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Experimental Parasitology
Journal Prestige (SJR): 0.635
Citation Impact (citeScore): 2
Number of Followers: 2  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0014-4894 - ISSN (Online) 1090-2449
Published by Elsevier Homepage  [3177 journals]
  • In vitro effect of curcumin on Schistosoma species viability, tegument
           ultrastructure and egg hatchability
    • Abstract: Publication date: April 2019Source: Experimental Parasitology, Volume 199Author(s): Marwa M. Abou El Dahab, Sondos M. Shahat, Soheir S.M. Mahmoud, Noha A. MahanaSchistosomiasis remains a severe problem of public health in developing countries. The development of resistance to praziquantel (PZQ) has justified the search for new alternative chemotherapies with new formulations, more effective, and without adverse effects. Curcumin (CUR), the major phenolic compound present in rhizome of turmeric (Curcuma longa L.), has been traditionally used against various diseases including parasitic infections. Here, the antischistosomal activity of CUR (50–500 μM), evaluated in parallel against S. mansoni and S. haematobium adult worms, appeared significant (P 
       
  • Editors’ commentary on the special issue on the “VI International
           Giardia and Cryptosporidium Conference (VI IGCC)”
    • Abstract: Publication date: April 2019Source: Experimental Parasitology, Volume 199Author(s): Marco Lalle, Alex Grinberg, Guadalupe Ortega Pierres
       
  • Zygocotyle lunata as a model for in vivo screening of anthelmintic
           activity against paramphistomes: Evaluation of efficacy of praziquantel,
           albendazole and closantel in experimentally infected mice
    • Abstract: Publication date: April 2019Source: Experimental Parasitology, Volume 199Author(s): Hudson A. Pinto, Jordana C.A. Assis, Beatriz C.M. Silva, Nicole Q. Gonçalves, Alan L. MeloParamphistomes are important parasites in veterinary medicine. There are few anthelmintic drugs available against them. The development of new drugs is urgently needed and this process can be accelerated through the development of rodent models for in vivo testing. Among the few paramphistomes that develop in rodents is the caecal fluke Zygocotyle lunata, a species with which several biological studies have been performed over several decades. Nevertheless, its use as a model for evaluation of anthelmintic drugs had not yet been evaluated. In the present study, we evaluated the efficacy of praziquantel (PZQ 300 mg/kg 5x), albendazole (ABZ 200 mg/kg 5x) and closantel (CLO 50 mg/kg single dose, 50 mg/kg 3x and 25 mg/kg 3x) for treatment of mice experimentally infected with Z. lunata. The animals were infected with 20 metacercariae of the parasite and were treated 30 days post-infection. Untreated groups were maintained as controls. Seven days after the treatments, the animals were euthanized for recovery and counting of parasites. We found that PZQ and ABZ, at the dosages and therapeutic schedule employed here, did not cause significant alterations in worm burden [worm counts 16.0 ± 2.8 (13–19), 17.6 ± 2.1 (14–19) and 16.2 ± 1.9 (13–18) (p = 0.51) in PZQ, ALB and control, respectively]. CLO 50 mg/kg in a single dose caused significant reduction in the number of parasites [treated: 1.8 ± 0.9 (1–3); control: 15.6 ± 2.5 (12–19)], although it did not result in complete elimination of the parasites in any animal. Despite the fact that three doses of CLO 50 mg/kg or CLO 25 mg/kg caused complete elimination of the parasites in most surviving animals, there was significant host mortality. In general, results here obtained are concordant with those of studies performed on ruminant paramphistomes. Given that Z. lunata can be maintained in laboratory rodents, it is a suitable model for screening anthelmintic drugs against paramphistomes.Graphical abstractImage 1
       
  • Efficacy of lapachol on treatment of cutaneous and visceral leishmaniasis
    • Abstract: Publication date: April 2019Source: Experimental Parasitology, Volume 199Author(s): Iasmin Aparecida Cunha Araújo, Renata Cristina de Paula, Ceres Luciana Alves, Karen Ferraz Faria, Marco Miguel de Oliveira, Gabriela Gonçalves Mendes, Eliane Martins Ferreira Abdias Dias, Raul Rio Ribeiro, Alaíde Braga de Oliveira, Sydnei Magno da SilvaLeishmaniasis is one of the most important neglected diseases worldwide. It is a life-threatening disease and causes significant morbidity, long-term disability, and early death. Treatment involves disease control or use of intervention measures, although the currently used drugs require long-lasting therapy, and display toxicity and reduced efficacy. The use of natural products isolated from plants, such as lapachol, an abundant naphthoquinone naturally occurring in South American Handroanthus species (Tabebuia, Bignoniaceae), is a promising option for the treatment of leishmaniasis. In this study, we investigated the leishmanicidal activity of lapachol in vitro and in vivo against Leishmania infantum and L. amazonensis, causative agents of visceral and cutaneous leishmaniasis, respectively. Low cytotoxicity in HepG2 cells (3405.8 ± 261.33 μM), good anti-Leishmania activity, and favorable selectivity indexes (SI) against promastigotes of both L. amazonensis (IC50 = 79.84 ± 9.10 μM, SI = 42.65) and L. infantum (IC50 = 135.79 ± 33.04 μM, SI = 25.08) were observed. Furthermore, anti-Leishmania activity assays performed on intracellular amastigotes showed good activity for lapachol (IC50 = 191.95 μM for L. amazonensis and 171.26 μM for L. infantum). Flow cytometric analysis demonstrated that the cytotoxic effect of lapachol in Leishmania promastigotes was caused by apoptosis-like death. Interestingly, the in vitro leishmanicidal effect of lapachol was confirmed in vivo in murine models of visceral and cutaneous leishmaniasis, as lapachol (25 mg/kg oral route for 24 h over 10 days) was able to significantly reduce the parasitic load in skin lesions, liver, and spleen, similar to amphotericin B, the reference drug. These results reinforce the therapeutic potential of lapachol, which warrants further investigations as an anti-leishmaniasis therapeutic.Graphical abstractLapachol induces apoptosis in Leishmania sp. and shows potential therapeutic potential for leishmaniasis.Image 10883
       
  • Interaction between natural magnetite sub-micrometric particles and the
           Fasciola hepatica egg: The role of the exposed surface area
    • Abstract: Publication date: April 2019Source: Experimental Parasitology, Volume 199Author(s): Mariana Raineri, Enio Lima, Marcela Larroza, M. Sergio Moreno, Marcelo Vásquez Mansilla, Juan Sebastián Pappalardo, Roberto D. ZyslerFasciolosis is a zoonotic world widely distributed disease caused by the liver fluke Fasciola hepatica, which affects animals and occasionally humans. On the other hand, natural iron oxide particles like magnetite are commonly found in soils where they participate in a wide range of environmental processes like organic matter decomposition, the adsorption of ions and molecules, and chemical reactions that involve the participation of soil living microorganisms. Since Fasciola eggs become soil components after being released with the infected animal faeces, this study focused on the characterization of the natural interaction between natural sub-micrometric magnetite particles and F. hepatica eggs. Our results indicate that particle binding to the F. hepatica egg depends on the particle size and it is also related to the exposed surface area since any condition that favors particle agglomeration leads to the reduction of the particle-eggshell binding intensity. Interestingly, this binding was avoided when proteins or phosphate were incorporated to the incubation solution, but not after formaldehyde fixation of eggs. Finally, when eggs were exposed to an external magnet after being incubated with magnetite particles, they were attracted to it without particles being detached, indicating a strong type of bonding between them. Therefore, the results presented here give new insights in order to improve the possibility of harvesting F. hepatica eggs by using magnetic materials.Graphical abstractImage 1
       
  • Oxfendazole kinetics in pigs: In vivo assessment of its pattern of
           accumulation in Ascaris suum
    • Abstract: Publication date: April 2019Source: Experimental Parasitology, Volume 199Author(s): Laura Ceballos, Candela Canton, Gabriela Cadenazzi, Guillermo Virkel, Paula Dominguez, Laura Moreno, Carlos Lanusse, Luis AlvarezAscaris suum is a widespread parasitic nematode that causes infection in pigs with high prevalence rates. Oxfendazole (OFZ) is effective against A. suum when used at a single high oral dose of 30 mg/kg. The aim of this study was to assess the pattern of distribution/accumulation of OFZ and its metabolites, in bloodstream (plasma), mucosal tissue and contents from small and large intestine and adult specimens of A. suum collected from infected and treated pigs. The activity of glutathione-S-transferases (GSTs) in A. suum was also investigated. Infected pigs were orally treated with OFZ (30 mg/kg) and sacrificed at 0, 3, 6 and 12 h after treatment. Samples of blood, mucosa and contents from both small and large intestine as well as adult worms were obtained and processed for quantification of OFZ/metabolites by HPLC. OFZ was the main analyte measured in all of the evaluated matrixes. The highest drug concentrations were determined in small (AUC0-t 718.7 ± 283.5 μg h/g) and large (399.6 ± 110.5 μg h/g) intestinal content. Concentrations ranging from 1.35 to 2.60 μg/g (OFZ) were measured in adult A. suum. GSTs activity was higher after exposure to OFZ both in vivo and ex vivo. The data obtained here suggest that the pattern of OFZ accumulation in A. suum would be more related to the concentration achieved in the fluid and mucosa of the small intestine than in other tissues/fluids. It is expected that increments in the amount of drug attained in the tissues/fluids of parasite location will correlate with increased drug concentration within the target parasite, and therefore with the resultant treatment efficacy. The results are particularly relevant considering the potential of OFZ to be used for soil transmitted helminths (STH) control programs and the advantages of pigs as a model to assess drug treatment to be implemented in humans.Graphical abstractImage 1
       
  • Cordycepin (3′-deoxyadenosine) and pentostatin (deoxycoformycin) against
           Trypanosoma cruzi
    • Abstract: Publication date: April 2019Source: Experimental Parasitology, Volume 199Author(s): Guilherme M. do Carmo, Mariângela F. de Sá, Thirssa H. Grando, Lucas T. Gressler, Matheus D. Baldissera, Silvia G. Monteiro, Luan C. Henker, Ricardo E. Mendes, Lenita M. Stefani, Aleksandro S. Da SilvaThe aim of this study was to evaluate in vitro the efficacy of cordycepin and pentostatin (alone or combined) against Trypanosoma cruzi, as well as the therapeutic efficiency of protocols of cordycepin and pentostatin combinations in mice experimentally infected with T. cruzi. In vitro, the cordycepin (3′-deoxyadenosine) and pentostatin (deoxycoformycin) exerted potent trypanocidal effect against T. cruzi (Colombian strain), similarly to benznidazole, which is the reference drug. For epimastigotes, the lethal dose of cordycepin capable of killing 50% (LD50) and 20% (LD20) of the parasites was 0.072 and 0.031 mg/mL, respectively and for trypomastigotes was 0.047 and 0.015 mg/mL, respectively. The combined use of cordycepin and pentostatin resulted in a LD50 and LD20 for epimastigotes of 0.068 and 0.027 mg/mL, respectively, as well as 0.056 and 0.018 mg/mL for trypomastigotes, respectively. In vivo, the combined use of cordycepin and pentostatin did not show the expected curative effect, however it was able to control the parasitema in the peak period. In summary, the combination of cordycepin and pentostatin showed no curative effect in mice infected by T. cruzi, despite the in vitro reduction of epimastigotes and trypomastigotes.Graphical abstractImage 1
       
  • Short- and long-term effects of orally administered azithromycin on
           Trypanosoma brucei brucei-infected mice
    • Abstract: Publication date: April 2019Source: Experimental Parasitology, Volume 199Author(s): Nthatisi I. Molefe, Peter S. Musinguzi, Daisuke Kondoh, Kenichi Watanabe, Oriel M.M. Thekisoe, Xuenan Xuan, Noboru Inoue, Keisuke SuganumaHuman African trypanosomosis (HAT) and animal African trypanosomosis (AAT) are diseases of economic importance in humans and animals that affect more than 36 African countries. The currently available trypanocidal drugs are associated with side effects, and the parasites are continually developing resistance. Thus, effective and safe drugs are needed for the treatment of HAT and AAT. This study aimed to evaluate the effects of azithromycin (AZM) on Trypanosoma brucei brucei-infected mice. Mice were randomly divided into 7 groups consisting of a vehicle control group, 5 test groups and a diminazene aceturate (DA)-treated group. Mice were treated orally for 7 and 28 days, as short-term and long-term treatments, respectively. Short-term AZM treatment cured 23% (16 of 70) of the overall treated mice whereas long-term treatment resulted in the survival of 70% of the mice in the groups that received AZM at doses of 300 and 400 mg/kg. Trypanosomes treated in vitro with 25 μg/mL of AZM were subjected to transmission electron microscopy, which revealed the presence of increased numbers of glycosomes and acidocalcisomes in comparison to the vehicle group. The current study showed the trypanocidal effect of AZM on T. b. brucei in vivo. The demonstrated efficacy increased with an increase in treatment period and an increased concentration of AZM.Graphical abstractImage 1
       
  • Evaluation of the in vitro and in vivo antileishmanial activity of a
           chloroquinolin derivative against Leishmania species capable of causing
           tegumentary and visceral leishmaniasis
    • Abstract: Publication date: April 2019Source: Experimental Parasitology, Volume 199Author(s): Tauane G. Soyer, Débora V.C. Mendonça, Grasiele S.V. Tavares, Daniela P. Lage, Daniel S. Dias, Patrícia A.F. Ribeiro, Luisa Perin, Fernanda Ludolf, Vinicio T.S. Coelho, Andreza C.G. Ferreira, Pedro H.A.S. Neves, Guilherme F. Matos, Miguel A. Chávez-Fumagalli, Elaine S. Coimbra, Guilherme R. Pereira, Eduardo A.F. Coelho, Luciana M.R. AntinarelliThe treatment against leishmaniasis presents problems, since the currently used drugs are toxic and/or have high costs. In addition, parasite resistance has increased. As a consequence, in this study, a chloroquinolin derivative, namely 2-(7-chloroquinolin-4- yl)oxy)-3-(3-methylbut-2- en- 1-yl)naphthalene-1,4- diona or GF1059, was in vitro and in vivo tested against Leishmania parasites. Experiments were performed to evaluate in vitro antileishmanial activity and cytotoxicity, as well as the treatment of infected macrophages and the inhibition of infection using pre-treated parasites. This study also investigated the GF1059 mechanism of action in L. amazonensis. Results showed that the compound was highly effective against L. infantum and L. amazonensis, presenting a selectivity index of 154.6 and 86.4, respectively, against promastigotes and of 137.6 and 74.3, respectively, against amastigotes. GF1059 was also effective in the treatment of infected macrophages and inhibited the infection of these cells when parasites were pre-incubated with it. The molecule also induced changes in the parasites’ mitochondrial membrane potential and cell integrity, and caused an increase in the reactive oxygen species production in L. amazonensis. Experiments performed in BALB/c mice, which had been previously infected with L. amazonensis promastigotes, and thus treated with GF1059, showed that these animals presented significant reductions in the parasite load when the infected tissue, spleen, liver, and draining lymph node were evaluated. GF1059-treated mice presented both lower parasitism and low levels of enzymatic markers, as compared to those receiving amphotericin B, which was used as control. In conclusion, data suggested that GF1059 can be considered a possible therapeutic target to be tested against leishmaniasis.Graphical abstractImage 1021
       
  • The modulatory effect of Artemisia annua L. on toll-like receptor
           expression in Acanthamoeba infected mouse lungs
    • Abstract: Publication date: April 2019Source: Experimental Parasitology, Volume 199Author(s): Agnieszka Wojtkowiak-Giera, Monika Derda, Danuta Kosik-Bogacka, Agnieszka Kolasa-Wołosiuk, Elżbieta Wandurska-Nowak, Paweł P. Jagodziński, Edward HadaśThe genus Acanthamoeba, which may cause different infections in humans, occurs widely in the environment. Lung inflammation caused by these parasites induces pulmonary pathological changes such as pulmonary necrosis, peribronchial plasma cell infiltration, moderate desquamation of alveolar cells and partial destruction of bronchial epithelial cells, and presence of numerous trophozoites and cysts among inflammatory cells.The aim of this study was to assess the influence of plant extracts from Artemisia annua L. on expression of the toll-like receptors TLR2 and TLR4 in lungs of mice with acanthamoebiasis. A. annua, which belongs to the family Asteraceae, is an annual plant that grows wild in Asia. In this study, statistically significant changes of expression of TLR2 and TLR4 were demonstrated. In the lungs of infected mice after application of extract from A. annua the expression of TLRs was observed mainly in bronchial epithelial cells, pneumocytes (to a lesser extent during the outbreak of infection), and in the course of high general TLR expression. TLR4 in particular was also visible in stromal cells of lung parenchyma.In conclusion, we confirmed that a plant extract of A. annua has a modulatory effect on components of the immune system such as TLR2 and TLR4.Graphical abstractImage 102108
       
  • Impact of phenolic compounds on Meloidogyne incognita in vitro
           and in tomato plants
    • Abstract: Publication date: April 2019Source: Experimental Parasitology, Volume 199Author(s): Denilson F. Oliveira, Viviane A. Costa, Willian C. Terra, Vicente P. Campos, Pacelli M. Paula, Samuel J. MartinsExposing second-stage juveniles (J2) of Meloidogyne incognita in vitro to a phenolic compound sometimes fails to cause J2 mortality, but in tests in vivo the same compound may reduce the infectivity and population of the nematode. This work aimed to study the effect of phenolic compounds on M. incognita through in vitro and in vivo assays. In the in vitro assay 49 phenolic compounds were screened for their toxicity to M. incognita J2. As a result, D-(−)-4-hydroxyphenylglycine, t-butylhydroquinone, L-3-(3,4-dihydroxyphenyl)alanine, sesamol, 2,4-dihydroxyacetophenone, and p-anisaldehyde increased the J2 mortality. These compounds presented, respectively, the following lethal concentrations to 50% of J2 (LC50): 365, 352, 251, 218, 210, and 85 μg/mL, while Carbofuran (positive control) had 150 μg/mL. However, none of these compounds were efficient in controlling the nematode in inoculated tomato plants, even when 2.77-fold of their LC50 were used. Although inactive in the in vitro test at 500 μg/mL, hydroquinone (3.5 mg per plant) reduced M. incognita population and galls by up to 99% to levels similar to the nematicide Carbofuran (1.2 mg per plant). Additionally, hydroquinone increased the root weight when compared to the negative and positive controls, water/NaOH and Carbofuran, respectively. In this study, we showed that some phenolic compounds, hydroquinone in particular, revealed a potential new option for the control of M. incognita.Graphical abstractImage 105125
       
  • The diagnosis of canine visceral leishmaniasis in Brazil: Confronting old
           problems
    • Abstract: Publication date: April 2019Source: Experimental Parasitology, Volume 199Author(s): Rômulo Pessoa-e-Silva, Victor Vaitkevicius-Antão, Thiago André Santos de Andrade, Anny Caroliny de Oliveira Silva, Gilsan Aparecida de Oliveira, Lays Adrianne Mendonça Trajano-Silva, Eiji Kevin Nakasone Nakasone, Milena de Paiva-CavalcantiIn Brazil, the main strategy adopted to contain Visceral Leishmaniasis (VL) is the controversial culling of dogs with reagent serology for Canine VL (CVL). Despite there are studies showing that significant reduction of human cases has not been observed, as well as there are works demonstrating the occurrence of false-positive results in the confirmatory test, the protocol has been maintained. Researches that can reinforce the existence and persistence of this problem, as well as bring concrete alternatives are pivotal. In this context, the aim of this work was to evaluate and compare the serological, molecular and parasitological methods employed for CVL detection in Brazil, in dogs with diverse clinical profiles, from two endemic areas of Pernambuco state. Comparisons among TR-DPP®, EIE-LVC and qPCR (animals from Goiana-PE: 91) demonstrated that agreements varied from ‘poor’ to ‘moderate’ (kappa = 0.162–0.442), and a triple agreement occurred in 61.36% (54/88) of the samples. The highest percentage of agreement was obtained between TR-DPP® and EIE-LVC within the polysymptomatic group (93.33%; 14/15). Of the 34 dogs with reagent serology from Caruaru-PE, 17 (50%) and 29 dogs (85.29%) were positive for qPCR and parasitological exam, respectively. By comparing serology, qPCR and parasitological exam, the lowest percentage of agreements were obtained within the asymptomatic group (40%–72.72%). It was possible to observe that the percentage of agreement tended to decrease according to the absence of clinical manifestations in the dogs. Thus, from the fact that all diagnostic tools evaluated have their limitations, it is very important to be careful before to propose an alternative set of diagnostic criteria. Besides, the answer for better results in the control of CVL may not be in the choose of the best set of diagnostic tools, but it may be in the strategy of culling itself. In this context, it is very important to invest in alternative control measures, such as mass vaccination and treatment of dogs, thus reducing the transmission to the vector and helping to avoid new canine and human cases.Graphical abstractImage 1025407
       
  • Resistance and tolerance: A hierarchical framework to compare individual
           versus family-level host contributions in an experimental
           amphibian-trematode system
    • Abstract: Publication date: April 2019Source: Experimental Parasitology, Volume 199Author(s): William E. Stutz, Dana M. Calhoun, Pieter T.J. JohnsonHosts have two general strategies for mitigating the fitness costs of parasite exposure and infection: resistance and tolerance. The resistance-tolerance framework has been well developed in plant systems, but only recently has it been applied to animal-parasite interactions. However, difficulties associated with estimating fitness, controlling parasite exposure, and quantifying parasite burden have limited application of this framework to animal systems. Here, we used an experimental approach to quantify the relative influence of variation among host individuals and genetic families in determining resistance and tolerance within an amphibian-trematode system. Importantly, we used multiple, alternative metrics to assess each strategy, and employed a Bayesian analytical framework to compare among responses while incorporating uncertainty. Relative to unexposed hosts, exposure to the pathogenic trematode (Ribeiroia ondatrae) reduced the survival and growth of California newts (Taricha torosa) (survival: 93% vs. 74%; growth: 0.29 vs. −0.5 vs mm day −1). Similarly, parasite infection success (the inverse of resistance) ranged from 8% to 100%. Yet despite this broad variation in host resistance and tolerance among individual newts, we found no evidence for transmissable, among-family variation in any of the resistance or tolerance metrics. This suggests that opportunities for evolution of these traits is limited, likely requiring significant increases in mutation, gene flow, or environmental heterogeneity. Our study provides a quantitative framework for evaluating the importance of alternative metrics of resistance and tolerance across multiple time points in the study of host-parasite interactions in animal systems.Graphical abstractImage 10100
       
  • Plant-based larvicidal agents: An overview from 2000 to 2018
    • Abstract: Publication date: April 2019Source: Experimental Parasitology, Volume 199Author(s): Mona Piplani, Deepak P. Bhagwat, Gautam Singhvi, Murugesan Sankaranarayanan, Rafael Balana-Fouce, Tarini Vats, Subhash ChanderCurrent review aims to systematically segregate, analyze and arrange the key findings of the scientific reports published on larvicidal plants including larvicidal formulations. The investigation was carried out by analyzing the published literature in various scientific databases, subsequently, the key findings of the selective scientific reports having larvicidal potency (LC50) of extract or isolated oil
       
  • Leishmania infantum amastigote nucleoside triphosphate diphosphohydrolase
           1 (NTPDase 1): Its inhibition as a new insight into mode of action of
           pentamidine
    • Abstract: Publication date: Available online 20 March 2019Source: Experimental ParasitologyAuthor(s): Ana Carolina Ribeiro Gomes Maia, Gabriane Nascimento Porcino, Michelle Lima Detoni, Leonardo Ramos Quellis, Nayara Braga Emídio, Danielle Gomes Marconato, Wagner Faria Messias, Laura Lavorato Soldati, Priscila Faria-Pinto, Priscila Vanessa da Silva Zabala Capriles, Elaine Soares Coimbra, Marcos José Marques, Eveline G. VasconcelosNucleoside triphosphate diphosphohydrolase (NTPDase) 1 from intracellular amastigotes of Leishmania infantum-infected macrophage was identified by immunocytochemistry and confocal laser scanning microscopy using antibodies that specifically recognize its B-domain. This enzyme was previously characterized in Leishmania promastigote form, and here it is shown to be susceptible to pentamidine isethionate (PEN). In initial assays, this antileishmanial compound (100 μM) reduced 60% phosphohydrolytic activity of promastigotes preparation. An active NTPDase 1 was then isolated by non-denaturing gel electrophoresis, and PEN (10 μM) inhibited 74% and 35% of the ATPase and ADPase activities, respectively, of this pure protein. In addition, PEN 0.1–1 μM inhibited 56% potato apyrase activity, a plant protein that shares high identity with Leishmania NTPDase 1. In contrast, amphotericin B, fluconazole, ketoconazole or allopurinol did not significantly affect phosphohydrolytic activity of either promastigotes preparation or potato apyrase. This work suggests amastigote NTPDase 1 as a new molecular target, and inhibition of its catalytic activity by pentamidine can be part of the mode of action of this drug contributing with the knowledge of its antileishmanial effect.Graphical abstractImage 1
       
  • Establishing an RNA extraction method from a small number of Demodex mites
           for transcriptome sequencing
    • Abstract: Publication date: Available online 20 March 2019Source: Experimental ParasitologyAuthor(s): Li Hu, YaE. Zhao, DongLing Niu, Rui YangDemodex is a type of parasitic mite which could cause serious dermatoses in 11 orders of mammals. However, due to the tiny body with thick chitin hard to be ruptured as well as the difficulty in obtaining a large number of mites, the quantity and quality of extracted RNA could hardly satisfied for transcriptome sequencing. This has hampered the research on functional genes and molecular pathogenesis of Demodex for a long time. To solve the problems above, the present study established a new RNA extraction method in combination Azanno method with liquid nitrogen grinding using 16 human and Canine Demodex mite samples. The RNA quality detection results of Agilent 2100 Bioanalyzer showed that 8 of 16 RNA samples met the requirements for trace RNA-Seq, with RIN of 5.0–6.5 and RNA quantity of 1.1–16.0 ng. RNA quality was affected by grinding process and parasitic position of Demodex. Enough grinding number (≥2000) in moderate time (≤20 min) was significant for mites' complete rupture and RNA degradation prevention. D. brevis (100%, 3/3) parasitizing in human sebaceous glands had significantly higher RNA qualification rate than D. folliculorum (57.14%, 4/7) parasitizing in human hair follicles. Yet D. canis parasitizing in dog had lower RNA qualification rate (16.67%, 1/6) as mites were embedded in skin tissues and blood clots. It should be pointed out that microplate reader had defects with a lower RNA qualification rate of 6.25% (1/16) unmatched with 2100 Bioanalyzer, reminding that it could be only used as reference in RNA quality evaluation.Graphical abstractImage 1
       
  • Mitochondrial and satellite real time-PCR for detecting T. cruzi DTU II
           strain in blood and organs of experimentally infected mice presenting
           different levels of parasite load
    • Abstract: Publication date: Available online 20 March 2019Source: Experimental ParasitologyAuthor(s): Júlio César Rente Ferreira Filho, Lucia Maria Almeida Braz, Marcos Luiz Alves Andrino, Lidia Yamamoto, Kelly Aparecida Kanunfre, Thelma Suely OkayAbstractThe choice of cost-effective molecular methods for diagnosing and monitoring of Chagas disease before and after treatment is crucial in endemic countries with high patients' demand and limited financial resources. To this end, a kDNA was compared to a satellite real-time quantitative PCR (sat-qPCR), both amplifications using Sybr Green instead of Taqman hydrolysis probes. Non-isogenic Swiss albino mice were infected with a small inoculum of the highly virulent and partially resistant to benznidazole Y strain, belonging to T. cruzi discrete typing unit II (DTU-II) that predominates in Atlantic and Central Brazil. DNA from EDTA-blood samples and 10 organs of mice containing high, moderate and low parasite load levels were extracted by a highly used commercial kit and tested in triplicate, showing no disagreements between the two qPCRs. The melting temperature of positive samples was 79.8 °C ± 1 °C for satellite-DNA and 78.1 °C ± 1 °C for kDNA. DNA from genetically-related parasites such as Leishmania sp. showed no cross-reactions, but the sympatric T. rangeli was detected by both qPCRs, more effectively by kDNA than the satellite system, which required the equivalent of 50 parasites to give a positive result. Samples from infected mice, regardless of the type of biological matrix (blood or organ samples) or the parasite load gave positive results by both qPCRs. The sensitivity of sat-qPCR was 2 × 10−3 parasite or 240 target copies, and for kDNA, 2 × 10−4 parasite or 24 target copies. Regarding repeatability and reproducibility, the coefficient of variation (CV) was always 
       
  • In vitro and in vivo evaluation of kojic acid against Toxoplasma gondii in
           experimental models of acute toxoplasmosis
    • Abstract: Publication date: Available online 20 March 2019Source: Experimental ParasitologyAuthor(s): Mahbobeh Montazeri, Saeed Emami, Hossein Asgarian-Omran, Soheil Azizi, Mehdi Sharif, Shahabeddin Sarvi, Fatemeh Rezaei, Mitra Sadeghi, Shaban Gohardehi, Ahmad DaryaniAs current toxoplasmosis chemotherapies have many side effects along with toxicity on patients, we examined the anti-Toxoplasma effect of a biologically important natural antibiotic, kojic acid, in vitro and in vivo. Vero cells were incubated with different concentrations of kojic acid or pyrimethamine (positive control), and the cellular viability was determined. Next, Vero cells were infected with T. gondii (RH strain) and treated with drugs. Then, we calculated the infection index, T. gondii intracellular proliferation and the number and measure of plaque. Moreover, the effect of kojic acid on survival times, serum levels of IFN-γ and TNF-α and histopathological changes in the liver and spleen of Balb/c mice infected with T. gondii were determined. Kojic acid reduced the infection index, intracellular proliferation, the number and measure of plaque in vitro when compared to untreated infected cells. Kojic acid (100 mg/kg/day) also showed a better survival rate than infected untreated control mice (P 
       
  • Antimalarial activity of vitamin D3 (VD3) does not result from VD3-induced
           antimicrobial agents including nitric oxide or cathelicidin
    • Abstract: Publication date: Available online 20 March 2019Source: Experimental ParasitologyAuthor(s): Kiichi Yamamoto, Kentaro Takahashi, Manabu Ato, Shiroh Iwanaga, Nobuo OhtaRecent evidence suggests that 1α,25-dihydroxyvitamin D3 (VD3), the active form of vitamin D, inhibits microbial proliferation. Previously, we used in vivo murine models to investigate the antimalarial activity of VD3 and confirmed potent antimalarial activity in the acute phase. This study aimed to clarify the mechanisms underlying the antimalarial activity of VD3 in vivo, particularly extensive inhibition of parasitemia in the acute phase, focusing on nitric oxide (NO), a potent antimalarial molecule. VD3 is a good NO inducer. When most Plasmodium chabaudi AS (PcAS)-infected mice treated with VD3 survived, NO was present in blood samples obtained from VD3-treated mice at a significantly higher rate at 2 and/or 3 days post-infection than that in vehicle-treated control mice. To verify the involvement of NO in the antimalarial activity of VD3, we used aminoguanidine (AG), an inducible NO synthase (iNOS) inhibitor, to abrogate the antimalarial activity of VD3. However, despite AG-induced reductions in NO levels, parasitemia remained inhibited during the acute phase, even in the presence of AG, and the antiplasmodial faculty of VD3 was not ablated. VD3-mediated antimalarial activity irrelevant of NO compelled us to consider another candidate. In a pilot experiment, we used cathelicidin (CAMP), an antimicrobial peptide, since it is known that VD3 induces CAMP synthesis. Serum CAMP levels increased on days 4 or 5 post-infection with or without VD3 administration, but experiments using exogenous CAMP did not display curative effects in PcAS-infected mice. The present study using VD3 to target the malarial parasite thus suggests a potential novel approach to treat malarial infections.Graphical abstractImage 1
       
  • Special issue on Free Living Amoebae (FLA): Recent Advances presented at
           the XVIIth International Meeting on the Biology and Pathogenicity of
           Free-Living Amoebae (FLAM 2017), Zarzis, Tunisia
    • Abstract: Publication date: Available online 19 March 2019Source: Experimental ParasitologyAuthor(s): Jacob Lorenzo-Morales, Ines Sifaoui, María Reyes-Batlle, Fernando Lares-Villa, Luis Fernando Lares-Jiménez, Maritza Omaña-Molina, Naveed A. Khan, Sutherland K. Maciver
       
  • Fate of internalized Campylobacter jejuni and Mycobacterium avium from
           encysted and excysted Acanthamoeba polyphaga
    • Abstract: Publication date: Available online 19 March 2019Source: Experimental ParasitologyAuthor(s): Rasha Maal-Bared, Brent Dixon, Diana Axelsson-OlssonAssociation of the water- and foodborne pathogen Campylobacter jejuni with free-living Acanthamoeba spp. trophozoites enhances C. jejuni survival and resistance to biocides and starvation. When facing less than optimal environmental conditions, however, the Acanthamoeba spp. host can temporarily transform from trophozoite to cyst and back to trophozoite, calling the survival of the internalized symbiont and resulting public health risk into question. Studies investigating internalized C. jejuni survival after A. castellanii trophozoite transformation have neither been able to detect its presence inside the Acanthamoeba cyst after encystation nor to confirm its presence upon excystation of trophozoites through culture-based techniques. The purpose of this study was to detect C. jejuni and Mycobacterium avium recovered from A. polyphaga trophozoites after co-culture and induction of trophozoite encystation using three different encystation methods (Neff’s medium, McMillen’s medium and refrigeration), as well as after cyst excystation. Internalized M. avium was used as a positive control, since studies have consistently detected the organism after co-culture and after host excystation. Concentrations of C. jejuni in A. polyphaga trophozoites were 4.5 x 105 CFU/ml, but it was not detected by PCR or culture post-encystation. This supports the hypothesis that C. jejuni may be digested during encystation of the amoebae. M. avium was recovered at a mean concentration of 1.9 x 104 from co-cultured trophozoites and 4.4 x 101 CFU/ml after excystation. The results also suggest that M. avium recovery post-excystation was statistically significantly different based on which encystation method was used, ranging from 1.3 x 101 for Neff’s medium to 5.4 x 101 CFU/ml for refrigeration. No M. avium was recovered from A. polyphaga cysts when trophozoites were encysted by McMillen’s medium. Since C. jejuni internalized in cysts would be more likely to survive harsh environmental conditions and disinfection, a better understanding of potential symbioses between free-living amoebae and campylobacters in drinking water distribution systems and food processing environments is needed to protect public health. Future co-culture experiments examining survival of internalized C. jejuni should carefully consider the encystation media used, and include molecular detection tools to falsify the hypothesis that C. jejuni may be present in a viable but not culturable state.Graphical abstractImage 1001454
       
  • Identification of sinensetin and nobiletin as major antitrypanosomal
           factors in a citrus cultivar
    • Abstract: Publication date: Available online 18 March 2019Source: Experimental ParasitologyAuthor(s): Masayuki Nakanishi, Mami Hino, Morio Yoshimura, Yoshiaki Amakura, Hiroshi NomotoCases of human African trypanosomiasis caused by infection with a protozoan parasite, Trypanosoma brucei, are decreasing due to enhanced surveillance and control. However, effective and safe treatments for this disease are still needed. In this study, we investigated the antitrypanosomal activity of citrus fruit peel. When 19 citrus cultivars were examined for activity against T. brucei in vitro, significant activities were observed in four closely related cultivars and a distantly related one. Among these five cultivars, “Setoka” was selected for identification of its active components due to exhibiting the highest activity. Solvent extraction and gel filtration followed by preparative thin-layer chromatography succeeded in isolating two compounds exhibiting IC50s of 4.8 and 2.4 µg/mL, respectively. The spectral data of these two compounds were well consistent with those of sinensetin and nobiletin belonging to the class of polymethoxyflavones. Authentic compounds also showed similar IC50s. These results indicate that the two polymethoxyflavones are the major active components involved in the inhibition of T. brucei proliferation and are abundant in Setoka cultivar peel compared with the levels in the other cultivars. Setoka peel and the naturally occurring polymethoxyflavones might serve as dietary components imparting resistance to T. brucei.Graphical abstractImage 1075991
       
  • The activity of encapsulated meglumine antimoniate in stearylamine-bearing
           liposomes against cutaneous leishmaniasis in BALB/c mice
    • Abstract: Publication date: Available online 18 March 2019Source: Experimental ParasitologyAuthor(s): Seyedeh Alia Moosavian, Maryam Fallah, Mahmoud Reza JaafariTopical treatment of cutaneous leishmaniasis has demonstrated appropriate alternative for reducing toxicity of conventional treatments, improving patients’ compliance and reducing treatment costs. Furthermore, outbreak of cutaneous leishmaniasis in war and conflict zones emerges finding an effective, economical and user-friendly treatment. In the context of liposomal topical drug delivery, we developed and characterized meglumine antimoniate (MA) loaded liposomes and investigated their effectiveness in topical treatment of cutaneous leishmaniasis. Previously, we showed the promising use of liposomal formulation of MA in treatment of cutaneous leishmaniasis in BALB/c mice. Here, we included Stearylamine (SA) in liposomes’ structure which has antileishmanial activity by itself. . Size and encapsulation efficiency of liposomes were measured and in vitro permeation was performed using mice model. In vitro toxicity of liposomes was measured against leishmania promastigotes and amastigotes. Liposomes were used topically twice a day for 4 weeks to treat leishmania lesions in BALB\c mice model. In vitro permeation study showed liposomal formulations improved the percent of MA permeation compared with MA-cream. Promastigotes and amastigotes assay results showed significant enhanced toxicity in Liposomal-MA containing SA compared to Lip-MA. In BALB\c mice model of cutaneous leishmaniasis, liposomal groups exhibited significantly smaller lesion size compared to control groups (p
       
  • In vitro evaluation on the scolicidal effect of Myrtus communis L. and
           Tripleurospermum disciforme L. methanolic extracts
    • Abstract: Publication date: Available online 9 March 2019Source: Experimental ParasitologyAuthor(s): Katayoon Amiri, Saeid Nasibi Davarani, Mitra Mehrabani, Mohammad Hadi Nematollahi, Majid Fasihi HarandiHydatid disease, a zoonotic disease, is still endemic in many developing countries that is caused by the metacestode of Echinococcus (E.) granulosus. Surgical management is one of the best choices for the treatment of the hydatidosis and using effective scolicidal agents during hydatid surgery is essential to prevent the secondary infection. The aim of the present in vitro study was to evaluate the scolicidal effect of the methanolic extract of Myrtus communis and Tripleurospermum disciforme against protoscoleces of hydatid cyst. Protoscoleces of E. granulosus were aspirated aseptically from infected livers. Various concentrations of M. communis and T. disciforme extracts at different exposure times were examined for their scolicidal activity. Normal saline and silver nitrate were used as negative and positive groups, correspondingly. The viability of protoscoleces was evaluated by 0.1% eosin. The result of the current study indicated that the highest scolicidal effect (100%) of M. communis was obtained at 100 and 50 mg/ml concentrations and LC50 in 10, 20 and 30 min were 11.64 mg/ml, 7.62 mg/ml, and 6.47 mg/ml respectively. The scolicidal activity of T. disciforme was negligible even at high concentration. The findings have shown that the scolicidal activity of M. communis against echinococcosis protoscoleces was strong, while the T. disciforme extract showed fewer effects. However, further studies are required for identification of the active ingredients in the extract and its safety on cells in effective concentrations.Graphical abstractImage 1
       
  • Anti-parasitic effect on Toxoplasma gondii induced by a spider
           peptide lycosin-I
    • Abstract: Publication date: March 2019Source: Experimental Parasitology, Volume 198Author(s): Yaqin Tang, Shengjie Hou, Xianyao Li, Mengqi Wu, Binbin Ma, Zheng Wang, Jinying Jiang, Meichun Deng, Zhigui Duan, Xing Tang, Yuan Liu, Wenhua Wang, Xiaoqing Han, Liping JiangToxoplasmosis is a widely distributed parasitic protozoan disease, caused by Toxoplasma gondii (T. gondii). High prevalence of toxoplasmosis and limitations of conventional treatments lead to a search for new therapeutic drugs. Lycosin-I is a linear peptide, derived from the venom of the spider Lycosa singoriensis. The aim of the present study was to determine the anti-parasitic effect of lycosin-Ι against T. gondii. In vitro, the anti-T. gondii activities of lycosin-Ι were evaluated by MTT assay, trypan blue exclusion assay, cell counting assay and plaque assay. Cytokines of IL-6 and IL-8 were measured by quantitative PCR. In addition, the structures of tachyzoites treated with lycosin-Ι were also observed by scanning and transmission electron microscopy. In vivo, mice were challenged with parasites treated by lycosin-I. The results revealed that lycosin-Ι had shown a significant ability to inhibit T. gondii invasion and proliferation. Cytokines of IL-6 and IL-8 were reduced by lycosin-Ι at transcription level in human foreskin fibroblast (HFF) cells infected with T. gondii tachyzoites, but they were increased compared to non-infected cells. For tachyzoites, lycosin-Ι induced their cell membrane alterations with formation of invaginations, some of them appeared to be vacuolated in their cytoplasm. Moreover, lycosin-Ι had prolonged the survival time of mice by controlling T. gondii proliferation. In conclusion, our present study provides the first evidence for anti-T. gondii by using the spider peptide lycosin-Ι. These findings suggest that lycosin-Ι is a potential alternative agent for the treatment of toxoplasmosis.Graphical abstractImage 105265
       
  • Proteomic analysis of Plasmodium falciparum histone deacetylase 1
           complex proteins
    • Abstract: Publication date: March 2019Source: Experimental Parasitology, Volume 198Author(s): Jessica A. Engel, Emma L. Norris, Paul Gilson, Jude Przyborski, Addmore Shonhai, Gregory L. Blatch, Tina S. Skinner-Adams, Jeffrey Gorman, Madeleine Headlam, Katherine T. AndrewsPlasmodium falciparum histone deacetylases (PfHDACs) are an important class of epigenetic regulators that alter protein lysine acetylation, contributing to regulation of gene expression and normal parasite growth and development. PfHDACs are therefore under investigation as drug targets for malaria. Despite this, our understanding of the biological roles of these enzymes is only just beginning to emerge. In higher eukaryotes, HDACs function as part of multi-protein complexes and act on both histone and non-histone substrates. Here, we present a proteomics analysis of PfHDAC1 immunoprecipitates, identifying 26 putative P. falciparum complex proteins in trophozoite-stage asexual intraerythrocytic parasites. The co-migration of two of these (P. falciparum heat shock proteins 70-1 and 90) with PfHDAC1 was validated using Blue Native PAGE combined with Western blot. These data provide a snapshot of possible PfHDAC1 interactions and a starting point for future studies focused on elucidating the broader function of PfHDACs in Plasmodium parasites.Graphical abstractImage 1
       
  • Progesterone in vitro increases growth, motility and progesterone receptor
           expression in third stage larvae of Toxocara canis
    • Abstract: Publication date: March 2019Source: Experimental Parasitology, Volume 198Author(s): L.E. Chávez-Güitrón, J. Morales-Montor, K.E. Nava-Castro, H. Ramírez-Álvarez, N.A. Moreno-Mendoza, M.G. Prado-Ochoa, M.A. Muñoz-Guzmán, F. Alba-HurtadoThe in vitro effect of progesterone in T. canis larvae on their enlargement and motility were evaluated, together to the possible presence of progesterone receptors (PRs). T. canis larvae were cultured in RPMI-1640 with different concentrations of progesterone (0, 20, 40, 80, 400 and 800 ng/mL). Enlargement and increases in motility were dependent on the concentration only from 0 to 80 ng/mL (p 
       
  • Establishing a protocol for water sample processing for the detection of
           Blastocystis sp.
    • Abstract: Publication date: March 2019Source: Experimental Parasitology, Volume 198Author(s): Ii Li Lee, Tian Chye Tan, Suresh Kumar GovindAbstractThis study was aimed at establishing a protocol for water sample processing for the detection of Blastocystis sp. using distilled water spiked with Blastocystis sp. cysts.The study established a protocol involving eight technical aspects, namely, storage temperature, storage duration, minimum water sample volume, optimum relative centrifugal force, centrifugation duration, minimum number of cyst for inoculation in Jones' medium and turn-around-time for the detection of vacuolar forms of Blastocystis sp. Results showed a minimum of 1.0 L water sample should be collected and processed on the same day. Otherwise, it should be stored at 4 °C and processed within 3 days. Water sample should be centrifuged at 1400×g for 10 min. For the isolation of Blastocystis sp. cysts, parasite pellet could be layered on top of Ficoll-Paque™ PLUS, centrifuged at 1400×g for 20 min and washed twice using 0.9% saline with centrifugation at 1400×g for 10 min. A minimum of 1 × 105 cysts could then be inoculated in Jones’ medium supplement with 10% horse serum, incubated at 37 °C and examined for any presence of vacuolar forms of Blastocystis sp. after 3 days of inoculation. A protocol for water sample processing for the detection of Blastocystis sp. has successfully been established. The protocol was validated using 106 various water samples. This protocol will be very useful in determining the extent of Blastocystis sp. contamination in water sources in order to identify the seriousness of contamination.
       
  • In vitro anthelmintic effect of biologically synthesized silver
           nanoparticles on liver amphistome, Gigantocotyle explanatum
    • Abstract: Publication date: March 2019Source: Experimental Parasitology, Volume 198Author(s): Abdur Rehman, Rizwan Ullah, Imran Uddin, Iram Zia, Lubna Rehman, S.M.A. AbidiIn order to ensure global food security a rationale approach is required to control all those factors which directly or indirectly affect the food productivity. The neglected helminthic diseases alone are responsible for huge economic losses to the agrarian stakeholders. The problem is further compounded by the emerging drug resistance in flukes against the commonly used anthelmintics like triclabendazole. Therefore, the search for alternatives including the nano-based approaches has become a necessity to develop future control strategies. In the present study the effect of biologically synthesized silver nanoparticles (AgNPs) was investigated on an economically important amphistome parasite, Gigantocotyle explanatum, obtained from the infected liver of the Indian water buffaloes, Bubalus bubalis. In vitro treatment of the adult worms with different doses of AgNPs severely affected the worm motility and caused ROS mediated damages in the treated flukes. The antioxidant system and the detoxification ability of the worms appeared to be disrupted along with pronounced DNA damage in the treated worms as compared to the controls. Following the treatment of worms with different concentrations of AgNPs there was a significant (p 
       
  • Construction of a novel phage display antibody library against Fasciola
           hepatica, and generation of a single-chain variable fragment specific for
           F. hepatica cathepsin L1
    • Abstract: Publication date: March 2019Source: Experimental Parasitology, Volume 198Author(s): Luke J. Norbury, Katarzyna Basałaj, Piotr Bąska, Alicja Kalinowska, Anna Zawistowska-Deniziak, Huan Yong Yap, Przemysław Wilkowski, Agnieszka Wesołowska, Halina WędrychowiczPhage display technology to produce recombinant monoclonal antibodies or antibody fragments permits the identification of sought after antibodies in short time frames at low cost along with direct and rapid selection for antibody characteristics. Monoclonal antibodies can facilitate the identification and characterisation of parasite molecules that function at the host-parasite interface to help understand at the molecular level the biology of the parasite and disease progression, which often leads to new drug targets, diagnostic antigens or vaccine candidates.The trematode Fasciola hepatica is an important veterinary and human parasite. In this work, we infected rats with F. hepatica and amplified the generated antibody repertoire to produce a single-chain variable fragment (scFv) phage display library. The library was used to identify a scFv that recognises cathepsin L1, a major component of the adult parasites excretory/secretory material and an important vaccine candidate.This is the first report of the construction of a phage display antibody library from a F. hepatica infected host, and also the first instance such a library has been used to identify an affinity-matured monoclonal antibody fragment that binds to a F. hepatica antigen. The scFv library and methods detailed should facilitate future research characterising F. hepatica antigens.Graphical abstractImage 1072
       
  • Albendazole-lipid nanocapsules: Optimization, characterization and
           chemoprophylactic efficacy in mice infected with Echinococcus granulosus
    • Abstract: Publication date: March 2019Source: Experimental Parasitology, Volume 198Author(s): Gabriela V. Ullio Gamboa, Patricia E. Pensel, María C. Elissondo, Sergio F. Sanchez Bruni, Jean-Pierre Benoit, Santiago D. Palma, Daniel A. AllemandiCystic echinococcosis (CE), which is caused during the metacestode larval stage of Echinococcus granulosus, is a life-threatening disease and is very difficult to treat. At present, the FDA-approved antihelmintic drugs are mebendazole (MBZ), albendazole (ABZ) and its principal metabolite ABZ sulfoxide (ABZSO), but as these have a therapeutic efficacy over 50%, underlining the need for new drug delivery systems. The aim of this work was the optimization and characterization of previously developed ABZ lipid nanocapsules (ABZ-LNCs) and evaluate their efficacy in mice infected with E. granulosus. LNCs were prepared by the phase inversion technique and characterized in terms of size, surface charge, drug loading, and in vitro stability followed by an in vivo proof-of-concept using a murine model infected with E. granulosus. Stable particle dispersions with a narrow size distribution and high efficiency of encapsulation (≥90%) were obtained. ABZ-LNCs showed a greater chemoprophylactic efficacy than ABZ suspension administered by the oral route as 4 out of the 10 ABZ-LNCs treated mice did not develop any cysts, whereas the infection progressed in all mice from the ABZ suspension group. Regarding the ultrastructural studies of cysts, mice treated with ABZ-LNCs or ABZ suspension revealed changes in the germinal layer. However, the extent of the damage appeared to be greater after ABZ-LNC administration compared to the suspension treatment. These results suggest that ABZ-LNCs could be a promising novel candidate for ABZ delivery to treat CE.Graphical abstractImage 1
       
  • Macro and microfilaricidal activities of extracts of Annona senegalensis
           and Milletia comosa against Onchocerca ochengi and Loa loa
    • Abstract: Publication date: March 2019Source: Experimental Parasitology, Volume 198Author(s): Adela Ngwewondo, Faustin Pascal Tsague Manfo, Moses Samje, Elvis Monya, Fidelis Cho-NgwaDespite the efforts employed for the control of onchocerciasis, the latter has remained a significant public health problem, due mainly to the lack of safe and effective adult worm drugs and/or microfilaricides that do not kill Loa loa microfilariae (mf). Serious adverse events have been encountered after administering ivermectin to some onchocerciasis patients coinfected with Loa loa. There is therefore, an urgent need for a macro and/or microfilaricidal drug which kills Onchocerca but not L. loa microfilariae. A total of 12 crude extracts from Milletia comosa and Annona senegalensis were prepared and screened in vitro against the bovine species of Onchocerca, O. ochengi, and L. loa mf from humans. Mf and male worm viabilities were determined by motility scoring using microscopy at 120 h of incubation with drug, while adult female worm viability and cytotoxicity were determined biochemically by MTT/formazan colorimetry after 120 h of incubation with drug. Out of the 12 extracts, all 6 from M. comosa and 4 from A. senegalensis were active against male, female and mf of O. ochengi. The hexane extract from M. comosa leaves (MCL hex) was the most active with IC50 values of 1.38, 0.86 and 17.74 μg/mL for O. ochengi adult males, adult female and the mf, respectively. About 58% of the extracts were more active against O. ochengi than L. loa mf. These results demonstrate that these extracts contain active principles that kill Onchocerca parasite and to a lesser extent L. loa, and suggest that they can be fractionated for isolation of lead molecules for the safe treatment of onchocerciasis.Graphical abstractImage 1
       
  • Therapeutic effects of Echinococcus granulosus cystic fluid on
           allergic airway inflammation
    • Abstract: Publication date: March 2019Source: Experimental Parasitology, Volume 198Author(s): Hye-Jin Kim, Shin-Ae Kang, Tai-Soon Yong, Myeong-Heon Shin, Kyu-Jae Lee, Gab-Man Park, Uktamjon Suvonkulov, Hak Sun YuPrevious studies showed that Echinococcus granulosus infection reduces allergic airway inflammation in experimentally infected hosts and the cystic fluid of E. granulosus is known to activate regulatory T (CD4+CD25+Foxp3+T, Treg) cells. To evaluate the effects of cystic fluid of E. granulosus on allergic airway inflammation, we investigated the regulation of the inflammatory reaction by cystic fluid using an allergic airway inflammation animal model. Cystic fluid was administered to C57BL/6 mice seven times every other day, after which allergic airway inflammation was induced using ovalbumin and aluminum. The airway resistance, number of eosinophils and other immune cells in the bronchoalveolar lavage fluid, and levels of Th2 and Th17-related cytokines were significantly reduced by cystic fluid pre-treatment in allergic airway inflammation-induced mice. The number IL-4+CD4+ T cells decreased, the number of Treg cells increased in the lung-draining lymph nodes and spleen of cystic fluid pre-treated mice. In conclusion, E. granulosus-derived cystic fluid may alleviate the Th2 allergic airway inflammatory response via Treg cells. Further studies of the immune regulation of cystic fluid may lead to the development of therapeutic agents for immune disorders.Graphical abstractImage 1
       
  • Functional analysis of iron-sulfur cluster biogenesis (SUF pathway) from
           Plasmodium vivax clinical isolates
    • Abstract: Publication date: March 2019Source: Experimental Parasitology, Volume 198Author(s): Zarna Rajeshkumar Pala, Vishal Saxena, Gagandeep Singh Saggu, Satish Kailasam Mani, Rajendra Prasad Pareek, Sanjay Kumar Kochar, Dhanpat Kumar Kochar, Shilpi GargIron-sulfur (Fe-S) clusters are critical metallo-cofactors required for cell function. Assembly of these cofactors is a carefully controlled process in cells to avoid toxicity from free iron and sulfide. In Plasmodium, two pathways for these Fe-S cluster biogenesis have been reported; ISC pathway in the mitochondria and SUF pathway functional in the apicoplast. Amongst these, SUF pathway is reported essential for the apicoplast maintenance and parasite survival. Many of its components have been studied from P. falciparum and P. berghei in recent years, still few queries remain to be addressed; one of them being the assembly and transfer of Fe-S clusters. In this study, using P. vivax clinical isolates, we have shown the in vitro interaction of SUF pathway proteins SufS and SufE responsible for sulfur mobilization in the apicoplast. The sulfur mobilized by the SufSE complex assembles on the scaffold protein PvSufA along with iron provided by the external source. Here, we demonstrate in vitro transfer of these labile Fe-S clusters from the scaffold protein on to an apo-protein, PvIspG (a protein involved in penultimate step of Isoprenoids biosynthesis pathway) in order to provide an insight into the interaction of different components for the biosynthesis and transfer of Fe-S clusters. Our analysis indicate that inspite of the presence of variations in pathway proteins, the overall pathway remains well conserved in the clinical isolates when compared to that reported in lab strains.Graphical abstractImage 1
       
  • Tissue damage and cytotoxic effects of Tagetes minuta essential oil
           against Lucilia cuprina
    • Abstract: Publication date: March 2019Source: Experimental Parasitology, Volume 198Author(s): Amanda Chaaban, Vera Maria Carvalho Silva Santos, Carlos Eduardo Nogueira Martins, Juliana Sperotto Brum, Fabiano Cleber Bertoldi, Marcelo Beltrão MolentoThe blowfly Lucilia cuprina has great medico-sanitary and veterinary importance due to the ability of its larval form to develop in decaying organic matter, parasitizing vertebrates. Fly eradication is challenging and the essential oil (EO) of Tagetes minuta (TMEO) have been reported to have therapeutic properties. This study aimed to determine the activity of EO from the aerial parts of T. minuta against third instar larvae (L3) of L. cuprina. Groups of 20 L3 were placed on filter paper, which were impregnated with varying concentrations (0.19; 0.39; 0.79; 1.59; 2.38; 3.18; 4.77; and 6.36 μL/cm2) of TMEO solubilized in acetone, ethanol or Tween 20. Histological tissue damage of TMEO was measured in L3 after 24, 48 and 96 h of exposure. Dihydrotagetone (67.64%), trans-ocimene (16.23%), trans-tagetone (10.14%) and verbenone (2.98%) were obtained as major compounds of TMEO. Lethal concentrations of 50%, 24 and 48 h after TMEO exposure were 1.02 and 0.73 μL/cm2 for acetone; 3.37 and 1.75 μL/cm2 for ethanol; and 7.46 and 6.11 μL/cm2 for Tween 20, respectively. TMEO had a significant L3 mortality of 96.6% in acetone, 48 h after contact. Cuticle abnormalities were observed, as well as the loss of digestive tract architecture and vacuolization in fat bodies. TMEO presented time and concentration-dependent effects against L. cuprina. As our study demonstrated a strong insecticide activity of TMEO, we consider that it could be developed into an ecofriendly product against L. cuprina.Graphical abstractImage 1
       
  • Exosome secretion by Leishmania infantum modulate the chemotactic behavior
           and cytokinic expression creating an environment permissive for early
           infection
    • Abstract: Publication date: March 2019Source: Experimental Parasitology, Volume 198Author(s): Germano Castelli, Federica Bruno, Laura Saieva, Riccardo Alessandro, Luca Galluzzi, Aurora Diotallevi, Fabrizio VitaleIn recent years, several studies demonstrated the role of exosomes in intercellular communications, several Leishmania species belonging to subgenera Leishmania and Viannia have been demonstrated to release exosomes, and their role in parasite-macrophage interactions and in leishmaniasis development has been investigated. However, the release of exosomes by Leishmania infantum has not been studied so far. The aim of this study was to isolate and characterize L. infantum exosomes, and to investigate the biological activity of these exosomes in macrophage cultures. To this end, exosomes were collected from both amastigote and promastigote L. infantum conditioned medium by ultracentrifugation. Exosomes were then characterized by monitoring the presence of HSP70, HSP83/90 and acetylcholinesterase activity. Moreover, extracellular vesicles-tracking analysis revealed that promastigote and amastigote exosomes had mean diameter of 122 ± 56 nm and 115 ± 65 nm, respectively. Human monocytic cell line U937-derived macrophages treated with promastigote and amastigote exosomes showed an increase in motility and an overproduction of interleukin IL-10 and IL-18 reduction, involved in immune response. Since L. infantum exosomes demonstrated the capacity to modulate the chemotactic behaviour of the cells studied and cytokines production, they could contribute in the disease establishment and may be considered an appropriate candidate for a vaccine therapy in prophylaxis and treatment.Graphical abstractImage 1
       
  • Anti-leishmanial effect of spiro dihydroquinoline-oxindoles on volume
           regulation decrease and sterol biosynthesis of Leishmania braziliensis
    • Abstract: Publication date: March 2019Source: Experimental Parasitology, Volume 198Author(s): Jacques Leañez, Jorge Nuñez, Yael García-Marchan, Felipe Sojo, Francisco Arvelo, Daniel Rodriguez, Ignacio Buscema, Alvaro Alvarez-Aular, Josué S. Bello Forero, Vladímir V. Kouznetsov, Xenón Serrano-MartínDiverse spiro dihydroquinoline-oxindoles (JS series) were prepared using the BF3•OEt2-catalyzed imino Diels-Alder reaction between ketimine-isatin derivatives and trans-isoeugenol. Ten spiro-oxiindole derivatives were selected and evaluated at different stages of the life cycle of Leishmania braziliensis parasites, responsible for cutaneous leishmaniasis in South America. Among them, the 8′-ethyl-4‘-(4-hydroxy-3-methoxyphenyl)-3′-methyl-3′,4′-dihydro-1′H-spiro[indoline-3,2′-quinolin]-2-one called JS87 was able to inhibit the growth of promastigotes without affecting the mammalian cells viability, and to decrease the number of intracellular amastigotes of L. braziliensis. This spiro compound was found to act through the alteration of parasite internal regulation by disrupting the regulatory volume decrease (RVD), and to affect the sterol biosynthetic pathway at level of squalene epoxidase (SE) enzyme. These results revealed that the spiro annulation between quinoline and oxindole scaffolds enhances the anti-leishmanial activity, and could assist in the development of potent quinoline-oxindole hybrids against Leishmania braziliensis, the main etiological agent of cutaneous leishmaniasis in South America.Graphical abstractImage 1094
       
  • Sodium arsenite augments sensitivity of Echinococcus granulosus
           protoscoleces to albendazole
    • Abstract: Publication date: Available online 19 February 2019Source: Experimental ParasitologyAuthor(s): Guoqiang Xing, Hui Zhang, Chunli Liu, Zhengyi Guo, Xiaoli Yang, Zhuo Wang, Bo Wang, Ying Lei, Rentan Yang, Yufeng Jiang, Hailong LvThis study aimed to observe the effects of sodium arsenite (NaAsO2) on apoptosis of Echinococcus granulosus protoscoleces induced by albendazole (ABZ), and to explore the potential mechanism of NaAsO2. According to the following final concentrations, the experimental groups were divided into 10 μM NaAsO2, 20 μM NaAsO2, 80 μM ABZ, 10 μM NaAsO2+80 μM ABZ, and 20 μM NaAsO2+80 μM ABZ. Viability was detected with 0.1% eosin staining. The ultrastructural alterations were visualized by scanning electron microscopy. Caspase-3 activity was assessed with colorimetric assay. Meanwhile, ELISA or WST were applied to detect the activities of antioxidases in NaAsO2 treatment groups. The maximum protoscolicidal effect was seen with the combination 20 μM NaAsO2+80 μM ABZ. The ultrastructural damage detected after NaAsO2+ABZ incubation were greater than those caused by ABZ alone and its primary damage site was the tegument of the parasite. The caspase-3 activity was clearly higher in protoscoleces treated with the combination of NaAsO2+ABZ than when drugs were used separately. The activities of NQO-1, HO-1, GST, and SOD were significantly lower in protoscoleces incubated with NaAsO2 than the untreated controls (P 
       
 
 
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