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Bernardo L, Ibarra-Meneses AV, Douanne N, Corbeil A, Solana JC, Beaudry F, Carrillo E, Moreno J, Fernandez-Prada C. Potential selection of antimony and methotrexate cross-resistance in Leishmania infantum circulating strains. PLoS Negl Trop Dis 2024; 18:e0012015. [PMID: 38422164 DOI: 10.1371/journal.pntd.0012015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 03/12/2024] [Accepted: 02/20/2024] [Indexed: 03/02/2024] Open
Abstract
BACKGROUND Visceral leishmaniasis (VL) resolution depends on a wide range of factors, including the instauration of an effective treatment coupled to a functional host immune system. Patients with a depressed immune system, like the ones receiving methotrexate (MTX), are at higher risk of developing VL and refusing antileishmanial drugs. Moreover, the alarmingly growing levels of antimicrobial resistance, especially in endemic areas, contribute to the increasing the burden of this complex zoonotic disease. PRINCIPAL FINDINGS To understand the potential links between immunosuppressants and antileishmanial drugs, we have studied the interaction of antimony (Sb) and MTX in a Leishmania infantum reference strain (LiWT) and in two L. infantum clinical strains (LiFS-A and LiFS-B) naturally circulating in non-treated VL dogs in Spain. The LiFS-A strain was isolated before Sb treatment in a case that responded positively to the treatment, while the LiFS-B strain was recovered from a dog before Sb treatment, with the dog later relapsing after the treatment. Our results show that, exposure to Sb or MTX leads to an increase in the production of reactive oxygen species (ROS) in LiWT which correlates with a sensitive phenotype against both drugs in promastigotes and intracellular amastigotes. LiFS-A was sensitive against Sb but resistant against MTX, displaying high levels of protection against ROS when exposed to MTX. LiFS-B was resistant to both drugs. Evaluation of the melting proteomes of the two LiFS, in the presence and absence of Sb and MTX, showed a differential enrichment of direct and indirect targets for both drugs, including common and unique pathways. CONCLUSION Our results show the potential selection of Sb-MTX cross-resistant parasites in the field, pointing to the possibility to undermine antileishmanial treatment of those patients being treated with immunosuppressant drugs in Leishmania endemic areas.
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Affiliation(s)
- Lorena Bernardo
- WHO Collaborating Centre for Leishmaniasis, Spanish National Center for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), ISCIII, Madrid, Spain
| | - Ana Victoria Ibarra-Meneses
- Département de Pathologie et Microbiologie, Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, Quebec, Canada
- The Research Group on Infectious Diseases in Production Animals (GREMIP), Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, Quebec, Canada
| | - Noelie Douanne
- Département de Pathologie et Microbiologie, Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, Quebec, Canada
- The Research Group on Infectious Diseases in Production Animals (GREMIP), Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, Quebec, Canada
| | - Audrey Corbeil
- Département de Pathologie et Microbiologie, Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, Quebec, Canada
- The Research Group on Infectious Diseases in Production Animals (GREMIP), Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, Quebec, Canada
| | - Jose Carlos Solana
- WHO Collaborating Centre for Leishmaniasis, Spanish National Center for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), ISCIII, Madrid, Spain
| | - Francis Beaudry
- Département de Biomédecine, Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, Quebec, Canada
- Centre de recherche sur le cerveau et l'apprentissage (CIRCA), Université de Montréal, Montréal, Quebec, Canada
| | - Eugenia Carrillo
- WHO Collaborating Centre for Leishmaniasis, Spanish National Center for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), ISCIII, Madrid, Spain
| | - Javier Moreno
- WHO Collaborating Centre for Leishmaniasis, Spanish National Center for Microbiology, Instituto de Salud Carlos III (ISCIII), Majadahonda, Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), ISCIII, Madrid, Spain
| | - Christopher Fernandez-Prada
- Département de Pathologie et Microbiologie, Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, Quebec, Canada
- The Research Group on Infectious Diseases in Production Animals (GREMIP), Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, Quebec, Canada
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Bernardo L, Solana JC, Romero-Kauss A, Sánchez C, Carrillo E, Moreno J. Effect of immunosuppressants on the parasite load developed in, and immune response to, visceral leishmaniasis: A comparative study in a mouse model. PLoS Negl Trop Dis 2021; 15:e0009126. [PMID: 33524030 PMCID: PMC7877784 DOI: 10.1371/journal.pntd.0009126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 02/11/2021] [Accepted: 01/12/2021] [Indexed: 11/29/2022] Open
Abstract
The increasing use of immunosuppressants in areas where visceral leishmaniasis (VL) is endemic has increased the number of people susceptible to developing more severe forms of the disease. Few studies have examined the quality of the immune response in immunosuppressed patients or experimental animals with VL. The present work characterises the parasite load developed in, and immune response to, Leishmania infantum-induced VL in C57BL/6 mice that, prior to and during infection, received immunosuppressant treatment with methylprednisolone (MPDN), anti-tumour necrosis factor (anti-TNF) antibodies, or methotrexate (MTX). The latter two treatments induced a significant reduction in the number of CD4+ T lymphocytes over the infection period. The anti-TNF treatment was also associated with a higher parasite load in the liver and a lower parasite load in the spleen. This, plus a possibly treatment-induced reduction in the number of cytokine-producing Th1 cells in the spleen, indicates the development of more severe VL. Interestingly, the MPDN and (especially) MTX treatments provoked a greater presence of soluble Leishmania antigen-specific multi-cytokine-producing T cells in the spleen and a lower liver parasite load than in control animals. These results highlight the need to better understand how immunosuppressant treatments might influence the severity of VL in human patients.
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Affiliation(s)
- Lorena Bernardo
- WHO Collaborating Centre for Leishmaniasis, National Center for Microbiology, Instituto de Salud Carlos III, Majadahonda (Madrid), Spain
| | - Jose Carlos Solana
- WHO Collaborating Centre for Leishmaniasis, National Center for Microbiology, Instituto de Salud Carlos III, Majadahonda (Madrid), Spain
| | - Alba Romero-Kauss
- WHO Collaborating Centre for Leishmaniasis, National Center for Microbiology, Instituto de Salud Carlos III, Majadahonda (Madrid), Spain
| | - Carmen Sánchez
- WHO Collaborating Centre for Leishmaniasis, National Center for Microbiology, Instituto de Salud Carlos III, Majadahonda (Madrid), Spain
| | - Eugenia Carrillo
- WHO Collaborating Centre for Leishmaniasis, National Center for Microbiology, Instituto de Salud Carlos III, Majadahonda (Madrid), Spain
| | - Javier Moreno
- WHO Collaborating Centre for Leishmaniasis, National Center for Microbiology, Instituto de Salud Carlos III, Majadahonda (Madrid), Spain
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Lu C, Liu Y, Li J, Liu L, Du G. Engineering of Biosynthesis Pathway and NADPH Supply for Improved L-5-Methyltetrahydrofolate Production by Lactococcus lactis. J Microbiol Biotechnol 2021; 31:154-162. [PMID: 31893598 PMCID: PMC9705839 DOI: 10.4014/jmb.1910.10069] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 12/17/2019] [Indexed: 12/15/2022]
Abstract
L-5-methyltetrahydrofolate (5-MTHF) is one of the biological active forms of folate, which is widely used as a nutraceutical. However, low yield and serious pollution associated with the chemical synthesis of 5-MTHF hampers its sustainable supply. In this study, 5-MTHF production was improved by engineering the 5-MTHF biosynthesis pathway and NADPH supply in Lactococcus lactis for developing a green and sustainable biosynthesis approach. Specifically, overexpressing the key rate-limiting enzyme methylenetetrahydrofolate reductase led to intracellular 5-MTHF accumulation, reaching 18 μg/l. Next, 5-MTHF synthesis was further enhanced by combinatorial overexpression of 5-MTHF synthesis pathway enzymes with methylenetetrahydrofolate reductase, resulting in 1.7-fold enhancement. The folate supply pathway was strengthened by expressing folE encoding GTP cyclohydrolase I, which increased 5-MTHF production 2.4-fold to 72 μg/l. Furthermore, glucose-6-phosphate dehydrogenase was overexpressed to improve the redox cofactor NADPH supply for 5-MTHF biosynthesis, which led to a 60% increase in intracellular NADPH and a 35% increase in 5-MTHF production (97 μg/l). To reduce formation of the by-product 5-formyltetrahydrofolate, overexpression of 5-formyltetrahydrofolate cyclo-ligase converted 5-formyltetrahydrofolate to 5,10-methyltetrahydrofolate, which enhanced the 5-MTHF titer to 132 μg/l. Finally, combinatorial addition of folate precursors to the fermentation medium boosted 5-MTHF production, reaching 300 μg/l. To the best of our knowledge, this titer is the highest achieved by L. lactis. This study lays the foundation for further engineering of L. lactis for efficient 5-MTHF biosynthesis.
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Affiliation(s)
- Chuanchuan Lu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 2422, P.R. China,Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 141, P.R. China
| | - Yanfeng Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 2422, P.R. China,Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 141, P.R. China,Corresponding authors Y.Liu Phone: +86-510-85197117 Fax: +86-510-85918309 E-mail:
| | - Jianghua Li
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 2422, P.R. China,Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 141, P.R. China
| | - Long Liu
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 2422, P.R. China,Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 141, P.R. China
| | - Guocheng Du
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi 2422, P.R. China,Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 141, P.R. China,G.Du Phone: +86-510-85918309 Fax: +86-510-85918309 E-mail:
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Naumovich V, Grishina M, Novak J, Pathak P, Potemkin V, Shahbaaz M, Abdellattif MH. Electronic properties investigation of human dihydrofolate reductase complexes with ligands. J Biomol Struct Dyn 2020; 40:4775-4790. [PMID: 33345753 DOI: 10.1080/07391102.2020.1861985] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Despite the fact that there are already drugs for cancer, they still show strong toxicity to the human organism. That is why it is necessary to establish the factors affecting activity in order to develop new, more effective drugs aimed at tumor cells, minimizing harm to healthy cells. The present research is based on electronic properties calculation of the complexes using AlteQ approach. In the focus of this study are complexes of human dihydrofolate reductase (hDHFR) with a series of known inhibitors bound in the active site. Further, a statistical analysis was performed to establish the relationships between a myriad electronic characteristics and IC50. The change in total volume and the change of own electrons number of hydrogen atoms in their atomic basins are identified as the descriptors correlating the most with the hDHFR inhibition potency. Additionally, two lipophilic parts of protein (Thr56, Ser59, Ile60 and Ile7, Val8, Ala9) were found, which act as a key factor in decreasing bioactivity. The depth analysis of intermolecular interactions showed that the interactions between water molecules and ligand play a crucial role in hDHFR inhibition. Furthermore, the molecular dynamics simulations were used for deeper understanding of the structural inhibition, each for 50 ns time scale in explicit water conditions. Thus, the AlteQ approach made it possible to determine the factors influencing the activity and evaluate them not only qualitatively, but also quantitatively.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Vladislav Naumovich
- Laboratory of Computational Modeling of Drugs, Higher Medical and Biological School, South Ural State University, Chelyabinsk, Russia
| | - Maria Grishina
- Laboratory of Computational Modeling of Drugs, Higher Medical and Biological School, South Ural State University, Chelyabinsk, Russia
| | - Jurica Novak
- Laboratory of Computational Modeling of Drugs, Higher Medical and Biological School, South Ural State University, Chelyabinsk, Russia
| | - Prateek Pathak
- Laboratory of Computational Modeling of Drugs, Higher Medical and Biological School, South Ural State University, Chelyabinsk, Russia
| | - Vladimir Potemkin
- Laboratory of Computational Modeling of Drugs, Higher Medical and Biological School, South Ural State University, Chelyabinsk, Russia
| | - Mohd Shahbaaz
- Laboratory of Computational Modeling of Drugs, Higher Medical and Biological School, South Ural State University, Chelyabinsk, Russia.,South African Medical Research Council Bioinformatics Unit, South African National Bioinformatics Institute, University of the Western Cape, Bellville, Cape Town, South Africa
| | - Magda H Abdellattif
- Department of Chemistry, College of Science, Deanship of Scientific Research, Taif University, Taif, Saudi Arabia
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MAHMOUDVAND H, KHEIRANDISH F, MIRBADIE SR, KAYEDI MH, REZAEI RIABI T, GHASEMI AA, BAMOROVAT M, SHARIFI I. The Potential Use of Methotrexate in the Treatment of Cutaneous Leishmaniasis: In Vitro Assays against Sensitive and Meglumine Antimoniate-resistant Strains of Leishmania tropica. IRANIAN JOURNAL OF PARASITOLOGY 2017; 12:339-347. [PMID: 28979343 PMCID: PMC5623913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 02/16/2017] [Indexed: 11/01/2022]
Abstract
BACKGROUND The present study aimed to evaluate the effect of methotrexate (MTX) alone and in combination with meglumine antimoniate (MA, Glucantime) against sensitive and MA-resistant Leishmania tropica stages in vitro. METHODS The present study was carried out in 2014 in Leishmaniasis Research Center at School of Medicine, Kerman University of Medical sciences, Kerman, Iran. The effects of MTX alone and along with MA on promastigote and amastigote stages of sensitive (SS) and MA-resistant (RS) L. tropica strains have been evaluated using a colorimetric MTT assay and in a macrophage model, respectively. In addition, the inhibitory effect of MTX on the Leishmania invasion of murine macrophages was assessed in promastigotes of both strains of L. tropica. Sensitive and MA resistant L. tropica are referred to those isolates that are responsive or non-responsive to one or two courses of treatment by MA systemically and/or intralesionally, respectively. RESULTS The findings of OD and IC50 showed that MTX plus MA (SS: 16.1 μg/ml, RS: 39.8 μg/ml) had a higher anti-leishmanial effect than MA (SS: 52.2 μg/ml, RS: 170 μg/ml) or MTX alone (SS: 22.2 μg/ml, RS: 51.4 μg/ml) on promastigotes of both strains of L. tropica. The MTX plus MA caused a significant decrease (P<0.05) in the mean infection rate (MIR) and the mean number of amastigotes in each macrophage compared with positive control. Infectivity of promastigotes is significantly (P<0.05) reduced when it was preincubated with MTX. CONCLUSION This study indicated high potency and a synergistic effect of MTX on MA in inhibiting the growth rateof promastigote and amastigote stages of sensitive and meglumine antimoniate-resistant L. tropica. Further works are needed to evaluate the anti-leishmanial effects of MTX on L. tropica using a clinical setting.
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Affiliation(s)
- Hossein MAHMOUDVAND
- Razi Herbal Medicines Research Center, Dept. of Medical Parasitology and Mycology, Lorestan University of Medical Sciences, Khorramabad, Iran
| | - Farnaz KHEIRANDISH
- Razi Herbal Medicines Research Center, Dept. of Medical Parasitology and Mycology, Lorestan University of Medical Sciences, Khorramabad, Iran
| | - Seyed Reza MIRBADIE
- Dept. of Medical Parasitology and Mycology, School of Medicine, Shahroud University of Medical Sciences, Shahroud, Iran
| | - Mohammad Hassan KAYEDI
- Razi Herbal Medicines Research Center, Dept. of Medical Parasitology and Mycology, Lorestan University of Medical Sciences, Khorramabad, Iran
| | - Tahereh REZAEI RIABI
- Leishmaniasis Research Center, Kerman University of Medical Sciences, Kerman, Iran
| | - Abbas Ali GHASEMI
- Leishmaniasis Research Center, Kerman University of Medical Sciences, Kerman, Iran
| | - Mehdi BAMOROVAT
- Leishmaniasis Research Center, Kerman University of Medical Sciences, Kerman, Iran
| | - Iraj SHARIFI
- Leishmaniasis Research Center, Kerman University of Medical Sciences, Kerman, Iran
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Verhoef H, Veenemans J, Mwangi MN, Prentice AM. Safety and benefits of interventions to increase folate status in malaria-endemic areas. Br J Haematol 2017; 177:905-918. [PMID: 28369746 PMCID: PMC5485039 DOI: 10.1111/bjh.14618] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
For decades, folic acid has routinely been given to prevent or treat anaemia in children, pregnant women and people with sickle cell disease. However, there is no conclusive evidence that folate deficiency anaemia constitutes a public health problem in any of these groups. Industrial flour fortification is recommended and implemented in many countries to combat neural tube defects. Dietary folates or folic acid can antagonise the action of antifolate drugs that play a critical role in the prevention and treatment of malaria. Randomised trials have shown that folic acid supplementation increases the rate of treatment failures with sulfadoxine-pyrimethamine. The efficacy of antifolate drugs against Plasmodium is maximized in the absence of exogenous folic acid, suggesting that there is no safe minimum dose of ingested folic acid. We here review the safety and benefits of interventions to increase folate status in malaria-endemic countries. We conclude that formal cost-benefit analyses are required.
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Affiliation(s)
- Hans Verhoef
- London School of Hygiene and Tropical Medicine, MRC International Nutrition Group, London, UK
- Nutrition Theme, MRC Unit The Gambia, Banjul, Gambia
- Cell Biology and Immunology Group, & Research, Wageningen, The Netherlands
- Division of Human Nutrition, Wageningen University and Research, Wageningen, The Netherlands
| | - Jacobien Veenemans
- Laboratory for Microbiology and Immunology, Admiral de Ruyter Hospital, Goes, The Netherlands
- Laboratory for Microbiology and Infection Control, Amphia Hospital, Breda, The Netherlands
| | - Martin N Mwangi
- Division of Human Nutrition, Wageningen University and Research, Wageningen, The Netherlands
| | - Andrew M Prentice
- London School of Hygiene and Tropical Medicine, MRC International Nutrition Group, London, UK
- Nutrition Theme, MRC Unit The Gambia, Banjul, Gambia
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Aderibigbe B, Ray SS. Preparation, characterization and in vitro release kinetics of polyaspartamide-based conjugates containing antimalarial and anticancer agents for combination therapy. J Drug Deliv Sci Technol 2016. [DOI: 10.1016/j.jddst.2016.09.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Abstract
Food fortified with folic acid has been available for consumption in North America for over a decade. This strategy has led to an increase in folate levels in the general population and, more importantly, a significant decrease in the incidence of neural tube defects. However, this increase in folate intake has been associated with a greater risk of cancer disease. Many African countries are now embracing this concept; however, because folate promotes malaria parasite division, as it does in cancer cells, there is a possibility of malaria exacerbation if folate intake is increased. A precedent for such a concern is the now compelling evidence showing that an increase in iron intake can lead to a higher malaria risk; as a result, mass administration of iron in malaria-endemic areas is not recommended. In this article, we review work on the effect of folate on malaria parasites. Although this topic has received little research attention, the available data suggest that the increase in folate concentration could be associated with an increase in malaria infection. Thus, the introduction of food fortification with folic acid in malaria-endemic areas should be attended by precautionary programs to monitor the risk of malaria.
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Affiliation(s)
- Alexis Nzila
- Department of Life Sciences, King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia
| | - John Okombo
- University of Cape Town, Cape Town, South Africa
| | - John Hyde
- Manchester Institute of Biotechnology (MIB), Manchester, United Kingdom
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Rijpma SR, van der Velden M, Bilos A, Jansen RS, Mahakena S, Russel FGM, Sauerwein RW, van de Wetering K, Koenderink JB. MRP1 mediates folate transport and antifolate sensitivity in Plasmodium falciparum. FEBS Lett 2016; 590:482-92. [PMID: 26900081 DOI: 10.1002/1873-3468.12079] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 01/12/2016] [Accepted: 01/18/2016] [Indexed: 11/05/2022]
Abstract
Multidrug resistance-associated proteins (MRP) of Plasmodium falciparum have been associated with altered drug sensitivity. Knowledge on MRP substrate specificity is indispensible for the characterization of resistance mechanisms and identifying its physiological roles. An untargeted metabolomics approach detected decreased folate concentrations in red blood cells infected with schizont stage parasites lacking expression of MRP1. Furthermore, a tenfold decrease in sensitivity toward the folate analog methotrexate was detected for parasites lacking MRP1. PfMRP1 is involved in the export of folate from parasites into red blood cells and is therefore a relevant factor for efficient malaria treatment through the folate pathway.
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Affiliation(s)
- Sanna R Rijpma
- Department of Pharmacology and Toxicology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Maarten van der Velden
- Department of Pharmacology and Toxicology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Albert Bilos
- Department of Pharmacology and Toxicology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Robert S Jansen
- Division of Molecular Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Sunny Mahakena
- Division of Molecular Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Frans G M Russel
- Department of Pharmacology and Toxicology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Robert W Sauerwein
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Koen van de Wetering
- Division of Molecular Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Jan B Koenderink
- Department of Pharmacology and Toxicology, Radboud University Medical Center, Nijmegen, The Netherlands
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De‐Regil LM, Peña‐Rosas JP, Fernández‐Gaxiola AC, Rayco‐Solon P. Effects and safety of periconceptional oral folate supplementation for preventing birth defects. Cochrane Database Syst Rev 2015; 2015:CD007950. [PMID: 26662928 PMCID: PMC8783750 DOI: 10.1002/14651858.cd007950.pub3] [Citation(s) in RCA: 178] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND It has been reported that neural tube defects (NTD) can be prevented with periconceptional folic acid supplementation. The effects of different doses, forms and schemes of folate supplementation for the prevention of other birth defects and maternal and infant outcomes are unclear. OBJECTIVES This review aims to examine whether periconceptional folate supplementation reduces the risk of neural tube and other congenital anomalies (including cleft palate) without causing adverse outcomes in mothers or babies. This is an update of a previously published Cochrane review on this topic. SEARCH METHODS We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 August 2015). Additionally, we searched the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (31 August 2015) and contacted relevant organisations to identify ongoing and unpublished studies. SELECTION CRITERIA We included all randomised or quasi-randomised trials evaluating the effect of periconceptional folate supplementation alone, or in combination with other vitamins and minerals, in women independent of age and parity. DATA COLLECTION AND ANALYSIS Two review authors independently assessed the eligibility of studies against the inclusion criteria, extracted data from included studies, checked data entry for accuracy and assessed the risk of bias of the included studies. We assessed the quality of the body of evidence using the GRADE approach. MAIN RESULTS Five trials involving 7391 women (2033 with a history of a pregnancy affected by a NTD and 5358 with no history of NTDs) were included. Four comparisons were made: 1) supplementation with any folate versus no intervention, placebo or other micronutrients without folate (five trials); 2) supplementation with folic acid alone versus no treatment or placebo (one trial); 3) supplementation with folate plus other micronutrients versus other micronutrients without folate (four trials); and 4) supplementation with folate plus other micronutrients versus the same other micronutrients without folate (two trials). The risk of bias of the trials was variable. Only one trial was considered to be at low risk of bias. The remaining studies lacked clarity regarding the randomisation method or whether the allocation to the intervention was concealed. All the participants were blinded to the intervention, though blinding was unclear for outcome assessors in the five trials.The results of the first comparison involving 6708 births with information on NTDs and other infant outcomes, show a protective effect of daily folic acid supplementation (alone or in combination with other vitamins and minerals) in preventing NTDs compared with no interventions/placebo or vitamins and minerals without folic acid (risk ratio (RR) 0.31, 95% confidence interval (CI) 0.17 to 0.58); five studies; 6708 births; high quality evidence). Only one study assessed the incidence of NTDs and showed no evidence of an effect (RR 0.07, 95% CI 0.00 to 1.32; 4862 births) although no events were found in the group that received folic acid. Folic acid had a significant protective effect for reoccurrence (RR 0.34, 95% CI 0.18 to 0.64); four studies; 1846 births). Subgroup analyses suggest that the positive effect of folic acid on NTD incidence and recurrence is not affected by the explored daily folic acid dosage (400 µg (0.4 mg) or higher) or whether folic acid is given alone or with other vitamins and minerals. These results are consistent across all four review comparisons.There is no evidence of any preventive or negative effects on cleft palate (RR 0.73, 95% CI 0.05 to 10.89; three studies; 5612 births; low quality evidence), cleft lip ((RR 0.79, 95% CI 0.14 to 4.36; three studies; 5612 births; low quality evidence), congenital cardiovascular defects (RR 0.57, 95% CI 0.24 to 1.33; three studies; 5612 births; low quality evidence), miscarriages (RR 1.10, 95% CI 0.94 to 1.28; five studies; 7391 pregnancies; moderate quality evidence) or any other birth defects (RR 0.94, 95% CI 0.53 to 1.66; three studies; 5612 births; low quality evidence). There were no included trials assessing the effects of this intervention on neonatal death, maternal blood folate or anaemia at term. AUTHORS' CONCLUSIONS Folic acid, alone or in combination with vitamins and minerals, prevents NTDs, but does not have a clear effect on other birth defects.
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Affiliation(s)
- Luz Maria De‐Regil
- Micronutrient InitiativeResearch and Evaluation180 Elgin Street, Suite 1000OttawaONCanadaK2P 2K3
| | - Juan Pablo Peña‐Rosas
- World Health OrganizationEvidence and Programme Guidance, Department of Nutrition for Health and Development20 Avenue AppiaGenevaSwitzerland1211
| | | | - Pura Rayco‐Solon
- World Health OrganizationEvidence and Programme Guidance, Department of Nutrition for Health and Development20 Avenue AppiaGenevaSwitzerland1211
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11
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Okombo J, Chibale K. Antiplasmodial drug targets: a patent review (2000 – 2013). Expert Opin Ther Pat 2015; 26:107-30. [DOI: 10.1517/13543776.2016.1113258] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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12
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Kundu CN, Das S, Nayak A, Satapathy SR, Das D, Siddharth S. Anti-malarials are anti-cancers and vice versa - one arrow two sparrows. Acta Trop 2015; 149:113-27. [PMID: 25963804 DOI: 10.1016/j.actatropica.2015.03.028] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 03/11/2015] [Accepted: 03/15/2015] [Indexed: 12/14/2022]
Abstract
Repurposing is the novel means of drug discovery in modern science due to its affordability, safety and availability. Here, we systematically discussed the efficacy and mode of action of multiple bioactive, synthetic compounds and their potential derivatives which are used to treat/prevent malaria and cancer. We have also discussed the detailed molecular pathway involved in anti-cancer potentiality of an anti-malarial drug and vice versa. Although the causative agents, pathophysiology and manifestation of both the diseases are different but special emphasis has been given on similar pathways governing disease manifestation and the drugs which act through deregulating those pathways. Finally, a future direction has been speculated to combat these two diseases by a single agent developed using nanotechnology. Extended combination and new formulation of existing drugs for one disease may lead to the discovery of drug for other diseases like an arrow for two sparrows.
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Affiliation(s)
- Chanakya Nath Kundu
- School of Biotechnology, Department of Cancer Biology, KIIT University, Campus-11, Patia, Bhubaneswar, Odisha 751024, India.
| | - Sarita Das
- School of Biotechnology, Department of Cancer Biology, KIIT University, Campus-11, Patia, Bhubaneswar, Odisha 751024, India
| | - Anmada Nayak
- School of Biotechnology, Department of Cancer Biology, KIIT University, Campus-11, Patia, Bhubaneswar, Odisha 751024, India
| | - Shakti Ranjan Satapathy
- School of Biotechnology, Department of Cancer Biology, KIIT University, Campus-11, Patia, Bhubaneswar, Odisha 751024, India
| | - Dipon Das
- School of Biotechnology, Department of Cancer Biology, KIIT University, Campus-11, Patia, Bhubaneswar, Odisha 751024, India
| | - Sumit Siddharth
- School of Biotechnology, Department of Cancer Biology, KIIT University, Campus-11, Patia, Bhubaneswar, Odisha 751024, India
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Heinberg A, Kirkman L. The molecular basis of antifolate resistance in Plasmodium falciparum: looking beyond point mutations. Ann N Y Acad Sci 2015; 1342:10-8. [PMID: 25694157 DOI: 10.1111/nyas.12662] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Drugs that target the folate-synthesis pathway have a long history of effectiveness against a variety of pathogens. As antimalarials, the antifolates were safe and well tolerated, but resistance emerged quickly and has persisted even with decreased drug pressure. The primary determinants of resistance in Plasmodium falciparum are well-described point mutations in the enzymes dihydropteroate synthase and dihydrofolate reductase targeted by the combination sulfadoxine-pyrimethamine. Recent work has highlighted the contributions of additional parasite adaptation to antifolate resistance. In fact, the evolution of antifolate-resistant parasites is multifaceted and complex. Gene amplification of the first enzyme in the parasite folate synthesis pathway, GTP-cyclohydrolase, is strongly associated with resistant parasites and potentially contributes to persistence of resistant parasites. Further understanding of how parasites adjust flux through the folate pathway is important to the further development of alternative agents targeting this crucial synthesis pathway.
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14
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Targeting the vitamin biosynthesis pathways for the treatment of malaria. Future Med Chem 2013; 5:769-79. [PMID: 23651091 DOI: 10.4155/fmc.13.43] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The most severe form of malaria is Malaria tropica, caused by Plasmodium falciparum. There are more than 1 billion people that are exposed to malaria parasites leading to more than 500,000 deaths annually. Vaccines are not available and the increasing drug resistance of the parasite prioritizes the need for novel drug targets and chemotherapeutics, which should be ideally designed to target selectively the parasite. In this sense, parasite-specific pathways, such as the vitamin biosyntheses, represent perfect drug-target characteristics because they are absent in humans. In the past, the vitamin B9 (folate) metabolism has been exploited by antifolates to treat infections caused by malaria parasites. Recently, two further vitamin biosynthesis pathways - for the vitamins B6 (pyridoxine) and B1 (thiamine) - have been identified in Plasmodium and analyzed for their suitability to discover new drugs. In this review, the current status of the druggability of plasmodial vitamin biosynthesis pathways is summarized.
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15
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Nzila A, Okombo J, Molloy AM. Impact of folate supplementation on the efficacy of sulfadoxine/pyrimethamine in preventing malaria in pregnancy: the potential of 5-methyl-tetrahydrofolate. J Antimicrob Chemother 2013; 69:323-30. [PMID: 24126794 DOI: 10.1093/jac/dkt394] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Malaria remains the leading cause of mortality and morbidity in children under the age of 5 years and pregnant women. To counterbalance the malaria burden in pregnancy, an intermittent preventive treatment strategy has been developed. This is based on the use of the antifolate sulfadoxine/pyrimethamine, taken at specified intervals during pregnancy, and reports show that this approach reduces the malaria burden in pregnancy. Pregnancy is also associated with the risk of neural tube defects (NTDs), especially in women with low folate status, and folic acid supplementation is recommended in pregnancy to lower the risk of NTDs. Thus, in malaria-endemic areas, pregnant women have to take both antifolate medication to prevent malaria and folic acid to lower the risk of NTDs. However, the concomitant use of folate and antifolate is associated with a decrease in antifolate efficacy, exposing pregnant women to malaria. Thus, there is genuine concern that this strategy may not be appropriate. We have reviewed work carried out on malaria folate metabolism and antifolate efficacy in the context of folate supplementation. This review shows that: (i) the folate supplementation effect on antifolate efficacy is dose-dependent, and folic acid doses required to protect pregnant women from NTDs will not decrease antifolate activity; and (ii) 5-methyl-tetrahydrofolate, the predominant form of folate in the blood circulation, could be administered (even at high dose) concomitantly with antifolate without affecting antifolate efficacy. Thus, strategies exist to protect pregnant women from malaria while maintaining adequate folate levels in the body to reduce the occurrence of NTDs.
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Affiliation(s)
- Alexis Nzila
- Department of Biology, King Fahd University of Petroleum and Minerals, PO Box 468, Dhahran, 31261, Saudi Arabia
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Salcedo-Sora JE, Ward SA. The folate metabolic network of Falciparum malaria. Mol Biochem Parasitol 2013; 188:51-62. [PMID: 23454873 DOI: 10.1016/j.molbiopara.2013.02.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Revised: 02/04/2013] [Accepted: 02/11/2013] [Indexed: 01/07/2023]
Abstract
The targeting of key enzymes in the folate pathway continues to be an effective chemotherapeutic approach that has earned antifolate drugs a valuable position in the medical pharmacopoeia. The successful therapeutic use of antifolates as antimalarials has been a catalyst for ongoing research into the biochemistry of folate and pterin biosynthesis in malaria parasites. However, our understanding of the parasites folate metabolism remains partial and patchy, especially in relation to the shikimate pathway, the folate cycle, and folate salvage. A sizeable number of potential folate targets remain to be characterised. Recent reports on the parasite specific transport of folate precursors that would normally be present in the human host awaken previous hypotheses on the salvage of folate precursors or by-products. As the parasite progresses through its life-cycle it encounters very contrasting host cell environments that present radically different metabolic milieus and biochemical challenges. It would seem probable that as the parasite encounters differing environments it would need to modify its biochemistry. This would be reflected in the folate homeostasis in Plasmodium. Recent drug screening efforts and insights into folate membrane transport substantiate the argument that folate metabolism may still offer unexplored opportunities for therapeutic attack.
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Affiliation(s)
- J Enrique Salcedo-Sora
- Department of Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK.
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Ichagichu M, Ngotho M, Karanja SM, Kokwaro G, Kariuki T, Nzila A, Ozwara H. Preclinical drug evaluation system in the Plasmodium knowlesi baboon model of malaria: the methotrexate study. J Med Primatol 2013; 42:62-70. [PMID: 23294369 DOI: 10.1111/jmp.12034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/10/2012] [Indexed: 11/30/2022]
Abstract
BACKGROUND Drug resistance against first-line antimalarials warrants search for new lead compounds and repurposing of drugs such as methotrexate. Animal models are required for preclinical drug development before clinical testing. This study aimed to develop a preclinical drug development system in baboons infected with Plasmodium knowlesi. METHODS Protocols for drug administration, pharmacokinetics, clinical chemistry and haematology were developed in the baboon model. Baboons were infected with P. knowlesi and methotrexate administered orally for 5 days. Clinical signs, parasitaemia, gross and histopathology examinations were conducted to determine effect of methotrexate in baboons. RESULTS No major clinical chemistry, haematology and pathological changes attributable to methotrexate were observed. Parasitaemia suppression of 77.67% was achieved at a methotrexate dose of 3.0 mg/kg. CONCLUSIONS A protocol for preclinical drug development in the baboon was optimized. Methotrexate suppressed P. knowlesi malaria in baboons. These findings warrant further characterization of methotrexate for use in combination therapy.
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Affiliation(s)
- M Ichagichu
- Department of Tropical and Infectious Diseases, Institute of Primate Research, Karen, Nairobi, Kenya
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Salcedo-Sora JE, Ochong E, Beveridge S, Johnson D, Nzila A, Biagini GA, Stocks PA, O'Neill PM, Krishna S, Bray PG, Ward SA. The molecular basis of folate salvage in Plasmodium falciparum: characterization of two folate transporters. J Biol Chem 2011; 286:44659-68. [PMID: 21998306 PMCID: PMC3247980 DOI: 10.1074/jbc.m111.286054] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Tetrahydrofolates are essential cofactors for DNA synthesis and methionine metabolism. Malaria parasites are capable both of synthesizing tetrahydrofolates and precursors de novo and of salvaging them from the environment. The biosynthetic route has been studied in some detail over decades, whereas the molecular mechanisms that underpin the salvage pathway lag behind. Here we identify two functional folate transporters (named PfFT1 and PfFT2) and delineate unexpected substrate preferences of the folate salvage pathway in Plasmodium falciparum. Both proteins are localized in the plasma membrane and internal membranes of the parasite intra-erythrocytic stages. Transport substrates include folic acid, folinic acid, the folate precursor p-amino benzoic acid (pABA), and the human folate catabolite pABAGn. Intriguingly, the major circulating plasma folate, 5-methyltetrahydrofolate, was a poor substrate for transport via PfFT2 and was not transported by PfFT1. Transport of all folates studied was inhibited by probenecid and methotrexate. Growth rescue in Escherichia coli and antifolate antagonism experiments in P. falciparum indicate that functional salvage of 5-methyltetrahydrofolate is detectable but trivial. In fact pABA was the only effective salvage substrate at normal physiological levels. Because pABA is neither synthesized nor required by the human host, pABA metabolism may offer opportunities for chemotherapeutic intervention.
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Affiliation(s)
- J Enrique Salcedo-Sora
- Molecular and Biochemical Parasitology Group, Liverpool School of Tropical Medicine, Liverpool L3 5QA, United Kingdom
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Scaling up of intermittent preventive treatment of malaria in pregnancy using sulphadoxine-pyrimethamine: prospects and challenges. Matern Child Health J 2011; 15:542-52. [PMID: 20425139 DOI: 10.1007/s10995-010-0608-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Intermittent preventive treatment of malaria during pregnancy with sulphadoxine-pyrimethamine (IPTpSP) is one of the major strategies of malaria control in most African countries where malaria is endemic. The use of sulphadoxine-pyrimethamine (SP) for intermittent preventive treatment of malaria during pregnancy was adopted when proof of its superiority to weekly prophylactic dosing with either chloroquine or pyrimethamine became evident from studies in different malaria endemic countries. The administration of 2 and 3 treatment doses of SP for HIV-negative and HIV-positive pregnant women respectively, given after quickening and at an interval not less than 4 weeks was recommended. The prospects of this control strategy lies on the efficacy of SP, convenient treatment dose and high compliance rate. However, the implementation of this strategy and the efficacy of SP are faced with challenges such as: timing of SP administration, rising levels of parasite resistance to SP in the general population, effect of folate supplementation, adequacy of the recommended doses with regards to malaria endemicity and HIV status, interactions between SP and antiretroviral drugs and low coverage in the bid to scale-up its use. This review highlights the prospects and challenges of scaling up IPTp-SP.
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Chilengi R, Juma R, Abdallah AM, Bashraheil M, Lodenyo H, Nyakundi P, Anabwani E, Salim A, Mwambingu G, Wenwa E, Jemutai J, Kipkeu C, Oyoo GO, Muchohi SN, Kokwaro G, Niehues T, Lang T, Nzila A. A phase I trial to evaluate the safety and pharmacokinetics of low-dose methotrexate as an anti-malarial drug in Kenyan adult healthy volunteers. Malar J 2011; 10:63. [PMID: 21410944 PMCID: PMC3072355 DOI: 10.1186/1475-2875-10-63] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2010] [Accepted: 03/16/2011] [Indexed: 11/11/2022] Open
Abstract
Background Previous investigations indicate that methotrexate, an old anticancer drug, could be used at low doses to treat malaria. A phase I evaluation was conducted to assess the safety and pharmacokinetic profile of this drug in healthy adult male Kenyan volunteers. Methods Twenty five healthy adult volunteers were recruited and admitted to receive a 5 mg dose of methotrexate/day/5 days. Pharmacokinetics blood sampling was carried out at 2, 4, 6, 12 and 24 hours following each dose. Nausea, vomiting, oral ulcers and other adverse events were solicited during follow up of 42 days. Results The mean age of participants was 23.9 ± 3.3 years. Adherence to protocol was 100%. No grade 3 solicited adverse events were observed. However, one case of transiently elevated liver enzymes, and one serious adverse event (not related to the product) were reported. The maximum concentration (Cmax) was 160-200 nM and after 6 hours, the effective concentration (Ceff) was <150 nM. Conclusion Low-dose methotraxate had an acceptable safety profile. However, methotrexate blood levels did not reach the desirable Ceff of 250-400-nM required to clear malaria infection in vivo. Further dose finding and safety studies are necessary to confirm suitability of this drug as an anti-malarial agent.
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Affiliation(s)
- Roma Chilengi
- Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, PO Box 230, 80108 Kilifi, Kenya
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Watkins B, Sibley C. Vivax Malaria: Old Drug, New Uses? J Infect Dis 2011; 203:144-5. [DOI: 10.1093/infdis/jiq027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Maria De-Regil L, Fernández-Gaxiola AC, Dowswell T, Peña-Rosas JP. Effects and safety of periconceptional folate supplementation for preventing birth defects. Cochrane Database Syst Rev 2010:CD007950. [PMID: 20927767 PMCID: PMC4160020 DOI: 10.1002/14651858.cd007950.pub2] [Citation(s) in RCA: 211] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND It has been reported that neural tube defects can be prevented with periconceptional folic acid supplementation. The effects of different doses, forms and schemes of folate supplementation for the prevention of other birth defects and maternal and infant outcomes are unclear. OBJECTIVES This review updates and expands a previous Cochrane Review assessing the effects of periconceptional supplementation with folic acid to reduce neural tube defects (NTDs). We examined whether folate supplementation before and during early pregnancy can reduce neural tube and other birth defects (including cleft palate) without causing adverse outcomes for mothers or babies. SEARCH STRATEGY We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (July 2010). Additionally, we searched the international clinical trials registry platform and contacted relevant organisations to identify ongoing and unpublished studies. SELECTION CRITERIA We included all randomised or quasi-randomised trials evaluating the effect of periconceptional folate supplementation alone, or in combination with other vitamins and minerals, in women independent of age and parity. DATA COLLECTION AND ANALYSIS We assessed trials for methodological quality using the standard Cochrane criteria. Two authors independently assessed the trials for inclusion, one author extracted data and a second checked for accuracy. MAIN RESULTS Five trials involving 6105 women (1949 with a history of a pregnancy affected by a NTD and 4156 with no history of NTDs) were included. Overall, the results are consistent in showing a protective effect of daily folic acid supplementation (alone or in combination with other vitamins and minerals) in preventing NTDs compared with no interventions/placebo or vitamins and minerals without folic acid (risk ratio (RR) 0.28, 95% confidence interval (CI) 0.15 to 0.52). Only one study assessed the incidence of NTDs and the effect was not statistically significant (RR 0.08, 95% CI 0.00 to 1.33) although no events were found in the group that received folic acid. Folic acid had a significant protective effect for reoccurrence (RR 0.32, 95% CI 0.17 to 0.60). There is no statistically significant evidence of any effects on prevention of cleft palate, cleft lip, congenital cardiovascular defects, miscarriages or any other birth defects. There were no included trials assessing the effects of this intervention on maternal blood folate or anaemia at term.We found no evidence of short-term side effects. AUTHORS' CONCLUSIONS Folic acid, alone or in combination with vitamins and minerals, prevents NTDs but does not have a clear effect on other birth defects.
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Affiliation(s)
- Luz Maria De-Regil
- Micronutrients Unit, Department of Nutrition for Health and Development, World Health Organization, Geneva, Switzerland
| | | | - Therese Dowswell
- Cochrane Pregnancy and Childbirth Group, School of Reproductive and Developmental Medicine, Division of Perinatal and Reproductive Medicine, The University of Liverpool, Liverpool, UK
| | - Juan Pablo Peña-Rosas
- Micronutrients Unit, Department of Nutrition for Health and Development, World Health Organization, Geneva, Switzerland
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Effects of in vitro exposure of Echinococcus multilocularis metacestodes to cytostatic drugs on in vivo growth and proliferation of the parasite. Parasitol Res 2010; 107:459-63. [DOI: 10.1007/s00436-010-1892-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2010] [Accepted: 04/20/2010] [Indexed: 12/28/2022]
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Preclinical evaluation of the antifolate QN254, 5-chloro- N'6'-(2,5-dimethoxy-benzyl)-quinazoline-2,4,6-triamine, as an antimalarial drug candidate. Antimicrob Agents Chemother 2010; 54:2603-10. [PMID: 20350951 DOI: 10.1128/aac.01526-09] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Drug resistance against dihydrofolate reductase (DHFR) inhibitors-such as pyrimethamine (PM)-has now spread to almost all regions where malaria is endemic, rendering antifolate-based malaria treatments highly ineffective. We have previously shown that the di-amino quinazoline QN254 [5-chloro-N'6'-(2,5-dimethoxy-benzyl)-quinazoline-2,4,6-triamine] is active against the highly PM-resistant Plasmodium falciparum V1S strain, suggesting that QN254 could be used to treat malaria in regions with a high prevalence of antifolate resistance. Here, we further demonstrate that QN254 is highly active against Plasmodium falciparum clinical isolates, displaying various levels of antifolate drug resistance, and we provide biochemical and structural evidence that QN254 binds and inhibits the function of both the wild-type and the quadruple-mutant (V1S) forms of the DHFR enzyme. In addition, we have assessed QN254 oral bioavailability, efficacy, and safety in vivo. The compound displays favorable pharmacokinetic properties after oral administration in rodents. The drug was remarkably efficacious against Plasmodium berghei and could fully cure infected mice with three daily oral doses of 30 mg/kg. In the course of these efficacy studies, we have uncovered some dose limiting toxicity at higher doses that was confirmed in rats. Thus, despite its relative in vitro selectivity toward the Plasmodium DHFR enzyme, QN254 does not show the adequate therapeutic index to justify its further development as a single agent.
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Wang P, Wang Q, Yang Y, Coward JK, Nzila A, Sims PF, Hyde JE. Characterisation of the bifunctional dihydrofolate synthase-folylpolyglutamate synthase from Plasmodium falciparum; a potential novel target for antimalarial antifolate inhibition. Mol Biochem Parasitol 2010; 172:41-51. [PMID: 20350571 PMCID: PMC2877875 DOI: 10.1016/j.molbiopara.2010.03.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Revised: 03/15/2010] [Accepted: 03/16/2010] [Indexed: 11/20/2022]
Abstract
Unusually for a eukaryote, the malaria parasite Plasmodium falciparum expresses dihydrofolate synthase (DHFS) and folylpolyglutamate synthase (FPGS) as a single bifunctional protein. The two activities contribute to the essential pathway of folate biosynthesis and modification. The DHFS activity of recombinant PfDHFS–FPGS exhibited non-standard kinetics at high co-substrate (glutamate and ATP) concentrations, being partially inhibited by increasing concentrations of its principal substrate, dihydropteroate (DHP). Binding of DHP to the catalytic and inhibitory sites exhibited dissociation constants of 0.50 μM and 1.25 μM, respectively. DHFS activity measured under lower co-substrate concentrations, where data fitted the Michaelis–Menten equation, yielded apparent Km values of 0.88 μM for DHP, 22.8 μM for ATP and 5.97 μM for glutamate. Of the substrates tested in FPGS assays, only tetrahydrofolate (THF) was efficiently converted to polyglutamylated forms, exhibiting standard kinetics with an apparent Km of 0.96 μM; dihydrofolate, folate and the folate analogue methotrexate (MTX) were negligibly processed, emphasising the importance of the oxidation state of the pterin moiety. Moreover, MTX inhibited neither DHFS nor FPGS, even at high concentrations. Conversely, two phosphinate analogues of 7,8-dihydrofolate that mimic tetrahedral intermediates formed during DHFS- and FPGS-catalysed glutamylation were powerfully inhibitory. The Ki value of an aryl phosphinate analogue against DHFS was 0.14 μM and for an alkyl phosphinate against FPGS 0.091 μM, with each inhibitor showing a high degree of specificity. This, combined with the absence of DHFS activity in humans, suggests PfDHFS–FPGS might represent a potential new drug target in the previously validated folate pathway of P. falciparum.
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Affiliation(s)
- Ping Wang
- Manchester Interdisciplinary Biocentre, Faculty of Life Sciences, University of Manchester, 131 Princess Street, Manchester M1 7DN, UK
| | - Qi Wang
- Manchester Interdisciplinary Biocentre, Faculty of Life Sciences, University of Manchester, 131 Princess Street, Manchester M1 7DN, UK
| | - Yonghong Yang
- Department of Medicinal Chemistry, University of Michigan, 930 N. University, Ann Arbor, MI 48109-1055, USA
- Department of Chemistry, University of Michigan, 930 N. University, Ann Arbor, MI 48109-1055, USA
| | - James K. Coward
- Department of Medicinal Chemistry, University of Michigan, 930 N. University, Ann Arbor, MI 48109-1055, USA
- Department of Chemistry, University of Michigan, 930 N. University, Ann Arbor, MI 48109-1055, USA
| | - Alexis Nzila
- KEMRI, Wellcome Trust Collaborative Research Programme, Kilifi 80108, Kenya
| | - Paul F.G. Sims
- Manchester Interdisciplinary Biocentre, Faculty of Life Sciences, University of Manchester, 131 Princess Street, Manchester M1 7DN, UK
| | - John E. Hyde
- Manchester Interdisciplinary Biocentre, Faculty of Life Sciences, University of Manchester, 131 Princess Street, Manchester M1 7DN, UK
- Corresponding author at: University of Manchester, Faculty of Life Sciences, Manchester Interdisciplinary Biocentre, 131 Princess St, Manchester M1 7DN, UK. Tel.: +44 161 306 4185; fax: +44 161 306 5201.
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Nzila A, Okombo J, Becker RP, Chilengi R, Lang T, Niehues T. Anticancer agents against malaria: time to revisit? Trends Parasitol 2010; 26:125-9. [PMID: 20056487 PMCID: PMC2927876 DOI: 10.1016/j.pt.2009.12.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2009] [Revised: 10/23/2009] [Accepted: 12/11/2009] [Indexed: 11/17/2022]
Abstract
The emergence of artemisinin resistance could adversely impact the current strategy for malaria treatment; thus, new drugs are urgently needed. A possible approach to developing new antimalarials is to find new uses for old drugs. Some anticancer agents such as methotrexate and trimetrexate are active against malaria. However, they are commonly perceived to be toxic and thus not suitable for malaria treatment. In this opinion article, we examine how the toxicity of anticancer agents is just a matter of dose or ‘only dose makes the poison’, as coined in Paracelsus’ law. Thus, the opportunity exists to discover new antimalarials using the anticancer pharmacopoeia.
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Affiliation(s)
- Alexis Nzila
- Kenya Medical Research Institute (KEMRI)/Wellcome Trust Collaborative Research Programme, Kilifi, Kenya.
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Müller IB, Hyde JE, Wrenger C. Vitamin B metabolism in Plasmodium falciparum as a source of drug targets. Trends Parasitol 2009; 26:35-43. [PMID: 19939733 DOI: 10.1016/j.pt.2009.10.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2009] [Revised: 09/25/2009] [Accepted: 10/22/2009] [Indexed: 10/20/2022]
Abstract
The malaria parasite Plasmodium falciparum depends primarily on nutrient sources from its human host. Most compounds, such as glucose, purines, amino acids, as well as cofactors and vitamins, are abundantly available in the host cell, and can be readily salvaged by the parasite. However, in some cases the parasite can also synthesize cofactors de novo in reactions that appear to be essential. Importantly, the three biosynthetic pathways that produce vitamins B(1), B(6) and B(9) are absent from the host, but are well established in P. falciparum. This review summarizes and updates the current knowledge of vitamin B de novo synthesis and salvage in P. falciparum and focuses on their potential as targets for drug intervention.
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Affiliation(s)
- Ingrid B Müller
- Department of Biochemistry, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.
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De Regil LM, Fernández-Gaxiola AC, Dowswell T, Peña-Rosas JP. Effects and safety of periconceptional folate supplementation for preventing birth defects. THE COCHRANE DATABASE OF SYSTEMATIC REVIEWS 2009. [DOI: 10.1002/14651858.cd007950] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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In vitro activity of antifolate and polymorphism in dihydrofolate reductase of Plasmodium falciparum isolates from the Kenyan coast: emergence of parasites with Ile-164-Leu mutation. Antimicrob Agents Chemother 2009; 53:3793-8. [PMID: 19528269 DOI: 10.1128/aac.00308-09] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We have analyzed the activities of the antifolates pyrimethamine (PM), chlorcycloguanil (CCG), WR99210, trimethoprim (TMP), methotrexate (MTX), and trimetrexate (TMX) against Kenyan Plasmodium falciparum isolates adapted in vitro for long-term culture. We have also assessed the relationship between these drug activities and mutations in dihydrofolate reductase (dhfr), a domain of the gene associated with antifolate resistance. As expected, WR99210 was the most potent drug, with a median 50% inhibitory concentration (IC50) of <0.075 nM, followed by TMX, with a median IC50 of 30 nM. The median IC50 of CCG was 37.80 nM, and that of MTX was 83.60 nM. PM and TMP were the least active drugs, with median IC50s of 733.26 nM and 29,656.04 nM, respectively. We analyzed parasite dhfr genotypes by the PCR-enzyme restriction technique. No wild-type dhfr parasite was found. Twenty-four of 33 parasites were triple mutants (mutations at codons 108, 51, and 59), and only 8/33 were double mutants (mutations at codons 108 and 51 or at codons 108 and 59). IC50s were 2.1-fold (PM) and 3.6-fold (TMP) higher in triple than in double mutants, though these differences were not statistically significant. Interestingly, we have identified a parasite harboring a mutation at codon 164 (Ile-164-Leu) in addition to mutations at codons 108, 51, and 59. This quadruple mutant parasite had the highest TMP IC50 and was in the upper 10th percentile against PM and CCG. We confirmed the presence of this mutation by sequencing. Thus, TMX and MTX are potent against P. falciparum, and quadruple mutants are now emerging in Africa.
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Irungu B, Kiboi D, Langat B, Rukunga G, Wittlin S, Nzila A. Methotrexate and aminopterin lack in vivo antimalarial activity against murine malaria species. Exp Parasitol 2009; 123:118-21. [PMID: 19527714 DOI: 10.1016/j.exppara.2009.06.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2009] [Revised: 06/03/2009] [Accepted: 06/09/2009] [Indexed: 11/16/2022]
Abstract
The antifolate anticancer drug methotrexate (MTX) has potent activity against Plasmodium falciparum in vitro. Experience of its use in the treatment of rheumatoid arthritis indicates that it could be safe and efficacious for treating malaria. We sought to establish a murine malaria model to study the mechanism of action and resistance of MTX and its analogue aminopterin (AMP). We used Plasmodium berghei, Plasmodium yoelii yoelii, Plasmodium chabaudi and Plasmodium vinckei. None of these species were susceptible to either drug. We have also tested the efficacy of pyrimethamine in combination with folic acid in P. berghei, and data indicate that folic acid does not influence pyrimethamine efficacy, which suggests that P. berghei may not transport folate. Since MTX and AMP utilise folate receptor/transport to gain access to cells, their lack of efficacy against the four tested murine malaria species may be the result of inefficiency of drug transport.
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Affiliation(s)
- Beatrice Irungu
- Centre for Traditional Medicine and Drug Research, Kenya Medical Research Institute, Nairobi City Square, Kenya
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Polymorphism in PfMRP1 (Plasmodium falciparum multidrug resistance protein 1) amino acid 1466 associated with resistance to sulfadoxine-pyrimethamine treatment. Antimicrob Agents Chemother 2009; 53:2553-6. [PMID: 19364873 DOI: 10.1128/aac.00091-09] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Sulfadoxine-pyrimethamine (SP) remains widely recommended for intermittent preventive treatment against Plasmodium falciparum malaria for pregnant women and infants in Africa. Resistance to SP is increasing and associated primarily with mutations in the P. falciparum dhfr (Pfdhfr) and Pfdhps genes. This study aimed to explore the hypothetical association of genetic alterations in the P. falciparum multidrug resistance protein gene (Pfmrp1) with the in vivo response to SP by detecting the selection of single nucleotide polymorphisms (SNPs) following standard single-dose treatment administered to children with acute uncomplicated P. falciparum malaria in Tanzania. We detected significant selection of parasites carrying the Pfmrp1 1466K allele in samples from children with recrudescent infections, with 12 (100%) of 12 such samples being positive for this allele, compared to 52 (67.5%) of 77 baseline samples (P = 0.017), in parallel with the selection of the Pfdhfr Pfdhps quintuple mutant haplotype in cases of recrudescence (P = 0.001). There was no association between the 1466K SNP and the Pfdhfr Pfdhps quintuple mutation, indicating independent selections. Our data point for the first time to a role for a P. falciparum multidrug resistance protein homologue in the antimalarial activity of SP. Moreover, they add to the growing evidence of the potential importance of Pfmrp1 in antimalarial drug resistance.
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In vitro chemosensitization of Plasmodium falciparum to antimalarials by verapamil and probenecid. Antimicrob Agents Chemother 2009; 53:3131-4. [PMID: 19364853 DOI: 10.1128/aac.01689-08] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We tested the effect of probenecid and verapamil in chemosensitizing Plasmodium falciparum to 14 antimalarials using the multidrug-resistant strain V1S and the drug-sensitive 3D7. Verapamil chemosensitizes V1S to quinine and chloroquine. Interestingly, probenecid profoundly chemosensitizes V1S to piperaquine. Thus, probenecid could be used to increase piperaquine efficacy in vivo.
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Muregi FW, Kino H, Ishih A. Plasmodium berghei: lack of antimalarial activity of an analogue of folate precursor, 2,4-diamino-6-hydroxymethylpteridine in a mouse model. Exp Parasitol 2008; 120:286-9. [PMID: 18789931 DOI: 10.1016/j.exppara.2008.08.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2008] [Revised: 07/24/2008] [Accepted: 08/12/2008] [Indexed: 11/27/2022]
Abstract
It was earlier hypothesized that the malarial parasite may convert precursors of folate analogues to synthesize de novo inhibitors toxic to itself, but not to the mammalian cell. It was suggested that one such analogue, 2,4-diamino-6-hydroxymethylpteridine (DAP) may be converted to aminopterin (AMP), a known dihydrofolate reductase inhibitor. In the present study, we evaluated the ability of DAP to inhibit proliferation of Plasmodium berghei NK65 in mice, with(out) folinic acid rescue. Cumulative dosages of DAP ranging from 0.1 to 20mg/kg bw. administered either orally or intraperitoneally showed no suppression of parasite growth, or gave mild activities that were not statistically significant (P>0.05). Our findings do not seem to support the hypothesis of selective de novo metabolism of DAP to AMP by the malarial parasite.
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Affiliation(s)
- Francis W Muregi
- Department of Parasitology, Hamamatsu University School of Medicine, Higashi-ku, Hamamatsu 431-3192, Japan.
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