carotene and lycopene. However, the effects of cigarette smoke on the composition of circulating lycopene in vivo are not well understood. In this study, we examined the lycopene profiles of plasma from non-smokers and smokers. No oxidative intermediates of lycopene that have been observed previously in vitro were detected in the plasma, but evidence of isomerization of the carotenoid was seen. Four geometric forms of lycopene were detected in the plasma of both smokers and non-smokers, namely the (5Z), (9Z), (13Z) and (all-E) forms. The relative amounts of these isomers differed between the two cohorts and there was a significant difference (p < 0.05) between smokers and non-smokers for the ratio of total-Z:all-E lycopene, and in the relative amounts of (13Z) and (all-E)-lycopene. The ratio of (all-E):(13Z)-lycopene was 0.84:1.00 in smokers compared to 1.04:1.00 in non-smokers. In smokers, the (13Z)-isomer was generated in preference to the more thermodynamically stable (5Z) and (9Z)-isomers. This mirrors the scenario seen in vitro, in which the formation of (13Z)-lycopene was the main isomer that accompanied the depletion of (all-E) lycopene, when exposed to cigarette smoke. The results suggest that the relative amount of (13Z)-lycopene could be used as an indicator of oxidative damage to lycopene in vivo.
      Citation: Antioxidants
      PubDate: 2017-09-13
      DOI: 10.3390/antiox6030069
      Issue No: Vol. 6, No. 3 (2017)
       
  • Antioxidants, Vol. 6, Pages 70: Antioxidant Activity of Spices and Their
           Impact on Human Health: A Review

    • Authors: Alexander Yashin, Yakov Yashin, Xiaoyan Xia, Boris Nemzer
      First page: 70
      Abstract: Antioxidants are substances that prevent oxidation of other compounds or neutralize free radicals. Spices and herbs are rich sources of antioxidants. They have been used in food and beverages to enhance flavor, aroma and color. Due to their excellent antioxidant activity, spices and herbs have also been used to treat some diseases. In this review article, the chemical composition and antioxidant activity of spices and culinary herbs are presented. The content of flavonoids and total polyphenols in different spices and herbs are summarized. The applications of spices and their impacts on human health are briefly described. The extraction and analytical methods for determination of antioxidant capacity are concisely reviewed.
      Citation: Antioxidants
      PubDate: 2017-09-15
      DOI: 10.3390/antiox6030070
      Issue No: Vol. 6, No. 3 (2017)
       
  • Antioxidants, Vol. 6, Pages 71: Phytochemical Constituents, Health
           Benefits, and Industrial Applications of Grape Seeds: A Mini-Review

    • Authors: Zheng Ma, Hongxia Zhang
      First page: 71
      Abstract: Grapes are one of the most widely grown fruits and have been used for winemaking since the ancient Greek and Roman civilizations. Grape seeds are rich in proanthocyanidins which have been shown to possess potent free radical scavenging activity. Grape seeds are a complex matrix containing 40% fiber, 16% oil, 11% proteins, and 7% complex phenols such as tannins. Grape seeds are rich sources of flavonoids and contain monomers, dimers, trimers, oligomers, and polymers. The monomeric compounds includes (+)-catechins, (−)-epicatechin, and (−)-epicatechin-3-O-gallate. Studies have reported that grape seeds exhibit a broad spectrum of pharmacological properties against oxidative stress. Their potential health benefits include protection against oxidative damage, and anti-diabetic, anti-cholesterol, and anti-platelet functions. Recognition of such health benefits of proanthocyanidins has led to the use of grape seeds as a dietary supplement by the consumers. This paper summarizes the studies of the phytochemical compounds, pharmacological properties, and industrial applications of grape seeds.
      Citation: Antioxidants
      PubDate: 2017-09-15
      DOI: 10.3390/antiox6030071
      Issue No: Vol. 6, No. 3 (2017)
       
  • Antioxidants, Vol. 6, Pages 72: Profiling of Polyphenol Composition and
           Antiradical Capacity of Erica cinerea

    • Authors: Alfredo Aires, Rosa Carvalho
      First page: 72
      Abstract: The aim of the current study was to determine the profile and content of polyphenols present in Erica cinerea, an important plant species from Northern Portuguese flora and often reported as having anti-inflammatory, antioxidant, and anti-radical activity. The analysis of polyphenols was performed by HPLC-DAD/UV-Vis, and the 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+) method was used to evaluate its radical scavenging activity. HPLC analysis showed that both plants presented a great diversity of compounds, with 33% flavones, 28% flavanols, and 26% hydroxycinnamic acids. The antiradical activity was dose-dependent, and the IC50 values were 0.251 mg mL−1. Based on our study, E. cinerea presented interesting bioactive compounds and it can be used to extract and purify bioactive polyphenols to be used in pharmaceutical or agro-food industries.
      Citation: Antioxidants
      PubDate: 2017-09-20
      DOI: 10.3390/antiox6030072
      Issue No: Vol. 6, No. 3 (2017)
       
  • Antioxidants, Vol. 6, Pages 22: Antioxidant Properties of Selenophene,
           Thiophene and Their Aminocarbonitrile Derivatives

    • Authors: Levon Tavadyan, Zaruhi Manukyan, Lusik Harutyunyan, Makich Musayelyan, Adrine Sahakyan, Hakob Tonikyan
      First page: 22
      Abstract: The oxygen radical absorbance capacity (ORAC) method was used to detect the antiperoxyradical ability of organoselenium compounds: selenophene and its derivative, 2-amino-4,5,6,7-tetrahydro-1-selenophene-3-carbonitrile (ATSe); while as a comparison, the sulfur-containing analogue of selenophene—thiophene and its derivative—2-amino-4,5,6,7-tetrahydro-1-thiophene-3-carbonitrile (ATS)—was selected. Cyclic voltammetry (CV), differential pulse voltammetry (DPV) and squarewave voltammetry (SWV) methods were used to determine the redox characteristics of organoselenium and organosulfur compounds. The antiradical activity and capacity of the studied compounds were also measured by using stable radical 2,2ʹ-diphenyl-1-picrylhydrazyl (DPPH). Detected anodic peaks of the oxidation of selenophene, thiophene and their derivatives in CV, DPV and SWV in the interval of −1200 ÷ (+1600) mV potentials in regard to the Ag/Ag+ medium of acetonitrile prove the presence of antiperoxyradical activity in regard to oxidizers, i.e., peroxyradicals. The chemical mechanism of the antiperoxyradical ability of selenophene, thiophene and their organic derivatives is proposed.
      PubDate: 2017-03-24
      DOI: 10.3390/antiox6020022
      Issue No: Vol. 6, No. 2 (2017)
       
  • Antioxidants, Vol. 6, Pages 23: Effects of Reactive Oxygen Species on
           Tubular Transport along the Nephron

    • Authors: Agustin Gonzalez-Vicente, Jeffrey Garvin
      First page: 23
      Abstract: Reactive oxygen species (ROS) are oxygen-containing molecules naturally occurring in both inorganic and biological chemical systems. Due to their high reactivity and potentially damaging effects to biomolecules, cells express a battery of enzymes to rapidly metabolize them to innocuous intermediaries. Initially, ROS were considered by biologists as dangerous byproducts of respiration capable of causing oxidative stress, a condition in which overproduction of ROS leads to a reduction in protective molecules and enzymes and consequent damage to lipids, proteins, and DNA. In fact, ROS are used by immune systems to kill virus and bacteria, causing inflammation and local tissue damage. Today, we know that the functions of ROS are not so limited, and that they also act as signaling molecules mediating processes as diverse as gene expression, mechanosensation, and epithelial transport. In the kidney, ROS such as nitric oxide (NO), superoxide (O2−), and their derivative molecules hydrogen peroxide (H2O2) and peroxynitrite (ONO2−) regulate solute and water reabsorption, which is vital to maintain electrolyte homeostasis and extracellular fluid volume. This article reviews the effects of NO, O2−, ONO2−, and H2O2 on water and electrolyte reabsorption in proximal tubules, thick ascending limbs, and collecting ducts, and the effects of NO and O2− in the macula densa on tubuloglomerular feedback.
      PubDate: 2017-03-23
      DOI: 10.3390/antiox6020023
      Issue No: Vol. 6, No. 2 (2017)
       
  • Antioxidants, Vol. 6, Pages 24: Zinc and Oxidative Stress: Current
           Mechanisms

    • Authors: Dilina Marreiro, Kyria Cruz, Jennifer Morais, Jéssica Beserra, Juliana Severo, Ana de Oliveira
      First page: 24
      Abstract: Oxidative stress is a metabolic dysfunction that favors the oxidation of biomolecules, contributing to the oxidative damage of cells and tissues. This consequently contributes to the development of several chronic diseases. In particular, zinc is one of the most relevant minerals to human health, because of its antioxidant properties. This review aims to provide updated information about the mechanisms involved in the protective role of zinc against oxidative stress. Zinc acts as a co-factor for important enzymes involved in the proper functioning of the antioxidant defense system. In addition, zinc protects cells against oxidative damage, acts in the stabilization of membranes and inhibits the enzyme nicotinamide adenine dinucleotide phosphate oxidase (NADPH-Oxidase). Zinc also induces the synthesis of metallothioneins, which are proteins effective in reducing hydroxyl radicals and sequestering reactive oxygen species (ROS) produced in stressful situations, such as in type 2 diabetes, obesity and cancer. Literature provides strong evidence for the role of zinc in the protection against oxidative stress in several diseases.
      PubDate: 2017-03-29
      DOI: 10.3390/antiox6020024
      Issue No: Vol. 6, No. 2 (2017)
       
  • Antioxidants, Vol. 6, Pages 25: Abnormalities of Mitochondrial Dynamics in
           Neurodegenerative Diseases

    • Authors: Ju Gao, Luwen Wang, Jingyi Liu, Fei Xie, Bo Su, Xinglong Wang
      First page: 25
      Abstract: Neurodegenerative diseases are incurable and devastating neurological disorders characterized by the progressive loss of the structure and function of neurons in the central nervous system or peripheral nervous system. Mitochondria, organelles found in most eukaryotic cells, are essential for neuronal survival and are involved in a number of neuronal functions. Mitochondrial dysfunction has long been demonstrated as a common prominent early pathological feature of a variety of common neurodegenerative diseases, including Alzheimer’s disease (AD), Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS), and Huntington’s disease (HD). Mitochondria are highly dynamic organelles that undergo continuous fusion, fission, and transport, the processes of which not only control mitochondrial morphology and number but also regulate mitochondrial function and location. The importance of mitochondrial dynamics in the pathogenesis of neurodegenerative diseases has been increasingly unraveled after the identification of several key fusion and fission regulators such as Drp1, OPA1, and mitofusins. In this review, after a brief discussion of molecular mechanisms regulating mitochondrial fusion, fission, distribution, and trafficking, as well as the important role of mitochondrial dynamics for neuronal function, we review previous and the most recent studies about mitochondrial dynamic abnormalities observed in various major neurodegenerative diseases and discuss the possibility of targeting mitochondrial dynamics as a likely novel therapeutic strategy for neurodegenerative diseases.
      PubDate: 2017-04-05
      DOI: 10.3390/antiox6020025
      Issue No: Vol. 6, No. 2 (2017)
       
  • Antioxidants, Vol. 6, Pages 26: Green Tea Catechins for Prostate Cancer
           Prevention: Present Achievements and Future Challenges

    • Authors: Valeria Naponelli, Ileana Ramazzina, Chiara Lenzi, Saverio Bettuzzi, Federica Rizzi
      First page: 26
      Abstract: Green tea catechins (GTCs) are a family of chemically related compounds usually classified as antioxidant molecules. Epidemiological evidences, supported by interventional studies, highlighted a more than promising role for GTCs in human prostate cancer (PCa) chemoprevention. In the last decades, many efforts have been made to gain new insights into the mechanism of action of GTCs. Now it is clear that GTCs’ anticancer action can no longer be simplistically limited to their direct antioxidant/pro-oxidant properties. Recent contributions to the advancement of knowledge in this field have shown that GTCs specifically interact with cellular targets, including cell surface receptors, lipid rafts, and endoplasmic reticulum, modulate gene expression through direct effect on transcription factors or indirect epigenetic mechanisms, and interfere with intracellular proteostasis at various levels. Many of the effects observed in vitro are dose and cell context dependent and take place at concentrations that cannot be achieved in vivo. Poor intestinal absorption together with an extensive systemic and enteric metabolism influence GTCs’ bioavailability through still poorly understood mechanisms. Recent efforts to develop delivery systems that increase GTCs’ overall bioavailability, by means of biopolymeric nanoparticles, represent the main way to translate preclinical results in a real clinical scenario for PCa chemoprevention.
      PubDate: 2017-04-05
      DOI: 10.3390/antiox6020026
      Issue No: Vol. 6, No. 2 (2017)
       
  • Antioxidants, Vol. 6, Pages 27: Strange Bedfellows: Nuclear Factor,
           Erythroid 2-Like 2 (Nrf2) and Hypoxia-Inducible Factor 1 (HIF-1) in Tumor
           Hypoxia

    • Authors: Rachel Toth, Noel Warfel
      First page: 27
      Abstract: The importance of the tumor microenvironment for cancer progression and therapeutic resistance is an emerging focus of cancer biology. Hypoxia, or low oxygen, is a hallmark of solid tumors that promotes metastasis and represents a significant obstacle to successful cancer therapy. In response to hypoxia, cancer cells activate a transcriptional program that allows them to survive and thrive in this harsh microenvironment. Hypoxia-inducible factor 1 (HIF-1) is considered the main effector of the cellular response to hypoxia, stimulating the transcription of genes involved in promoting angiogenesis and altering cellular metabolism. However, growing evidence suggests that the cellular response to hypoxia is much more complex, involving coordinated signaling through stress response pathways. One key signaling molecule that is activated in response to hypoxia is nuclear factor, erythroid 2 like-2 (Nrf2). Nrf2 is a transcription factor that controls the expression of antioxidant-response genes, allowing the cell to regulate reactive oxygen species. Nrf2 is also activated in various cancer types due to genetic and epigenetic alterations, and is associated with poor survival and resistance to therapy. Emerging evidence suggests that coordinated signaling through Nrf2 and HIF-1 is critical for tumor survival and progression. In this review, we discuss the distinct and overlapping roles of HIF-1 and Nrf2 in the cellular response to hypoxia, with a focus on how targeting Nrf2 could provide novel chemotherapeutic modalities for treating solid tumors.
      PubDate: 2017-04-06
      DOI: 10.3390/antiox6020027
      Issue No: Vol. 6, No. 2 (2017)
       
  • Antioxidants, Vol. 6, Pages 28: Acute Pre-/Post-Treatment with 8th Day
           SOD-Like Supreme (a Free Radical Scavenging Health Product) Protects
           against Oxidant-Induced Injury in Cultured Cardiomyocytes and Hepatocytes
           In Vitro as Well as in Mouse Myocardium and Liver In Vivo

    • Authors: Pou Leong, Jihang Chen, Wing Chan, Hoi Leung, Lincoln Chan, Kam Ko
      First page: 28
      Abstract: 8th Day superoxide dismutase (SOD)-Like Supreme (SOD-Like Supreme, a free radical scavenging health product) is an antioxidant-enriched fermentation preparation with free radical scavenging properties. In the present study, the cellular/tissue protective actions of SOD-Like Supreme against menadione toxicity in cultured H9c2 cardiomyocytes and in AML12 hepatocytes as well as oxidant-induced injury in the mouse myocardium and liver were investigated. SOD-Like Supreme was found to possess potent free radical scavenging activity in vitro as assessed by an oxygen radical absorbance capacity assay. Incubation with SOD-Like Supreme (0.5–3% (v/v)) was shown to protect against menadione-induced toxicity in H9c2 and AML12 cells, as evidenced by increases in cell viability. The ability of SOD-Like Supreme to protect against menadione cytotoxicity was associated with an elevation in the cellular reduced glutathione (GSH)/oxidized glutathione (GSSG) ratio in menadione-challenged cells. Consistent with the cell-based studies, pre-/post-treatment with SOD-Like Supreme (0.69 and 2.06 mL/kg, three intermittent doses per day for two consecutive days) was found to protect against isoproterenol-induced myocardial injury and carbon tetrachloride hepatotoxicity in mice. The cardio/hepatoprotection afforded by SOD-Like Supreme was also paralleled by increases in myocardial/hepatic mitochondrial GSH/GSSG ratios in the SOD-Like Supreme-treated/oxidant-challenged mice. In conclusion, incubation/treatment with SOD-Like Supreme was found to protect against oxidant-induced injury in vitro and in vivo, presumably by virtue of its free radical scavenging activity.
      PubDate: 2017-04-10
      DOI: 10.3390/antiox6020028
      Issue No: Vol. 6, No. 2 (2017)
       
  • Antioxidants, Vol. 6, Pages 29: HO-1 Induction in Cancer Progression: A
           Matter of Cell Adaptation

    • Authors: Mariapaola Nitti, Sabrina Piras, Umberto Marinari, Lorenzo Moretta, Maria Pronzato, Anna Furfaro
      First page: 29
      Abstract: The upregulation of heme oxygenase-1 (HO-1) is one of the most important mechanisms of cell adaptation to stress. Indeed, the redox sensitive transcription factor Nrf2 is the pivotal regulator of HO-1 induction. Through the antioxidant, antiapoptotic, and antinflammatory properties of its metabolic products, HO-1 plays a key role in healthy cells in maintaining redox homeostasis and in preventing carcinogenesis. Nevertheless, several lines of evidence have highlighted the role of HO-1 in cancer progression and its expression correlates with tumor growth, aggressiveness, metastatic and angiogenetic potential, resistance to therapy, tumor escape, and poor prognosis, even though a tumor- and tissue-specific activity has been observed. In this review, we summarize the current literature regarding the pro-tumorigenic role of HO-1 dependent tumor progression as a promising target in anticancer strategy.
      PubDate: 2017-05-05
      DOI: 10.3390/antiox6020029
      Issue No: Vol. 6, No. 2 (2017)
       
  • Antioxidants, Vol. 6, Pages 30: Natural Phenol Polymers: Recent Advances
           in Food and Health Applications

    • Authors: Lucia Panzella, Alessandra Napolitano
      First page: 30
      Abstract: Natural phenol polymers are widely represented in nature and include a variety of classes including tannins and lignins as the most prominent. Largely consumed foods are rich sources of phenol polymers, notably black foods traditionally used in East Asia, but other non-edible, easily accessible sources, e.g., seaweeds and wood, have been considered with increasing interest together with waste materials from agro-based industries, primarily grape pomace and other byproducts of fruit and coffee processing. Not in all cases were the main structural components of these materials identified because of their highly heterogeneous nature. The great beneficial effects of natural phenol-based polymers on human health and their potential in improving the quality of food were largely explored, and this review critically addresses the most interesting and innovative reports in the field of nutrition and biomedicine that have appeared in the last five years. Several in vivo human and animal trials supported the proposed use of these materials as food supplements and for amelioration of the health and production of livestock. Biocompatible and stable functional polymers prepared by peroxidase-catalyzed polymerization of natural phenols, as well as natural phenol polymers were exploited as conventional and green plastic additives in smart packaging and food-spoilage prevention applications. The potential of natural phenol polymers in regenerative biomedicine as additives of biomaterials to promote growth and differentiation of osteoblasts is also discussed.
      PubDate: 2017-04-14
      DOI: 10.3390/antiox6020030
      Issue No: Vol. 6, No. 2 (2017)
       
  • Antioxidants, Vol. 6, Pages 31: Phenolic Compositions and Antioxidant
           Properties in Bark, Flower, Inner Skin, Kernel and Leaf Extracts of
           Castanea crenata Sieb. et Zucc

    • Authors: Phung Tuyen, Tran Xuan, Do Khang, Ateeque Ahmad, Nguyen Quan, Truong Tu Anh, La Anh, Truong Minh
      First page: 31
      Abstract: In this study, different plant parts (barks, flowers, inner skins, kernels and leaves) of Castanea crenata (Japanese chestnut) were analyzed for total phenolic, flavonoid, and tannin contents. Antioxidant properties were evaluated by using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), reducing power, and β-carotene bleaching methods. The highest total phenolic and tannin contents were found in the inner skins (1034 ± 7.21 mg gallic acid equivalent/g extract and 253.89 ± 5.59 mg catechin equivalent/g extract, respectively). The maximum total flavonoid content was observed in the flowers (147.41 ± 1.61 mg rutin equivalent/g extract). The inner skins showed the strongest antioxidant activities in all evaluated assays. Thirteen phenolic acids and eight flavonoids were detected and quantified for the first time. Major phenolic acids were gallic, ellagic, sinapic, and p-coumaric acids, while the principal flavonoids were myricetin and isoquercitrin. The inner skin extract was further fractionated by column chromatography to yield four fractions, of which fraction F3 exhibited the most remarkable DPPH scavenging capacity. These results suggest that C. crenata provides promising antioxidant capacities, and is a potential natural preservative agent in food and pharmaceutical industries.
      PubDate: 2017-05-05
      DOI: 10.3390/antiox6020031
      Issue No: Vol. 6, No. 2 (2017)
       
  • Antioxidants, Vol. 6, Pages 32: The Importance of NADPH Oxidases and Redox
           Signaling in Angiogenesis

    • Authors: Rodrigo Prieto-Bermejo, Angel Hernández-Hernández
      First page: 32
      Abstract: Eukaryotic cells have to cope with the constant generation of reactive oxygen species (ROS). Although the excessive production of ROS might be deleterious for cell biology, there is a plethora of evidence showing that moderate levels of ROS are important for the control of cell signaling and gene expression. The family of the nicotinamide adenine dinucleotide phosphate oxidases (NADPH oxidases or Nox) has evolved to produce ROS in response to different signals; therefore, they fulfil a central role in the control of redox signaling. The role of NADPH oxidases in vascular physiology has been a field of intense study over the last two decades. In this review we will briefly analyze how ROS can regulate signaling and gene expression. We will address the implication of NADPH oxidases and redox signaling in angiogenesis, and finally, the therapeutic possibilities derived from this knowledge will be discussed.
      PubDate: 2017-05-13
      DOI: 10.3390/antiox6020032
      Issue No: Vol. 6, No. 2 (2017)
       
  • Antioxidants, Vol. 6, Pages 33: The Interplay between Oncogenic Signaling
           Networks and Mitochondrial Dynamics

    • Authors: Sarbajeet Nagdas, David Kashatus
      First page: 33
      Abstract: Mitochondria are dynamic organelles that alter their organization in response to a variety of cellular cues. Mitochondria are central in many biologic processes, such as cellular bioenergetics and apoptosis, and mitochondrial network morphology can contribute to those physiologic processes. Some of the biologic processes that are in part governed by mitochondria are also commonly deregulated in cancers. Furthermore, patient tumor samples from a variety of cancers have revealed that mitochondrial dynamics machinery may be deregulated in tumors. In this review, we will discuss how commonly mutated oncogenes and their downstream effector pathways regulate the mitochondrial dynamics machinery to promote changes in mitochondrial morphology as well as the physiologic consequences of altered mitochondrial morphology for tumorigenic growth.
      PubDate: 2017-05-17
      DOI: 10.3390/antiox6020033
      Issue No: Vol. 6, No. 2 (2017)
       
  • Antioxidants, Vol. 6, Pages 34: A Study of the Protective Properties of
           Iraqi Olive Leaves against Oxidation and Pathogenic Bacteria in Food
           Applications

    • Authors: Ammar Altemimi
      First page: 34
      Abstract: There is an ancient and prodigious history of olive trees because of their nutritional, medicinal, and traditional uses. Intensive studies have been conducted on olive leaves because they have many positive and beneficial effects for human health. In this study, different solvents were used to examine the olive leaves for their antioxidant and antimicrobial activities and their possible food applications. The obtained results showed that the amounts of phenolic compounds of the olive leaf were 190.44 ± 0.50, 173 ± 1.72, 147.78 ± 0.69, and 147.50 ± 0.05 mg gallic acid/g extracts using methanol, ethanol, diethyl ether, and hexanol, respectively. The statistical analysis revealed that there was a significant difference in the phenolic contents in terms of the used solvents. The stability of the olive leaves extraction was also studied and the results indicated that increasing the storage temperature could negatively affect and encourage the degradation of the phenolic compounds. Furthermore, the olive leaf extraction was applied to raw sheep meat slides at 0.5%, 1.5%, and 2.5% (w/v) in order to test its antioxidant and antimicrobial effects. The results obviously showed that the sample treated with 2.5% olive leaf extract had the significantly (p < 0.05) lowest Thiobarbituric Acid (TBA) values of 1.92 ± 0.12 (mg Malonaldehyde MDA/kg) throughout 12 days of cold storage. Moreover, the results showed that the sample, which was treated with 2.5% olive leaf extract, had low total bacterial count and total coliform bacteria (6.23 ± 0.05, 5.2 ± 0.35 log colony forming unit (CFU)/g, respectively) among the control, 0.5%, and 1.5% olive leaf treated samples throughout 12 days of storage. The phenolic extracts from the olive leaf extract had significant antioxidant and antimicrobial activities, which could be used as a source of potential antioxidant and antimicrobial agents.
      PubDate: 2017-05-17
      DOI: 10.3390/antiox6020034
      Issue No: Vol. 6, No. 2 (2017)
       
  • Antioxidants, Vol. 6, Pages 35: Green Synthesized Zinc Oxide (ZnO)
           Nanoparticles Induce Oxidative Stress and DNA Damage in Lathyrus sativus
           L. Root Bioassay System

    • Authors: Kamal Panda, Dambaru Golari, A. Venugopal, V. Achary, Ganngam Phaomei, Narasimham Parinandi, Hrushi Sahu, Brahma Panda
      First page: 35
      Abstract: Zinc oxide nanoparticles (ZnONP-GS) were synthesised from the precursor zinc acetate (Zn(CH3COO)2) through the green route using the milky latex from milk weed (Calotropis gigantea L. R. Br) by alkaline precipitation. Formation of the ZnONP-GS was monitored by UV-visible spectroscopy followed by characterization and confirmation by energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), and X-ray diffraction (XRD). Both the ZnONP-GS and the commercially available ZnONP-S (Sigma-Aldrich) and cationic Zn2+ from Zn(CH3COO)2 were tested in a dose range of 0–100 mg·L−1 for their potency (i) to induce oxidative stress as measured by the generation reactive oxygen species (ROS: O2•−, H2O2 and •OH), cell death, and lipid peroxidation; (ii) to modulate the activities of antioxidant enzymes: catalase (CAT), superoxide dismutase (SOD), guaiacol peroxidase (GPX), and ascorbate peroxidase (APX); and (iii) to cause DNA damage as determined by Comet assay in Lathyrus sativus L. root bioassay system. Antioxidants such as Tiron and dimethylthiourea significantly attenuated the ZnONP-induced oxidative and DNA damage, suggesting the involvement of ROS therein. Our study demonstrated that both ZnONP-GS and ZnONP-S induced oxidative stress and DNA damage to a similar extent but were significantly less potent than Zn2+ alone.
      PubDate: 2017-05-18
      DOI: 10.3390/antiox6020035
      Issue No: Vol. 6, No. 2 (2017)
       
  • Antioxidants, Vol. 6, Pages 36: Hormetic Property of Ginseng Steroids on
           Anti-Oxidant Status against Exercise Challenge in Rat Skeletal Muscle

    • Authors: Ming-Fen Hsu, Szu-Hsien Yu, Mallikarjuna Korivi, Wei-Horng Jean, Shin-Da Lee, Chih-Yang Huang, Yi-Hung Liao, Jessica Lu, Chia-Hua Kuo
      First page: 36
      Abstract: Background: Existing literature on anti-oxidant capacity of ginseng has been inconsistent due to variance in the profile of ginseng steroids (Ginsenosides) that is because of differences in seasons and species. Methods: We used various doses of ginseng steroids to determine its effect on oxidative stress and anti-oxidant capacity of rat skeletal muscle against exercise. Results: Under non-exercise conditions, we found increased thiobarbituric acid reactive substance (TBARS) levels and decreased reduced/oxidized glutathione ratio (GSH/GSSG) in rat skeletal muscle as dose increases (p < 0.05), which indicates the pro-oxidant property of ginseng steroids at baseline. Intriguingly, exhaustive exercise-induced increased TBARS and decreased GSH/GSSG ratio were attenuated with low and medium doses of ginseng steroids (20 and 40 mg per kg), but not with high dose (120 mg per kg). At rest, anti-oxidant enzyme activities, including catalase (CAT), glutathione reductase (GR) and glutathione S-transferase (GST) were increased above vehicle-treated level, but not with the high dose, suggesting a hormetic dose-response of ginseng steroids. Conclusion: The results of this study provide an explanation for the inconsistent findings on anti-oxidative property among previous ginseng studies. For optimizing the anti-oxidant outcome, ginseng supplementation at high dose should be avoided.
      PubDate: 2017-05-19
      DOI: 10.3390/antiox6020036
      Issue No: Vol. 6, No. 2 (2017)
       
  • Antioxidants, Vol. 6, Pages 37: Effects of β-Carotene and Its Cleavage
           Products in Primary Pneumocyte Type II Cells

    • Authors: Cornelia Haider, Franziska Ferk, Ekramije Bojaxhi, Giuseppe Martano, Hanno Stutz, Nikolaus Bresgen, Siegfried Knasmüller, Avdulla Alija, Peter Eckl
      First page: 37
      Abstract: β-Carotene has been shown to increase the risk of developing lung cancer in smokers and asbestos workers in two large scale trails, the Beta-Carotene and Retinol Efficacy Trial (CARET) and the Alpha-Tocopherol Beta-carotene Cancer Prevention Trial (ATBC). Based on this observation, it was proposed that genotoxic oxidative breakdown products may cause this effect. In support of this assumption, increased levels of sister chromatid exchanges, micronuclei, and chromosomal aberrations were found in primary hepatocyte cultures treated with a mixture of cleavage products (CPs) and the major product apo-8′carotenal. However, because these findings cannot directly be transferred to the lung due to the exceptional biotransformation capacity of the liver, potential genotoxic and cytotoxic effects of β-carotene under oxidative stress and its CPs were investigated in primary pneumocyte type II cells. The results indicate that increased concentrations of β-carotene in the presence of the redox cycling quinone dimethoxynaphthoquinone (DMNQ) exhibit a cytotoxic potential, as evidenced by an increase of apoptotic cells and loss of cell density at concentrations > 10 µM. On the other hand, the analysis of micronucleated cells gave no clear picture due to the cytotoxicity related reduction of mitotic cells. Last, although CPs induced significant levels of DNA strand breaks even at concentrations ≥ 1 µM and 5 µM, respectively, β-carotene in the presence of DMNQ did not cause DNA damage. Instead, β-carotene appeared to act as an antioxidant. These findings are in contrast with what was demonstrated for primary hepatocytes and may reflect different sensitivities to and different metabolism of β-carotene in the two cell types.
      PubDate: 2017-05-21
      DOI: 10.3390/antiox6020037
      Issue No: Vol. 6, No. 2 (2017)
       
  • Antioxidants, Vol. 6, Pages 38: The Reactive Sulfur Species Concept: 15
           Years On

    • Authors: Gregory Giles, Muhammad Nasim, Wesam Ali, Claus Jacob
      First page: 38
      Abstract: Fifteen years ago, in 2001, the concept of “Reactive Sulfur Species” or RSS was advocated as a working hypothesis. Since then various organic as well as inorganic RSS have attracted considerable interest and stimulated many new and often unexpected avenues in research and product development. During this time, it has become apparent that molecules with sulfur-containing functional groups are not just the passive “victims” of oxidative stress or simple conveyors of signals in cells, but can also be stressors in their own right, with pivotal roles in cellular function and homeostasis. Many “exotic” sulfur-based compounds, often of natural origin, have entered the fray in the context of nutrition, ageing, chemoprevention and therapy. In parallel, the field of inorganic RSS has come to the forefront of research, with short-lived yet metabolically important intermediates, such as various sulfur-nitrogen species and polysulfides (Sx2−), playing important roles. Between 2003 and 2005 several breath-taking discoveries emerged characterising unusual sulfur redox states in biology, and since then the truly unique role of sulfur-dependent redox systems has become apparent. Following these discoveries, over the last decade a “hunt” and, more recently, mining for such modifications has begun—and still continues—often in conjunction with new, innovative and complex labelling and analytical methods to capture the (entire) sulfur “redoxome”. A key distinction for RSS is that, unlike oxygen or nitrogen, sulfur not only forms a plethora of specific reactive species, but sulfur also targets itself, as sulfur containing molecules, i.e., peptides, proteins and enzymes, preferentially react with RSS. Not surprisingly, today this sulfur-centred redox signalling and control inside the living cell is a burning issue, which has moved on from the predominantly thiol/disulfide biochemistry of the past to a complex labyrinth of interacting signalling and control pathways which involve various sulfur oxidation states, sulfur species and reactions. RSS are omnipresent and, in some instances, are even considered as the true bearers of redox control, perhaps being more important than the Reactive Oxygen Species (ROS) or Reactive Nitrogen Species (RNS) which for decades have dominated the redox field. In other(s) words, in 2017, sulfur redox is “on the rise”, and the idea of RSS resonates throughout the Life Sciences. Still, the RSS story isn’t over yet. Many RSS are at the heart of “mistaken identities” which urgently require clarification and may even provide the foundations for further scientific revolutions in the years to come. In light of these developments, it is therefore the perfect time to revisit the original hypotheses, to select highlights in the field and to question and eventually update our concept of “Reactive Sulfur Species”.
      PubDate: 2017-05-23
      DOI: 10.3390/antiox6020038
      Issue No: Vol. 6, No. 2 (2017)
       
  • Antioxidants, Vol. 6, Pages 39: Is Root Catalase a Bifunctional
           Catalase-Peroxidase'

    • Authors: Vasileia Chioti, George Zervoudakis
      First page: 39
      Abstract: Plant catalases exhibit spatial and temporal distribution of their activity. Moreover, except from the typical monofunctional catalase, a bifunctional catalase-peroxidase has been reported. The aim of this study was to investigate whether the leaf and root catalases from six different plant species (Lactuca sativa, Cichorium endivia, Apium graveolens, Petroselinum crispum, Lycopersicon esculentum, and Solanum melongena) correspond to the monofunctional or the bifunctional type based on their sensitivity to the inhibitor 3-amino-1,2,4-triazole (3-AT). The leaf catalases from all species seem to be monofunctional since they are very sensitive to 3-AT. On the other hand, the root enzymes from Lactuca sativa, Cichorium endivia, Lycopersicon esculentum, and Solanum melongena seem to be bifunctional catalase-peroxidases, considering that they are relatively insensitive to 3-AT, whereas the catalases from Apium graveolens and Petroselinum crispum display the same monofunctional characteristics as the leaves’ enzymes. The leaf catalase activity is usually higher (Lactuca sativa, Petroselinum crispum, and Solanum melongena) or similar (Cichorium endivia and Apium graveolens) to the root one, except for the enzyme from Lycopersicon esculentum, while in all plant species the leaf protein concentration is significantly higher than the root protein concentration. These results suggest that there are differences between leaf and root catalases—differences that may correspond to their physiological role.
      PubDate: 2017-05-25
      DOI: 10.3390/antiox6020039
      Issue No: Vol. 6, No. 2 (2017)
       
  • Antioxidants, Vol. 6, Pages 40: Roles of Nicotinamide Adenine Dinucleotide
           Phosphate (NADPH) Oxidase in Angiogenesis: Isoform-Specific Effects

    • Authors: Haibo Wang, M. Hartnett
      First page: 40
      Abstract: Angiogenesis is the formation of new blood vessels from preexisting ones and is implicated in physiologic vascular development, pathologic blood vessel growth, and vascular restoration. This is in contrast to vasculogenesis, which is de novo growth of vessels from vascular precursors, or from vascular repair that occurs when circulating endothelial progenitor cells home into an area and develop into blood vessels. The objective of this review is to discuss the isoform-specific role of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) in physiologic and pathologic angiogenesis and vascular repair, but will not specifically address vasculogenesis. As the major source of reactive oxygen species (ROS) in vascular endothelial cells (ECs), NOX has gained increasing attention in angiogenesis. Activation of NOX leads to events necessary for physiologic and pathologic angiogenesis, including EC migration, proliferation and tube formation. However, activation of different NOX isoforms has different effects in angiogenesis. Activation of NOX2 promotes pathologic angiogenesis and vascular inflammation, but may be beneficial in revascularization in the hindlimb ischemic model. In contrast, activation of NOX4 appears to promote physiologic angiogenesis mainly by protecting the vasculature during ischemia, hypoxia and inflammation and by restoring vascularization, except in models of oxygen-induced retinopathy and diabetes where NOX4 activation leads to pathologic angiogenesis.
      PubDate: 2017-06-03
      DOI: 10.3390/antiox6020040
      Issue No: Vol. 6, No. 2 (2017)
       
  • Antioxidants, Vol. 6, Pages 41: Undernutrition and Overnutrition Burden
           for Diseases in Developing Countries: The Role of Oxidative Stress
           Biomarkers to Assess Disease Risk and Interventional Strategies

    • Authors: Francesca Mastorci, Cristina Vassalle, Kyriazoula Chatzianagnostou, Claudio Marabotti, Khawer Siddiqui, Ahmed Eba, Soueid Mhamed, Arun Bandopadhyay, Marco Nazzaro, Mirko Passera, Alessandro Pingitore
      First page: 41
      Abstract: The increased life expectancy, urbanization, and unhealthy lifestyle characterized by a shift towards a sedentary lifestyle and decreased energy expenditure are considered the main drivers of epidemiological transition. In particular, developing countries are facing a double burden caused by coexisting under- and over-nutrition, which causes a change in the disease profile from infectious diseases to a chronic degenerative pattern. This review discusses the under- and over-nutrition context in Mauritania and India, two countries that are experiencing a nutritional transition, and where we began a collaboration with local medical staff to integrate interventional and diagnostic guidelines. If many studies about diet and its relationship to non-communicable diseases are available for India, very few nutrition and cardiovascular risk studies have been conducted in Mauritania. Presently, with the exponential increase of nutrition-related diseases, targeted approaches are needed to provide balanced diets in parallel with the development of national preventive health systems and screening programs adapted to local needs. In this context, the measurement of oxidative stress biomarkers could be promising as an additive tool to assess cardiovascular (CV) risk in general population, and ameliorating prevention in patients at CV risk or with overt CV disease. Moreover, the possibility of improving the outcome by the direct employment of antioxidant remains plausible. Moreover, studies on the content of antioxidant in different foods may be helpful to develop a balanced diet, and achieve the maximal nutritional and functional properties of cultivars with benefits for human health.
      PubDate: 2017-06-08
      DOI: 10.3390/antiox6020041
      Issue No: Vol. 6, No. 2 (2017)
       
  • Antioxidants, Vol. 6, Pages 42: The Role of NOX4 and TRX2 in Angiogenesis
           and Their Potential Cross-Talk

    • Authors: Chaofei Chen, Li Li, Huanjiao Zhou, Wang Min
      First page: 42
      Abstract: The nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) family is the major source of reactive oxygen species (ROS) in the vascular system. In this family, NOX4, a constitutive active form of NOXs, plays an important role in angiogenesis. Thioredoxin 2 (TRX2) is a key mitochondrial redox protein that maintains normal protein function and also provides electrons to peroxiredoxin 3 (PRX3) to scavenge H2O2 in mitochondria. Angiogenesis, a process of new blood vessel formation, is involved in a variety of physiological processes and pathological conditions. It seems to be paradoxical for ROS-producing NOX4 and ROS-scavenging TRX2 to have a similar role in promoting angiogenesis. In this review, we will focus on data supporting the role of NOX4 and TRX2 in angiogenesis and their cross-talks and discuss how ROS can positively or negatively regulate angiogenesis, depending on their species, levels and locations. NOX4 and TRX2-mediated ROS signaling could be promising targets for the treatment of angiogenesis-related diseases.
      PubDate: 2017-06-08
      DOI: 10.3390/antiox6020042
      Issue No: Vol. 6, No. 2 (2017)
       
  • Antioxidants, Vol. 6, Pages 43: NOX2-Induced Activation of Arginase and
           Diabetes-Induced Retinal Endothelial Cell Senescence

    • Authors: Modesto Rojas, Tahira Lemtalsi, Haroldo Toque, Zhimin Xu, David Fulton, Robert Caldwell, Ruth Caldwell
      First page: 43
      Abstract: Increases in reactive oxygen species (ROS) and decreases in nitric oxide (NO) have been linked to vascular dysfunction during diabetic retinopathy (DR). Diabetes can reduce NO by increasing ROS and by increasing activity of arginase, which competes with nitric oxide synthase (NOS) for their commons substrate l-arginine. Increased ROS and decreased NO can cause premature endothelial cell (EC) senescence leading to defective vascular repair. We have previously demonstrated the involvement of NADPH oxidase 2 (NOX2)-derived ROS, decreased NO and overactive arginase in DR. Here, we investigated their impact on diabetes-induced EC senescence. Studies using diabetic mice and retinal ECs treated with high glucose or H2O2 showed that increases in ROS formation, elevated arginase expression and activity, and decreased NO formation led to premature EC senescence. NOX2 blockade or arginase inhibition prevented these effects. EC senescence was also increased by inhibition of NOS activity and this was prevented by treatment with a NO donor. These results indicate that diabetes/high glucose-induced activation of arginase and decreases in NO bioavailability accelerate EC senescence. NOX2-generated ROS contribute importantly to this process. Blockade of NOX2 or arginase represents a strategy to prevent diabetes-induced premature EC senescence by preserving NO bioavailability.
      PubDate: 2017-06-15
      DOI: 10.3390/antiox6020043
      Issue No: Vol. 6, No. 2 (2017)
       
  • Antioxidants, Vol. 6, Pages 4: Acknowledgement to Reviewers of
           Antioxidants in 2016

    • Authors: Antioxidants Editorial Office
      First page: 4
      Abstract: The editors of Antioxidants would like to express their sincere gratitude to the following reviewers for assessing manuscripts in 2016.[...]
      PubDate: 2017-01-11
      DOI: 10.3390/antiox6010004
      Issue No: Vol. 6, No. 1 (2017)
       
  • Antioxidants, Vol. 6, Pages 5: Use of Saliva Biomarkers to Monitor
           Efficacy of Vitamin C in Exercise-Induced Oxidative Stress

    • Authors: Levi Evans, Stanley Omaye
      First page: 5
      Abstract: Saliva is easily obtainable for medical research and requires little effort or training for collection. Because saliva contains a variety of biological compounds, including vitamin C, malondialdehyde, amylase, and proteomes, it has been successfully used as a biospecimen for the reflection of health status. A popular topic of discussion in medical research is the potential association between oxidative stress and negative outcomes. Systemic biomarkers that represent oxidative stress can be found in saliva. It is unclear, however, if saliva is an accurate biospecimen as is blood and/or plasma. Exercise can induce oxidative stress, resulting in a trend of antioxidant supplementation to combat its assumed detriments. Vitamin C is a popular antioxidant supplement in the realm of sports and exercise. One potential avenue for evaluating exercise induced oxidative stress is through assessment of biomarkers like vitamin C and malondialdehyde in saliva. At present, limited research has been done in this area. The current state of research involving exercise-induced oxidative stress, salivary biomarkers, and vitamin C supplementation is reviewed in this article.
      PubDate: 2017-01-12
      DOI: 10.3390/antiox6010005
      Issue No: Vol. 6, No. 1 (2017)
       
  • Antioxidants, Vol. 6, Pages 6: Exercise-Induced Oxidative Stress Responses
           in the Pediatric Population

    • Authors: Alexandra Avloniti, Athanasios Chatzinikolaou, Chariklia Deli, Dimitris Vlachopoulos, Luis Gracia-Marco, Diamanda Leontsini, Dimitrios Draganidis, Athanasios Jamurtas, George Mastorakos, Ioannis Fatouros
      First page: 6
      Abstract: Adults demonstrate an upregulation of their pro- and anti-oxidant mechanisms in response to acute exercise while systematic exercise training enhances their antioxidant capacity, thereby leading to a reduced generation of free radicals both at rest and in response to exercise stress. However, less information exists regarding oxidative stress responses and the underlying mechanisms in the pediatric population. Evidence suggests that exercise-induced redox perturbations may be valuable in order to monitor exercise-induced inflammatory responses and as such training overload in children and adolescents as well as monitor optimal growth and development. The purpose of this review was to provide an update on oxidative stress responses to acute and chronic exercise in youth. It has been documented that acute exercise induces age-specific transient alterations in both oxidant and antioxidant markers in children and adolescents. However, these responses seem to be affected by factors such as training phase, training load, fitness level, mode of exercise etc. In relation to chronic adaptation, the role of training on oxidative stress adaptation has not been adequately investigated. The two studies performed so far indicate that children and adolescents exhibit positive adaptations of their antioxidant system, as adults do. More studies are needed in order to shed light on oxidative stress and antioxidant responses, following acute exercise and training adaptations in youth. Available evidence suggests that small amounts of oxidative stress may be necessary for growth whereas the transition to adolescence from childhood may promote maturation of pro- and anti-oxidant mechanisms. Available evidence also suggests that obesity may negatively affect basal and exercise-related antioxidant responses in the peripubertal period during pre- and early-puberty.
      PubDate: 2017-01-17
      DOI: 10.3390/antiox6010006
      Issue No: Vol. 6, No. 1 (2017)
       
  • Antioxidants, Vol. 6, Pages 7: Red Fruits: Extraction of Antioxidants,
           Phenolic Content, and Radical Scavenging Determination: A Review

    • Authors: Gádor-Indra Hidalgo, María Almajano
      First page: 7
      Abstract: Red fruits, as rich antioxidant foods, have gained over recent years capital importance for consumers and manufacturers. The industrial extraction of the phenolic molecules from this source has been taking place with the conventional solvent extraction method. New non-conventional extraction methods have been devised as environmentally friendly alternatives to the former method, such as ultrasound, microwave, and pressure assisted extractions. The aim of this review is to compile the results of recent studies using different extraction methodologies, identify the red fruits with higher antioxidant activity, and give a global overview of the research trends regarding this topic. As the amount of data available is overwhelming, only results referring to berries are included, leaving aside other plant parts such as roots, stems, or even buds and flowers. Several researchers have drawn attention to the efficacy of non-conventional extraction methods, accomplishing similar or even better results using these new techniques. Some pilot-scale trials have been performed, corroborating the applicability of green alternative methods to the industrial scale. Blueberries (Vaccinium corymbosum L.) and bilberries (Vaccinium myrtillus L.) emerge as the berries with the highest antioxidant content and capacity. However, several new up and coming berries are gaining attention due to global availability and elevated anthocyanin content.
      PubDate: 2017-01-19
      DOI: 10.3390/antiox6010007
      Issue No: Vol. 6, No. 1 (2017)
       
  • Antioxidants, Vol. 6, Pages 8: A Comparative Study of the Phenolic and
           Technological Maturities of Red Grapes Grown in Lebanon

    • Authors: Hiba Rajha, Nada Darra, Sally Kantar, Zeina Hobaika, Nicolas Louka, Richard Maroun
      First page: 8
      Abstract: Grape harvest date is determined according to the technological and phenolic maturities. These parameters were calculated for different red grape (Vitis vinifera L.) varieties (Cabernet Sauvignon, Merlot, Syrah, Cabernet Franc) over four years (2008, 2009, 2010, and 2011) (642 samples). Titratable acidity and sugar content of the grapes were used to determine the technological maturity, whereas Glories (1 and 2) and ITV (Institut Technique de la Vigne et du Vin) methods were used to monitor their phenolic maturity. The ITV method allows the monitoring of phenolic maturity by the quantification of total polyphenol index and anthocyanins, while the Glories method enables the quantitative evolution of extractable anthocyanins and tannins of the grapes. A correlation was shown between the harvest dates obtained by both ITV and Glories (R2 = 0.7 – 0.93). Phenolic maturity of grapes can, therefore, be optimized by the application of both ITV and Glories. Similarly, a correlation was observed between technological and phenolic harvest dates. The effect of climate on the phenolic content of grapes was also studied. The highest temperatures(up to 25◦C)accompanied by the lowest rainfall (null value), induced the maximal concentration of polyphenols in grapes. Thermal and water stresses were also shown to enhance the grapes’ polyphenolic production.
      PubDate: 2017-01-26
      DOI: 10.3390/antiox6010008
      Issue No: Vol. 6, No. 1 (2017)
       
  • Antioxidants, Vol. 6, Pages 9: Hydroxybenzoic Acids Are Significant
           Contributors to the Antioxidant Effect of Borututu Bark, Cochlospermum
           angolensis Welw. ex Oliv

    • Authors: Ehab Abourashed, Hao Fu
      First page: 9
      Abstract: Borututu (Cochlospermum angolensis) is an African tree whose bark has recently emerged as a herbal dietary supplement with claims for antioxidant activity. In order to substantiate the claimed activity of borututu supplements, we performed an activity-guided fractionation of the total extract utilizing a 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay. Subsequent flash and centrifugal chromatography resulted in the isolation of gallic acid (1) and protocatechuic acid (2) as the main antioxidant constituents. Two apocarotenoids and one flavonoid were also isolated from the chloroform fraction and were identified as cochloxanthin (3), dihydrocochloxanthin (4), and 7,4′-dimethyltaxifolin (5), respectively. A High-performance liquid chromatography (HPLC) method was also developed for fingerprinting borututu samples, with Compounds 1–4 suggested as chemical markers for quality control purposes.
      PubDate: 2017-01-28
      DOI: 10.3390/antiox6010009
      Issue No: Vol. 6, No. 1 (2017)
       
  • Antioxidants, Vol. 6, Pages 10: Antioxidant Compound Extraction from Maqui
           (Aristotelia chilensis [Mol] Stuntz) Berries: Optimization by Response
           Surface Methodology

    • Authors: Issis Quispe-Fuentes, Antonio Vega-Gálvez, Víctor Campos-Requena
      First page: 10
      Abstract: The optimum conditions for the antioxidant extraction from maqui berry were determined using a response surface methodology. A three level D-optimal design was used to investigate the effects of three independent variables namely, solvent type (methanol, acetone and ethanol), solvent concentration and extraction time over total antioxidant capacity by using the oxygen radical absorbance capacity (ORAC) method. The D-optimal design considered 42 experiments including 10 central point replicates. A second-order polynomial model showed that more than 89% of the variation is explained with a satisfactory prediction (78%). ORAC values are higher when acetone was used as a solvent at lower concentrations, and the extraction time range studied showed no significant influence on ORAC values. The optimal conditions for antioxidant extraction obtained were 29% of acetone for 159 min under agitation. From the results obtained it can be concluded that the given predictive model describes an antioxidant extraction process from maqui berry.
      PubDate: 2017-02-02
      DOI: 10.3390/antiox6010010
      Issue No: Vol. 6, No. 1 (2017)
       
  • Antioxidants, Vol. 6, Pages 11: In Vitro Lipophilic Antioxidant Capacity,
           Antidiabetic and Antibacterial Activity of Citrus Fruits Extracts from
           Aceh, Indonesia

    • Authors: Ernawita, Ruri Wahyuono, Jana Hesse, Uta-Christina Hipler, Peter Elsner, Volker Böhm
      First page: 11
      Abstract: This study reports in vitro lipophilic antioxidant, inhibition of α-amylase and antibacterial activities of extracts of peel and pulp of citrus samples from Aceh, Indonesia. HPLC (high-performance liquid chromatography), phytochemical, and FTIR (fourier transform infrared) analysis detected carotenoids, flavonoids, phenolic acids and terpenoids, contributing to the biological potencies. Most peel and pulp extracts contained lutein and lower concentrations of zeaxanthin, α-carotene, β-carotene and β-cryptoxanthin. The extracts also contained flavanone glycosides (hesperidin, naringin and neohesperidin), flavonol (quercetin) and polymethoxylated flavones (sinensetin, tangeretin). L-TEAC (lipophilic trolox equivalent antioxidant capacity) test determined for peel extracts higher antioxidant capacity compared to pulp extracts. All extracts presented α-amylase inhibitory activity, pulp extracts showing stronger inhibitory activity compared to peel extracts. All extracts inhibited the growth of both gram (+) and gram (−) bacteria, with peel and pulp extracts of makin showing the strongest inhibitory activity. Therefore, local citrus species from Aceh are potential sources of beneficial compounds with possible health preventive effects.
      PubDate: 2017-02-03
      DOI: 10.3390/antiox6010011
      Issue No: Vol. 6, No. 1 (2017)
       
  • Antioxidants, Vol. 6, Pages 12: Proanthocyanidin Characterization and
           Bioactivity of Extracts from Different Parts of Uncaria tomentosa L.
           (Cat’s Claw)

    • Authors: Mirtha Navarro-Hoyos, Rosa Lebrón-Aguilar, Jesús Quintanilla-López, Carolina Cueva, David Hevia, Silvia Quesada, Gabriela Azofeifa, M. Moreno-Arribas, María Monagas, Begoña Bartolomé
      First page: 12
      Abstract: Apart from alkaloids, bioactive properties of Uncaria tomentosa L. have been attributed to its phenolic constituents. Although there are some reports concerning low-molecular-weight polyphenols in U. tomentosa, its polymeric phenolic composition has been scarcely studied. In this study, phenolic-rich extracts from leaves, stems, bark and wood (n = 14) of Uncaria tomentosa plants from several regions of Costa Rica were obtained and analysed in respect to their proanthocyanidin profile determined by a quadrupole-time-of-flight analyser (ESI-QTOF MS). Main structural characteristics found for U. tomentosa proanthocyanidins were: (a) monomer composition, including pure procyanidins (only composed of (epi)catechin units) and propelargonidins (only composed of (epi)afzelechin units) as well as mixed proanthocyanidins; and (b) degree of polymerization, from 3 up to 11 units. In addition, U. tomentosa phenolic extracts were found to exhibit reasonable antioxidant capacity (ORAC (Oxygen Radical Absorbance Capacity) values between 1.5 and 18.8 mmol TE/g) and antimicrobial activity against potential respiratory pathogens (minimum IC50 of 133 µg/mL). There were also found to be particularly cytotoxic to gastric adenocarcinoma AGS and colon adenocarcinoma SW620 cell lines. The results state the particularities of U. tomentosa proanthocyanidins and suggest the potential value of these extracts with prospective use as functional ingredients.
      PubDate: 2017-02-04
      DOI: 10.3390/antiox6010012
      Issue No: Vol. 6, No. 1 (2017)
       
  • Antioxidants, Vol. 6, Pages 13: Selenium- and Tellurium-Based Antioxidants
           for Modulating Inflammation and Effects on Osteoblastic Activity

    • Authors: Xi Lu, Gemma Mestres, Vijay Singh, Pedram Effati, Jia-Fei Poon, Lars Engman, Marjam Ott
      First page: 13
      Abstract: Increased oxidative stress plays a significant role in the etiology of bone diseases. Heightened levels of H2O2 disrupt bone homeostasis, leading to greater bone resorption than bone formation. Organochalcogen compounds could act as free radical trapping agents or glutathione peroxidase mimetics, reducing oxidative stress in inflammatory diseases. In this report, we synthesized and screened a library of organoselenium and organotellurium compounds for hydrogen peroxide scavenging activity, using macrophagic cell lines RAW264.7 and THP-1, as well as human mono- and poly-nuclear cells. These cells were stimulated to release H2O2, using phorbol 12-myristate 13-acetate, with and without organochalogens. Released H2O2 was then measured using a chemiluminescent assay over a period of 2 h. The screening identified an organoselenium compound which scavenged H2O2 more effectively than the vitamin E analog, Trolox. We also found that this organoselenium compound protected MC3T3 cells against H2O2-induced toxicity, whereas Trolox did not. The organoselenium compound exhibited no cytotoxicity to the cells and had no deleterious effects on cell proliferation, viability, or alkaline phosphatase activity. The rapidity of H2O2 scavenging and protection suggests that the mechanism of protection is due to the direct scavenging of extracellular H2O2. This compound is a promising modulators of inflammation and could potentially treat diseases involving high levels of oxidative stress.
      PubDate: 2017-02-14
      DOI: 10.3390/antiox6010013
      Issue No: Vol. 6, No. 1 (2017)
       
  • Antioxidants, Vol. 6, Pages 14: Inorganic Reactive Sulfur-Nitrogen
           Species: Intricate Release Mechanisms or Cacophony in Yellow, Blue and
           Red?

    • Authors: Marian Grman, Muhammad Nasim, Roman Leontiev, Anton Misak, Veronika Jakusova, Karol Ondrias, Claus Jacob
      First page: 14
      Abstract: Since the heydays of Reactive Sulfur Species (RSS) research during the first decade of the Millennium, numerous sulfur species involved in cellular regulation and signalling have been discovered. Yet despite the general predominance of organic species in organisms, recent years have also seen the emergence of inorganic reactive sulfur species, ranging from inorganic polysulfides (HSx−/Sx2−) to thionitrous acid (HSNO) and nitrosopersulfide (SSNO−). These inorganic species engage in a complex interplay of reactions in vitro and possibly also in vivo. Employing a combination of spectrophotometry and sulfide assays, we have investigated the role of polysulfanes from garlic during the release of nitric oxide (•NO) from S-nitrosoglutathione (GSNO) in the absence and presence of thiol reducing agents. Our studies reveal a distinct enhancement of GSNO decomposition by compounds such as diallyltrisulfane, which is most pronounced in the presence of cysteine and glutathione and presumably proceeds via the initial release of an inorganic mono- or polysulfides, i.e., hydrogen sulfide (H2S) or HSx−, from the organic polysulfane. Albeit being of a preliminary nature, our spectrophotometric data also reveals a complicated underlying mechanism which appears to involve transient species such as SSNO−. Eventually, more in depth studies are required to further explore the underlying chemistry and wider biological and nutritional implications of this interplay between edible garlic compounds, reductive activation, inorganic polysulfides and their interplay with •NO storage and release.
      PubDate: 2017-02-15
      DOI: 10.3390/antiox6010014
      Issue No: Vol. 6, No. 1 (2017)
       
  • Antioxidants, Vol. 6, Pages 15: Treating Cancer by Targeting Telomeres and
           Telomerase

    • Authors: Marko Ivancich, Zachary Schrank, Luke Wojdyla, Brandon Leviskas, Adijan Kuckovic, Ankita Sanjali, Neelu Puri
      First page: 15
      Abstract: Telomerase is expressed in more than 85% of cancer cells. Tumor cells with metastatic potential may have a high telomerase activity, allowing cells to escape from the inhibition of cell proliferation due to shortened telomeres. Human telomerase primarily consists of two main components: hTERT, a catalytic subunit, and hTR, an RNA template whose sequence is complimentary to the telomeric 5′-dTTAGGG-3′ repeat. In humans, telomerase activity is typically restricted to renewing tissues, such as germ cells and stem cells, and is generally absent in normal cells. While hTR is constitutively expressed in most tissue types, hTERT expression levels are low enough that telomere length cannot be maintained, which sets a proliferative lifespan on normal cells. However, in the majority of cancers, telomerase maintains stable telomere length, thereby conferring cell immortality. Levels of hTERT mRNA are directly related to telomerase activity, thereby making it a more suitable therapeutic target than hTR. Recent data suggests that stabilization of telomeric G-quadruplexes may act to indirectly inhibit telomerase action by blocking hTR binding. Telomeric DNA has the propensity to spontaneously form intramolecular G-quadruplexes, four-stranded DNA secondary structures that are stabilized by the stacking of guanine residues in a planar arrangement. The functional roles of telomeric G-quadruplexes are not completely understood, but recent evidence suggests that they can stall the replication fork during DNA synthesis and inhibit telomere replication by preventing telomerase and related proteins from binding to the telomere. Long-term treatment with G-quadruplex stabilizers induces a gradual reduction in the length of the G-rich 3’ end of the telomere without a reduction of the total telomere length, suggesting that telomerase activity is inhibited. However, inhibition of telomerase, either directly or indirectly, has shown only moderate success in cancer patients. Another promising approach of targeting the telomere is the use of guanine-rich oligonucleotides (GROs) homologous to the 3’ telomere overhang sequence (T-oligos). T-oligos, particularly a specific 11-base oligonucleotide (5’-dGTTAGGGTTAG-3’) called T11, have been shown to induce DNA damage responses (DDRs) such as senescence, apoptosis, and cell cycle arrest in numerous cancer cell types with minimal or no cytostatic effects in normal, non-transformed cells. As a result, T-oligos and other GROs are being investigated as prospective anticancer therapeutics. Interestingly, the DDRs induced by T-oligos in cancer cells are similar to the effects seen after progressive telomere degradation in normal cells. The loss of telomeres is an important tumor suppressor mechanism that is commonly absent in transformed malignant cells, and hence, T-oligos have garnered significant interest as a novel strategy to combat cancer. However, little is known about their mechanism of action. In this review, we discuss the current understanding of how T-oligos exert their antiproliferative effects in cancer cells and their role in inhibition of telomerase. We also discuss the current understanding of telomerase in cancer and various therapeutic targets related to the telomeres and telomerase.
      PubDate: 2017-02-19
      DOI: 10.3390/antiox6010015
      Issue No: Vol. 6, No. 1 (2017)
       
  • Antioxidants, Vol. 6, Pages 16: The Effect of Gender and Menstrual Phase
           on Serum Creatine Kinase Activity and Muscle Soreness Following Downhill
           Running

    • Authors: Tanja Oosthuyse, Andrew Bosch
      First page: 16
      Abstract: Serum creatine kinase (CK) activity reflects muscle membrane disruption. Oestrogen has antioxidant and membrane stabilising properties, yet no study has compared the CK and muscle soreness (DOMS) response to unaccustomed exercise between genders when all menstrual phases are represented in women. Fifteen eumenorrhoeic women (early follicular, EF (n = 5); late follicular, LF (n = 5); mid-luteal, ML (n = 5) phase) and six men performed 20 min of downhill running (−10% gradient) at 9 km/h. Serum CK activity and visual analogue scale rating of perceived muscle soreness were measured before, immediately, 24-h, 48-h and 72-h after exercise. The 24-h peak CK response (relative to pre-exercise) was similar between women and men (mean change (95% confidence interval): 58.5 (25.2 to 91.7) IU/L; 68.8 (31.3 to 106.3) IU/L, respectively). However, serum CK activity was restored to pre-exercise levels quicker in women (regardless of menstrual phase) than men; after 48-h post exercise in women (16.3 (−4.4 to 37.0) IU/L; 56.3 (37.0 to 75.6) IU/L, respectively) but only after 72-h in men (14.9 (−14.8 to 44.6) IU/L). Parallel to the CK response, muscle soreness recovered by 72-h in men. Conversely, the women still reported muscle soreness at 72-h despite CK levels being restored by 48-h; delayed recovery of muscle soreness appeared mainly in EF and LF. The CK and DOMS response to downhill running is gender-specific. The CK response recovers quicker in women than men. The CK and DOMS response occur in concert in men but not in women. The DOMS response in women is prolonged and may be influenced by menstrual phase.
      PubDate: 2017-02-23
      DOI: 10.3390/antiox6010016
      Issue No: Vol. 6, No. 1 (2017)
       
  • Antioxidants, Vol. 6, Pages 17: Current Insights to Regulation and Role of
           Telomerase in Human Diseases

    • Authors: Mert Ozturk, Yinghui Li, Vinay Tergaonkar
      First page: 17
      Abstract: The telomerase ribonucleoprotein complex has a pivotal role in regulating the proliferation and senescence of normal somatic cells as well as cancer cells. This complex is comprised mainly of telomerase reverse transcriptase (TERT), telomerase RNA component (TERC) and other associated proteins that function to elongate telomeres localized at the end of the chromosomes. While reactivation of telomerase is a major hallmark of most cancers, together with the synergistic activation of other oncogenic signals, deficiency in telomerase and telomeric proteins might lead to aging and senescence-associated disorders. Therefore, it is critically important to understand the canonical as well as non-canonical functions of telomerase through TERT to develop a therapeutic strategy against telomerase-related diseases. In this review, we shed light on the regulation and function of telomerase, and current therapeutic strategies against telomerase in cancer and age-related diseases.
      PubDate: 2017-02-28
      DOI: 10.3390/antiox6010017
      Issue No: Vol. 6, No. 1 (2017)
       
  • Antioxidants, Vol. 6, Pages 18: Na/K-ATPase Signaling and Salt
           Sensitivity: The Role of Oxidative Stress

    • Authors: Jiang Liu, Yanling Yan, Ying Nie, Joseph Shapiro
      First page: 18
      Abstract: Other than genetic regulation of salt sensitivity of blood pressure, many factors have been shown to regulate renal sodium handling which contributes to long-term blood pressure regulation and have been extensively reviewed. Here we present our progress on the Na/K-ATPase signaling mediated sodium reabsorption in renal proximal tubules, from cardiotonic steroids-mediated to reactive oxygen species (ROS)-mediated Na/K-ATPase signaling that contributes to experimental salt sensitivity.
      PubDate: 2017-03-02
      DOI: 10.3390/antiox6010018
      Issue No: Vol. 6, No. 1 (2017)
       
  • Antioxidants, Vol. 6, Pages 19: Effect of Leaves of Caesalpinia decapetala
           on Oxidative Stability of Oil-in-Water Emulsions

    • Authors: María Gallego, Monika Skowyra, Michael Gordon, Nurul Azman, María Almajano
      First page: 19
      Abstract: Caesalpinia decapetala (Roth) Alston (Fabaceae) (CD) is used in folk medicine to prevent colds and treat bronchitis. This plant has antitumor and antioxidant activity. The antioxidant effects of an extract from Caesalpinia decapetala (Fabaceae) were assessed by storage of model food oil-in-water emulsions with analysis of primary and secondary oxidation products. The antioxidant capacity of the plant extract was evaluated by the diphenylpicrylhydrazyl (DPPH), Trolox equivalent antioxidant capacity (TEAC), oxygen radical absorbance capacity (ORAC) and ferric reducing antioxidant power (FRAP) assays and by electron paramagnetic resonance (EPR) spectroscopy. Lyophilized extracts of CD were added at concentrations of 0.002%, 0.02% and 0.2% into oil-in-water emulsions, which were stored for 30 days at 33 ± 1 °C, and then, oxidative stability was evaluated. The CD extract had high antioxidant activity (700 ± 70 µmol Trolox/g dry plant for the ORAC assay), mainly due to its phenolic components: gallic acid, quercetin, catechin, 4-hydroxybenzoic acid and p-coumaric acid. At a concentration of 0.2%, the extract significantly reduced the oxidative deterioration of oil-in-water emulsions. The results of the present study show the possibility of utilizing CD as a promising source of natural antioxidants for retarding lipid oxidation in the food and cosmetic industries.
      PubDate: 2017-03-04
      DOI: 10.3390/antiox6010019
      Issue No: Vol. 6, No. 1 (2017)
       
  • Antioxidants, Vol. 6, Pages 20: Vitamin E Nicotinate

    • Authors: Kimbell Duncan, Yuichiro Suzuki
      First page: 20
      Abstract: Vitamin E refers to a family of compounds that function as lipid-soluble antioxidants capable of preventing lipid peroxidation. Naturally occurring forms of vitamin E include tocopherols and tocotrienols. Vitamin E in dietary supplements and fortified foods is often an esterified form of α-tocopherol, the most common esters being acetate and succinate. The vitamin E esters are hydrolyzed and converted into free α-tocopherol prior to absorption in the intestinal tract. Because its functions are relevant to many chronic diseases, vitamin E has been extensively studied in respect to a variety of diseases as well as cosmetic applications. The forms of vitamin E most studied are natural α-tocopherol and the esters α-tocopheryl acetate and α-tocopheryl succinate. A small number of studies include or focus on another ester form, α-tocopheryl nicotinate, an ester of vitamin E and niacin. Some of these studies raise the possibility of differences in metabolism and in efficacy between vitamin E nicotinate and other forms of vitamin E. Recently, through metabolomics studies, we identified that α-tocopheryl nicotinate occurs endogenously in the heart and that its level is dramatically decreased in heart failure, indicating the possible biological importance of this vitamin E ester. Since knowledge about vitamin E nicotinate is not readily available in the literature, the purpose of this review is to summarize and evaluate published reports, specifically with respect to α-tocopheryl nicotinate with an emphasis on the differences from natural α-tocopherol or α-tocopheryl acetate.
      PubDate: 2017-03-13
      DOI: 10.3390/antiox6010020
      Issue No: Vol. 6, No. 1 (2017)
       
  • Antioxidants, Vol. 6, Pages 21: Krebs Cycle Intermediates Protective
           against Oxidative Stress by Modulating the Level of Reactive Oxygen
           Species in Neuronal HT22 Cells

    • Authors: Kenta Sawa, Takumi Uematsu, Yusuke Korenaga, Ryuya Hirasawa, Masatoshi Kikuchi, Kyohei Murata, Jian Zhang, Xiaoqing Gai, Kazuichi Sakamoto, Tomoyuki Koyama, Takumi Satoh
      First page: 21
      Abstract: Krebs cycle intermediates (KCIs) are reported to function as energy substrates in mitochondria and to exert antioxidants effects on the brain. The present study was designed to identify which KCIs are effective neuroprotective compounds against oxidative stress in neuronal cells. Here we found that pyruvate, oxaloacetate, and α-ketoglutarate, but not lactate, citrate, iso-citrate, succinate, fumarate, or malate, protected HT22 cells against hydrogen peroxide-mediated toxicity. These three intermediates reduced the production of hydrogen peroxide-activated reactive oxygen species, measured in terms of 2′,7′-dichlorofluorescein diacetate fluorescence. In contrast, none of the KCIs—used at 1 mM—protected against cell death induced by high concentrations of glutamate—another type of oxidative stress-induced neuronal cell death. Because these protective KCIs did not have any toxic effects (at least up to 10 mM), they have potential use for therapeutic intervention against chronic neurodegenerative diseases.
      PubDate: 2017-03-16
      DOI: 10.3390/antiox6010021
      Issue No: Vol. 6, No. 1 (2017)
       
 
 
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