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  Subjects -> BIOLOGY (Total: 3106 journals)
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BIOLOGY (1471 journals)                  1 2 3 4 5 6 7 8 | Last

Showing 1 - 200 of 1720 Journals sorted alphabetically
AAPS Journal     Hybrid Journal   (Followers: 21)
Achievements in the Life Sciences     Open Access   (Followers: 5)
ACS Synthetic Biology     Full-text available via subscription   (Followers: 24)
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: 27)
Acta Biotheoretica     Hybrid Journal   (Followers: 4)
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: 10)
Acta Scientiarum. Biological Sciences     Open Access   (Followers: 2)
Acta Scientifica Naturalis     Open Access   (Followers: 3)
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: 2)
Advances in Bioinformatics     Open Access   (Followers: 17)
Advances in Biological Regulation     Hybrid Journal   (Followers: 4)
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Advances in Cell Biology     Open Access   (Followers: 25)
Advances in Cellular and Molecular Biology of Membranes and Organelles     Full-text available via subscription   (Followers: 12)
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Advances in DNA Sequence-Specific Agents     Full-text available via subscription   (Followers: 5)
Advances in Ecological Research     Full-text available via subscription   (Followers: 42)
Advances in Environmental Sciences - International Journal of the Bioflux Society     Open Access   (Followers: 17)
Advances in Enzyme Research     Open Access   (Followers: 9)
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Advances in Human Biology     Open Access   (Followers: 3)
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Advances in Planar Lipid Bilayers and Liposomes     Full-text available via subscription   (Followers: 3)
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Advances in Structural Biology     Full-text available via subscription   (Followers: 5)
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: 10)
Aging Cell     Open Access   (Followers: 12)
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: 14)
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)
Alces : A Journal Devoted to the Biology and Management of Moose     Open Access  
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Biology Teacher     Full-text available via subscription   (Followers: 14)
American Fern Journal     Full-text available via subscription   (Followers: 1)
American Journal of Agricultural and Biological Sciences     Open Access   (Followers: 8)
American Journal of Bioethics     Hybrid Journal   (Followers: 10)
American Journal of Human Biology     Hybrid Journal   (Followers: 13)
American Journal of Medical and Biological Research     Open Access   (Followers: 8)
American Journal of Plant Sciences     Open Access   (Followers: 18)
American Journal of Primatology     Hybrid Journal   (Followers: 14)
American Malacological Bulletin     Full-text available via subscription   (Followers: 3)
American Naturalist     Full-text available via subscription   (Followers: 70)
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: 5)
Annual Review of Biomedical Engineering     Full-text available via subscription   (Followers: 15)
Annual Review of Biophysics     Full-text available via subscription   (Followers: 23)
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: 37)
Annual Review of Food Science and Technology     Full-text available via subscription   (Followers: 13)
Annual Review of Genomics and Human Genetics     Full-text available via subscription   (Followers: 23)
Annual Review of Phytopathology     Full-text available via subscription   (Followers: 10)
Anthropological Review     Open Access   (Followers: 23)
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: 10)
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: 33)
Aquatic Ecosystem Health & Management     Hybrid Journal   (Followers: 14)
Aquatic Science and Technology     Open Access   (Followers: 3)
Aquatic Toxicology     Hybrid Journal   (Followers: 21)
Archaea     Open Access   (Followers: 3)
Archiv für Molluskenkunde: International Journal of Malacology     Full-text available via subscription   (Followers: 3)
Archives of Biological Sciences     Open Access  
Archives of Microbiology     Hybrid Journal   (Followers: 8)
Archives of Natural History     Hybrid Journal   (Followers: 6)
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: 2)
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: 3)
Artificial Photosynthesis     Open Access   (Followers: 1)
Asian Bioethics Review     Full-text available via subscription   (Followers: 3)
Asian Journal of Biodiversity     Open Access   (Followers: 4)
Asian Journal of Biological Sciences     Open Access   (Followers: 3)
Asian Journal of Cell Biology     Open Access   (Followers: 5)
Asian Journal of Developmental Biology     Open Access   (Followers: 2)
Asian Journal of Medical and Biological Research     Open Access   (Followers: 3)
Asian Journal of Nematology     Open Access   (Followers: 4)
Asian Journal of Poultry Science     Open Access   (Followers: 3)
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: 4)
Avian Conservation and Ecology     Open Access   (Followers: 11)
Bacteriology Journal     Open Access   (Followers: 1)
Bacteriophage     Full-text available via subscription   (Followers: 3)
Bangladesh Journal of Bioethics     Open Access  
Bangladesh Journal of Plant Taxonomy     Open Access  
Bangladesh Journal of Scientific Research     Open Access   (Followers: 1)
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: 15)
Biochimie     Hybrid Journal   (Followers: 7)
BioControl     Hybrid Journal   (Followers: 5)
Biocontrol Science and Technology     Hybrid Journal   (Followers: 5)
Biodemography and Social Biology     Hybrid Journal  
BioDiscovery     Open Access   (Followers: 2)
Biodiversitas : Journal of Biological Diversity     Open Access  
Biodiversity : Research and Conservation     Open Access   (Followers: 26)
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: 5)
Biofilms     Full-text available via subscription   (Followers: 1)
Biogeosciences (BG)     Open Access   (Followers: 10)
Biogeosciences Discussions (BGD)     Open Access   (Followers: 2)
Bioinformatics     Hybrid Journal   (Followers: 289)
Bioinformatics and Biology Insights     Open Access   (Followers: 11)
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: 6)
Biological Control     Hybrid Journal   (Followers: 4)
Biological Invasions     Hybrid Journal   (Followers: 18)
Biological Journal of the Linnean Society     Hybrid Journal   (Followers: 18)
Biological Letters     Open Access   (Followers: 5)
Biological Procedures Online     Open Access  
Biological Psychiatry     Hybrid Journal   (Followers: 45)
Biological Psychology     Hybrid Journal   (Followers: 7)
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   (Followers: 1)
Biologie in Unserer Zeit (Biuz)     Hybrid Journal   (Followers: 40)
Biologija     Open Access  
Biology     Open Access   (Followers: 3)
Biology and Philosophy     Hybrid Journal   (Followers: 19)

        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  [202 journals]
  • Antioxidants, Vol. 7, Pages 34: Quantification of Phenolic Compounds and
           In Vitro Radical Scavenging Abilities with Leaf Extracts from Two
           Varieties of Psidium guajava L.

    • Authors: Julio Camarena-Tello, Héctor Martínez-Flores, Ma. Garnica-Romo, José Padilla-Ramírez, Alfredo Saavedra-Molina, Osvaldo Alvarez-Cortes, María Bartolomé-Camacho, José Rodiles-López
      First page: 34
      Abstract: Guava leaf (Psidium guajava L.) extracts are used in both traditional medicine and the pharmaceutical industry. The antioxidant compounds in P. guajava leaves can have positive effects including anti-inflammatory, anti-hyperglycemic, hepatoprotective, analgesic, anti-cancer effects, as well as protecting against cardiovascular diseases. In the present study, phenolic compounds and in vitro antioxidant capacity were measured in extracts obtained with polar and non-polar solvents from leaves of two varieties of guava, Calvillo Siglo XXI and Hidrozac. The quantity of total phenolics and total flavonoids were expressed as equivalents of gallic acid and quercetin, respectively. Hydroxyl radical, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and Oxygen Radical Absorbance Capacity using fluorescein (ORAC-FL) in vitro tests were used to assess the radical scavenging abilities of the extracts. The total phenolics were higher in the aqueous fraction of the variety Calvillo Siglo XXI, while in the Hidrozac variety total phenolics were higher in the acetone and chloroform fractions. Total flavonoids were higher in all fractions in the variety Calvillo Siglo XXI. Total phenolics showed a highly positive correlation for ORAC-FL, and a moderately positive correlation with hydroxyl radicals. Finally, total flavonoids showed a slightly positive correlation for ORAC-FL and hydroxyl radicals. Both varieties of guava leaf extract showed excellent antioxidant properties.
      Citation: Antioxidants
      PubDate: 2018-02-27
      DOI: 10.3390/antiox7030034
      Issue No: Vol. 7, No. 3 (2018)
       
  • Antioxidants, Vol. 7, Pages 35: A Possible Role for Singlet Oxygen in the
           Degradation of Various Antioxidants. A Meta-Analysis and Review of
           Literature Data

    • Authors: Athinoula Petrou, Petros Petrou, Theodoros Ntanos, Antonis Liapis
      First page: 35
      Abstract: The thermodynamic parameters Eact, ΔH≠, ΔS≠, and ΔG≠ for various processes involving antioxidants were calculated using literature kinetic data (k, T). The ΔG≠ values of the antioxidants’ processes vary in the range 91.27–116.46 kJmol−1 at 310 K. The similarity of the ΔG≠ values (for all of the antioxidants studied) is supported to be an indication that a common mechanism in the above antioxidant processes may be taking place. A value of about 10–30 kJmol−1 is the activation energy for the diffusion of reactants depending on the reaction and the medium. The energy 92 kJmol−1 is needed for the excitation of O2 from the ground to the first excited state (1Δg, singlet oxygen). We suggest the same role of the oxidative stress and specifically of singlet oxygen to the processes of antioxidants as in the processes of proteinaceous diseases. We therefore suggest a competition between the various antioxidants and the proteins of proteinaceous diseases in capturing singlet oxygen’s empty π* orbital. The concentration of the antioxidants could be a crucial factor for the competition. Also, the structures of the antioxidant molecules play a significant role since the various structures have a different number of regions of high electron density.
      Citation: Antioxidants
      PubDate: 2018-02-27
      DOI: 10.3390/antiox7030035
      Issue No: Vol. 7, No. 3 (2018)
       
  • Antioxidants, Vol. 7, Pages 36: Selenium and Selenoproteins in Gut
           Inflammation—A Review

    • Authors: Shaneice Nettleford, K. Prabhu
      First page: 36
      Abstract: Inflammatory bowel disease (IBD), characterized by severe flares and remissions, is a debilitating condition. While the etiology is unknown, many immune cells, such as macrophages, T cells and innate lymphoid cells, are implicated in the pathogenesis of the disease. Previous studies have shown the ability of micronutrient selenium (Se) and selenoproteins to impact inflammatory signaling pathways implicated in the pathogenesis of the disease. In particular, two transcription factors, nuclear factor-κB (NF-κB), and peroxisome proliferator activated receptor (PPAR)γ, which are involved in the activation of immune cells, and are also implicated in various stages of inflammation and resolution, respectively, are impacted by Se status. Available therapies for IBD produce detrimental side effects, resulting in the need for alternative therapies. Here, we review the current understanding of the role of NF-κB and PPARγ in the activation of immune cells during IBD, and how Se and selenoproteins modulate effective resolution of inflammation to be considered as a promising alternative to treat IBD.
      Citation: Antioxidants
      PubDate: 2018-03-01
      DOI: 10.3390/antiox7030036
      Issue No: Vol. 7, No. 3 (2018)
       
  • Antioxidants, Vol. 7, Pages 37: The Energy Costs of Prematurity and the
           Neonatal Intensive Care Unit (NICU) Experience

    • Authors: John Tan, Danilo Boskovic, Danilyn Angeles
      First page: 37
      Abstract: Premature neonates are in an energy deficient state due to (1) oxygen desaturation and hypoxia events, (2) painful and stressful stimuli, (3) illness, and (4) neurodevelopmental energy requirements. Failure to correct energy deficiency in premature infants may lead to adverse effects such as neurodevelopmental delay and negative long-term metabolic and cardiovascular outcomes. The effects of energy dysregulation and the challenges that clinicians in the Neonatal Intensive Care Unit (NICU) face in meeting the premature infant’s metabolic demands are discussed. Specifically, the focus is on the effects of pain and stress on energy homeostasis. Energy deficiency is a complex problem and requires a multi-faceted solution to promote optimum development of premature infants.
      Citation: Antioxidants
      PubDate: 2018-03-02
      DOI: 10.3390/antiox7030037
      Issue No: Vol. 7, No. 3 (2018)
       
  • Antioxidants, Vol. 7, Pages 38: Synthetic Lignan Secoisolariciresinol
           Diglucoside (LGM2605) Reduces Asbestos-Induced Cytotoxicity in an
           Nrf2-Dependent and -Independent Manner

    • Authors: Ralph Pietrofesa, Shampa Chatterjee, Kyewon Park, Evguenia Arguiri, Steven Albelda, Melpo Christofidou-Solomidou
      First page: 38
      Abstract: Asbestos exposure triggers inflammatory processes associated with oxidative stress and tissue damage linked to malignancy. LGM2605 is the synthetic lignan secoisolariciresinol diglucoside (SDG) with free radical scavenging, antioxidant, and anti-inflammatory properties in diverse inflammatory cell and mouse models, including exposure to asbestos fibers. Nuclear factor-E2 related factor 2 (Nrf2) activation and boosting of endogenous tissue defenses were associated with the protective action of LGM2605 from asbestos-induced cellular damage. To elucidate the role of Nrf2 induction by LGM2605 in protection from asbestos-induced cellular damage, we evaluated LGM2605 in asbestos-exposed macrophages from wild-type (WT) and Nrf2 disrupted (Nrf2−/−) mice. Cells were pretreated with LGM2605 (50 µM and 100 µM) and exposed to asbestos fibers (20 µg/cm2) and evaluated 8 h and 24 h later for inflammasome activation, secreted cytokine levels (interleukin-1β (IL-1β), interleukin-18 (IL-18), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNFα)), cytotoxicity and cell death, nitrosative stress, and Nrf2-regulated enzyme levels. Asbestos exposure induced robust oxidative and nitrosative stress, cell death and cytotoxicity, which were equally mitigated by LGM2605. Inflammasome activation was significantly attenuated in Nrf2−/− macrophages compared to WT, and the protective action of LGM2605 was seen only in WT cells. In conclusion, in a cell model of asbestos-induced toxicity, LGM2605 acts via protective mechanisms that may not involve Nrf2 activation.
      Citation: Antioxidants
      PubDate: 2018-03-02
      DOI: 10.3390/antiox7030038
      Issue No: Vol. 7, No. 3 (2018)
       
  • Antioxidants, Vol. 7, Pages 39: Systems-Level Feedbacks of NRF2
           Controlling Autophagy upon Oxidative Stress Response

    • Authors: Orsolya Kapuy, Diána Papp, Tibor Vellai, Gábor Bánhegyi, Tamás Korcsmáros
      First page: 39
      Abstract: Although the primary role of autophagy-dependent cellular self-eating is cytoprotective upon various stress events (such as starvation, oxidative stress, and high temperatures), sustained autophagy might lead to cell death. A transcription factor called NRF2 (nuclear factor erythroid-related factor 2) seems to be essential in maintaining cellular homeostasis in the presence of either reactive oxygen or nitrogen species generated by internal metabolism or external exposure. Accumulating experimental evidence reveals that oxidative stress also influences the balance of the 5′ AMP-activated protein kinase (AMPK)/rapamycin (mammalian kinase target of rapamycin or mTOR) signaling pathway, thereby inducing autophagy. Based on computational modeling here we propose that the regulatory triangle of AMPK, NRF2 and mTOR guaranties a precise oxidative stress response mechanism comprising of autophagy. We suggest that under conditions of oxidative stress, AMPK is crucial for autophagy induction via mTOR down-regulation, while NRF2 fine-tunes the process of autophagy according to the level of oxidative stress. We claim that the cellular oxidative stress response mechanism achieves an incoherently amplified negative feedback loop involving NRF2, mTOR and AMPK. The mTOR-NRF2 double negative feedback generates bistability, supporting the proper separation of two alternative steady states, called autophagy-dependent survival (at low stress) and cell death (at high stress). In addition, an AMPK-mTOR-NRF2 negative feedback loop suggests an oscillatory characteristic of autophagy upon prolonged intermediate levels of oxidative stress, resulting in new rounds of autophagy stimulation until the stress events cannot be dissolved. Our results indicate that AMPK-, NRF2- and mTOR-controlled autophagy induction provides a dynamic adaptation to altering environmental conditions, assuming their new frontier in biomedicine.
      Citation: Antioxidants
      PubDate: 2018-03-05
      DOI: 10.3390/antiox7030039
      Issue No: Vol. 7, No. 3 (2018)
       
  • Antioxidants, Vol. 7, Pages 40: Post-Irradiation Treatment with a
           Superoxide Dismutase Mimic, MnTnHex-2-PyP5+, Mitigates Radiation Injury in
           the Lungs of Non-Human Primates after Whole-Thorax Exposure to Ionizing
           Radiation

    • Authors: John Cline, Greg Dugan, John Bourland, Donna Perry, Joel Stitzel, Ashley Weaver, Chen Jiang, Artak Tovmasyan, Kouros Owzar, Ivan Spasojevic, Ines Batinic-Haberle, Zeljko Vujaskovic
      First page: 40
      Abstract: Radiation injury to the lung is the result of acute and chronic free radical formation, and there are currently few effective means of mitigating such injury. Studies in rodents indicate that superoxide dismutase mimetics may be effective in this regard; however, studies in humans or large animals are lacking. We hypothesized that post-exposure treatment with the lipophilic mitochondrial superoxide dismutase mimetic, MnTnHex-2-PyP5+ (hexyl), would reduce radiation-induced pneumonitis and fibrosis in the lungs of nonhuman primates. Rhesus monkeys (Macaca mulatta) received 10 Gy whole thorax irradiation, 10 Gy + hexyl treatment, sham irradiation, or sham irradiation + hexyl. Hexyl was given twice daily, subcutaneously, at 0.05 mg/kg, for 2 months. Animals were monitored daily, and respiratory rates, pulse oximetry, hematology and serum chemistry panels were performed weekly. Computed tomography scans were performed at 0, 2, and 4 months after irradiation. Supportive fluid therapy, corticosteroids, analgesics, and antibiotics were given as needed. All animals were humanely euthanized 4.5 months after irradiation, and pathologic assessments were made. Multifocal, progressive lung lesions were seen at 2 and 4 months in both irradiated groups. Hexyl treatment delayed the onset of radiation-induced lung lesions, reduced elevations of respiratory rate, and reduced pathologic increases in lung weight. No adverse effects of hexyl treatment were found. These results demonstrate (1) development of a nonhuman primate model of radiation-induced lung injury, (2) a significant mitigating effect of hexyl treatment on lung pathology in this model, and (3) no evidence for toxicity of hexyl at the dose studied.
      Citation: Antioxidants
      PubDate: 2018-03-07
      DOI: 10.3390/antiox7030040
      Issue No: Vol. 7, No. 3 (2018)
       
  • Antioxidants, Vol. 7, Pages 41: Influence of Vitamin C on Lymphocytes: An
           Overview

    • Authors: Gwendolyn van Gorkom, Roel Klein Wolterink, Catharina Van Elssen, Lotte Wieten, Wilfred Germeraad, Gerard Bos
      First page: 41
      Abstract: Vitamin C or ascorbic acid (AA) is implicated in many biological processes and has been proposed as a supplement for various conditions, including cancer. In this review, we discuss the effects of AA on the development and function of lymphocytes. This is important in the light of cancer treatment, as the immune system needs to regenerate following chemotherapy or stem cell transplantation, while cancer patients are often AA-deficient. We focus on lymphocytes, as these white blood cells are the slowest to restore, rendering patients susceptible to often lethal infections. T lymphocytes mediate cellular immunity and have been most extensively studied in the context of AA biology. In vitro studies demonstrate that T cell development requires AA, while AA also enhances T cell proliferation and may influence T cell function. There are limited and opposing data on the effects of AA on B lymphocytes that mediate humoral immunity. However, AA enhances the proliferation of NK cells, a group of cytotoxic innate lymphocytes. The influence of AA on natural killer (NK) cell function is less clear. In summary, an increasing body of evidence indicates that AA positively influences lymphocyte development and function. Since AA is a safe and cheap nutritional supplement, it is worthwhile to further explore its potential benefits for immune reconstitution of cancer patients treated with immunotoxic drugs.
      Citation: Antioxidants
      PubDate: 2018-03-10
      DOI: 10.3390/antiox7030041
      Issue No: Vol. 7, No. 3 (2018)
       
  • Antioxidants, Vol. 7, Pages 42: Redistribution of Extracellular Superoxide
           Dismutase Causes Neonatal Pulmonary Vascular Remodeling and PH but
           Protects Against Experimental Bronchopulmonary Dysplasia

    • Authors: Laurie Sherlock, Ashley Trumpie, Laura Hernandez-Lagunas, Sarah McKenna, Susan Fisher, Russell Bowler, Clyde Wright, Cassidy Delaney, Eva Nozik-Grayck
      First page: 42
      Abstract: Background: A naturally occurring single nucleotide polymorphism (SNP), (R213G), in extracellular superoxide dismutase (SOD3), decreases SOD3 matrix binding affinity. Humans and mature mice expressing the R213G SNP exhibit increased cardiovascular disease but decreased lung disease. The impact of this SNP on the neonatal lung at baseline or with injury is unknown. Methods: Wild type and homozygous R213G mice were injected with intraperitoneal bleomycin or phosphate buffered saline (PBS) three times weekly for three weeks and tissue harvested at 22 days of life. Vascular and alveolar development were evaluated by morphometric analysis and immunostaining of lung sections. Pulmonary hypertension (PH) was assessed by right ventricular hypertrophy (RVH). Lung protein expression for superoxide dismutase (SOD) isoforms, catalase, vascular endothelial growth factor receptor 2 (VEGFR2), endothelial nitric oxide synthase (eNOS) and guanosine triphosphate cyclohydrolase-1 (GTPCH-1) was evaluated by western blot. SOD activity and SOD3 expression were measured in serum. Results: In R213G mice, SOD3 lung protein expression decreased, serum SOD3 protein expression and SOD serum activity increased compared to wild type (WT) mice. Under control conditions, R213G mice developed pulmonary vascular remodeling (decreased vessel density and increased medial wall thickness) and PH; alveolar development was similar between strains. After bleomycin injury, in contrast to WT, R213G mice were protected from impaired alveolar development and their vascular abnormalities and PH did not worsen. Bleomycin decreased VEGFR2 and GTPCH-1 only in WT mice. Conclusion: R213G neonatal mice demonstrate impaired vascular development and PH at baseline without alveolar simplification, yet are protected from bleomycin induced lung injury and worsening of pulmonary vascular remodeling and PH. These results show that vessel bound SOD3 is essential in normal pulmonary vascular development, and increased serum SOD3 expression and SOD activity prevent lung injury in experimental bronchopulmonary dysplasia (BPD) and PH.
      Citation: Antioxidants
      PubDate: 2018-03-14
      DOI: 10.3390/antiox7030042
      Issue No: Vol. 7, No. 3 (2018)
       
  • Antioxidants, Vol. 7, Pages 43: Microbial Biotransformation of a
           Polyphenol-Rich Potato Extract Affects Antioxidant Capacity in a Simulated
           Gastrointestinal Model

    • Authors: Joelle Khairallah, Shima Sadeghi Ekbatan, Kebba Sabally, Michèle Iskandar, Raza Hussain, Atef Nassar, Lekha Sleno, Laetitia Rodes, Satya Prakash, Danielle Donnelly, Stan Kubow
      First page: 43
      Abstract: A multistage human gastrointestinal model was used to digest a polyphenol-rich potato extract containing chlorogenic acid, caffeic acid, ferulic acid, and rutin as the primary polyphenols, to assess for their microbial biotransformation and to measure changes in antioxidant capacity in up to 24 h of digestion. The biotransformation of polyphenols was assessed by liquid chromatography–mass spectrometry. Antioxidant capacity was measured by the ferric reducing antioxidant power (FRAP) assay. Among the colonic reactors, parent (poly)phenols were detected in the ascending (AC), but not the transverse (TC) or descending (DC) colons. The most abundant microbial phenolic metabolites in all colonic reactors included derivatives of propionic acid, acetic acid, and benzoic acid. As compared to the baseline, an earlier increase in antioxidant capacity (T = 8 h) was seen in the stomach and small intestine vessels as compared to the AC (T = 16 h) and TC and DC (T = 24 h). The increase in antioxidant capacity observed in the DC and TC can be linked to the accumulation of microbial smaller-molecular-weight phenolic catabolites, as the parent polyphenolics had completely degraded in those vessels. The colonic microbial digestion of potato-based polyphenols could lead to improved colonic health, as this generates phenolic metabolites with significant antioxidant potential.
      Citation: Antioxidants
      PubDate: 2018-03-20
      DOI: 10.3390/antiox7030043
      Issue No: Vol. 7, No. 3 (2018)
       
  • Antioxidants, Vol. 7, Pages 44: Vitamin E

    • Authors: Volker Böhm
      First page: 44
      Abstract: Vitamin E is the major lipid-soluble antioxidant in the cell antioxidant system and is exclusively obtained from the diet[...]
      Citation: Antioxidants
      PubDate: 2018-03-20
      DOI: 10.3390/antiox7030044
      Issue No: Vol. 7, No. 3 (2018)
       
  • Antioxidants, Vol. 7, Pages 22: Vitamin E as an Antioxidant in Female
           Reproductive Health

    • Authors: Siti Mohd Mutalip, Sharaniza Ab-Rahim, Mohd Rajikin
      First page: 22
      Abstract: Vitamin E was first discovered in 1922 as a substance necessary for reproduction. Following this discovery, vitamin E was extensively studied, and it has become widely known as a powerful lipid-soluble antioxidant. There has been increasing interest in the role of vitamin E as an antioxidant, as it has been discovered to lower body cholesterol levels and act as an anticancer agent. Numerous studies have reported that vitamin E exhibits anti-proliferative, anti-survival, pro-apoptotic, and anti-angiogenic effects in cancer, as well as anti-inflammatory activities. There are various reports on the benefits of vitamin E on health in general. However, despite it being initially discovered as a vitamin necessary for reproduction, to date, studies relating to its effects in this area are lacking. Hence, this paper was written with the intention of providing a review of the known roles of vitamin E as an antioxidant in female reproductive health.
      Citation: Antioxidants
      PubDate: 2018-01-26
      DOI: 10.3390/antiox7020022
      Issue No: Vol. 7, No. 2 (2018)
       
  • Antioxidants, Vol. 7, Pages 23: Resuspendable Powders of Lyophilized
           Chalcogen Particles with Activity against Microorganisms

    • Authors: Sharoon Griffin, Muhammad Sarfraz, Steffen Hartmann, Shashank Pinnapireddy, Muhammad Nasim, Udo Bakowsky, Cornelia Keck, Claus Jacob
      First page: 23
      Abstract: Many organic sulfur, selenium and tellurium compounds show considerable activity against microorganisms, including bacteria and fungi. This pronounced activity is often due to the specific, oxidizing redox behavior of the chalcogen-chalcogen bond present in such molecules. Interestingly, similar chalcogen-chalcogen motifs are also found in the elemental forms of these elements, and while those materials are insoluble in aqueous media, it has recently been possible to unlock their biological activities using naturally produced or homogenized suspensions of respective chalcogen nanoparticles. Those suspensions can be employed readily and often effectively against common pathogenic microorganisms, still their practical uses are limited as such suspensions are difficult to transport, store and apply. Using mannitol as stabilizer, it is now possible to lyophilize such suspensions to produce solid forms of the nanoparticles, which upon resuspension in water essentially retain their initial size and exhibit considerable biological activity. The sequence of Nanosizing, Lyophilization and Resuspension (NaLyRe) eventually provides access to a range of lyophilized materials which may be considered as easy-to-handle, ready-to-use and at the same time as bioavailable, active forms of otherwise insoluble or sparingly substances. In the case of elemental sulfur, selenium and tellurium, this approach promises wider practical applications, for instance in the medical or agricultural arena.
      Citation: Antioxidants
      PubDate: 2018-01-27
      DOI: 10.3390/antiox7020023
      Issue No: Vol. 7, No. 2 (2018)
       
  • Antioxidants, Vol. 7, Pages 24: Impact of Thermal Degradation of
           Cyanidin-3-O-Glucoside of Haskap Berry on Cytotoxicity of Hepatocellular
           Carcinoma HepG2 and Breast Cancer MDA-MB-231 Cells

    • Authors: Eric Pace, Yuanyuan Jiang, Amy Clemens, Tennille Crossman, H.P. Rupasinghe
      First page: 24
      Abstract: Cyanidin-3-O-glucoside (C3G), the predominant anthocyanin in haskap berries (Lonicera caerulea L.), possesses antioxidant and many other biological activities. This study investigated the impact of temperature and pH on the degradation of the C3G-rich haskap fraction. The effect of the thermal degradation products on the viability of hepatocellular carcinoma HepG2 and breast cancer MDA-MB-231 cells was also studied in vitro. Using column chromatography, the C3G-rich fraction was isolated from acetone extracts of haskap berries. The C3G stability in these fractions was studied under elevated temperatures (70 °C and 90 °C) at three different pH values (2.5, 4, and 7) by monitoring the concentration of C3G and its major degradation products, protocatechuic acid (PCA) and phloroglucinaldehyde (PGA), using liquid chromatography mass spectrometry. Significant degradation of C3G was observed at elevated temperatures and at neutral pH. Conversely, the PCA and PGA concentration increased at higher pH and temperature. Similar to C3G, neutral pH also has a prominent effect on the degradation of PGA, which is further accelerated by heating. The C3G-rich fraction exhibited dose-dependent inhibitory effects on cell metabolic activity when the HepG2 cells were exposed for 48 h. Interestingly, PGA but not PCA exhibited cytotoxic effects against both MDA-MB-231 and HepG2 cells. The results suggest that thermal food processing of haskap could influence its biological properties due to the degradation of C3G.
      Citation: Antioxidants
      PubDate: 2018-01-27
      DOI: 10.3390/antiox7020024
      Issue No: Vol. 7, No. 2 (2018)
       
  • Antioxidants, Vol. 7, Pages 25: A Review of the Catalytic Mechanism of
           Human Manganese Superoxide Dismutase

    • Authors: Jahaun Azadmanesh, Gloria Borgstahl
      First page: 25
      Abstract: Superoxide dismutases (SODs) are necessary antioxidant enzymes that protect cells from reactive oxygen species (ROS). Decreased levels of SODs or mutations that affect their catalytic activity have serious phenotypic consequences. SODs perform their bio-protective role by converting superoxide into oxygen and hydrogen peroxide by cyclic oxidation and reduction reactions with the active site metal. Mutations of SODs can cause cancer of the lung, colon, and lymphatic system, as well as neurodegenerative diseases such as Parkinson’s disease and amyotrophic lateral sclerosis. While SODs have proven to be of significant biological importance since their discovery in 1968, the mechanistic nature of their catalytic function remains elusive. Extensive investigations with a multitude of approaches have tried to unveil the catalytic workings of SODs, but experimental limitations have impeded direct observations of the mechanism. Here, we focus on human MnSOD, the most significant enzyme in protecting against ROS in the human body. Human MnSOD resides in the mitochondrial matrix, the location of up to 90% of cellular ROS generation. We review the current knowledge of the MnSOD enzymatic mechanism and ongoing studies into solving the remaining mysteries.
      Citation: Antioxidants
      PubDate: 2018-01-30
      DOI: 10.3390/antiox7020025
      Issue No: Vol. 7, No. 2 (2018)
       
  • Antioxidants, Vol. 7, Pages 26: Do Coffee Polyphenols Have a Preventive
           Action on Metabolic Syndrome Associated Endothelial Dysfunctions' An
           Assessment of the Current Evidence

    • Authors: Kazuo Yamagata
      First page: 26
      Abstract: Epidemiologic studies from several countries have found that mortality rates associated with the metabolic syndrome are inversely associated with coffee consumption. Metabolic syndrome can lead to arteriosclerosis by endothelial dysfunction, and increases the risk for myocardial and cerebral infarction. Accordingly, it is important to understand the possible protective effects of coffee against components of the metabolic syndrome, including vascular endothelial function impairment, obesity and diabetes. Coffee contains many components, including caffeine, chlorogenic acid, diterpenes and trigonelline. Studies have found that coffee polyphenols, such as chlorogenic acids, have many health-promoting properties, such as antioxidant, anti-inflammatory, anti-cancer, anti-diabetes, and antihypertensive properties. Chlorogenic acids may exert protective effects against metabolic syndrome risk through their antioxidant properties, in particular toward vascular endothelial cells, in which nitric oxide production may be enhanced, by promoting endothelial nitric oxide synthase expression. These effects indicate that coffee components may support the maintenance of normal endothelial function and play an important role in the prevention of metabolic syndrome. However, results related to coffee consumption and the metabolic syndrome are heterogeneous among studies, and the mechanisms of its functions and corresponding molecular targets remain largely elusive. This review describes the results of studies exploring the putative effects of coffee components, especially in protecting vascular endothelial function and preventing metabolic syndrome.
      Citation: Antioxidants
      PubDate: 2018-02-04
      DOI: 10.3390/antiox7020026
      Issue No: Vol. 7, No. 2 (2018)
       
  • Antioxidants, Vol. 7, Pages 27: A Naturally Occurring Antioxidant Complex
           from Unripe Grapes: The Case of Sangiovese (v. Vitis vinifera)

    • Authors: Giovanna Fia, Claudio Gori, Ginevra Bucalossi, Francesca Borghini, Bruno Zanoni
      First page: 27
      Abstract: The wine industry is well known for its production of a large amount of wastes and by-products. Among them, unripe grapes from thinning operations are an undervalued by-product. Grapes are an interesting source of natural antioxidants such as flavonoids, non-flavonoids and stilbenes. A potential strategy to exploit unripe grapes was investigated in this study. Juice from unripe grapes, v. Sangiovese, was obtained by an innovative technique of solid-liquid extraction without the use of solvents. The juice was dried by a spray-drying technique with the addition of arabic gum as support to obtain powder; juice and powder were characterized for antioxidant activity, phenolic concentration and profile. Phenolic acids, flavonols, flava-3-ols, procyanidins and resveratrol were detected in the juice and powder. The powder was used as anti-browning additive in white wine to test the potential re-use of the unripe grapes in the wine industry. The results indicated that the antioxidant complex from unripe grapes contributed to increasing the anti-browning capacity of white wine. Other applications, such as food and nutraceutical products development, can be considered for the antioxidant complex extracted from unripe grapes. In conclusion, the method proposed in this study may contribute to the exploitation of unripe grapes as a by-product of the winemaking process.
      Citation: Antioxidants
      PubDate: 2018-02-08
      DOI: 10.3390/antiox7020027
      Issue No: Vol. 7, No. 2 (2018)
       
  • Antioxidants, Vol. 7, Pages 28: Carotenoids—Antioxidant Properties

    • Authors: Andrew Young, Gordon Lowe
      First page: 28
      Abstract: The carotenoid group of pigments are ubiquitous in nature and more than 600 different carotenoids have been identified and characterized [1].[...]
      Citation: Antioxidants
      PubDate: 2018-02-11
      DOI: 10.3390/antiox7020028
      Issue No: Vol. 7, No. 2 (2018)
       
  • Antioxidants, Vol. 7, Pages 29: Appropriate Handling, Processing and
           Analysis of Blood Samples Is Essential to Avoid Oxidation of Vitamin C to
           Dehydroascorbic Acid

    • Authors: Juliet Pullar, Simone Bayer, Anitra Carr
      First page: 29
      Abstract: Vitamin C (ascorbate) is the major water-soluble antioxidant in plasma and its oxidation to dehydroascorbic acid (DHA) has been proposed as a marker of oxidative stress in vivo. However, controversy exists in the literature around the amount of DHA detected in blood samples collected from various patient cohorts. In this study, we report on DHA concentrations in a selection of different clinical cohorts (diabetes, pneumonia, cancer, and critically ill). All clinical samples were collected into EDTA anticoagulant tubes and processed at 4 °C prior to storage at −80 °C for subsequent analysis by HPLC with electrochemical detection. We also investigated the effects of different handling and processing conditions on short-term and long-term ascorbate and DHA stability in vitro and in whole blood and plasma samples. These conditions included metal chelation, anticoagulants (EDTA and heparin), and processing temperatures (ice, 4 °C and room temperature). Analysis of our clinical cohorts indicated very low to negligible DHA concentrations. Samples exhibiting haemolysis contained significantly higher concentrations of DHA. Metal chelation inhibited oxidation of vitamin C in vitro, confirming the involvement of contaminating metal ions. Although EDTA is an effective metal chelator, complexes with transition metal ions are still redox active, thus its use as an anticoagulant can facilitate metal ion-dependent oxidation of vitamin C in whole blood and plasma. Handling and processing blood samples on ice (or at 4 °C) delayed oxidation of vitamin C by a number of hours. A review of the literature regarding DHA concentrations in clinical cohorts highlighted the fact that studies using colourimetric or fluorometric assays reported significantly higher concentrations of DHA compared to those using HPLC with electrochemical detection. In conclusion, careful handling and processing of samples, combined with appropriate analysis, is crucial for accurate determination of ascorbate and DHA in clinical samples.
      Citation: Antioxidants
      PubDate: 2018-02-11
      DOI: 10.3390/antiox7020029
      Issue No: Vol. 7, No. 2 (2018)
       
  • Antioxidants, Vol. 7, Pages 30: Morphological Pathways of Mitochondrial
           Division

    • Authors: Bernard Tandler, Charles L. Hoppel, Jason A. Mears
      First page: 30
      Abstract: Mitochondrial fission is essential for distributing cellular energy throughout cells and for isolating damaged regions of the organelle that are targeted for degradation. Excessive fission is associated with the progression of cell death as well. Therefore, this multistep process is tightly regulated and several physiologic cues directly impact mitochondrial division. The double membrane structure of mitochondria complicates this process, and protein factors that drive membrane scission need to coordinate the separation of both the outer and inner mitochondrial membranes. In this review, we discuss studies that characterize distinct morphological changes associated with mitochondrial division. Specifically, coordinated partitioning and pinching of mitochondria have been identified as alternative mechanisms associated with fission. Additionally, we highlight the major protein constituents that drive mitochondrial fission and the role of connections with the endoplasmic reticulum in establishing sites of membrane division. Collectively, we review decades of research that worked to define the molecular framework of mitochondrial fission. Ongoing studies will continue to sort through the complex network of interactions that drive this critical event.
      Citation: Antioxidants
      PubDate: 2018-02-15
      DOI: 10.3390/antiox7020030
      Issue No: Vol. 7, No. 2 (2018)
       
  • Antioxidants, Vol. 7, Pages 31: Nanotherapy and Reactive Oxygen Species
           (ROS) in Cancer: A Novel Perspective

    • Authors: Peter Brenneisen, Andreas Reichert
      First page: 31
      Abstract: The incidence of numerous types of cancer has been increasing over recent years, representing the second-most frequent cause of death after cardiovascular diseases. Even though, the number of effective anticancer drugs is increasing as well, a large number of patients suffer from severe side effects (e.g., cardiomyopathies) caused by these drugs. This adversely affects the patients’ well-being and quality of life. On the molecular level, tumor cells that survive treatment modalities can become chemotherapy-resistant. In addition, adverse impacts on normal (healthy, stromal) cells occur concomitantly. Strategies that minimize these negative impacts on normal cells and which at the same time target tumor cells efficiently are needed. Recent studies suggest that redox-based combinational nanotherapies may represent one option in this direction. Here, we discuss recent advances in the application of nanoparticles, alone or in combination with other drugs, as a promising anticancer tool. Such novel strategies could well minimize harmful side effects and improve patients’ health prognoses.
      Citation: Antioxidants
      PubDate: 2018-02-22
      DOI: 10.3390/antiox7020031
      Issue No: Vol. 7, No. 2 (2018)
       
  • Antioxidants, Vol. 7, Pages 32: Phytochemicals in Human Milk and Their
           Potential Antioxidative Protection

    • Authors: Apollinaire Tsopmo
      First page: 32
      Abstract: Diets contain secondary plant metabolites commonly referred to as phytochemicals. Many of them are believed to impact human health through various mechanisms, including protection against oxidative stress and inflammation, and decreased risks of developing chronic diseases. For mothers and other people, phytochemical intake occurs through the consumption of foods such as fruits, vegetables, and grains. Research has shown that some these phytochemicals are present in the mother’s milk and can contribute to its oxidative stability. For infants, human milk (HM) represents the primary and preferred source of nutrition because it is a complete food. Studies have reported that the benefit provided by HM goes beyond basic nutrition. It can, for example, reduce oxidative stress in infants, thereby reducing the risk of lung and intestinal diseases in infants. This paper summarizes the phytochemicals present in HM and their potential contribution to infant health.
      Citation: Antioxidants
      PubDate: 2018-02-22
      DOI: 10.3390/antiox7020032
      Issue No: Vol. 7, No. 2 (2018)
       
  • Antioxidants, Vol. 7, Pages 33: Antioxidant Tocols as Radiation
           Countermeasures (Challenges to be Addressed to Use Tocols as Radiation
           Countermeasures in Humans)

    • Authors: Ujwani Nukala, Shraddha Thakkar, Kimberly Krager, Philip Breen, Cesar Compadre, Nukhet Aykin-Burns
      First page: 33
      Abstract: Radiation countermeasures fall under three categories, radiation protectors, radiation mitigators, and radiation therapeutics. Radiation protectors are agents that are administered before radiation exposure to protect from radiation-induced injuries by numerous mechanisms, including scavenging free radicals that are generated by initial radiochemical events. Radiation mitigators are agents that are administered after the exposure of radiation but before the onset of symptoms by accelerating the recovery and repair from radiation-induced injuries. Whereas radiation therapeutic agents administered after the onset of symptoms act by regenerating the tissues that are injured by radiation. Vitamin E is an antioxidant that neutralizes free radicals generated by radiation exposure by donating H atoms. The vitamin E family consists of eight different vitamers, including four tocopherols and four tocotrienols. Though alpha-tocopherol was extensively studied in the past, tocotrienols have recently gained attention as radiation countermeasures. Despite several studies performed on tocotrienols, there is no clear evidence on the factors that are responsible for their superior radiation protection properties over tocopherols. Their absorption and bioavailability are also not well understood. In this review, we discuss tocopherol’s and tocotrienol’s efficacy as radiation countermeasures and identify the challenges to be addressed to develop them into radiation countermeasures for human use in the event of radiological emergencies.
      Citation: Antioxidants
      PubDate: 2018-02-23
      DOI: 10.3390/antiox7020033
      Issue No: Vol. 7, No. 2 (2018)
       
  • Antioxidants, Vol. 7, Pages 5: Singlet Oxygen and Free Radical Reactions
           of Retinoids and Carotenoids—A Review

    • Authors: Ruth Edge, T. Truscott
      First page: 5
      Abstract: We report on studies of reactions of singlet oxygen with carotenoids and retinoids and a range of free radical studies on carotenoids and retinoids with emphasis on recent work, dietary carotenoids and the role of oxygen in biological processes. Many previous reviews are cited and updated together with new data not previously reviewed. The review does not deal with computational studies but the emphasis is on laboratory-based results. We contrast the ease of study of both singlet oxygen and polyene radical cations compared to neutral radicals. Of particular interest is the switch from anti- to pro-oxidant behavior of a carotenoid with change of oxygen concentration: results for lycopene in a cellular model system show total protection of the human cells studied at zero oxygen concentration, but zero protection at 100% oxygen concentration.
      Citation: Antioxidants
      PubDate: 2018-01-01
      DOI: 10.3390/antiox7010005
      Issue No: Vol. 7, No. 1 (2018)
       
  • Antioxidants, Vol. 7, Pages 6: Genotypic and Environmental Effects on
           Tocopherol Content in Almond

    • Authors: Ossama Kodad, Rafel Socias i Company, José Alonso
      First page: 6
      Abstract: Almond is the most important nut species worldwide and almond kernels show the highest levels of tocopherols among all nuts. In almond, tocopherols not only play a substantial role as a healthy food for human consumption, but also in protecting lipids against oxidation and, thus, lengthening the storage time of almond kernels. The main tocopherol homologues detected in almond in decreasing content and biological importance are α-, γ-, δ-, and β-tocopherol. Tocopherol concentration in almond depends on the genotype and the environment, such as the climatic conditions of the year and the growing management of the orchard. The range of variability for the different tocopherol homologues is of 335–657 mg/kg of almond oil for α-, 2–50 for γ-, and 0.1–22 for β-tocopherol. Drought and heat have been the most important stresses affecting tocopherol content in almond, with increased levels at higher temperatures and in water deficit conditions. The right cultivar and the most appropriate growing conditions may be selected to obtain crops with effective kernel storage and for the most beneficial effects of almond consumption for human nutrition and health.
      Citation: Antioxidants
      PubDate: 2018-01-05
      DOI: 10.3390/antiox7010006
      Issue No: Vol. 7, No. 1 (2018)
       
  • Antioxidants, Vol. 7, Pages 7: Exercise and Mitochondrial Dynamics:
           Keeping in Shape with ROS and AMPK

    • Authors: Adam Trewin, Brandon Berry, Andrew Wojtovich
      First page: 7
      Abstract: Exercise is a robust stimulus for mitochondrial adaptations in skeletal muscle which consequently plays a central role in enhancing metabolic health. Despite this, the precise molecular events that underpin these beneficial effects remain elusive. In this review, we discuss molecular signals generated during exercise leading to altered mitochondrial morphology and dynamics. In particular, we focus on the interdependence between reactive oxygen species (ROS) and redox homeostasis, the sensing of cellular bioenergetic status via 5’ adenosine monophosphate (AMP)-activated protein kinase (AMPK), and the regulation of mitochondrial fission and fusion. Precisely how exercise regulates the network of these responses and their effects on mitochondrial dynamics is not fully understood at present. We highlight the limitations that exist with the techniques currently available, and discuss novel molecular tools to potentially advance the fields of redox biology and mitochondrial bioenergetics. Ultimately, a greater understanding of these processes may lead to novel mitochondria-targeted therapeutic strategies to augment or mimic exercise in order to attenuate or reverse pathophysiology.
      Citation: Antioxidants
      PubDate: 2018-01-06
      DOI: 10.3390/antiox7010007
      Issue No: Vol. 7, No. 1 (2018)
       
  • Antioxidants, Vol. 7, Pages 8: Acknowledgement to Reviewers of
           Antioxidants in 2017

    • Authors: Antioxidants Editorial Office
      First page: 8
      Abstract: Peer review is an essential part in the publication process, ensuring that Antioxidants maintains high quality standards for its published papers.[...]
      Citation: Antioxidants
      PubDate: 2018-01-10
      DOI: 10.3390/antiox7010008
      Issue No: Vol. 7, No. 1 (2018)
       
  • Antioxidants, Vol. 7, Pages 9: Dietary Antioxidants and Health Promotion

    • Authors: Dejian Huang
      First page: 9
      Abstract: Accumulating scientific evidence suggests that over-production of reactive oxygen species (ROS) may be the root cause of chronic diseases such as cancer, cardiovascular diseases, neurodegeneration, and ageing per se [1,2].[...]
      Citation: Antioxidants
      PubDate: 2018-01-12
      DOI: 10.3390/antiox7010009
      Issue No: Vol. 7, No. 1 (2018)
       
  • Antioxidants, Vol. 7, Pages 10: Long-Chain Metabolites of Vitamin E:
           

    • Authors: Martin Schubert, Stefan Kluge, Lisa Schmölz, Maria Wallert, Francesco Galli, Marc Birringer, Stefan Lorkowski
      First page: 10
      Abstract: Vitamins E, A, D and K comprise the class of lipid-soluble vitamins. For vitamins A and D, a metabolic conversion of precursors to active metabolites has already been described. During the metabolism of vitamin E, the long-chain metabolites (LCMs) 13′-hydroxychromanol (13′-OH) and 13′-carboxychromanol (13′-COOH) are formed by oxidative modification of the side-chain. The occurrence of these metabolites in human serum indicates a physiological relevance. Indeed, effects of the LCMs on lipid metabolism, apoptosis, proliferation and inflammatory actions as well as tocopherol and xenobiotic metabolism have been shown. Interestingly, there are several parallels between the actions of the LCMs of vitamin E and the active metabolites of vitamin A and D. The recent findings that the LCMs exert effects different from that of their precursors support their putative role as regulatory metabolites. Hence, it could be proposed that the mode of action of the LCMs might be mediated by a mechanism similar to vitamin A and D metabolites. If the physiological relevance and this concept of action of the LCMs can be confirmed, a general concept of activation of lipid-soluble vitamins via their metabolites might be deduced.
      Citation: Antioxidants
      PubDate: 2018-01-12
      DOI: 10.3390/antiox7010010
      Issue No: Vol. 7, No. 1 (2018)
       
  • Antioxidants, Vol. 7, Pages 11: Effect of the Extraction Process on the
           Biological Activity of Lyophilized Apricot Extracts Recovered from Apricot
           Pomace

    • Authors: Dina Cheaib, Nada El Darra, Hiba Rajha, Iman El-Ghazzawi, Richard Maroun, Nicolas Louka
      First page: 11
      Abstract: The preservation of polyphenols in fruits by lyophilization has gained great interest in the recent decades. The present study aims to assess the impact of the pre-treatment extraction methods heat-assisted extraction (HAE) and infrared (IR) on lyophilized apricot pomace extracts. Then to test the conservation of polyphenols quantities as well as their bioactivities (antiradical and antibacterial) in lyophilized extract. An aqueous extract was obtained through either heat-assisted extraction or infrared pre-treatments then lyophilized to obtain a dried form. Results showed that the content of polyphenols, the antiradical and antibacterial activities in lyophilized extracts exhibited a slighter decrease in infrared sample compared to the heat-assisted extraction ones. The High-performance liquid chromatography (HPLC) analysis showed that lyophilized extracts IR and HAE preserved the same phenolic molecules (rutin, catechin and epicatechin) detected in liquid extracts (IR and HAE) with a smaller yield. Lyophilization can be used as a widely process in the food industry to conserve many bioactive molecules.
      Citation: Antioxidants
      PubDate: 2018-01-14
      DOI: 10.3390/antiox7010011
      Issue No: Vol. 7, No. 1 (2018)
       
  • Antioxidants, Vol. 7, Pages 12: Vitamin E as a Treatment for Nonalcoholic
           Fatty Liver Disease: Reality or Myth'

    • Authors: Hamza Hadi, Roberto Vettor, Marco Rossato
      First page: 12
      Abstract: Obesity is one of the major epidemics of this millennium, and its incidence is growing worldwide. Following the epidemics of obesity, nonalcoholic fatty liver disease (NAFLD) has become a disease of increasing prevalence and a leading cause of morbidity and mortality closely related to cardiovascular disease, malignancies, and cirrhosis. It is believed that oxidative stress is a main player in the development and progression of NAFLD. Currently, a pharmacological approach has become necessary in NAFLD because of a failure to modify lifestyle and dietary habits in most patients. Vitamin E is a potent antioxidant that has been shown to reduce oxidative stress in NAFLD. This review summarizes the biological activities of vitamin E, with a primary focus on its therapeutic efficacy in NAFLD.
      Citation: Antioxidants
      PubDate: 2018-01-16
      DOI: 10.3390/antiox7010012
      Issue No: Vol. 7, No. 1 (2018)
       
  • Antioxidants, Vol. 7, Pages 13: Reactive Oxygen Species and Mitochondrial
           Dynamics: The Yin and Yang of Mitochondrial Dysfunction and Cancer
           Progression

    • Authors: Jan Ježek, Katrina Cooper, Randy Strich
      First page: 13
      Abstract: Mitochondria are organelles with a highly dynamic ultrastructure maintained by a delicate equilibrium between its fission and fusion rates. Understanding the factors influencing this balance is important as perturbations to mitochondrial dynamics can result in pathological states. As a terminal site of nutrient oxidation for the cell, mitochondrial powerhouses harness energy in the form of ATP in a process driven by the electron transport chain. Contemporaneously, electrons translocated within the electron transport chain undergo spontaneous side reactions with oxygen, giving rise to superoxide and a variety of other downstream reactive oxygen species (ROS). Mitochondrially-derived ROS can mediate redox signaling or, in excess, cause cell injury and even cell death. Recent evidence suggests that mitochondrial ultrastructure is tightly coupled to ROS generation depending on the physiological status of the cell. Yet, the mechanism by which changes in mitochondrial shape modulate mitochondrial function and redox homeostasis is less clear. Aberrant mitochondrial morphology may lead to enhanced ROS formation, which, in turn, may deteriorate mitochondrial health and further exacerbate oxidative stress in a self-perpetuating vicious cycle. Here, we review the latest findings on the intricate relationship between mitochondrial dynamics and ROS production, focusing mainly on its role in malignant disease.
      Citation: Antioxidants
      PubDate: 2018-01-16
      DOI: 10.3390/antiox7010013
      Issue No: Vol. 7, No. 1 (2018)
       
  • Antioxidants, Vol. 7, Pages 14: Subcellular Reactive Oxygen Species (ROS)
           in Cardiovascular Pathophysiology

    • Authors: Sarah Aldosari, Maan Awad, Elizabeth Harrington, Frank Sellke, M. Abid
      First page: 14
      Abstract: There exist two opposing perspectives regarding reactive oxygen species (ROS) and their roles in angiogenesis and cardiovascular system, one that favors harmful and causal effects of ROS, while the other supports beneficial effects. Recent studies have shown that interaction between ROS in different sub-cellular compartments plays a crucial role in determining the outcomes (beneficial vs. deleterious) of ROS exposures on the vascular system. Oxidant radicals in one cellular organelle can affect the ROS content and function in other sub-cellular compartments in endothelial cells (ECs). In this review, we will focus on a critical fact that the effects or the final phenotypic outcome of ROS exposure to EC are tissue- or organ-specific, and depend on the spatial (subcellular localization) and temporal (duration of ROS exposure) modulation of ROS levels.
      Citation: Antioxidants
      PubDate: 2018-01-16
      DOI: 10.3390/antiox7010014
      Issue No: Vol. 7, No. 1 (2018)
       
  • Antioxidants, Vol. 7, Pages 15: Regulation of Mitochondrial Dynamics by
           Proteolytic Processing and Protein Turnover

    • Authors: Sumaira Ali, Gavin McStay
      First page: 15
      Abstract: The mitochondrial network is a dynamic organization within eukaryotic cells that participates in a variety of essential cellular processes, such as adenosine triphosphate (ATP) synthesis, central metabolism, apoptosis and inflammation. The mitochondrial network is balanced between rates of fusion and fission that respond to pathophysiologic signals to coordinate appropriate mitochondrial processes. Mitochondrial fusion and fission are regulated by proteins that either reside in or translocate to the inner or outer mitochondrial membranes or are soluble in the inter-membrane space. Mitochondrial fission and fusion are performed by guanosine triphosphatases (GTPases) on the outer and inner mitochondrial membranes with the assistance of other mitochondrial proteins. Due to the essential nature of mitochondrial function for cellular homeostasis, regulation of mitochondrial dynamics is under strict control. Some of the mechanisms used to regulate the function of these proteins are post-translational proteolysis and/or turnover, and this review will discuss these mechanisms required for correct mitochondrial network organization.
      Citation: Antioxidants
      PubDate: 2018-01-17
      DOI: 10.3390/antiox7010015
      Issue No: Vol. 7, No. 1 (2018)
       
  • Antioxidants, Vol. 7, Pages 16: Metabolic Alterations in Cancer Cells and
           the Emerging Role of Oncometabolites as Drivers of Neoplastic Change

    • Authors: Zhengqiu Zhou, Elochukwu Ibekwe, Yevgen Chornenkyy
      First page: 16
      Abstract: The mitochondrion is an important organelle and provides energy for a plethora of intracellular reactions. Metabolic dysregulation has dire consequences for the cell, and alteration in metabolism has been identified in multiple disease states—cancer being one. Otto Warburg demonstrated that cancer cells, in the presence of oxygen, undergo glycolysis by reprogramming their metabolism—termed “aerobic glycolysis”. Alterations in metabolism enable cancer cells to gain a growth advantage by obtaining precursors for macromolecule biosynthesis, such as nucleic acids and lipids. To date, several molecules, termed “oncometabolites”, have been identified to be elevated in cancer cells and arise from mutations in nuclear encoded mitochondrial enzymes. Furthermore, there is evidence that oncometabolites can affect mitochondrial dynamics. It is believed that oncometabolites can assist in reprogramming enzymatic pathways and providing cancer cells with selective advantages. In this review, we will touch upon the effects of normal and aberrant mitochondrial metabolism in normal and cancer cells, the advantages of metabolic reprogramming, effects of oncometabolites on metabolism and mitochondrial dynamics and therapies aimed at targeting oncometabolites and metabolic aberrations.
      Citation: Antioxidants
      PubDate: 2018-01-17
      DOI: 10.3390/antiox7010016
      Issue No: Vol. 7, No. 1 (2018)
       
  • Antioxidants, Vol. 7, Pages 17: Cytokine Response to Exercise and Its
           Modulation

    • Authors: Katsuhiko Suzuki
      First page: 17
      Abstract: Strenuous exercise induces such inflammatory responses as leukocytosis (neutrophilia) and symptoms as delayed-onset muscle soreness and swelling. However, the association between inflammatory mediator cytokines and oxidative stress is not fully delineated. Herein, in addition to basic background information on cytokines, research findings on exertional effects on cytokine release and the underlying mechanisms and triggers are introduced. Then, the associations among cytokine responses, oxidative stress, and tissue damage are described not only in overloaded skeletal muscle, but also in other internal organs. Furthermore, we introduce preventive countermeasures against the exhaustive exercise-induced pathogenesis together with the possibility of antioxidant interventions.
      Citation: Antioxidants
      PubDate: 2018-01-17
      DOI: 10.3390/antiox7010017
      Issue No: Vol. 7, No. 1 (2018)
       
  • Antioxidants, Vol. 7, Pages 18: Superoxide Dismutase Mimetic GC4419
           Enhances the Oxidation of Pharmacological Ascorbate and Its Anticancer
           Effects in an H2O2-Dependent Manner

    • Authors: Collin Heer, Andrew Davis, David Riffe, Brett Wagner, Kelly Falls, Bryan Allen, Garry Buettner, Robert Beardsley, Dennis Riley, Douglas Spitz
      First page: 18
      Abstract: Lung cancer, together with head and neck cancer, accounts for more than one-fourth of cancer deaths worldwide. New, non-toxic therapeutic approaches are needed. High-dose IV vitamin C (aka, pharmacological ascorbate; P-AscH−) represents a promising adjuvant to radiochemotherapy that exerts its anti-cancer effects via metal-catalyzed oxidation to form H2O2. Mn(III)-porphyrins possessing superoxide dismutase (SOD) mimetic activity have been shown to increase the rate of oxidation of AscH−, enhancing the anti-tumor effects of AscH− in several cancer types. The current study demonstrates that the Mn(II)-containing pentaazamacrocyclic selective SOD mimetic GC4419 may serve as an AscH−/O2•− oxidoreductase as evidenced by the increased rate of oxygen consumption, steady-state concentrations of ascorbate radical, and H2O2 production in complete cell culture media. GC4419, but not CuZnSOD, was shown to significantly enhance the toxicity of AscH− in H1299, SCC25, SQ20B, and Cal27 cancer cell lines. This enhanced cancer cell killing was dependent upon the catalytic activity of the SOD mimetic and the generation of H2O2, as determined using conditional overexpression of catalase in H1299T cells. GC4419 combined with AscH− was also capable of enhancing radiation-induced cancer cell killing. Currently, AscH− and GC4419 are each being tested separately in clinical trials in combination with radiation therapy. Data presented here support the hypothesis that the combination of GC4419 and AscH− may provide an effective means by which to further enhance radiation therapy responses.
      Citation: Antioxidants
      PubDate: 2018-01-19
      DOI: 10.3390/antiox7010018
      Issue No: Vol. 7, No. 1 (2018)
       
  • Antioxidants, Vol. 7, Pages 19: Interplay between Selenium Levels and
           Replicative Senescence in WI-38 Human Fibroblasts: A Proteomic Approach

    • Authors: Ghania Hammad, Yona Legrain, Zahia Touat-Hamici, Stéphane Duhieu, David Cornu, Anne-Laure Bulteau, Laurent Chavatte
      First page: 19
      Abstract: Selenoproteins are essential components of antioxidant defense, redox homeostasis, and cell signaling in mammals, where selenium is found in the form of a rare amino acid, selenocysteine. Selenium, which is often limited both in food intake and cell culture media, is a strong regulator of selenoprotein expression and selenoenzyme activity. Aging is a slow, complex, and multifactorial process, resulting in a gradual and irreversible decline of various functions of the body. Several cellular aspects of organismal aging are recapitulated in the replicative senescence of cultured human diploid fibroblasts, such as embryonic lung fibroblast WI-38 cells. We previously reported that the long-term growth of young WI-38 cells with high (supplemented), moderate (control), or low (depleted) concentrations of selenium in the culture medium impacts their replicative lifespan, due to rapid changes in replicative senescence-associated markers and signaling pathways. In order to gain insight into the molecular link between selenium levels and replicative senescence, in the present work, we have applied a quantitative proteomic approach based on 2-Dimensional Differential in-Gel Electrophoresis (2D-DIGE) to the study of young and presenescent cells grown in selenium-supplemented, control, or depleted media. Applying a restrictive cut-off (spot intensity ±50% and a p value < 0.05) to the 2D-DIGE analyses revealed 81 differentially expressed protein spots, from which 123 proteins of interest were identified by mass spectrometry. We compared the changes in protein abundance for three different conditions: (i) spots varying between young and presenescent cells, (ii) spots varying in response to selenium concentration in young cells, and (iii) spots varying in response to selenium concentration in presenescent cells. Interestingly, a 72% overlap between the impact of senescence and selenium was observed in our proteomic results, demonstrating a strong interplay between selenium, selenoproteins, and replicative senescence.
      Citation: Antioxidants
      PubDate: 2018-01-20
      DOI: 10.3390/antiox7010019
      Issue No: Vol. 7, No. 1 (2018)
       
  • Antioxidants, Vol. 7, Pages 20: Polyphenolic Compounds Analysis of Old and
           New Apple Cultivars and Contribution of Polyphenolic Profile to the In
           Vitro Antioxidant Capacity

    • Authors: Josephine Kschonsek, Theresa Wolfram, Annette Stöckl, Volker Böhm
      First page: 20
      Abstract: Polyphenols are antioxidant ingredients in apples and are related to human health because of their free radical scavenging activities. The polyphenolic profiles of old and new apple cultivars (n = 15) were analysed using high-performance liquid chromatography (HPLC) with diode array detection (DAD). The in vitro antioxidant capacity was determined by total phenolic content (TPC) assay, hydrophilic trolox equivalent antioxidant capacity (H-TEAC) assay and hydrophilic oxygen radical absorbance (H-ORAC) assay. Twenty polyphenolic compounds were identified in all investigated apples by HPLC analysis. Quercetin glycosides (203 ± 108 mg/100 g) were the main polyphenols in the peel and phenolic acids (10 ± 5 mg/100 g) in the flesh. The calculated relative contribution of single compounds indicated flavonols (peel) and vitamin C (flesh) as the major contributors to the antioxidant capacity, in all cultivars investigated. The polyphenolic content (HPLC data) of the flesh differed significantly between old (29 ± 7 mg/100 g) and new (13 ± 4 mg/100 g) cultivars, and the antioxidant capacity of old apple cultivars was up to 30% stronger compared to new ones.
      Citation: Antioxidants
      PubDate: 2018-01-24
      DOI: 10.3390/antiox7010020
      Issue No: Vol. 7, No. 1 (2018)
       
  • Antioxidants, Vol. 7, Pages 21: The Addition of Manganese Porphyrins
           during Radiation Inhibits Prostate Cancer Growth and Simultaneously
           Protects Normal Prostate Tissue from Radiation Damage

    • Authors: Arpita Chatterjee, Yuxiang Zhu, Qiang Tong, Elizabeth Kosmacek, Eliezer Lichter, Rebecca Oberley-Deegan
      First page: 21
      Abstract: Radiation therapy is commonly used for prostate cancer treatment; however, normal tissues can be damaged from the reactive oxygen species (ROS) produced by radiation. In separate reports, we and others have shown that manganese porphyrins (MnPs), ROS scavengers, protect normal cells from radiation-induced damage but inhibit prostate cancer cell growth. However, there have been no studies demonstrating that MnPs protect normal tissues, while inhibiting tumor growth in the same model. LNCaP or PC3 cells were orthotopically implanted into athymic mice and treated with radiation (2 Gy, for 5 consecutive days) in the presence or absence of MnPs. With radiation, MnPs enhanced overall life expectancy and significantly decreased the average tumor volume, as compared to the radiated alone group. MnPs enhanced lipid oxidation in tumor cells but reduced oxidative damage to normal prostate tissue adjacent to the prostate tumor in combination with radiation. Mechanistically, MnPs behave as pro-oxidants or antioxidants depending on the level of oxidative stress inside the treated cell. We found that MnPs act as pro-oxidants in prostate cancer cells, while in normal cells and tissues the MnPs act as antioxidants. For the first time, in the same in vivo model, this study reveals that MnPs enhance the tumoricidal effect of radiation and reduce oxidative damage to normal prostate tissue adjacent to the prostate tumor in the presence of radiation. This study suggests that MnPs are effective radio-protectors for radiation-mediated prostate cancer treatment.
      Citation: Antioxidants
      PubDate: 2018-01-25
      DOI: 10.3390/antiox7010021
      Issue No: Vol. 7, No. 1 (2018)
       
  • Antioxidants, Vol. 7, Pages 1: Biological Implications of Differential
           Expression of Mitochondrial-Shaping Proteins in Parkinson’s Disease

    • Authors: Sara Rocha, Ana Freitas, Sofia Guimaraes, Rui Vitorino, Miguel Aroso, Maria Gomez-Lazaro
      First page: 1
      Abstract: It has long been accepted that mitochondrial function and morphology is affected in Parkinson’s disease, and that mitochondrial function can be directly related to its morphology. So far, mitochondrial morphological alterations studies, in the context of this neurodegenerative disease, have been performed through microscopic methodologies. The goal of the present work is to address if the modifications in the mitochondrial-shaping proteins occurring in this disorder have implications in other cellular pathways, which might constitute important pathways for the disease progression. To do so, we conducted a novel approach through a thorough exploration of the available proteomics-based studies in the context of Parkinson’s disease. The analysis provided insight into the altered biological pathways affected by changes in the expression of mitochondrial-shaping proteins via different bioinformatic tools. Unexpectedly, we observed that the mitochondrial-shaping proteins altered in the context of Parkinson’s disease are, in the vast majority, related to the organization of the mitochondrial cristae. Conversely, in the studies that have resorted to microscopy-based techniques, the most widely reported alteration in the context of this disorder is mitochondria fragmentation. Cristae membrane organization is pivotal for mitochondrial ATP production, and changes in their morphology have a direct impact on the organization and function of the oxidative phosphorylation (OXPHOS) complexes. To understand which biological processes are affected by the alteration of these proteins we analyzed the binding partners of the mitochondrial-shaping proteins that were found altered in Parkinson’s disease. We showed that the binding partners fall into seven different cellular components, which include mitochondria, proteasome, and endoplasmic reticulum (ER), amongst others. It is noteworthy that, by evaluating the biological process in which these modified proteins are involved, we showed that they are related to the production and metabolism of ATP, immune response, cytoskeleton alteration, and oxidative stress, amongst others. In summary, with our bioinformatics approach using the data on the modified proteins in Parkinson’s disease patients, we were able to relate the alteration of mitochondrial-shaping proteins to modifications of crucial cellular pathways affected in this disease.
      Citation: Antioxidants
      PubDate: 2017-12-21
      DOI: 10.3390/antiox7010001
      Issue No: Vol. 7, No. 1 (2017)
       
  • Antioxidants, Vol. 7, Pages 2: Vitamin E Biosynthesis and Its Regulation
           in Plants

    • Authors: Laurent Mène-Saffrané
      First page: 2
      Abstract: Vitamin E is one of the 13 vitamins that are essential to animals that do not produce them. To date, six natural organic compounds belonging to the chemical family of tocochromanols—four tocopherols and two tocotrienols—have been demonstrated as exhibiting vitamin E activity in animals. Edible plant-derived products, notably seed oils, are the main sources of vitamin E in the human diet. Although this vitamin is readily available, independent nutritional surveys have shown that human populations do not consume enough vitamin E, and suffer from mild to severe deficiency. Tocochromanols are mostly produced by plants, algae, and some cyanobacteria. Tocochromanol metabolism has been mainly studied in higher plants that produce tocopherols, tocotrienols, plastochromanol-8, and tocomonoenols. In contrast to the tocochromanol biosynthetic pathways that are well characterized, our understanding of the physiological and molecular mechanisms regulating tocochromanol biosynthesis is in its infancy. Although it is known that tocochromanol biosynthesis is strongly conditioned by the availability in homogentisate and polyprenyl pyrophosphate, its polar and lipophilic biosynthetic precursors, respectively, the mechanisms regulating their biosyntheses are barely known. This review summarizes our current knowledge of tocochromanol biosynthesis in plants, and highlights future challenges regarding the understanding of its regulation.
      Citation: Antioxidants
      PubDate: 2017-12-25
      DOI: 10.3390/antiox7010002
      Issue No: Vol. 7, No. 1 (2017)
       
  • Antioxidants, Vol. 7, Pages 3: Natural Nanoparticles: A Particular Matter
           Inspired by Nature

    • Authors: Sharoon Griffin, Muhammad Masood, Muhammad Nasim, Muhammad Sarfraz, Azubuike Ebokaiwe, Karl-Herbert Schäfer, Cornelia Keck, Claus Jacob
      First page: 3
      Abstract: During the last couple of decades, the rapidly advancing field of nanotechnology has produced a wide palette of nanomaterials, most of which are considered as “synthetic” and, among the wider public, are often met with a certain suspicion. Despite the technological sophistication behind many of these materials, “nano” does not always equate with “artificial”. Indeed, nature itself is an excellent nanotechnologist. It provides us with a range of fine particles, from inorganic ash, soot, sulfur and mineral particles found in the air or in wells, to sulfur and selenium nanoparticles produced by many bacteria and yeasts. These nanomaterials are entirely natural, and, not surprisingly, there is a growing interest in the development of natural nanoproducts, for instance in the emerging fields of phyto- and phyco-nanotechnology. This review will highlight some of the most recent—and sometimes unexpected—advances in this exciting and diverse field of research and development. Naturally occurring nanomaterials, artificially produced nanomaterials of natural products as well as naturally occurring or produced nanomaterials of natural products all show their own, particular chemical and physical properties, biological activities and promise for applications, especially in the fields of medicine, nutrition, cosmetics and agriculture. In the future, such natural nanoparticles will not only stimulate research and add a greener outlook to a traditionally high-tech field, they will also provide solutions—pardon—suspensions for a range of problems. Here, we may anticipate specific biogenic factories, valuable new materials based on waste, the effective removal of contaminants as part of nano-bioremediation, and the conversion of poorly soluble substances and materials to biologically available forms for practical uses.
      Citation: Antioxidants
      PubDate: 2017-12-29
      DOI: 10.3390/antiox7010003
      Issue No: Vol. 7, No. 1 (2017)
       
  • Antioxidants, Vol. 7, Pages 4: Selenoprotein K Increases Efficiency of
           DHHC6 Catalyzed Protein Palmitoylation by Stabilizing the Acyl-DHHC6
           Intermediate

    • Authors: Gregory Fredericks, FuKun Hoffmann, Robert Hondal, Sharon Rozovsky, Johann Urschitz, Peter Hoffmann
      First page: 4
      Abstract: Selenoprotein K (SELENOK) is a selenocysteine (Sec)-containing protein localized in the endoplasmic reticulum (ER) membrane where it interacts with the DHHC6 (where single letter symbols represent Asp-His-His-Cys amino acids) enzyme to promote protein acyl transferase (PAT) reactions. PAT reactions involve the DHHC enzymatic capture of palmitate via a thioester bond to cysteine (Cys) residues that form an unstable palmitoyl-DHHC intermediate, followed by transfer of palmitate to Cys residues of target proteins. How SELENOK facilitates this reaction has not been determined. Splenocyte microsomal preparations from wild-type mice versus SELENOK knockout mice were used to establish PAT assays and showed decreased PAT activity (~50%) under conditions of SELENOK deficiency. Using recombinant, soluble versions of DHHC6 along with SELENOK containing Sec92, Cys92, or alanine (Ala92), we evaluated the stability of the acyl-DHHC6 intermediate and its capacity to transfer the palmitate residue to Cys residues on target peptides. Versions of SELENOK containing either Ala or Cys residues in place of Sec were equivalently less effective than Sec at stabilizing the acyl-DHHC6 intermediate or promoting PAT activity. These data suggest that Sec92 in SELENOK serves to stabilize the palmitoyl-DHHC6 intermediate by reducing hydrolyzation of the thioester bond until transfer of the palmitoyl group to the Cys residue on the target protein can occur.
      Citation: Antioxidants
      PubDate: 2017-12-29
      DOI: 10.3390/antiox7010004
      Issue No: Vol. 7, No. 1 (2017)
       
  • 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 103: Co-Enzyme Q10 and n-3 Polyunsaturated
           Fatty Acid Supplementation Reverse Intermittent Hypoxia-Induced Growth
           Restriction and Improved Antioxidant Profiles in Neonatal Rats

    • Authors: Kay Beharry, Charles Cai, Michael Henry, Sara Chowdhury, Gloria Valencia, Jacob Aranda
      First page: 103
      Abstract: Neonatal intermittent hypoxia (IH) increases the risk for many morbidities in extremely low birth weight/gestational age (ELBW/ELGA) neonates with compromised antioxidant systems and poor growth. We hypothesized that supplementation with coenzyme Q10 (CoQ10, ubiquinol) or n-3 polyunsaturated fatty acids (PUFAs) during neonatal IH improves antioxidant profiles and somatic growth in neonatal rats. Newborn rats were exposed to two IH paradigms at birth (P0): (1) 50% O2 with brief hypoxic episodes (12% O2); or (2) room air (RA) with brief hypoxia, until P14 during which they received daily oral CoQ10 in olive oil, n-3 PUFAs in fish oil, or olive oil only from P0 to P14. Pups were studied at P14 or placed in RA until P21 for recovery from IH (IHR). Body weight and length; organ weights; and serum antioxidants and growth factors were determined at P14 and P21. Neonatal IH resulted in sustained reductions in somatic growth, an effect that was reversed with n-3 PUFAs. Improved growth was associated with higher serum growth factors. CoQ10 decreased superoxide dismutase (SOD) and glutathione, but increased catalase, suggesting reduced oxidative stress. Further studies are needed to determine the synergistic effects of CoQ10 and n-3 PUFA co-administration for the prevention of IH-induced oxidative stress and postnatal growth deficits.
      Citation: Antioxidants
      PubDate: 2017-12-16
      DOI: 10.3390/antiox6040103
      Issue No: Vol. 6, No. 4 (2017)
       
  • Antioxidants, Vol. 6, Pages 104: The Role of Nicotinamide Adenine
           Dinucleotide Phosphate Oxidases in Lung Architecture Remodeling

    • Authors: Anantha Harijith, Viswanathan Natarajan, Panfeng Fu
      First page: 104
      Abstract: Chronic lung disorders, such as pulmonary artery hypertension (PAH), chronic obstructive pulmonary disease (COPD), asthma and neonatal bronchopulmonary dysplasia (BPD), are characterized by airway and/or vascular remodeling. Despite differences in the pathology, reactive oxygen species (ROS) have been highlighted as a critical contributor to the initiation and development of airway and vascular remodeling. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (Nox) appear to play a pivotal role in lung signaling, leading to marked changes in pulmonary airway and vascular cell phenotypes, including proliferation, hypertrophy and apoptosis. In this review, we summarized the current literature regarding the role of Nox in the airway and vascular remodeling.
      Citation: Antioxidants
      PubDate: 2017-12-19
      DOI: 10.3390/antiox6040104
      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 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)
       
 
 
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