1
|
Lvova MN, Ponomarev DV, Tarasenko AA, Kovner AV, Minkova GA, Tsyganov MA, Li M, Lou Y, Evseenko VI, Dushkin AV, Sorokina IV, Tolstikova TG, Mordvinov VA, Avgustinovich DF. Curcumin and Its Supramolecular Complex with Disodium Glycyrrhizinate as Potential Drugs for the Liver Fluke Infection Caused by Opisthorchis felineus. Pathogens 2023; 12:819. [PMID: 37375509 DOI: 10.3390/pathogens12060819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 06/06/2023] [Accepted: 06/07/2023] [Indexed: 06/29/2023] Open
Abstract
Opisthorchiosis is a parasitic liver disease found in mammals that is widespread throughout the world and causes systemic inflammation. Praziquantel remains the drug of choice for the treatment of opisthorchiosis, despite its many adverse effects. An anthelmintic effect is attributed to the main curcuminoid of Curcuma longa L. roots-curcumin (Cur)-along with many other therapeutic properties. To overcome the poor solubility of curcumin in water, a micellar complex of curcumin with the disodium salt of glycyrrhizic acid (Cur:Na2GA, molar ratio 1:1) was prepared via solid-phase mechanical processing. In vitro experiments revealed a noticeable immobilizing effect of curcumin and of Cur:Na2GA on mature and juvenile Opisthorchis felineus individuals. In vivo experiments showed that curcumin (50 mg/kg) had an anthelmintic effect after 30 days of administration to O. felineus-infected hamsters, but the effect was weaker than that of a single administration of praziquantel (400 mg/kg). Cur:Na2GA (50 mg/kg, 30 days), which contains less free curcumin, did not exert this action. The complex, just as free curcumin or better, activated the expression of bile acid synthesis genes (Cyp7A1, Fxr, and Rxra), which was suppressed by O. felineus infection and by praziquantel. Curcumin reduced the rate of inflammatory infiltration, whereas Cur:Na2GA reduced periductal fibrosis. Immunohistochemically, a decrease in liver inflammation markers was found, which is determined by calculating the numbers of tumor-necrosis-factor-positive cells during the curcumin treatment and of kynurenine-3-monooxygenase-positive cells during the Cur:Na2GA treatment. A biochemical blood test revealed a normalizing effect of Cur:Na2GA (comparable to that of curcumin) on lipid metabolism. We believe that the further development and investigation of therapeutics based on curcuminoids in relation Opisthorchis felineus and other trematode infections will be useful for clinical practice and veterinary medicine.
Collapse
Affiliation(s)
- Maria N Lvova
- Institute of Cytology and Genetics, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia
| | - Denis V Ponomarev
- Institute of Cytology and Genetics, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia
| | - Alena A Tarasenko
- Institute of Cytology and Genetics, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia
| | - Anna V Kovner
- Institute of Cytology and Genetics, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia
| | - Galina A Minkova
- Institute of Cytology and Genetics, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia
| | - Michail A Tsyganov
- Institute of Cytology and Genetics, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Meijun Li
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Yan Lou
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Veronica I Evseenko
- Institute of Solid State Chemistry and Mechanochemistry, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia
| | - Alexander V Dushkin
- Institute of Solid State Chemistry and Mechanochemistry, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia
| | - Irina V Sorokina
- N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia
| | - Tatiana G Tolstikova
- N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia
| | - Viatcheslav A Mordvinov
- Institute of Cytology and Genetics, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia
| | - Damira F Avgustinovich
- Institute of Cytology and Genetics, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia
- Institute of Solid State Chemistry and Mechanochemistry, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Russia
| |
Collapse
|
2
|
Ren R, Wang X, Leas DA, Häberli C, Cal M, Dong Y, Kaiser M, Keiser J, Vennerstrom JL. Antischistosomal tetrahydro-γ-carboline sulfonamides. Bioorg Med Chem Lett 2022; 59:128546. [PMID: 35031451 PMCID: PMC8826590 DOI: 10.1016/j.bmcl.2022.128546] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 01/07/2022] [Accepted: 01/09/2022] [Indexed: 01/08/2023]
Abstract
We discovered tetrahydro-γ-carboline sulfonamides as a new antischistosomal chemotype. The aryl sulfonamide and tetrahydro-γ-carboline substructures were required for high antischistosomal activity. Increasing polarity improved solubility and metabolic stability but decreased antischistosomal activity. We identified two compounds with IC50 values <5 µM against ex vivo Schistosoma mansoni.
Collapse
Affiliation(s)
- Rongguo Ren
- College of Pharmacy, University of Nebraska Medical Center, 986125 Nebraska Medical Center, Omaha, NE, United States
| | - Xiaofang Wang
- College of Pharmacy, University of Nebraska Medical Center, 986125 Nebraska Medical Center, Omaha, NE, United States
| | - Derek A. Leas
- College of Pharmacy, University of Nebraska Medical Center, 986125 Nebraska Medical Center, Omaha, NE, United States
| | - Cécile Häberli
- Department of Medical Parasitology and Infection Biology, Swiss Tropical Institute, Socinstrasse 57, CH-4002 Basel, Switzerland,University of Basel, CH-4003 Basel, Switzerland
| | - Monica Cal
- Department of Medical Parasitology and Infection Biology, Swiss Tropical Institute, Socinstrasse 57, CH-4002 Basel, Switzerland,University of Basel, CH-4003 Basel, Switzerland
| | - Yuxiang Dong
- College of Pharmacy, University of Nebraska Medical Center, 986125 Nebraska Medical Center, Omaha, NE, United States
| | - Marcel Kaiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical Institute, Socinstrasse 57, CH-4002 Basel, Switzerland,University of Basel, CH-4003 Basel, Switzerland
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical Institute, Socinstrasse 57, CH-4002 Basel, Switzerland,University of Basel, CH-4003 Basel, Switzerland
| | - Jonathan L. Vennerstrom
- College of Pharmacy, University of Nebraska Medical Center, 986125 Nebraska Medical Center, Omaha, NE, United States
| |
Collapse
|
3
|
Drug associations as alternative and complementary therapy for neglected tropical diseases. Acta Trop 2022; 225:106210. [PMID: 34687644 DOI: 10.1016/j.actatropica.2021.106210] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 10/02/2021] [Accepted: 10/15/2021] [Indexed: 12/23/2022]
Abstract
The present paper aims to establish different treatments for neglected tropical disease by a survey on drug conjugations and possible fixed-dose combinations (FDC) used to obtain alternative, safer and more effective treatments. The source databases used were Science Direct and PubMed/Medline, in the intervals between 2015 and 2021 with the drugs key-words or diseases, like "schistosomiasis", "praziquantel", "malaria", "artesunate", "Chagas' disease", "benznidazole", "filariasis", diethylcarbamazine", "ivermectin", " albendazole". 118 works were the object of intense analysis, other articles and documents were used to increase the quality of the studies, such as consensuses for harmonizing therapeutics and historical articles. As a result, an effective NTD control can be achieved when different public health approaches are combined with interventions guided by the epidemiology of each location and the availability of appropriate measures to detect, prevent and control disease. It was also possible to verify that the FDCs promote a simplification of the therapeutic regimen, which promotes better patient compliance and enables a reduction in the development of parasitic resistance, requiring further studies aimed at resistant strains, since the combined APIs usually act by different mechanisms or at different target sites. In addition to eliminating the process of developing a new drug based on the identification and validation of active compounds, which is a complex, long process and requires a strong long-term investment, other advantages that FDCs have are related to productive gain and gain from the industrial plant, which can favor and encourage the R&D of new FDCs not only for NTDs but also for other diseases that require the use of more than one drug.
Collapse
|
4
|
Therapeutic Effect of Diminazene Aceturate on Parasitic Blood Fluke Schistosoma mansoni Infection. Antimicrob Agents Chemother 2020; 64:AAC.01372-20. [PMID: 32816737 DOI: 10.1128/aac.01372-20] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 08/13/2020] [Indexed: 01/30/2023] Open
Abstract
Praziquantel is currently the only drug available to treat schistosomiasis, a disease of enormous public health significance caused by a blood fluke of the genus Schistosoma Diminazene, a drug approved by the FDA, has been successfully used to treat diseases caused by blood protozoan parasites. In this study, we evaluated the antiparasitic properties of diminazene against Schistosoma mansoni ex vivo and in mice harboring either chronic or early S. mansoni infections. In vitro, we monitored phenotypic and tegumental changes as well as the effects of the drug on pairing and egg production. In mice infected with either adult (chronic infection) or immature (early infection) worms, diminazene was administered intraperitoneally (10 to 100 mg/kg of body weight) or by oral gavage (100 to 400 mg/kg), and we studied the influence of the drug on worm burden and egg production. Liver and spleen pathologies and serum aminotransferase levels were also analyzed. In vitro, 50% effective concentrations (EC50) and EC90 revealed that diminazene is able to kill both immature and adult parasites, and its effect was time and concentration dependent. In addition, confocal laser scanning microscopy showed morphological alterations in the teguments of schistosomes. In an animal model, the influence of the drug on worm burden, egg production, hepatomegaly, and splenomegaly depended on the dosing regimen applied and the route of administration. Diminazene also caused a significant reduction in aminotransferase levels. Comparatively, diminazene treatment was more effective in chronic infection than in early infection. In tandem, our study revealed that diminazene possesses anthelmintic properties and inhibits liver injury caused by Schistosoma eggs.
Collapse
|
5
|
Eissa MM, El-Azzouni MZ, El-Khordagui LK, Abdel Bary A, El-Moslemany RM, Abdel Salam SA. Single oral fixed-dose praziquantel-miltefosine nanocombination for effective control of experimental schistosomiasis mansoni. Parasit Vectors 2020; 13:474. [PMID: 32933556 PMCID: PMC7493353 DOI: 10.1186/s13071-020-04346-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Accepted: 09/05/2020] [Indexed: 12/13/2022] Open
Abstract
Background The control of schistosomiasis has been centered to date on a single drug, praziquantel, with shortcomings including treatment failure, reinfection, and emergence of drug resistance. Drug repurposing, combination therapy or nanotechnology were explored to improve antischistosomal treatment. The aim of the present study was to utilize a novel combination of the three strategies to improve the therapeutic profile of praziquantel. This was based on a fixed-dose nanocombination of praziquantel and miltefosine, an antischistosomal repurposing candidate, co-loaded at reduced doses into lipid nanocapsules, for single dose oral therapy. Methods Two nanocombinations were prepared to provide 250 mg praziquantel-20 mg miltefosine/kg (higher fixed-dose) or 125 mg praziquantel-10 mg miltefosine/kg (lower fixed-dose), respectively. Their antischistosomal efficacy in comparison with a non-treated control and their praziquantel or miltefosine singly loaded counterparts was assessed in murine schistosomiasis mansoni. A single oral dose of either formulation was administered on the initial day of infection, and on days 21 and 42 post-infection. Scanning electron microscopic, parasitological, and histopathological studies were used for assessment. Preclinical data were subjected to analysis of variance and Tukeyʼs post-hoc test for pairwise comparisons. Results Lipid nanocapsules (~ 58 nm) showed high entrapment efficiency of both drugs (> 97%). Compared to singly loaded praziquantel-lipid nanocapsules, the higher nanocombination dose showed a significant increase in antischistosomal efficacy in terms of statistically significant decrease in mean worm burden, particularly against invasive and juvenile worms, and amelioration of hepatic granulomas (P ≤ 0.05). In addition, scanning electron microscopy examination showed extensive dorsal tegumental damage with noticeable deposition of nanostructures. Conclusions The therapeutic profile of praziquantel could be improved by a novel multiple approach integrating drug repurposing, combination therapy and nanotechnology. Multistage activity and amelioration of liver pathology could be achieved by a new praziquantel-miltefosine fixed-dose nanocombination providing 250 mg praziquantel-20 mg miltefosine/kg. To the best of our knowledge, this is the first report of a fixed-dose nano-based combinatorial therapy for schistosomiasis mansoni. Further studies are needed to document the nanocombination safety and explore its prophylactic activity and potential to hinder the onset of resistance to the drug components.![]()
Collapse
Affiliation(s)
- Maha M Eissa
- Department of Medical Parasitology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Mervat Z El-Azzouni
- Department of Medical Parasitology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Labiba K El-Khordagui
- Department of Pharmaceutics, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt.
| | - Amany Abdel Bary
- Department of Pathology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
| | - Riham M El-Moslemany
- Department of Pharmaceutics, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt
| | - Sara A Abdel Salam
- Department of Medical Parasitology, Faculty of Medicine, Alexandria University, Alexandria, Egypt
| |
Collapse
|
6
|
Zdesenko G, Mutapi F. Drug metabolism and pharmacokinetics of praziquantel: A review of variable drug exposure during schistosomiasis treatment in human hosts and experimental models. PLoS Negl Trop Dis 2020; 14:e0008649. [PMID: 32976496 PMCID: PMC7518612 DOI: 10.1371/journal.pntd.0008649] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Schistosomiasis control is heavily reliant on the drug praziquantel (PZQ), which is used as preventive chemotherapy as part of national helminth control strategies. Given the heavy reliance on PZQ for mass drug administration, there has been considerable research on the potential of parasites developing resistance to the drug, resulting in decreased drug efficacy. However, there have been comparatively fewer studies of other factors that can potentially alter PZQ efficacy. Here, we investigate whether host PZQ metabolism contributes towards variable cure rates. We evaluate factors that can influence the metabolism of PZQ and the resultant effect on the efficacy of PZQ treatment to determine factors that potentially influence an individual's response to the drug. The literature search was directed at published studies from three online databases: Web of Science, PubMed, and EMBASE. The search terms for the review comprised of ([praziquantel OR PZQ] AND [schistosom* OR bilharzia] AND [pharmaco*]) and included studies evaluating PZQ metabolism. Publications were categorised into pharmacokinetics, drug-drug interactions, pharmacogenetics, and metabolite analysis. Forty publications describing human and experimental studies fitted the inclusion criteria and were subjected to data extraction and analysis. The analyses showed that variable exposure to PZQ was associated with alterations in the liver's capacity to metabolise PZQ and observed drug-drug interactions. Other factors influencing the efficacy of PZQ were brand, formulation, and co-administered food. Although some work has been performed on metabolite identification, there was minimal information on PZQ's metabolic pathway, and no pharmacogenetics studies were identified. The study indicated that in both human and experimental studies alterations in the liver's capacity to metabolise PZQ as well as drug-drug interactions affected systemic levels of PZQ that could result in variable cure rates. The study confirmed previous findings of higher antischistosomal activity of (R)-PZQ enantiomer when administered alone compared to the racemate at the same dose as well as improved efficacy when the drug is administered with food. The study also highlighted the need for more comprehensive studies of the PZQ metabolic pathway and PZQ pharmacogenetic studies in humans.
Collapse
Affiliation(s)
- Grace Zdesenko
- Institute of Immunology & Infection Research, University of Edinburgh, Ashworth Laboratories, King’s Buildings, Edinburgh, United Kingdom
- NIHR Global Health Research Unit Tackling Infections to Benefit Africa (TIBA), University of Edinburgh, Ashworth Laboratories, King’s Buildings, Edinburgh, United Kingdom
| | - Francisca Mutapi
- Institute of Immunology & Infection Research, University of Edinburgh, Ashworth Laboratories, King’s Buildings, Edinburgh, United Kingdom
- NIHR Global Health Research Unit Tackling Infections to Benefit Africa (TIBA), University of Edinburgh, Ashworth Laboratories, King’s Buildings, Edinburgh, United Kingdom
| |
Collapse
|
7
|
Gouveia MJ, Brindley PJ, Gärtner F, Vale N. Activity of Combinations of Antioxidants and Anthelmintic Drugs against the Adult Stage of Schistosoma mansoni. J Parasitol Res 2020; 2020:8843808. [PMID: 32832132 PMCID: PMC7429017 DOI: 10.1155/2020/8843808] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/19/2020] [Accepted: 07/15/2020] [Indexed: 12/25/2022] Open
Abstract
Schistosomiasis remains a major neglected tropical disease. The treatment and control of schistosomiasis rely on a single drug, praziquantel (PZQ). Despite its efficacy, treatment with PZQ presents some major drawbacks including an inability of the chemotherapy to reverse disease-induced fibrosis and the prospect of the emergence of drug resistance. Here, we investigated a novel therapeutic approach with antioxidant biomolecules in combination with PZQ against the adult developmental stage of Schistosoma mansoni and oviposition in vitro, given that this therapeutic approach achieved synergistic/additive activity against larval schistosomes. The antioxidants curcumin and oxadiazole per se exhibited antischistosomal activity against adult worms leading to severe morphological alterations and death. Additionally, the antioxidant flavone combined with vandetanib or imatinib improved antischistosomal activity against adult forms. By contrast, however, these antioxidant-anthelmintic combinations were not as effective against adults in comparison to larval schistosomes. Nevertheless, the antioxidants alone or combined with drugs inhibited oviposition.
Collapse
Affiliation(s)
- Maria João Gouveia
- Department of Molecular Pathology and Immunology, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal
- Center for the Study in Animal Science, University of Porto (CECA/ICETA), Rua de D. Manuel II, Apartado 55142, 4051-401 Porto, Portugal
| | - Paul J. Brindley
- Department of Microbiology, Immunology & Tropical Medicine, Research Center for Neglected Diseases of Poverty, School of Medicine & Health Sciences, George Washington University, Washington, DC 20037, USA
| | - Fátima Gärtner
- Department of Molecular Pathology and Immunology, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Rua Júlio Amaral de Carvalho 45, 4200-135 Porto, Portugal
- i3S, Instituto de Investigação e Inovação em Saúde da Universidade do Porto, Rua Alfredo Allen 208, 4200-135 Porto, Portugal
| | - Nuno Vale
- OncoPharma Research Group, Center for Health Technology and Services Research (CINTESIS), Rua Dr. Plácido da Costa, 4200-450 Porto, Portugal
- Faculty of Medicine, University of Porto, Al. Prof. Hernâni Monteiro, 4200-319 Porto, Portugal
| |
Collapse
|
8
|
Ravaynia PS, Lombardo FC, Biendl S, Dupuch MA, Keiser J, Hierlemann A, Modena MM. Parallelized Impedance-Based Platform for Continuous Dose-Response Characterization of Antischistosomal Drugs. ACTA ACUST UNITED AC 2020; 4:e1900304. [PMID: 32510834 DOI: 10.1002/adbi.201900304] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 05/19/2020] [Indexed: 11/11/2022]
Abstract
Schistosomiasis is an acute and chronic disease caused by tropical parasitic worms of the genus Schistosoma, which parasitizes annually over 200 million people worldwide. Screening of antischistosomal compounds is hampered by the low throughput and potential subjectivity of the visual evaluation of the parasite phenotypes, which affects the current drug assays. Here, an impedance-based platform, capable of assessing the viability of Schistosoma mansoni schistosomula exposed to drugs, is presented. This automated and parallelized platform enables unbiased and continuous measurements of dose-response relationships for more than 48 h. The platform performance is established by exposure of schistosomula to three test compounds, praziquantel, oxethazaine, and mefloquine, which are known to affect the larvae phenotypes. The system is thereafter used to investigate the response of schistosomula to methiothepine, an antipsychotic compound, which causes complex drug-induced effects. Continuous monitoring of the parasites reveals transient behavioral phenotypes and allows for extracting temporal characteristics of dose-response curves, which are essential for selecting drugs that feature high activity and fast kinetics of action. These measurements demonstrate that impedance-based detection provides a wealth of information for the in vitro characterization of candidate antischistosomals and, represents a promising tool for the identification of new lead compounds.
Collapse
Affiliation(s)
- Paolo S Ravaynia
- Bioengineering Laboratory, Department of Biosystems Science and Engineering, ETH Zürich, Mattenstrasse 26, Basel, 4058, Switzerland
| | - Flavio C Lombardo
- Swiss Tropical and Public Health Institute, Department of Medical Parasitology and Infection Biology, University of Basel, Socinstrasse 57, Basel, 4051, Switzerland
| | - Stefan Biendl
- Swiss Tropical and Public Health Institute, Department of Medical Parasitology and Infection Biology, University of Basel, Socinstrasse 57, Basel, 4051, Switzerland
| | - Matthias A Dupuch
- Micro and Nanosystems, Department of Mechanical and Process Engineering, ETH Zürich, Tannenstrasse 3, Zurich, 8092, Switzerland
| | - Jennifer Keiser
- Swiss Tropical and Public Health Institute, Department of Medical Parasitology and Infection Biology, University of Basel, Socinstrasse 57, Basel, 4051, Switzerland
| | - Andreas Hierlemann
- Bioengineering Laboratory, Department of Biosystems Science and Engineering, ETH Zürich, Mattenstrasse 26, Basel, 4058, Switzerland
| | - Mario M Modena
- Bioengineering Laboratory, Department of Biosystems Science and Engineering, ETH Zürich, Mattenstrasse 26, Basel, 4058, Switzerland
| |
Collapse
|
9
|
Gouveia MJ, Brindley PJ, Azevedo C, Gärtner F, da Costa JMC, Vale N. The antioxidants resveratrol and N-acetylcysteine enhance anthelmintic activity of praziquantel and artesunate against Schistosoma mansoni. Parasit Vectors 2019; 12:309. [PMID: 31221193 PMCID: PMC6585032 DOI: 10.1186/s13071-019-3566-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Accepted: 06/15/2019] [Indexed: 01/13/2023] Open
Abstract
Background Treatment of schistosomiasis has relied on the anthelmintic drug praziquantel (PZQ) for more than a generation. Despite its celebrated performance for treatment and control of schistosomiasis and other platyhelminth infections, praziquantel has some shortcomings and the inability of this drug to counteract disease sequelae prompts the need for novel therapeutic strategies. Methods Using a host-parasite model involving Biomphalaria glabrata and Schistosoma mansoni we established mechanical transformation of S. mansoni cercariae into newly transformed schistosomula (NTS) and characterized optimal culture conditions. Thereafter, we investigated the antischistosomal activity and ability of the antioxidants N-acetylcysteine (NAC) and resveratrol (RESV) to augment the performance of praziquantel and/or artesunate (AS) against larval stages of the parasite. Drug effects were evaluated by using an automated microscopical system to study live and fixed parasites and by transmission electron microscopy (TEM). Results Transformation rates of cercariae to schistosomula reached ~ 70% when the manipulation process was optimized. Several culture media were tested, with M199 supplemented with HEPES found to be suitable for S. mansoni NTS. Among the antioxidants studied, RESV alone or combined with anthelminthic drugs achieved better results rather N-acetylcysteine (NAC). TEM observations demonstrated that the combination of AS + RESV induced severe, extensive alterations to the tegument and subtegument of NTS when compared to the constituent compounds alone. Two anthelmintic–antioxidant combinations, praziquantel-resveratrol [combination index (CI) = 0.74] and artesunate-resveratrol (CI = 0.34) displayed moderate and strong synergy, respectively. Conclusions The use of viability markers including staining with propidium iodide increased the accuracy of drug screening assays against S. mansoni NTS. The synergies observed might be the consequence of increased action by RESV on targets of AS and PZQ and/or they may act through concomitantly on discrete targets to enhance overall antischistosomal action. Combinations of active agents, preferably with discrete modes of action including activity against developmental stages and/or the potential to ameliorate infection-associated pathology, might be pursued in order to identify novel therapeutic interventions. Electronic supplementary material The online version of this article (10.1186/s13071-019-3566-9) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Maria João Gouveia
- Center for the Study of Animal Science, CECA-ICETA, University of Porto, Praça Gomes Teixeira, Apartado 55142, 4051-401, Porto, Portugal.,i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135, Porto, Portugal.,ICBAS-UP, Institute of Biomedical Sciences Abel Salazar, University of Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-343, Porto, Portugal
| | - Paul J Brindley
- Department of Microbiology, Immunology and Tropical Medicine and Research Center for Neglected Diseases of Poverty, School of Medicine and Health Sciences, George Washington University, 20037, Washington, DC, USA
| | - Carlos Azevedo
- Laboratory of Cell Biology, Institute of Biomedical Sciences (ICBAS/UP), University of Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal
| | - Fátima Gärtner
- Center for the Study of Animal Science, CECA-ICETA, University of Porto, Praça Gomes Teixeira, Apartado 55142, 4051-401, Porto, Portugal.,ICBAS-UP, Institute of Biomedical Sciences Abel Salazar, University of Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-343, Porto, Portugal.,Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Rua Júlio Amaral de Carvalho, 45, 4200-135, Porto, Portugal
| | - José M C da Costa
- Center for the Study of Animal Science, CECA-ICETA, University of Porto, Praça Gomes Teixeira, Apartado 55142, 4051-401, Porto, Portugal.,National Health Institute Dr. Ricardo Jorge (INSA), Rua Alexandre Herculano, 321, 4000-055, Porto, Portugal
| | - Nuno Vale
- i3S, Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, 4200-135, Porto, Portugal. .,ICBAS-UP, Institute of Biomedical Sciences Abel Salazar, University of Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-343, Porto, Portugal. .,Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Rua Júlio Amaral de Carvalho, 45, 4200-135, Porto, Portugal. .,Laboratory of Pharmacology, Department of Drug Sciences, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313, Porto, Portugal.
| |
Collapse
|
10
|
Avgustinovich D, Tsyganov M, Vishnivetskaya G, Kovner A, Sorokina I, Orlovskaya I, Toporkova L, Goiman E, Tolstikova T, Dushkin A, Lyakhov N, Mordvinov V. Effects of supramolecular complexation of praziquantel with disodium glycyrrhizinate on the liver fluke Opisthorchis felineus: An in vitro and in vivo study. Acta Trop 2019; 194:1-12. [PMID: 30871990 DOI: 10.1016/j.actatropica.2019.03.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 02/24/2019] [Accepted: 03/10/2019] [Indexed: 02/09/2023]
Abstract
Millions of people worldwide have a chronic infection with the liver fluke Opisthorchis felineus, which causes opisthorchiasis in humans and animals. The only known effective drug for this disease is praziquantel (PrzQ); however, its efficacy is below 100%, and it has some adverse effects. In this study, a water-soluble complex of PrzQ with a disodium salt of glycyrrhizic acid (disodium glycyrrhizinate; Na2GA) in a 1:10 ratio (PrzQ:GA) allowed the PrzQ dose to be decreased 11-fold for effective killing of O. felineus. An in vitro experiment showed a sufficient anthelmintic efficiency of PrzQ:GA against both adult and juvenile O. felineus individuals. A Syrian golden hamster model of opisthorchiasis revealed a considerable anthelmintic effect at all tested PrzQ:GA doses (50, 100, 200, 400, and 1100 mg/kg) with the best performance at 400 and 1100 mg/kg. Further comparison of the effects of PrzQ (400 mg/kg) and PrzQ:GA (400 mg/kg) regarding the state of the host indicated significant advantages of the latter. Histological examination showed that PrzQ:GA was better at decreasing the O. felineus-induced inflammatory infiltration (as compared with PrzQ alone) as well as interfered with the development of epithelial dysplasia and metaplasia in large bile ducts and cholangiofibrosis. Both PrzQ and PrzQ:GA decreased the number of myeloid (CFU-GM) and erythroid (BFU-E + CFU-E) colonies induced by O. felineus infection. The drugs had no negative effect on the animal behavior in an open field test 2-4 h after administration. Thus, PrzQ:GA proved to be a good anthelmintic agent having no evident adverse effects on the host, thereby suggesting that further preclinical and clinical trials would be warranted.
Collapse
|
11
|
Gouveia MJ, Brindley PJ, Rinaldi G, Gärtner F, Correia da Costa JM, Vale N. Combination Anthelmintic/Antioxidant Activity Against Schistosoma Mansoni. Biomolecules 2019; 9:E54. [PMID: 30764562 PMCID: PMC6406910 DOI: 10.3390/biom9020054] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 01/29/2019] [Accepted: 01/31/2019] [Indexed: 01/11/2023] Open
Abstract
Schistosomiasis is a major neglected tropical disease. Treatment for schistosomiasis with praziquantel (PZQ), which is effective against the parasite, by itself is not capable to counteract infection-associated disease lesions including hepatic fibrosis. There is a pressing need for novel therapies. Due to their biological properties, antioxidant biomolecules might be useful in treating and reverting associated pathological sequelae. Here, we investigated a novel therapy approach based on a combination of anthelmintic drugs with antioxidant biomolecules. We used a host-parasite model involving Bioamphalaria glabrata and newly transformed schistosomula (NTS) of Schistosoma mansoni. For in vitro drug screening assays, was selected several antioxidants and evaluated not only antischistosomal activity but also ability to enhance activity of the anthelmintic drugs praziquantel (PZQ) and artesunate (AS). The morphological alterations induced by compounds alone/combined were assessed on daily basis using an inverted and automated microscope to quantify NTS viability by a fluorometric-based method. The findings indicated that not only do some antioxidants improve antischistosomal activity of the two anthelmintics, but they exhibit activity per se, leading to high mortality of NTS post-exposure. The combination index (CI) of PZQ + Mel (CI = 0.80), PZQ + Resv (CI = 0.74), AS + Resv (CI = 0.34), AS + NAC (CI = 0.89), VDT + Flav (CI = 1.03) and VDT + Resv (CI = 1.06) reveal that they display moderate to strong synergism. The combination of compounds with discrete mechanisms of action might provide a valuable adjunct to contribution for treatment of schistosomiasis-associated disease.
Collapse
Affiliation(s)
- Maria João Gouveia
- Center for the Study in Animal Science, University of Porto, (CECA/ICETA), Rua de D. Manuel II, Apt 55142, 4051-401 Porto, Portugal.
- Department of Molecular Pathology and Immunology, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
- Department of Drug Sciences, Laboratory of Pharmacology, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
| | - Paul J Brindley
- Department of Microbiology, Immunology & Tropical Medicine, Research Center for Neglected Diseases of Poverty, School of Medicine & Health Sciences, George Washington University, Washington, DC 20037, USA.
| | - Gabriel Rinaldi
- Department of Microbiology, Immunology & Tropical Medicine, Research Center for Neglected Diseases of Poverty, School of Medicine & Health Sciences, George Washington University, Washington, DC 20037, USA.
| | - Fátima Gärtner
- Department of Molecular Pathology and Immunology, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Rua Júlio Amaral de Carvalho 45, 4200-135 Porto, Portugal.
- University of Porto, i3S, Instituto de Investigação e Inovação em Saúde, Rua Alfredo Allen 208, 4200-135 Porto, Portugal.
| | - José Manuel Correia da Costa
- Center for the Study in Animal Science, University of Porto, (CECA/ICETA), Rua de D. Manuel II, Apt 55142, 4051-401 Porto, Portugal.
- Department of Infectious Diseases, INSA-National Institute of Health Dr. Ricardo Jorge, Rua Alexandre Herculano 321, 4000-055 Porto, Portugal.
| | - Nuno Vale
- Department of Molecular Pathology and Immunology, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
- Department of Drug Sciences, Laboratory of Pharmacology, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Rua Júlio Amaral de Carvalho 45, 4200-135 Porto, Portugal.
- University of Porto, i3S, Instituto de Investigação e Inovação em Saúde, Rua Alfredo Allen 208, 4200-135 Porto, Portugal.
| |
Collapse
|
12
|
Botros SS, William S, Sabra ANA, El-Lakkany NM, Seif El-Din SH, García-Rubia A, Sebastián-Pérez V, Blaazer AR, de Heuvel E, Sijm M, Zheng Y, Salado IG, Munday JC, Maes L, de Esch IJP, Sterk GJ, Augustyns K, Leurs R, Gil C, De Koning HP. Screening of a PDE-focused library identifies imidazoles with in vitro and in vivo antischistosomal activity. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2019; 9:35-43. [PMID: 30669086 PMCID: PMC6350229 DOI: 10.1016/j.ijpddr.2019.01.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 01/10/2019] [Accepted: 01/13/2019] [Indexed: 01/10/2023]
Abstract
We report the evaluation of 265 compounds from a PDE-focused library for their antischistosomal activity, assessed in vitro using Schistosoma mansoni. Of the tested compounds, 171 (64%) displayed selective in vitro activity, with 16 causing worm hypermotility/spastic contractions and 41 inducing various degrees of worm killing at 100 μM, with the surviving worms displaying sluggish movement, worm unpairing and complete absence of eggs. The compounds that did not affect worm viability (n = 72) induced a complete cessation of ovipositing. 82% of the compounds had an impact on male worms whereas female worms were barely affected. In vivo evaluation in S. mansoni-infected mice with the in vitro 'hit' NPD-0274 at 20 mg/kg/day orally for 5 days resulted in worm burden reductions of 29% and intestinal tissue egg load reduction of 35% at 10 days post-treatment. Combination of praziquantel (PZQ) at 10 mg/kg/day for 5 days with NPD-0274 or NPD-0298 resulted in significantly higher worm killing than PZQ alone, as well as a reduction in intestinal tissue egg load, disappearance of immature eggs and an increase in the number of dead eggs.
Collapse
Affiliation(s)
- Sanaa S Botros
- Pharmacology Department, Theodor Bilharz Research Institute, Warrak El-Hadar, Imbaba, P.O. Box 30, Giza, 12411, Egypt
| | - Samia William
- Parasitology Department, Theodor Bilharz Research Institute, Warrak El-Hadar, Imbaba, P.O. Box 30, Giza, 12411, Egypt
| | - Abdel-Nasser A Sabra
- Pharmacology Department, Theodor Bilharz Research Institute, Warrak El-Hadar, Imbaba, P.O. Box 30, Giza, 12411, Egypt
| | - Naglaa M El-Lakkany
- Pharmacology Department, Theodor Bilharz Research Institute, Warrak El-Hadar, Imbaba, P.O. Box 30, Giza, 12411, Egypt
| | - Sayed H Seif El-Din
- Pharmacology Department, Theodor Bilharz Research Institute, Warrak El-Hadar, Imbaba, P.O. Box 30, Giza, 12411, Egypt
| | | | | | - Antoni R Blaazer
- Medicinal Chemistry Vrije Universiteit Amsterdam (VUA), the Netherlands
| | - Erik de Heuvel
- Medicinal Chemistry Vrije Universiteit Amsterdam (VUA), the Netherlands
| | - Maarten Sijm
- Medicinal Chemistry Vrije Universiteit Amsterdam (VUA), the Netherlands
| | - Yang Zheng
- Medicinal Chemistry Vrije Universiteit Amsterdam (VUA), the Netherlands
| | | | - Jane C Munday
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, G12 8TA, UK
| | | | - Iwan J P de Esch
- Medicinal Chemistry Vrije Universiteit Amsterdam (VUA), the Netherlands
| | - Geert J Sterk
- Medicinal Chemistry Vrije Universiteit Amsterdam (VUA), the Netherlands
| | | | - Rob Leurs
- Medicinal Chemistry Vrije Universiteit Amsterdam (VUA), the Netherlands
| | - Carmen Gil
- Centro de Investigaciones Biológicas (CIB-CSIC), Madrid, Spain
| | - Harry P De Koning
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, G12 8TA, UK.
| |
Collapse
|
13
|
Chawla K, Modena MM, Ravaynia PS, Lombardo FC, Leonhardt M, Panic G, Bürgel SC, Keiser J, Hierlemann A. Impedance-Based Microfluidic Assay for Automated Antischistosomal Drug Screening. ACS Sens 2018; 3:2613-2620. [PMID: 30426744 PMCID: PMC6396876 DOI: 10.1021/acssensors.8b01027] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Schistosomiasis is a neglected tropical disease, caused by parasitic worms, which affects almost 200 million people worldwide. For over 40 years, chemotherapeutic treatment has relied on the administration of praziquantel, an efficacious drug against schistosomiasis. However, concerns about developing drug resistance require the discovery of novel drug compounds. Currently, the drug-screening process is mostly based on the visual evaluation of drug effects on worm larvae in vitro by a trained operator. This manual process is extremely labor-intensive, has limited throughput, and may be affected by subjectivity of the operator evaluation. In this paper, we introduce a microfluidic platform with integrated electrodes for the automated detection of worm larvae viability using an impedance-based approach. The microfluidic analysis unit consists of two sets of electrodes and a channel of variable geometry to enable counting and size detection of single parasite larvae and the collective evaluation of the motility of the larvae as an unbiased estimator for their viability. The current platform also allows for multiplexing of the analysis units resulting in increased throughput. We used our platform to record size and motility variations of Schistosoma mansoni larvae exposed to different concentrations of mefloquine, a drug with established in vitro antischistosomal properties. The developed platform demonstrates the potential of integrated microfluidic platforms for high-throughput antischistosomal drug screening.
Collapse
Affiliation(s)
- Ketki Chawla
- ETH Zurich, Dept. of Biosystems Science and Engineering, Bio Engineering Laboratory, Basel, Switzerland
| | - Mario M. Modena
- ETH Zurich, Dept. of Biosystems Science and Engineering, Bio Engineering Laboratory, Basel, Switzerland
| | - Paolo S. Ravaynia
- ETH Zurich, Dept. of Biosystems Science and Engineering, Bio Engineering Laboratory, Basel, Switzerland
| | - Flavio C. Lombardo
- Swiss Tropical and Public Health Institute, Department of Medical Parasitology and Infection Biology, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Martin Leonhardt
- ETH Zurich, Dept. of Biosystems Science and Engineering, Bio Engineering Laboratory, Basel, Switzerland
| | - Gordana Panic
- Swiss Tropical and Public Health Institute, Department of Medical Parasitology and Infection Biology, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Sebastian C. Bürgel
- ETH Zurich, Dept. of Biosystems Science and Engineering, Bio Engineering Laboratory, Basel, Switzerland
| | - Jennifer Keiser
- Swiss Tropical and Public Health Institute, Department of Medical Parasitology and Infection Biology, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Andreas Hierlemann
- ETH Zurich, Dept. of Biosystems Science and Engineering, Bio Engineering Laboratory, Basel, Switzerland
| |
Collapse
|
14
|
Wang H, Tian L, Liu J, Goldstein A, Bado I, Zhang W, Arenkiel BR, Li Z, Yang M, Du S, Zhao H, Rowley DR, Wong STC, Gugala Z, Zhang XHF. The Osteogenic Niche Is a Calcium Reservoir of Bone Micrometastases and Confers Unexpected Therapeutic Vulnerability. Cancer Cell 2018; 34:823-839.e7. [PMID: 30423299 PMCID: PMC6239211 DOI: 10.1016/j.ccell.2018.10.002] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 07/10/2018] [Accepted: 10/02/2018] [Indexed: 02/06/2023]
Abstract
The fate of disseminated tumor cells is largely determined by microenvironment (ME) niche. The osteogenic niche promotes cancer cell proliferation and bone metastasis progression. We investigated the underlying mechanisms using pre-clinical models and analyses of clinical data. We discovered that the osteogenic niche serves as a calcium (Ca) reservoir for cancer cells through gap junctions. Cancer cells cannot efficiently absorb Ca from ME, but depend on osteogenic cells to increase intracellular Ca concentration. The Ca signaling, together with previously identified mammalian target of rapamycin signaling, promotes bone metastasis progression. Interestingly, effective inhibition of these pathways can be achieved by danusertib, or a combination of everolimus and arsenic trioxide, which provide possibilities of eliminating bone micrometastases using clinically established drugs.
Collapse
Affiliation(s)
- Hai Wang
- Lester and Sue Smith Breast Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Dan L. Duncan Cancer Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Lin Tian
- Lester and Sue Smith Breast Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Dan L. Duncan Cancer Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Jun Liu
- Lester and Sue Smith Breast Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Dan L. Duncan Cancer Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Amit Goldstein
- Lester and Sue Smith Breast Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Dan L. Duncan Cancer Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Igor Bado
- Lester and Sue Smith Breast Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Dan L. Duncan Cancer Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Weijie Zhang
- Lester and Sue Smith Breast Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Dan L. Duncan Cancer Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Benjamin R Arenkiel
- Department of Human and Molecular Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; McNair Medical Institute, Baylor College of Medicine, BCM600, One Baylor Plaza, Houston, TX 77030, USA
| | - Zonghai Li
- State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200032, P.R. China
| | - Meng Yang
- Department of General Surgery, China-Japan Friendship Hospital, Beijing 100029, China
| | - Shiyu Du
- Department of Gastroenterology, China-Japan Friendship Hospital, Beijing 100029, China
| | - Hong Zhao
- Department of Systems Medicine and Bioengineering, Houston Methodist Research Institute, 6670 Bertner Avenue, Houston, TX 77030, USA
| | - David R Rowley
- Dan L. Duncan Cancer Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
| | - Stephen T C Wong
- Dan L. Duncan Cancer Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Department of Systems Medicine and Bioengineering, Houston Methodist Research Institute, 6670 Bertner Avenue, Houston, TX 77030, USA
| | - Zbigniew Gugala
- Department of Orthopaedic Surgery & Rehabilitation, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Xiang H-F Zhang
- Lester and Sue Smith Breast Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Dan L. Duncan Cancer Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA; McNair Medical Institute, Baylor College of Medicine, BCM600, One Baylor Plaza, Houston, TX 77030, USA.
| |
Collapse
|
15
|
Wu J, Wang C, Häberli C, White KL, Shackleford DM, Chen G, Dong Y, Charman SA, Keiser J, Vennerstrom JL. SAR of a new antischistosomal urea carboxylic acid. Bioorg Med Chem Lett 2018; 28:3648-3651. [PMID: 30389288 DOI: 10.1016/j.bmcl.2018.10.039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 09/19/2018] [Accepted: 10/24/2018] [Indexed: 02/06/2023]
Abstract
Urea carboxylic acids, products of aryl hydantoin hydrolysis, were recently identified as a new antischistosomal chemotype. We now describe a baseline structure-activity relationship (SAR) for this compound series. With one exception, analogs of lead urea carboxylic acid 2 were quite polar with Log D7.4 values ranging from -1.9 to 1.8, had high aqueous solubilities in the range of 25-100 µg/mL, and were metabolically stable. None of the compounds had measurable in vitro antischistosomal activity or cytotoxicity, but four of these had moderate worm burden reduction (WBR) values of 42-70% when they were administered as single 100 mg/kg oral doses to S. mansoni-infected mice. These data indicate that with the exception of the gem-dimethyl substructure and the distal nitrogen atom of the urea functional group, the rest of the structure of 2 is required for in vivo antischistosomal activity.
Collapse
Affiliation(s)
- Jianbo Wu
- College of Pharmacy, University of Nebraska Medical Center, 986025 Nebraska Medical Center, Omaha, NE, United States
| | - Chunkai Wang
- College of Pharmacy, University of Nebraska Medical Center, 986025 Nebraska Medical Center, Omaha, NE, United States
| | - Cécile Häberli
- Department of Medical Parasitology and Infection Biology, Swiss Tropical Institute, Socinstrasse 57, CH-4002 Basel, Switzerland; University of Basel, CH-4003 Basel, Switzerland
| | - Karen L White
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - David M Shackleford
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Gong Chen
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Yuxiang Dong
- College of Pharmacy, University of Nebraska Medical Center, 986025 Nebraska Medical Center, Omaha, NE, United States
| | - Susan A Charman
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical Institute, Socinstrasse 57, CH-4002 Basel, Switzerland; University of Basel, CH-4003 Basel, Switzerland
| | - Jonathan L Vennerstrom
- College of Pharmacy, University of Nebraska Medical Center, 986025 Nebraska Medical Center, Omaha, NE, United States.
| |
Collapse
|
16
|
Gouveia MJ, Brindley PJ, Gärtner F, Costa JMCD, Vale N. Drug Repurposing for Schistosomiasis: Combinations of Drugs or Biomolecules. Pharmaceuticals (Basel) 2018; 11:E15. [PMID: 29401734 PMCID: PMC5874711 DOI: 10.3390/ph11010015] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 01/19/2018] [Accepted: 01/31/2018] [Indexed: 12/17/2022] Open
Abstract
Schistosomiasis is a major neglected tropical disease. Control of schistosomiasis currently relies on a single drug, praziquantel, and despite its efficacy against the all schistosome species that parasitize humans, it displays some problematic drawbacks and alone is ineffective in counteracting adverse pathologies associated with infection. Moreover, due to the development of the potential emergence of PZQ-resistant strains, the search for additional or alternative antischistosomal drugs have become a public health priority. The current drug discovery for schistosomiasis has been slow and uninspiring. By contrast, repurposing of existing approved drugs may offer a safe, rapid and cost-effective alternative. Combined treatment with PZQ and other drugs with different mode of action, i.e., antimalarials, shows promise results. In addition, a combination of anthelminthic drugs with antioxidant might be advantageous for modulating oxidative processes associated with schistosomiasis. Herein, we review studies dealing with combination therapies that involve PZQ and other anthelminthic drugs and/or antioxidant agents in treatment of schistosomiasis. Whereas PZQ combined with antioxidant agents might or might not interfere with anthelminthic efficacy, combinations may nonetheless ameliorate tissue damage and infection-associated complications. In fact, alone or combine with other drugs, antioxidants might be a valuable adjuvant to reduce morbidity and mortality of schistosomiasis. Therefore, attempting new combinations of anthelmintic drugs with other biomolecules such as antioxidants provides new avenues for discovery of alternatives to PZQ.
Collapse
Affiliation(s)
- Maria João Gouveia
- UCBIO/REQUIMTE, Laboratory of Pharmacology, Department of Drug Sciences, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo, 228, 4050-313 Porto, Portugal.
- Center for the Study of Animal Science, ICETA, University of Porto, Praça Gomes Teixeira, Apartado 55142, 4031-401 Porto, Portugal.
- Department of Molecular Pathology and Immunology, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
| | - Paul J Brindley
- Department of Microbiology, Immunology & Tropical Medicine, and Research Center for Neglected Diseases of Poverty, School of Medicine & Health Sciences, George Washington University, Washington, DC 20037, USA.
| | - Fátima Gärtner
- Department of Molecular Pathology and Immunology, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
- Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Rua Júlio Amaral de Carvalho, 45, 4200-135 Porto, Portugal.
- Institute of Investigation and Innovation in Health (i3s), Rua Alfredo Allen, 4200-135 Porto, Portugal.
| | - José M Correia da Costa
- Center for the Study of Animal Science, ICETA, University of Porto, Praça Gomes Teixeira, Apartado 55142, 4031-401 Porto, Portugal.
- Department of Infectious Diseases, INSA-National Health Institute Dr. Ricardo Jorge, Rua Alexandre Herculano 321, 4000-055 Porto, Portugal.
| | - Nuno Vale
- UCBIO/REQUIMTE, Laboratory of Pharmacology, Department of Drug Sciences, Faculty of Pharmacy, University of Porto, Rua de Jorge Viterbo, 228, 4050-313 Porto, Portugal.
| |
Collapse
|
17
|
Wu J, Wang C, Leas D, Vargas M, White KL, Shackleford DM, Chen G, Sanford AG, Hemsley RM, Davis PH, Dong Y, Charman SA, Keiser J, Vennerstrom JL. Progress in antischistosomal N,N'-diaryl urea SAR. Bioorg Med Chem Lett 2017; 28:244-248. [PMID: 29317164 DOI: 10.1016/j.bmcl.2017.12.064] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 12/27/2017] [Accepted: 12/28/2017] [Indexed: 02/08/2023]
Abstract
N,N'-Diaryl ureas have recently emerged as a new antischistosomal chemotype. We now describe physicochemical profiling, in vitro ADME, plasma exposure, and ex vivo and in vivo activities against Schistosoma mansoni for twenty new N,N'-diaryl ureas designed primarily to increase aqueous solubility, but also to maximize structural diversity. Replacement of one of the 4-fluoro-3-trifluoromethylphenyl substructures of lead N,N'-diaryl urea 1 with azaheterocycles and benzoic acids, benzamides, or benzonitriles decreased lipophilicity, and in most cases, increased aqueous solubility. There was no clear relationship between lipophilicity and metabolic stability, although all compounds with 3-trifluoromethyl-4-pyridyl substructures were metabolically stable. N,N'-diaryl ureas containing 4-fluoro-3-trifluoromethylphenyl, 3-trifluoromethyl-4-pyridyl, 2,2-difluorobenzodioxole, or 4-benzonitrile substructures had high activity against ex vivo S. mansoni and relatively low cytotoxicity. N,N-diaryl ureas with 3-trifluoromethyl-4-pyridyl and 2,2-difluorobenzodioxole substructures had the highest exposures whereas those with 4-fluoro-3-trifluoromethylphenyl substructures had the best in vivo antischistosomal activities. There was no direct correlation between compound exposure and in vivo activity.
Collapse
Affiliation(s)
- Jianbo Wu
- College of Pharmacy, University of Nebraska Medical Center, 986025 Nebraska Medical Center, Omaha, NE, United States
| | - Chunkai Wang
- College of Pharmacy, University of Nebraska Medical Center, 986025 Nebraska Medical Center, Omaha, NE, United States
| | - Derek Leas
- College of Pharmacy, University of Nebraska Medical Center, 986025 Nebraska Medical Center, Omaha, NE, United States
| | - Mireille Vargas
- Department of Medical Parasitology and Infection Biology, Swiss Tropical Institute, Socinstrasse 57, CH-4002 Basel, Switzerland; University of Basel, CH-4003 Basel, Switzerland
| | - Karen L White
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - David M Shackleford
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Gong Chen
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Austin G Sanford
- Department of Biology, University of Nebraska at Omaha, Omaha, NE, United States
| | - Ryan M Hemsley
- Department of Biology, University of Nebraska at Omaha, Omaha, NE, United States
| | - Paul H Davis
- Department of Biology, University of Nebraska at Omaha, Omaha, NE, United States
| | - Yuxiang Dong
- College of Pharmacy, University of Nebraska Medical Center, 986025 Nebraska Medical Center, Omaha, NE, United States
| | - Susan A Charman
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical Institute, Socinstrasse 57, CH-4002 Basel, Switzerland; University of Basel, CH-4003 Basel, Switzerland
| | - Jonathan L Vennerstrom
- College of Pharmacy, University of Nebraska Medical Center, 986025 Nebraska Medical Center, Omaha, NE, United States.
| |
Collapse
|
18
|
Zhou S, Huang G. Design, synthesis and bioactivities of phenithionate analogues or derivatives for anti-schistosomiasis. MEDCHEMCOMM 2017; 9:328-336. [PMID: 30108926 DOI: 10.1039/c7md00590c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 12/11/2017] [Indexed: 12/16/2022]
Abstract
A novel series of phenithionate analogues or derivatives were designed and synthesized using phenithionate as the lead compound, and their bioactivities were studied. Their structures were confirmed by 1H NMR, 13C NMR, HR-ESI-MS, and elemental analysis, respectively. The results of in vitro inhibitory activity measurement proved that compounds 5a, 5c, 5g, 5i, 5m and 5o had a better inhibitory effect on larva and imago schistosoma. Among them, the inhibitory activity of compound 5i for larva schistosoma was IC50 = 5.21 ± 0.04 μg mL-1, and for imago schistosoma it was IC50 = 6.35 ± 0.08 μg mL-1. Moreover, the experimental results of in vivo anti-schistosomiasis activity measurement showed that they had good anti-schistosomiasis activity. Therefore, these compounds had better drugability.
Collapse
Affiliation(s)
- Shiyang Zhou
- College of Chemistry , Chongqing Normal University , Chongqing 401331 , China . .,Engineering Research Center of Ministry of Education for Biotechnology of Active Substances in Chongqing Normal University , Chongqing 401331 , China
| | - Gangliang Huang
- College of Chemistry , Chongqing Normal University , Chongqing 401331 , China . .,Engineering Research Center of Ministry of Education for Biotechnology of Active Substances in Chongqing Normal University , Chongqing 401331 , China
| |
Collapse
|
19
|
Immunohistochemical Investigations of Treatment with Ro 13-3978, Praziquantel, Oxamniquine, and Mefloquine in Schistosoma mansoni-Infected Mice. Antimicrob Agents Chemother 2017; 61:AAC.01142-17. [PMID: 28971860 DOI: 10.1128/aac.01142-17] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 09/22/2017] [Indexed: 11/20/2022] Open
Abstract
To date, there is only one drug in use, praziquantel, to treat more than 250 million people afflicted with schistosomiasis, a debilitating parasitic disease. The aryl hydantoin Ro 13-3978 is a promising drug candidate with in vivo activity superior to that of praziquantel against both adult and juvenile Schistosoma mansoni organisms. Given the drug's contrasting low activity in vitro and the timing of its onset of action in vivo, it was postulated that immune-assisted parasite clearance could contribute to the drug's in vivo activity. We undertook histopathological studies to investigate this hypothesis. Infected mice were treated with an effective dose of Ro 13-3978 (100 mg/kg of body weight) and were dissected before and after the drug's in vivo onset of action. The veins and livers were excised, paraffin-embedded, and sectioned, and macrophages (IBA-1), neutrophils (Neutro), B cells (CD45R), and T cells (CD3) were stained by immunohistochemistry. For comparison, samples from infected untreated mice and mice treated with effective doses of praziquantel (400 mg/kg), oxamniquine (200 mg/kg), and mefloquine (200 mg/kg) were examined. At 24 h after treatment with Ro 13-3978, significant macrophage recruitment to the veins was observed, along with a modest increase in circulating B cells, and at 48 h, neutrophils and T cells are also present. Treatment with praziquantel and oxamniquine showed similar patterns of recruitment but with comparatively higher cellular levels, whereas mefloquine treatment resulted in minimal cell recruitment until 3 days posttreatment. Our study sheds light on the immediate immune responses to antischistosomal treatment in mice and provides further insight into immune effector mechanisms of schistosome clearance.
Collapse
|
20
|
Abla N, Keiser J, Vargas M, Reimers N, Haas H, Spangenberg T. Evaluation of the pharmacokinetic-pharmacodynamic relationship of praziquantel in the Schistosoma mansoni mouse model. PLoS Negl Trop Dis 2017; 11:e0005942. [PMID: 28934207 PMCID: PMC5626502 DOI: 10.1371/journal.pntd.0005942] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 10/03/2017] [Accepted: 09/07/2017] [Indexed: 12/27/2022] Open
Abstract
After more than 40 years of use, Praziquantel (PZQ) still remains the drug of choice for the treatment of intestinal and urogenital schistosomiasis. Its anti-parasitic activity resides primarily in the (R)-enantiomer. Hitherto neither the molecular target nor the pharmacokinetic-pharmacodynamic relationship have been fully elucidated. Here we investigated the efficacy and pharmacokinetics of PZQ in the Schistosoma mansoni mouse model to determine the key factors that drive its efficacy. Dose-response studies with racemic PZQ with or without addition of an irreversible pan-cytochrome P450 (CYP) inhibitor, 1-aminobenzotriazole (ABT), were performed. In addition, efficacy of PZQ in the presence of the CYP inducer, dexamethasone (DEX), was determined. Plasma samples were obtained by tail vein bleeding at 4 time points. The (R)-PZQ levels were determined using a LC-MS/MS method. Non-compartmental pharmacokinetic analysis was performed using PKsolver. In addition, experiments using an enhanced in vitro assay were conducted. We found that the use of ABT increased (R)-PZQ plasma exposures in the systemic circulation by ~10 to 20 fold but the latter were not predictive of efficacy. The use of DEX decreased plasma exposures of (R)-PZQ in the systemic circulation by ~10 fold without reducing efficacy. We extrapolated the (R)-PZQ concentrations in mouse portal vein / mesenteric veins from the systemic exposures and found that a free exposure of (R)-PZQ of ~ 20 μM*h in the portal vein was needed to obtain a worm burden reduction >60%. It is suggested that the high (R)-PZQ concentrations available before the hepatic first pass metabolism drive the efficacy against S. mansoni adult worms residing in the mesenteric veins. It is then possible that the current dosing regimen of 40 mg/kg in preventive chemotherapy programs may provide suboptimal concentrations in low-weight patients such as children, due to smaller total amounts of drug administered, and may consequently result in lower cure rates.
Collapse
Affiliation(s)
- Nada Abla
- Merck Global Health Institute, Ares Trading S.A., a subsidiary of Merck KGaA (Darmstadt, Germany), Coinsins, Switzerland
- Medicines for Malaria Venture, Geneva, Switzerland
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Mireille Vargas
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | | | - Helmut Haas
- helminGuard, Research Center Borstel, Borstel, Germany
| | - Thomas Spangenberg
- Merck Global Health Institute, Ares Trading S.A., a subsidiary of Merck KGaA (Darmstadt, Germany), Coinsins, Switzerland
- * E-mail:
| |
Collapse
|
21
|
Campelo YDM, Mafud AC, Véras LMC, Guimarães MA, Yamaguchi LF, Lima DF, Arcanjo DDR, Kato MJ, Mendonça RZ, Pinto PLS, Mascarenhas YP, Silva MPN, de Moraes J, Eaton P, de Souza de Almeida Leite JR. Synergistic effects of in vitro combinations of piplartine, epiisopiloturine and praziquantel against Schistosoma mansoni. Biomed Pharmacother 2017; 88:488-499. [PMID: 28126674 DOI: 10.1016/j.biopha.2016.12.057] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Revised: 12/09/2016] [Accepted: 12/14/2016] [Indexed: 01/22/2023] Open
Abstract
Schistosomiasis is a world health problem, and praziquantel is the only drug currently used for the treatment. There is some evidence that extensive monotherapy of praziquantel may be leading to drug resistance in the parasite. In order to find alternative treatments, the effects of the combination of epiisopiloturine (EPI), piplartine (PPT) and praziquantel (PZQ) were evaluated. Similarity analysis of these compounds was performed using optimized molecular structures to compare the shape and the charge modeling of combinations between PZQ and EPI or PPT. Supported by this data, in vitro association of PZQ-PPT, PZQ-EPI, and EPI-PPT was carried out, and the activity of these combinations against Schistosoma mansoni was assessed. The results showed synergistic activity with a combination index (CI) of 0.42 for the treatment with PZQ-PPT. Both PZQ-EPI and EPI-PPT combinations also showed synergistic effects, with CI values of 0.86 and 0.61, respectively. Surface alterations in the tegument of adult schistosomes after the treatments were observed using laser confocal microscopy and scanning electron microscopy. Additionally, the association of EPI-PPT decreased the cytotoxicity when compared with both isolated compounds in three different lines of mammalian cells. Thus, synergistic combinations of PZQ-PPT, PZQ-EPI, and EPI-PPT create the possibility of reduced doses to be used against Schistosoma mansoni.
Collapse
Affiliation(s)
- Yuri Dias Macedo Campelo
- Biodiversity and Biotechnology Research Center, Biotec, Federal University of Piauí, UFPI, Parnaíba, PI, 64202020, Brazil; Institute of Higher Education of Vale do Parnaíba, FAHESP/IESVAP, Parnaíba, PI, Brazil
| | - Ana Carolina Mafud
- São Carlos Institute of Physics, University of São Paulo, São Carlos, SP, Brazil
| | - Leiz Maria Costa Véras
- Biodiversity and Biotechnology Research Center, Biotec, Federal University of Piauí, UFPI, Parnaíba, PI, 64202020, Brazil
| | - Maria Adelaide Guimarães
- Biodiversity and Biotechnology Research Center, Biotec, Federal University of Piauí, UFPI, Parnaíba, PI, 64202020, Brazil; Phytobios Nordeste LTDA, Centroflora Group, Parnaíba, PI, Brazil
| | - Lydia F Yamaguchi
- Institute of Chemistry, University of São Paulo, São Paulo, SP, Brazil
| | - David Fernandes Lima
- Biodiversity and Biotechnology Research Center, Biotec, Federal University of Piauí, UFPI, Parnaíba, PI, 64202020, Brazil; Federal University of Vale do São Francisco, Paulo Afonso, BA, Brazil
| | - Daniel Dias Rufino Arcanjo
- Biodiversity and Biotechnology Research Center, Biotec, Federal University of Piauí, UFPI, Parnaíba, PI, 64202020, Brazil
| | - Massuo J Kato
- Institute of Chemistry, University of São Paulo, São Paulo, SP, Brazil
| | | | | | | | - Marcos P N Silva
- Research Center for Neglected Diseases, Guarulhos University, Guarulhos, SP, Brazil
| | - Josué de Moraes
- Research Center for Neglected Diseases, Guarulhos University, Guarulhos, SP, Brazil
| | - Peter Eaton
- Biodiversity and Biotechnology Research Center, Biotec, Federal University of Piauí, UFPI, Parnaíba, PI, 64202020, Brazil; UCIBIO/REQUIMTE, Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, Portugal
| | - José Roberto de Souza de Almeida Leite
- Biodiversity and Biotechnology Research Center, Biotec, Federal University of Piauí, UFPI, Parnaíba, PI, 64202020, Brazil; Faculty of Medicine, University of Brasilia, UnB, Brasília, DF, Brazil.
| |
Collapse
|
22
|
Bergquist R, Utzinger J, Keiser J. Controlling schistosomiasis with praziquantel: How much longer without a viable alternative? Infect Dis Poverty 2017; 6:74. [PMID: 28351414 PMCID: PMC5371198 DOI: 10.1186/s40249-017-0286-2] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 03/14/2017] [Indexed: 12/11/2022] Open
Abstract
The current approach of morbidity control of schistosomiasis, a helminth disease of poverty with considerable public health and socioeconomic impact, is based on preventive chemotherapy with praziquantel. There is a pressing need for new drugs against this disease whose control entirely depends on this single drug that has been widely used over the past 40 years. We argue that a broader anthelminthic approach supplementing praziquantel with new antischistosomals targeting different parasite development stages would not only increase efficacy but also reduce the risk for drug resistance. Repositioning drugs already approved for other diseases provides a shortcut to clinical trials, as it is expected that such drugs rapidly pass the regulatory authorities. The antischistosomal properties of antimalarial drugs (e.g., semisynthetic artemisinins, synthetic trioxolanes, trioxaquines and mefloquine) and of drugs being developed or registered for other purposes (e.g., moxidectin and miltefosin), administered alone or in combination with praziquantel, have been tested in the laboratory and clinical trials. Another avenue to follow is the continued search for new antischistosomal properties in plants. Here, we summarise recent progress made in schistosomiasis chemotherapy, placing particular emphasis on repositioning of existing drugs against schistosomiasis.
Collapse
Affiliation(s)
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, P.O. Box, CH-4002, Basel, Switzerland.,University of Basel, P.O. Box, CH-4003, Basel, Switzerland
| | - Jennifer Keiser
- Swiss Tropical and Public Health Institute, P.O. Box, CH-4002, Basel, Switzerland. .,University of Basel, P.O. Box, CH-4003, Basel, Switzerland.
| |
Collapse
|
23
|
Matthews H, Deakin J, Rajab M, Idris-Usman M, Nirmalan NJ. Investigating antimalarial drug interactions of emetine dihydrochloride hydrate using CalcuSyn-based interactivity calculations. PLoS One 2017; 12:e0173303. [PMID: 28257497 PMCID: PMC5336292 DOI: 10.1371/journal.pone.0173303] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 02/17/2017] [Indexed: 11/18/2022] Open
Abstract
The widespread introduction of artemisinin-based combination therapy has contributed to recent reductions in malaria mortality. Combination therapies have a range of advantages, including synergism, toxicity reduction, and delaying the onset of resistance acquisition. Unfortunately, antimalarial combination therapy is limited by the depleting repertoire of effective drugs with distinct target pathways. To fast-track antimalarial drug discovery, we have previously employed drug-repositioning to identify the anti-amoebic drug, emetine dihydrochloride hydrate, as a potential candidate for repositioned use against malaria. Despite its 1000-fold increase in in vitro antimalarial potency (ED50 47 nM) compared with its anti-amoebic potency (ED50 26–32 uM), practical use of the compound has been limited by dose-dependent toxicity (emesis and cardiotoxicity). Identification of a synergistic partner drug would present an opportunity for dose-reduction, thus increasing the therapeutic window. The lack of reliable and standardised methodology to enable the in vitro definition of synergistic potential for antimalarials is a major drawback. Here we use isobologram and combination-index data generated by CalcuSyn software analyses (Biosoft v2.1) to define drug interactivity in an objective, automated manner. The method, based on the median effect principle proposed by Chou and Talalay, was initially validated for antimalarial application using the known synergistic combination (atovaquone-proguanil). The combination was used to further understand the relationship between SYBR Green viability and cytocidal versus cytostatic effects of drugs at higher levels of inhibition. We report here the use of the optimised Chou Talalay method to define synergistic antimalarial drug interactivity between emetine dihydrochloride hydrate and atovaquone. The novel findings present a potential route to harness the nanomolar antimalarial efficacy of this affordable natural product.
Collapse
Affiliation(s)
- Holly Matthews
- Environment and Life sciences, University of Salford, Greater Manchester, United Kingdom
| | - Jon Deakin
- Environment and Life sciences, University of Salford, Greater Manchester, United Kingdom
| | - May Rajab
- Environment and Life sciences, University of Salford, Greater Manchester, United Kingdom
| | - Maryam Idris-Usman
- Environment and Life sciences, University of Salford, Greater Manchester, United Kingdom
| | - Niroshini J. Nirmalan
- Environment and Life sciences, University of Salford, Greater Manchester, United Kingdom
- * E-mail:
| |
Collapse
|
24
|
The Role of Natural Products in Drug Discovery and Development against Neglected Tropical Diseases. Molecules 2016; 22:molecules22010058. [PMID: 28042865 PMCID: PMC6155950 DOI: 10.3390/molecules22010058] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 12/23/2016] [Accepted: 12/27/2016] [Indexed: 12/20/2022] Open
Abstract
Endemic in 149 tropical and subtropical countries, neglected tropical diseases (NTDs) affect more than 1 billion people annually, including 875 million children in developing economies. These diseases are also responsible for over 500,000 deaths per year and are characterized by long-term disability and severe pain. The impact of the combined NTDs closely rivals that of malaria and tuberculosis. Current treatment options are associated with various limitations including widespread drug resistance, severe adverse effects, lengthy treatment duration, unfavorable toxicity profiles, and complicated drug administration procedures. Natural products have been a valuable source of drug regimens that form the cornerstone of modern pharmaceutical care. In this review, we highlight the potential that remains untapped in natural products as drug leads for NTDs. We cover natural products from plant, marine, and microbial sources including natural-product-inspired semi-synthetic derivatives which have been evaluated against the various causative agents of NTDs. Our coverage is limited to four major NTDs which include human African trypanosomiasis (sleeping sickness), leishmaniasis, schistosomiasis and lymphatic filariasis.
Collapse
|
25
|
Wang C, Zhao Q, Vargas M, Jones JO, White KL, Shackleford DM, Chen G, Saunders J, Ng ACF, Chiu FCK, Dong Y, Charman SA, Keiser J, Vennerstrom JL. Revisiting the SAR of the Antischistosomal Aryl Hydantoin (Ro 13-3978). J Med Chem 2016; 59:10705-10718. [PMID: 27933964 PMCID: PMC5150661 DOI: 10.1021/acs.jmedchem.6b01410] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
![]()
The aryl hydantoin 1 (Ro 13-3978) was identified in
the early 1980s as a promising antischistosomal lead compound. However,
this series of aryl hydantoins produced antiandrogenic side effects
in the host, a not unexpected outcome given their close structural
similarity to the antiandrogenic drug nilutamide. Building on the
known SAR of this compound series, we now describe a number of analogs
of 1 designed to maximize structural diversity guided
by incorporation of substructures and functional groups known to diminish
ligand–androgen receptor interactions. These analogs had calculated
polar surface area (PSA), measured LogD7.4, aqueous kinetic
solubility, and estimated plasma protein binding values in ranges
predictive of good ADME profiles. The principal SAR insight was that
the hydantoin core of 1 is required for high antischistosomal
activity. We identified several compounds with high antischistosomal
efficacy that were less antiandrogenic than 1. These
data provide direction for the ongoing optimization of antischistosomal
hydantoins.
Collapse
Affiliation(s)
- Chunkai Wang
- College of Pharmacy, University of Nebraska Medical Center , 986125 Nebraska Medical Center, Omaha, Nebraska 68198, United States
| | - Qingjie Zhao
- College of Pharmacy, University of Nebraska Medical Center , 986125 Nebraska Medical Center, Omaha, Nebraska 68198, United States
| | - Mireille Vargas
- Department of Medical Parasitology and Infection Biology, Swiss Tropical Institute , Socinstrasse 57, CH-4002 Basel, Switzerland.,University of Basel , CH-4003 Basel, Switzerland
| | - Jeremy O Jones
- Department of Cancer Biology, Beckman Research Institute, City of Hope National Medical Center , Duarte, California 91010, United States
| | - Karen L White
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville Campus) , 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - David M Shackleford
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville Campus) , 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Gong Chen
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville Campus) , 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Jessica Saunders
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville Campus) , 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Alice C F Ng
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville Campus) , 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Francis C K Chiu
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville Campus) , 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Yuxiang Dong
- College of Pharmacy, University of Nebraska Medical Center , 986125 Nebraska Medical Center, Omaha, Nebraska 68198, United States
| | - Susan A Charman
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville Campus) , 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical Institute , Socinstrasse 57, CH-4002 Basel, Switzerland.,University of Basel , CH-4003 Basel, Switzerland
| | - Jonathan L Vennerstrom
- College of Pharmacy, University of Nebraska Medical Center , 986125 Nebraska Medical Center, Omaha, Nebraska 68198, United States
| |
Collapse
|
26
|
Pharmacokinetics of the Antischistosomal Lead Ozonide OZ418 in Uninfected Mice Determined by Liquid Chromatography-Tandem Mass Spectrometry. Antimicrob Agents Chemother 2016; 60:7364-7371. [PMID: 27697760 DOI: 10.1128/aac.02394-15] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 09/27/2016] [Indexed: 11/20/2022] Open
Abstract
One of the major neglected tropical diseases, schistosomiasis, is currently treated and controlled with a single drug, praziquantel. The quest for an alternative drug is fueled by the lack of activity of praziquantel against juvenile Schistosoma worms and the fear of emerging resistance. The synthetic ozonide OZ418 has shown high activity against Schistosoma mansoni, S. haematobium, and S. japonicum in vivo, but its drug disposition remains unknown. To bridge this gap, our study determined the basic pharmacokinetic (PK) parameters of a single oral dose (400 mg/kg of body weight) of OZ418 in uninfected mice. First, a simple liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to quantify OZ418 concentrations in mouse plasma was successfully developed and validated according to U.S. FDA guidelines. This method proved to be selective, accurate (93 to 103%), precise (5 to 16%), and devoid of significant matrix effects (90 to 102%) and provided excellent recovery (101 to 102%). A median peak concentration of 190 (range, 185 to 231) μg/ml was reached at 2 h (2 to 3 h) posttreatment. A naive pooled noncompartmental PK analysis estimated a mean area under the plasma concentration-versus-time curve (AUC) of 9,303 μg h/ml (7,039.2 to 11,908.5 μg h/ml) and a half-life of 38.7 h (20 to 64.6 h). Thus, the OZ418 level in plasma remained well above its in vitro 50% inhibitory concentrations (IC50s) of 27.4 μg/ml (adult S. mansoni worms at 72 h) for at least 75 h. Consistently, OZ418 degraded little in plasma at 37°C (<20% in 121 h) and weakly inhibited cytochrome P450 (CYP450) metabolism (IC50 of 37 to 144 μM). Our results provide a first insight into the disposition of OZ418, paving the way for further studies of its biological fate and effect.
Collapse
|
27
|
Abou-Shady OM, Mohammed SS, Attia SS, Yusuf HAS, Helmy DO. Therapeutic effect of mefloquine on Schistosoma mansoni in experimental infection in mice. J Parasit Dis 2016; 40:259-67. [PMID: 27413290 PMCID: PMC4927471 DOI: 10.1007/s12639-014-0489-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Accepted: 05/15/2014] [Indexed: 11/25/2022] Open
Abstract
Schistosomiasis is one of the most prevalent parasitic infections worldwide. Praziquantel is the drug of choice for treatment of schistosomiasis for its high efficacy. The present work was carried out on 160 mice to evaluate the therapeutic effect of mefloquine on experimental schistosomiasis mansoni. Mice were classified into 3 groups; group I (20 infected non-treated mice), group II included 60 infected mice which were further divided into group IIm (20 mice treated with 400 mg/kg mefloquine), group IIp (20 mice treated with 1,000 mg/kg/2 days praziquantel) and group IIpm (20 mice treated with 200 mg/kg mefloquine and 500 mg/kg praziquantel), group III included 80 non-infected mice subdivided into group IIIn (20 non-treated mice), group IIIm (20 mice treated with 400 mg/kg mefloquine), group IIIp (20 mice treated with 1,000 mg/kg/2 days praziquantel), group IIIpm (20 mice treated with 200 mg mefloquine and 500 mg praziquantel). Mefloquine significantly reduced worm burden, tissue egg load, number of liver granulomas and increased the percent of dead ova within granulomas. Combination of mefloquine and praziquantel gave better curative effects than praziquantel or mefloquine given alone.
Collapse
Affiliation(s)
| | | | - Samar Sayed Attia
- />Medical Parasitology Department, Faculty of Medicine, Cairo University, Cairo, Egypt
| | | | - Dina Omar Helmy
- />Pathology Department, Faculty of Medicine, Cairo University, Cairo, Egypt
| |
Collapse
|
28
|
Repurposing pharma assets: an accelerated mechanism for strengthening the schistosomiasis drug development pipeline. Future Med Chem 2016; 7:727-35. [PMID: 25996066 DOI: 10.4155/fmc.15.26] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Schistosomiasis, one of 17 diseases deemed to be neglected by the World Health Organization, has received little attention from the biopharmaceutical industry. Due to this, only a handful of drugs have been developed to treat schistosomiasis, with only one, praziquantel, used in most endemic regions. Growing concern over resistance coupled with praziquantel's incomplete efficacy across all stages of the Schistosoma platyhelminth life cycle highlights the urgent need for new drugs. The WIPO Re:Search consortium is a platform whereupon biopharmaceutical company compounds are being repurposed to efficiently and cost-effectively develop new drugs for neglected diseases such as schistosomiasis. This article summarizes recent clinical-stage efforts to identify new antischistosomals and highlights biopharmaceutical company compounds with potential for repurposing to treat schistosomiasis.
Collapse
|
29
|
Tao Y, Xue J, Jiang B, Zhang HB, Xiao SH. Significance of higher drug concentration in erythrocytes of mice infected with Schistosoma japonicum and treated orally with mefloquine at single doses. Parasitol Res 2015; 114:4521-30. [PMID: 26341799 DOI: 10.1007/s00436-015-4696-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 08/24/2015] [Indexed: 12/01/2022]
Abstract
The purpose of the present study is to understand the pharmacokinetic feature of mefloquine measured by erythrocytes and plasma in Schistosoma japonicum (S. j.)-infected mice and non-infected mice after oral administration of the drug at single doses. A high-performance liquid chromatography (HPLC) method was used to measure the plasma and erythrocyte concentrations of mefloquine at varying intervals posttreatment. Our results demonstrated that in non-infected mice treated orally with mefloquine at an ineffective dose of 50 mg/kg or effective dose of 200 mg/kg for 2-72 h, the erythrocyte-to-plasma ratios of mefloquine were 5.8-11.2 or 2-14.2. On the other hand, in S. j.-infected mice treated with the same single doses of the drug, the erythrocyte and plasma drug concentration ratios were 3.1-4.6 or 2.9-8.5, manifesting that either in infected mice or in non-infected mice that received oral mefloquine resulted in higher concentration of mefloquine in erythrocytes than that in plasma. Unexpectedly, under oral administration of mefloquine at a higher single dose of 200 mg/kg, the pharmacokinetic parameter C max values for plasma from S. j.-infected and non-infected mice were 1.6 ± 0.3 and 2.0 ± 0.4 μg/mL, respectively, which were below the determined in vitro LC50 (50 % lethal concentration) value of 4.93 μg/mL. Therefore, the plasma concentration of mefloquine may display a little effect against schistosomes during the treatment. Although the values of T 1/2 and AUC0-∞ for erythrocytes were significantly longer and higher in infected mice than those of corresponding non-infect mice that received the same single mefloqine dose of 50 mg/kg, the C max value was only 2.6 ± 0.4 μg/mL lower than the determined in vitro LC50, which may explain why this low single dose is ineffective against schistosomes in vivo. After administration of higher mefloquine dose of 200 mg/kg, the C max value for erythrocytes in infected mice was 30 % (7.4 ± 0.7 versus 10.7 ± 2.7 μg/mL) lower than that in the corresponding non-infected mice, but its level was above the determined in vitro LC95 (95 % lethal concentration) value of 6.12 μg/mL. Meanwhile, longer T 1/2 value of 159.2 ± 129.3 h in infected mice led to significant increase in AUC0-∞ value (1969.3 ± 1057.7 vs 486.4 ± 53.0 μg/mL·h), relative to corresponding non-infected mice. In addition, the mean residence time (MRT0-∞) in infected mice was also significantly longer than that in non-infected mice. All these results may beneficial for the treatment. According to the results, we suggest that higher ratios of mefloquine concentration in erythrocytes to plasma may offer a way to transport mefloquine to the worm gut through ingestion of erythrocytes by the worms, where the gut is the site for displaying the effect by mefloquine.
Collapse
Affiliation(s)
- Yi Tao
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Key Laboratory of Parasite and Vector Biology, MOH, WHO Collaborating Centre for Malaria, Schistosomiasis, and Filariasis, Shanghai, 200025, People's Republic of China.
| | - Jian Xue
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Key Laboratory of Parasite and Vector Biology, MOH, WHO Collaborating Centre for Malaria, Schistosomiasis, and Filariasis, Shanghai, 200025, People's Republic of China.
| | - Bin Jiang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Key Laboratory of Parasite and Vector Biology, MOH, WHO Collaborating Centre for Malaria, Schistosomiasis, and Filariasis, Shanghai, 200025, People's Republic of China.
| | - Hao-Bing Zhang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Key Laboratory of Parasite and Vector Biology, MOH, WHO Collaborating Centre for Malaria, Schistosomiasis, and Filariasis, Shanghai, 200025, People's Republic of China.
| | - Shu-Hua Xiao
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Key Laboratory of Parasite and Vector Biology, MOH, WHO Collaborating Centre for Malaria, Schistosomiasis, and Filariasis, Shanghai, 200025, People's Republic of China.
| |
Collapse
|
30
|
Korkmaz S, Zararsiz G, Goksuluk D. MLViS: A Web Tool for Machine Learning-Based Virtual Screening in Early-Phase of Drug Discovery and Development. PLoS One 2015; 10:e0124600. [PMID: 25928885 PMCID: PMC4415797 DOI: 10.1371/journal.pone.0124600] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 03/03/2015] [Indexed: 12/18/2022] Open
Abstract
Virtual screening is an important step in early-phase of drug discovery process. Since there are thousands of compounds, this step should be both fast and effective in order to distinguish drug-like and nondrug-like molecules. Statistical machine learning methods are widely used in drug discovery studies for classification purpose. Here, we aim to develop a new tool, which can classify molecules as drug-like and nondrug-like based on various machine learning methods, including discriminant, tree-based, kernel-based, ensemble and other algorithms. To construct this tool, first, performances of twenty-three different machine learning algorithms are compared by ten different measures, then, ten best performing algorithms have been selected based on principal component and hierarchical cluster analysis results. Besides classification, this application has also ability to create heat map and dendrogram for visual inspection of the molecules through hierarchical cluster analysis. Moreover, users can connect the PubChem database to download molecular information and to create two-dimensional structures of compounds. This application is freely available through www.biosoft.hacettepe.edu.tr/MLViS/.
Collapse
Affiliation(s)
- Selcuk Korkmaz
- Department of Biostatistics, Faculty of Medicine, Hacettepe University, Sihhiye, Ankara, Turkey
- * E-mail:
| | - Gokmen Zararsiz
- Department of Biostatistics, Faculty of Medicine, Hacettepe University, Sihhiye, Ankara, Turkey
| | - Dincer Goksuluk
- Department of Biostatistics, Faculty of Medicine, Hacettepe University, Sihhiye, Ankara, Turkey
| |
Collapse
|
31
|
Pakharukova MY, Shilov AG, Pirozhkova DS, Katokhin AV, Mordvinov VA. The first comprehensive study of praziquantel effects in vivo and in vitro on European liver fluke Opisthorchis felineus (Trematoda). Int J Antimicrob Agents 2015; 46:94-100. [PMID: 25862308 DOI: 10.1016/j.ijantimicag.2015.02.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 01/20/2015] [Accepted: 02/12/2015] [Indexed: 10/23/2022]
Abstract
The European liver fluke Opisthorchis felineus (Rivolta, 1884) is an epidemiologically important parasite infecting mammals, including humans. Opisthorchis felineus is widespread in Russia, Kazakhstan and Eastern European countries. Praziquantel (PZQ) is the drug of choice for the treatment of opisthorchiasis, but the effects of this drug on O. felineus are poorly studied. The aims of this work were (i) to perform a study of PZQ effects in vitro, (ii) to identify morphological markers of PZQ action on O. felineus, (iii) to analyse damage to the worm surface and (iv) to assess the efficacy of PZQ in vivo in a hamster model. Light microscopy, optical sectioning and fluorescence microscopy were used to study morphological changes. In vivo, PZQ at a dose of 400mg/kg reduced the rate of infection in experimental acute and chronic opisthorchiasis in hamsters by 70% and 79%, respectively. In vitro, the drug caused destruction and vacuolisation of the tegument of O. felineus, contractions of the worm musculature, paralysis, and irreversible changes in morphology (IC50=0.14μg/mL). Differences in susceptibility to the drug between adult and newly excysted metacercariae were also observed. Qualitative effects of PZQ in vivo and in vitro were similar to the drug's effects on other trematodes, including epidemiologically important liver flukes. Nevertheless, high heterogeneity of O. felineus specimens in terms of susceptibility to the drug was observed. In addition, we describe for the first time the high rate of recovery of O. felineus following the destructive action of PZQ.
Collapse
Affiliation(s)
- Mariya Y Pakharukova
- Institute of Cytology and Genetics (ICG), Siberian Branch of the Russian Academy of Sciences (SB RAS), 10 Lavrentiev Ave., Novosibirsk 630090, Russia; Novosibirsk State University, 2 Pirogov Street, Novosibirsk 630060, Russia.
| | - Alexander G Shilov
- Institute of Cytology and Genetics (ICG), Siberian Branch of the Russian Academy of Sciences (SB RAS), 10 Lavrentiev Ave., Novosibirsk 630090, Russia
| | - Darya S Pirozhkova
- Institute of Cytology and Genetics (ICG), Siberian Branch of the Russian Academy of Sciences (SB RAS), 10 Lavrentiev Ave., Novosibirsk 630090, Russia
| | - Alexey V Katokhin
- Institute of Cytology and Genetics (ICG), Siberian Branch of the Russian Academy of Sciences (SB RAS), 10 Lavrentiev Ave., Novosibirsk 630090, Russia
| | - Viatcheslav A Mordvinov
- Institute of Cytology and Genetics (ICG), Siberian Branch of the Russian Academy of Sciences (SB RAS), 10 Lavrentiev Ave., Novosibirsk 630090, Russia; Institute of Molecular Biology and Biophysics, Siberian Branch of the Russian Academy of Sciences (SB RAMS), Tymakova 2, Novosibirsk 630060, Russia
| |
Collapse
|
32
|
Drug-induced exposure of Schistosoma mansoni antigens SmCD59a and SmKK7. PLoS Negl Trop Dis 2015; 9:e0003593. [PMID: 25774883 PMCID: PMC4361651 DOI: 10.1371/journal.pntd.0003593] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 02/05/2015] [Indexed: 11/22/2022] Open
Abstract
Background Schistosomiasis is a serious health problem especially in developing countries and affects more than 243 million people. Only few anthelmintic drugs are available up to now. A major obstacle for drug treatment is the different developmental stages and the varying host compartments during worm development. Anthelmintic drugs have been tested mainly on adult schistosomes or freshly transformed cercariae. Knowledge concerning the larval stages is lacking. Methodology/Principal Findings In this study, we used in vitro-grown schistosomula (aged between 2 to 14 days) to investigate drug effects of the three anthelmintics praziquantel, artemether, and oxamniquine. Further, we analyzed the antibody accessibility of two exemplary schistosome antigens SmCD59a and SmKK7, before and after drug treatment. Our results demonstrated that praziquantel applied at a concentration of 1 μM inhibited development of all life stages. Application of 10 μM praziquantel led to dramatic morphological changes of all schistosomula. Artemether at 1 and 10 μM had differential effects depending on whether it was applied to 2-day as compared to 7- and 14-day schistosomula. While 2-day schistosomula were not killed but inhibited from further development, severe morphological damage was seen in 7- and 14-day schistosomula. Oxamniquine (1 and 10 μM) led to severe morphological impairment in all life stages. Analyzing the accessibility of the antigens SmCD59a and SmKK7 before drug treatment showed no antibody binding on living intact schistosomula. However, when schistosomula were treated with anthelmintics, both antigens became exposed on the larvae. Oxamniquine turned out to be most effective in promoting antibody binding to all schistosomula stages. Conclusion This study has revealed marked differences in anthelmintic drug effects against larvae. Drug treatment increases surface antigen presentation and renders larvae accessible to antibody attack. Schistosomiasis is one of the major parasitic diseases in developing countries and still causes 200,000 deaths per year. Mass drug administration programs with praziquantel, the drug of choice against schistosomiasis, are currently undertaken in Sub-Saharan Africa. Praziquantel, although efficient against adult worms, fails to cure early infection. The complex developmental stages of schistosomes and migration through varying host compartments with different local drug concentration are a challenge for drug treatment. After infecting their mammalian host, schistosomula traverse through skin and the vasculature of lung, liver and intestines. During their migration, they develop from larvae to paired adults in approximately 4 to 5 weeks. So far, drug effects have been analyzed on adult worms or freshly transformed schistosomula only. Information about the effects on the larval stages is lacking. We were able to transfer the larval development of the first three weeks into the culture dish. This tool can be used for the analysis of drug effects against schistosomula and for investigation of the accessibility, expression and localization of antigens. Rendering the parasite’s larvae vulnerable to the host’s immune system by increasing antigen presentation is an important aspect of drug activity. We demonstrate on in vitro-cultured Schistosoma mansoni larvae, that SmCD59a and SmKK7, as examples for hidden antigens, become accessible to antibodies following drug treatment.
Collapse
|
33
|
Attia SS, Abou-Shady OM, Mohammed SS, Yusuf HAS, Helmy DO. In vitro Effect of Mefloquine on Adult Schistosoma mansoni. ACTA ACUST UNITED AC 2015. [DOI: 10.3923/jp.2015.111.119] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
34
|
Keiser J, Panic G, Vargas M, Wang C, Dong Y, Gautam N, Vennerstrom JL. Aryl hydantoin Ro 13-3978, a broad-spectrum antischistosomal. J Antimicrob Chemother 2015; 70:1788-97. [PMID: 25691324 DOI: 10.1093/jac/dkv016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 01/07/2015] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVES Praziquantel is the only drug available for the treatment of schistosomiasis and the state of the exhausted drug discovery pipeline is alarming. We restarted investigations on the abandoned antischistosomal Ro 13-3978, an aryl hydantoin discovered in the early 1980s by Hoffmann La-Roche. METHODS Newly transformed schistosomula and adult Schistosoma mansoni were studied in the presence of Ro 13-3978 in vitro. The metabolic stability of Ro 13-3978 was determined in vitro using human and mouse liver S9 fractions. Dose-response relationship, stage specificity, hepatic shift and scanning electron microscopy studies were carried out in S. mansoni-infected mice. In addition, efficacy experiments were conducted in rodents infected with Echinostoma caproni and Fasciola hepatica as well as in S. mansoni-infected immunocompromised nude (Foxn1(nu)) mice. RESULTS Ro 13-3978 showed minor in vitro activity and no damage to the tegument was found. No cytotoxicity was detected for Ro 13-3978. Ro 13-3978 was metabolically stable. ED50 values of 138.9 and 14.6 mg/kg were calculated for the treatment of juvenile and adult S. mansoni infections, respectively, with a single oral dose of Ro 13-3978. SEM studies revealed severe damage to the worms 48 h post-treatment of infected mice. A single oral dose of Ro 13-3978 (100 mg/kg) administered to S. mansoni-infected (Foxn1(nu)) mice reduced the worm burden by 88%. Ro 13-3978 was not active against E. caproni and F. hepatica in vivo. CONCLUSIONS Ro 13-3978 has excellent antischistosomal properties in vivo. Structure-activity relationship studies with the aryl hydantoins have been launched in order to elucidate active pharmacophores, further investigate the mechanism of action and to identify a derivative with minimal antiandrogenic effects.
Collapse
Affiliation(s)
- Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, CH-4002 Basel, Switzerland University of Basel, CH-4003 Basel, Switzerland
| | - Gordana Panic
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, CH-4002 Basel, Switzerland University of Basel, CH-4003 Basel, Switzerland
| | - Mireille Vargas
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, CH-4002 Basel, Switzerland University of Basel, CH-4003 Basel, Switzerland
| | - Chunkai Wang
- College of Pharmacy, University of Nebraska Medical Center, Omaha, NE, USA
| | - Yuxiang Dong
- College of Pharmacy, University of Nebraska Medical Center, Omaha, NE, USA
| | - Nagsen Gautam
- College of Pharmacy, University of Nebraska Medical Center, Omaha, NE, USA
| | | |
Collapse
|
35
|
Neves BJ, Andrade CH, Cravo PVL. Natural products as leads in schistosome drug discovery. Molecules 2015; 20:1872-903. [PMID: 25625682 PMCID: PMC6272663 DOI: 10.3390/molecules20021872] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 12/31/2014] [Accepted: 01/14/2015] [Indexed: 11/16/2022] Open
Abstract
Schistosomiasis is a neglected parasitic tropical disease that claims around 200,000 human lives every year. Praziquantel (PZQ), the only drug recommended by the World Health Organization for the treatment and control of human schistosomiasis, is now facing the threat of drug resistance, indicating the urgent need for new effective compounds to treat this disease. Therefore, globally, there is renewed interest in natural products (NPs) as a starting point for drug discovery and development for schistosomiasis. Recent advances in genomics, proteomics, bioinformatics, and cheminformatics have brought about unprecedented opportunities for the rapid and more cost-effective discovery of new bioactive compounds against neglected tropical diseases. This review highlights the main contributions that NP drug discovery and development have made in the treatment of schistosomiasis and it discusses how integration with virtual screening (VS) strategies may contribute to accelerating the development of new schistosomidal leads, especially through the identification of unexplored, biologically active chemical scaffolds and structural optimization of NPs with previously established activity.
Collapse
Affiliation(s)
- Bruno J Neves
- LabMol-Laboratory for Drug Design and Molecular Modeling, Faculdade de Farmácia, Universidade Federal de Goiás, Goiânia 74605-170, Brazil.
| | - Carolina H Andrade
- LabMol-Laboratory for Drug Design and Molecular Modeling, Faculdade de Farmácia, Universidade Federal de Goiás, Goiânia 74605-170, Brazil.
| | - Pedro V L Cravo
- GenoBio-Laboratory of Genomics and Biotechnology, Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia 74605-050, Brazil.
| |
Collapse
|
36
|
|
37
|
Yepes E, Varela-M RE, López-Abán J, Dakir ELH, Mollinedo F, Muro A. In vitro and in vivo anti-schistosomal activity of the alkylphospholipid analog edelfosine. PLoS One 2014; 9:e109431. [PMID: 25302497 PMCID: PMC4193788 DOI: 10.1371/journal.pone.0109431] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 09/01/2014] [Indexed: 12/20/2022] Open
Abstract
Background Schistosomiasis is a parasitic disease caused by trematodes of the genus Schistosoma. Five species of Schistosoma are known to infect humans, out of which S. haematobium is the most prevalent, causing the chronic parasitic disease schistosomiasis that still represents a major problem of public health in many regions of the world and especially in tropical areas, leading to serious manifestations and mortality in developing countries. Since the 1970s, praziquantel (PZQ) is the drug of choice for the treatment of schistosomiasis, but concerns about relying on a single drug to treat millions of people, and the potential appearance of drug resistance, make identification of alternative schistosomiasis chemotherapies a high priority. Alkylphospholipid analogs (APLs), together with their prototypic molecule edelfosine (EDLF), are a family of synthetic antineoplastic compounds that show additional pharmacological actions, including antiparasitic activities against several protozoan parasites. Methodology/Principal Findings We found APLs ranked edelfosine> perifosine> erucylphosphocholine> miltefosine for their in vitro schistosomicidal activity against adult S. mansoni worms. Edelfosine accumulated mainly in the worm tegument, and led to tegumental alterations, membrane permeabilization, motility impairment, blockade of male-female pairing as well as induction of apoptosis-like processes in cells in the close vicinity to the tegument. Edelfosine oral treatment also showed in vivo schistosomicidal activity and decreased significantly the egg burden in the liver, a key event in schistosomiasis. Conclusions/Significance Our data show that edelfosine is the most potent APL in killing S. mansoni adult worms in vitro. Edelfosine schistosomicidal activity seems to depend on its action on the tegumental structure, leading to tegumental damage, membrane permeabilization and apoptosis-like cell death. Oral administration of edelfosine diminished worm and egg burdens in S. mansoni-infected CD1 mice. Here we report that edelfosine showed promising antischistosomal properties in vitro and in vivo.
Collapse
Affiliation(s)
- Edward Yepes
- IBSAL-CIETUS (Instituto de Investigación Biomédica de Salamanca-Centro de Investigación de Enfermedades Tropicales de la Universidad de Salamanca), Facultad de Farmacia, Universidad de Salamanca, Salamanca, Spain
- Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer, CSIC-Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain
| | - Rubén E. Varela-M
- Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer, CSIC-Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain
| | - Julio López-Abán
- IBSAL-CIETUS (Instituto de Investigación Biomédica de Salamanca-Centro de Investigación de Enfermedades Tropicales de la Universidad de Salamanca), Facultad de Farmacia, Universidad de Salamanca, Salamanca, Spain
| | - E. L. Habib Dakir
- Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer, CSIC-Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain
| | - Faustino Mollinedo
- Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer, CSIC-Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain
| | - Antonio Muro
- IBSAL-CIETUS (Instituto de Investigación Biomédica de Salamanca-Centro de Investigación de Enfermedades Tropicales de la Universidad de Salamanca), Facultad de Farmacia, Universidad de Salamanca, Salamanca, Spain
- * E-mail:
| |
Collapse
|
38
|
Keiser J, Silué KD, Adiossan LK, N'Guessan NA, Monsan N, Utzinger J, N'Goran EK. Praziquantel, mefloquine-praziquantel, and mefloquine-artesunate-praziquantel against Schistosoma haematobium: a randomized, exploratory, open-label trial. PLoS Negl Trop Dis 2014; 8:e2975. [PMID: 25033291 PMCID: PMC4102459 DOI: 10.1371/journal.pntd.0002975] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 05/11/2014] [Indexed: 11/28/2022] Open
Abstract
Background Treatment and morbidity control of schistosomiasis relies on a single drug, praziquantel. Hence, there is a pressing need to develop additional therapeutics against schistosomiasis. The antimalarial drug mefloquine shows antischistosomal activity in animal models and clinical trials, which calls for further investigations. Methodology We comparatively assessed the efficacy and tolerability of the following treatments against Schistosoma haematobium in school-aged children in Côte d'Ivoire: (i) praziquantel (40 mg/kg; standard treatment); (ii) mefloquine (25 mg/kg) combined with praziquantel (40 mg/kg); and (iii) mefloquine-artesunate (3× (100 mg artesunate +250 mg mefloquine)) combined with praziquantel (40 mg/kg) (treatments administered on subsequent days). Two urine samples were collected before, and on days 21–22 and 78–79 after the first dosing. Principal Findings Sixty-one children were present on all examination time points and had complete datasets. No difference in efficacy was observed between the three treatment groups on either follow-up. On the 21–22 day posttreatment follow-up, based on available case analysis, cure rates of 33% (95% confidence interval (CI) 11–55%), 29% (95% CI 8–50%), and 26% (95% CI 5–48%) were observed for praziquantel, mefloquine-artesunate-praziquantel, and mefloquine-praziquantel, respectively. The corresponding egg reduction rates were 94% and above. On the second follow-up, observed cure rates ranged from 19% (praziquantel) to 33% (mefloquine-artesunate-praziquantel), and egg reduction rates were above 90%. Praziquantel monotherapy was the best tolerated treatment. In the mefloquine-artesunate-praziquantel group, adverse events were reported by 91% of the participants, and in the mefloquine-praziquantel group, 95% experienced adverse events. With the exception of abdominal pain at moderate severity, adverse events were mild. Conclusions/Significance The addition of mefloquine or mefloquine-artesunate does not increase the efficacy of praziquantel against chronic S. haematobium infection. Additional studies are necessary to elucidate the effect of the combinations against acute schistosomiasis. The antimalarial drug mefloquine shows activity against blood flukes that cause the disease schistosomiasis. In animal studies it has been found that a mefloquine-praziquantel combination kills blood flukes more effectively than praziquantel alone. Combining praziquantel with another drug might therefore increase efficacy, broaden the spectrum of activity, and delay the development of drug resistance. We designed a study in Ivorian school children to assess the efficacy and tolerability of mefloquine and mefloquine-artesunate combined with praziquantel against the blood fluke Schistosoma haematobium. The administration of the antimalarials and praziquantel was spaced by a day. Treatment outcomes were assessed twice, on days 21–22 and 78–79 after the first dosing to determine the effect against adult and juvenile S. haematobium, respectively. At both follow-ups, high reduction in the intensity of infection (egg reduction rates of 94–96%), but low cure rates (26–33%) were observed in the three treatment groups. Adverse events were common, particularly in children treated with mefloquine-praziquantel and mefloquine-artesunate-praziquantel. Our study suggests that the addition of mefloquine and mefloquine-artesunate to praziquantel has no benefit in the treatment of chronic S. haematobium infection. However, further investigations are warranted to evaluate the effect of combination therapy on juvenile flukes and longer-term morbidity profiles.
Collapse
Affiliation(s)
- Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- * E-mail:
| | - Kigbafori D. Silué
- Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d'Ivoire
- Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire
| | | | - Nicaise A. N'Guessan
- Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d'Ivoire
| | - N'Chou Monsan
- Institut National de la Santé Publique, Abidjan, Côte d'Ivoire
| | - Jürg Utzinger
- University of Basel, Basel, Switzerland
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Eliézer K. N'Goran
- Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d'Ivoire
- Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire
| |
Collapse
|
39
|
Activity of praziquantel enantiomers and main metabolites against Schistosoma mansoni. Antimicrob Agents Chemother 2014; 58:5466-72. [PMID: 24982093 DOI: 10.1128/aac.02741-14] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
A racemic mixture of R and S enantiomers of praziquantel (PZQ) is currently the treatment of choice for schistosomiasis. Though the S enantiomer and the metabolites are presumed to contribute only a little to the activity of the drug, in-depth side-by-side studies are lacking. The aim of this study was to investigate the in vitro activities of PZQ and its main metabolites, namely, R- and S-cis- and R- and S-trans-4'-hydroxypraziquantel, against adult worms and newly transformed schistosomula (NTS). Additionally, we explored the in vivo activity and hepatic shift (i.e., the migration of the worms to the liver) produced by each PZQ enantiomer in mice. Fifty percent inhibitory concentrations of R-PZQ, S-PZQ, and R-trans- and R-cis-4'-hydroxypraziquantel of 0.02, 5.85, 4.08, and 2.42 μg/ml, respectively, for adult S. mansoni were determined in vitro. S-trans- and S-cis-4'-hydroxypraziquantel were not active at 100 μg/ml. These results are consistent with microcalorimetry data and studies with NTS. In vivo, single 400-mg/kg oral doses of R-PZQ and S-PZQ achieved worm burden reductions of 100 and 19%, respectively. Moreover, worms treated in vivo with S-PZQ displayed an only transient hepatic shift and returned to the mesenteric veins within 24 h. Our data confirm that R-PZQ is the main effector molecule, while S-PZQ and the metabolites do not play a significant role in the antischistosomal properties of PZQ.
Collapse
|
40
|
de Paula RG, Ornelas AMDM, Morais ER, Borges WDC, Natale M, Magalhães LG, Rodrigues V. Biochemical characterization and role of the proteasome in the oxidative stress response of adult Schistosoma mansoni worms. Parasitol Res 2014; 113:2887-97. [PMID: 24870249 DOI: 10.1007/s00436-014-3950-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 05/06/2014] [Indexed: 11/28/2022]
Abstract
The trematode Schistosoma mansoni, an important parasite of humans, is the principle agent of the disease schistosomiasis. In the human host, one of the most important stress factors of this parasite is the oxidative stress generated by both the metabolism of the worm and the immune system of the host. The proteasomal system is responsible for protein homeostasis during oxidative stress. The 26S proteasome is a multicatalytic protease formed by two compartments, a 20S core and regulatory particle 19S, and controls the degradation of intracellular proteins, hence regulating many cellular processes. In the present report, we describe the biochemical characterization and role of the 20S proteasome in the response of adult S. mansoni worms exposed to hydrogen peroxide. Characterization of the response to the oxidative stress included the evaluation of viability, egg production, mortality, tegument integrity, and both expression and activity of proteasome. We observed decreases in viability, egg production as well as 100% mortality at the higher concentrations of hydrogen peroxide tested. The main changes observed in the tegument of adult worms were peeling as well as the appearance of bubbles and a decrease of spines on the tubercles. Furthermore, there were increases in 26S activity to the same extent as 20S proteasome activity, although there was increase of 20S proteasome content, suggesting that degradation of protein oxidized in adult worms is due to the 20S proteasome. It was demonstrated that adult S. mansoni worms are sensitive to oxidative stress, and that a variety of processes in this parasite are altered under this condition. The work contributes to a better understanding of the mechanisms employed by S. mansoni to survive under oxidative stress.
Collapse
Affiliation(s)
- Renato Graciano de Paula
- Faculdade de Medicina de Ribeirão Preto, Departamento de Bioquímica e Imunologia, Universidade de São Paulo, Avenida Bandeirantes, 3900, 14049-900, Ribeirão Preto, SP, Brazil,
| | | | | | | | | | | | | |
Collapse
|
41
|
Xiao SH, Qiao C, Xue J, Wang L. Mefloquine in combination with hemin causes severe damage to adult Schistosoma japonicum in vitro. Acta Trop 2014; 131:71-8. [PMID: 24361723 DOI: 10.1016/j.actatropica.2013.12.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Revised: 12/01/2013] [Accepted: 12/04/2013] [Indexed: 12/20/2022]
Abstract
In order to explore the interaction of mefloquine with hemin against adult Schistosoma japonicum in vitro, the 50% and 95% lethal concentration (LC50 and LC95) of mefloquine and hemin against schistosomes, some factors, such as other iron providing agents, iron chelaters, zinc protoporphyrin-IX, and biological relevant reductants, that might impact on antischistosomal activity induced by interaction of mefloquine with hemin, and preliminary analysis of chemical interaction of both compounds were undertaken. The LC50 and LC95 of mefloquine and hemin alone against schistosomes were determined to be 6.5μg/ml and 7.8μg/ml as well as 232μg/ml and 355μg/ml, respectively. The LC50 and LC95 of mefloquine in the presence of hemin 100μg/ml was 0.24μg/ml and 0.59μg/ml, respectively. On the other hand the LC50 and LC95 of hemin in the presence of mefloquine 1μg/ml was 23.2μg/ml and 77.2μg/ml, respectively. Meanwhile, mefloquine/hemin combinations showed potential synergistic effects against adult S. japonicum, with combination index (CI) values <1. Apart from hemin, zinc protoporphyrin-IX, and other iron providing agents such as ferrous sulfate and ferriammonium sulfate combined with mefloquine exhibited no toxic effect against schistosomes. On the other hand, addition of iron chelators (deferiprone, desferrioxamine mesylate, or 2,2'-bipyridine) to the medium containing mefloquine-hemin resulted in no protective effect on the worms. Furthermore, biological reductants like glutathione, vitamine C or cysteine showed no apparent worm protection effect from toxic mefloquine-hemin even at higher concentrations (242.3-614.6μg/ml, i.e., 6.4-17.8-fold higher than the concentration of hemin). Chemical interaction of mefloquine with hemin was studied in 40% DMSO-Tris buffer solution. Both UV-Vis spectrum and mass spectrum demonstrated the strong interaction of mefloquine with hemin, which resulted in a reduction of hemin color and emergence of an adduct formed by mefloquine and hemin. The results confirm that mefloquine combined with hemin exhibits potential synergistic effect against adult S. japonicum in vitro.
Collapse
|
42
|
Olliaro P, Delgado-Romero P, Keiser J. The little we know about the pharmacokinetics and pharmacodynamics of praziquantel (racemate and R-enantiomer). J Antimicrob Chemother 2014; 69:863-70. [PMID: 24390933 DOI: 10.1093/jac/dkt491] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Praziquantel has been the mainstay of schistosomiasis control since 1984 and widely distributed since 2006 through 'preventive chemotherapy' programmes to school-aged children or at-risk populations. In addition, preschool-aged children are now recognized as a vulnerable population and a group for targeted treatment, but they may be difficult to dose correctly with the available product--a racemate, based on the biologically active enantiomer (R-praziquantel) and the inactive distomer (S-praziquantel), which contributes the bitter taste and doubles the size of the tablets. Hence, a paediatric formulation is required, possibly enantiomerically pure. Developing such a product and extending its use to younger children should be pharmacologically guided, but limited data exist on pharmacokinetics and pharmacokinetic/pharmacodynamic correlations for praziquantel. This article presents available data on the chemistry, pharmacokinetics and pharmacodynamics of praziquantel, as well as R-praziquantel, and points to gaps in our knowledge.
Collapse
Affiliation(s)
- Piero Olliaro
- UNICEF/UNDP/World Bank/WHO Special Programme on Research & Training in Tropical Diseases (TDR), World Health Organization, 20 Avenue Appia, CH-1211, Geneva 27, Switzerland
| | | | | |
Collapse
|
43
|
Zhang SM, Coultas KA. Identification of plumbagin and sanguinarine as effective chemotherapeutic agents for treatment of schistosomiasis. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2013; 3:28-34. [PMID: 23641325 PMCID: PMC3638872 DOI: 10.1016/j.ijpddr.2012.12.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Schistosomiasis, a snail-borne parasitic disease, affects more than 200 million people worldwide. Currently the treatment of schistosomiasis relies on a single therapy of praziquantel, a drug developed over 30 years ago. Thus, there is an urgent need to develop alternative antischistosomal drugs. In the pursuit of novel antischistosomal drugs, we examined the antischistosomal activities of 45 compounds that had been reported to exhibit antimicrobial and/or antiparasitic activities. Two plant-derived compounds, plumbagin and sanguinarine, were found to possess potent antischistosomal activities in vitro. For both the compounds, a concentration of 10 μM (equivalent to 1.88 μg/ml for plumbagin and 3.68 μg/ml for sanguinarine) resulted in 100% mortality at 48 h, which meets the World Health Organization's (WHO) criterion of "hit" compounds for the control of schistosomiasis. Morphological changes and tegumental alterations of the dead worms treated by the two compounds were quite different. The significant morphological changes of worms after treatment by the two compounds suggest the two compounds target different biological pathways, both of which result in parasite's death. This study provides evidence to suggest plumbagin and sanguinarine have real potential as effective alternative chemotherapeutic agents for the treatment of schistosomiasis.
Collapse
Affiliation(s)
- Si-Ming Zhang
- Center for Evolutionary and Theoretical Immunology, Department of Biology, MSC03 2020, University of New Mexico, Albuquerque, NM 87131, United States
| | | |
Collapse
|
44
|
“Omics” in the study of the major parasitic diseases malaria and schistosomiasis. INFECTION GENETICS AND EVOLUTION 2013; 19:258-73. [DOI: 10.1016/j.meegid.2013.07.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2012] [Revised: 07/04/2013] [Accepted: 07/07/2013] [Indexed: 01/21/2023]
|
45
|
Xiao SH. Mefloquine, a new type of compound against schistosomes and other helminthes in experimental studies. Parasitol Res 2013; 112:3723-40. [PMID: 23979493 DOI: 10.1007/s00436-013-3559-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Accepted: 07/24/2013] [Indexed: 12/23/2022]
Abstract
Up to date, schistosomiasis is still prevalent worldwide. It is estimated that more than 200 million individuals are infected, and 120 million suffer from clinical morbidity. Facing such huge cases of schistosomiasis, only heavy reliance on a single praziquantel for schistosomiasis control does not adapt and may promote the selection and spread of drug-resistant parasites. Therefore, it is an urgent need to develop the new antischistosomal drug. In 2008-2009, the antimalarial drug mefloquine, an arylaminoalcohol compound, has been found to be effective against schistosomes. According to the experimental studies, the deepest impression on the antischistosomal properties of mefloquine can be summarized as following points: (1) single dose of mefloquine possesses potential effect against three major species of schistosomes (Schistosoma mansoni, Schistosoma haematobium, and Schistosoma japonicum) infecting humans; (2) the drug displays similar effects against developing stages of juvenile and adult schistosomes, which are superior to that of artemisinins and praziquantel; (3) in vitro mefloquine exerts direct killing effect on juvenile and adult schistosomes, while in vivo, the efficacy of the drug is independent to host immune response, (4) mefloquine causes extensive and severe morphological, histopathological, and ultrastructural damage to adult and juvenile schistosomes, particularly, the worm tegument, musculature, gut, and vitelline glands of female worms are the key sites attacked by the drug; (5) combined treatment with mefloquine and praziquantel, or artemisinins shows synergistic effect against schistosome in experimental therapy,while in initially clinical trial, mefloquine in combination with artesunate also exhibits higher cure rates against schistosomiasis hematobia and schistosomiasis mansoni, and (6) several mefloquine-related arylmethanols exhibit potential effect against schistosomes in vivo, which is a useful clue helpful for development of new antischistosomal compound. In the present review, we have summarized the major results published in recent years, and the significance as well as the prospect for the future study of mefloquine have been discussed briefly.
Collapse
Affiliation(s)
- Shu-hua Xiao
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Key Laboratory of Parasite and Vector Biology, MOH, WHO Collaborating Centre for Malaria, Schistosomiasis, and Filariasis, Shanghai, 200025, People's Republic of China,
| |
Collapse
|
46
|
Vanaerschot M, Huijben S, Van den Broeck F, Dujardin JC. Drug resistance in vectorborne parasites: multiple actors and scenarios for an evolutionary arms race. FEMS Microbiol Rev 2013; 38:41-55. [PMID: 23815683 DOI: 10.1111/1574-6976.12032] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 06/17/2013] [Accepted: 06/25/2013] [Indexed: 12/14/2022] Open
Abstract
Drug-resistant pathogens emerge faster than new drugs come out of drug discovery pipelines. Current and future drug options should therefore be better protected, requiring a clear understanding of the factors that contribute to the natural history of drug resistance. Although many of these factors are relatively well understood for most bacteria, this proves to be more complex for vectorborne parasites. In this review, we discuss considering three key models (Plasmodium, Leishmania and Schistosoma) how drug resistance can emerge, spread and persist. We demonstrate a multiplicity of scenarios, clearly resulting from the biological diversity of the different organisms, but also from the different modes of action of the drugs used, the specific within- and between-host ecology of the parasites, and environmental factors that may have direct or indirect effects. We conclude that integrated control of drug-resistant vectorborne parasites is not dependent upon chemotherapy only, but also requires a better insight into the ecology of these parasites and how their transmission can be impaired.
Collapse
Affiliation(s)
- Manu Vanaerschot
- Unit of Molecular Parasitology, Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
| | | | | | | |
Collapse
|
47
|
Rocha VPC, Nonato FR, Guimarães ET, Rodrigues de Freitas LA, Soares MBP. Activity of antimalarial drugs in vitro and in a murine model of cutaneous leishmaniasis. J Med Microbiol 2013; 62:1001-1010. [DOI: 10.1099/jmm.0.058115-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The currently used treatments for leishmaniasis, a neglected parasitic disease, are associated with several side effects, high cost and resistance of the Leishmania parasites. Here we evaluated in vitro and in vivo the antileishmanial activity of five antimalarial drugs against Leishmania amazonensis. Mefloquine was effective against promastigotes in axenic cultures and showed an IC50 (concentration giving half-maximal inhibition) value of 8.4±0.7 µM. In addition, mefloquine, chloroquine and hydroxychloroquine were active against intracellular amastigotes in macrophage-infected cultures, presenting IC50 values of 1.56±0.19 µM, 0.78±0.08 µM and 0.67±0.12 µM, respectively. The ultrastructural analysis of chloroquine- or mefloquine-treated amastigotes showed an accumulation of multivesicular bodies in the cytoplasm of the parasite, suggesting endocytic pathway impairment, in addition to the formation of myelin-like figures and enlargement of the Golgi cisternae. CBA mice were infected with L. amazonensis in the ear dermis, and treated by oral and/or topical routes with chloroquine and mefloquine. Treatment of L. amazonensis-infected mice with chloroquine by the oral route reduced lesion size, which was associated with a decrease in the number of parasites in the ear, as well as the parasite burden in the draining lymph nodes. In contrast, mefloquine administration by both routes decreased the lesion size in infected mice without causing a reduction in parasite burden. Our results revealed a promising antileishmanial effect of chloroquine and suggest its use in cutaneous leishmaniasis treatment.
Collapse
Affiliation(s)
- Vinícius Pinto Costa Rocha
- Laboratório de Engenharia Tecidual e Imunofarmacologia, Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, Rua Waldemar Falcão 121, Candeal, 40296-70, Salvador, Bahia, Brazil
| | - Fabiana Regina Nonato
- Laboratório de Engenharia Tecidual e Imunofarmacologia, Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, Rua Waldemar Falcão 121, Candeal, 40296-70, Salvador, Bahia, Brazil
| | - Elisalva Teixeira Guimarães
- Departamento de Ciências da Vida, Universidade do Estado da Bahia, Rua Silveira Martins, 2555, Cabula, 41150-000, Salvador, Bahia, Brazil
- Laboratório de Engenharia Tecidual e Imunofarmacologia, Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, Rua Waldemar Falcão 121, Candeal, 40296-70, Salvador, Bahia, Brazil
| | - Luiz Antônio Rodrigues de Freitas
- Faculdade de Medicina, Universidade Federal da Bahia, Avenida Reitor Miguel Calmon, s/n°, Vale do Canela, 40025-010, Salvador, Bahia, Brazil
- Laboratório de Patologia e Biointervenção, Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, Rua Waldemar Falcão 121, Candeal, 40296-70, Salvador, Bahia, Brazil
| | - Milena Botelho Pereira Soares
- Centro de Biotecnologia e Terapia Celular, Hospital São Rafael, Avenida São Rafael 2152, 41253-190, Salvador, Bahia, Brazil
- Laboratório de Engenharia Tecidual e Imunofarmacologia, Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, Rua Waldemar Falcão 121, Candeal, 40296-70, Salvador, Bahia, Brazil
| |
Collapse
|
48
|
Paveley RA, Mansour NR, Hallyburton I, Bleicher LS, Benn AE, Mikic I, Guidi A, Gilbert IH, Hopkins AL, Bickle QD. Whole organism high-content screening by label-free, image-based Bayesian classification for parasitic diseases. PLoS Negl Trop Dis 2012; 6:e1762. [PMID: 22860151 PMCID: PMC3409125 DOI: 10.1371/journal.pntd.0001762] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Accepted: 06/21/2012] [Indexed: 02/07/2023] Open
Abstract
Sole reliance on one drug, Praziquantel, for treatment and control of schistosomiasis raises concerns about development of widespread resistance, prompting renewed interest in the discovery of new anthelmintics. To discover new leads we designed an automated label-free, high content-based, high throughput screen (HTS) to assess drug-induced effects on in vitro cultured larvae (schistosomula) using bright-field imaging. Automatic image analysis and Bayesian prediction models define morphological damage, hit/non-hit prediction and larval phenotype characterization. Motility was also assessed from time-lapse images. In screening a 10,041 compound library the HTS correctly detected 99.8% of the hits scored visually. A proportion of these larval hits were also active in an adult worm ex-vivo screen and are the subject of ongoing studies. The method allows, for the first time, screening of large compound collections against schistosomes and the methods are adaptable to other whole organism and cell-based screening by morphology and motility phenotyping.
Collapse
Affiliation(s)
- Ross A. Paveley
- Department of Infection and Immunity, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Nuha R. Mansour
- Department of Infection and Immunity, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Irene Hallyburton
- Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Leo S. Bleicher
- Accelrys Inc., San Diego, California, United States of America
| | | | - Ivana Mikic
- Accelrys Inc., San Diego, California, United States of America
| | - Alessandra Guidi
- Department of Infection and Immunity, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Ian H. Gilbert
- Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Andrew L. Hopkins
- Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Quentin D. Bickle
- Department of Infection and Immunity, London School of Hygiene and Tropical Medicine, London, United Kingdom
| |
Collapse
|
49
|
Ingram K, Ellis W, Keiser J. Antischistosomal activities of mefloquine-related arylmethanols. Antimicrob Agents Chemother 2012; 56:3207-15. [PMID: 22470113 PMCID: PMC3370792 DOI: 10.1128/aac.06177-11] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2011] [Accepted: 03/23/2012] [Indexed: 11/20/2022] Open
Abstract
Interesting antischistosomal properties have been documented for the antimalarial mefloquine, a 4-quinolinemethanol. We evaluated the antischistosomal activities of nine mefloquine-related compounds belonging to the 4-pyridinemethanols, 9-phenanthrenmethanols, and 4-quinolinemethanols. Eight compounds revealed high activities against Schistosoma mansoni in vitro, with two drugs (the 4-quinolinemethanols WR7573 and WR7930) characterized by significantly lower half-maximal inhibitory concentrations (IC(50)s) (2.7 and 3.5 μM, respectively) compared to mefloquine (11.4 μM). Mefloquine and WR7930 showed significantly decreased IC(50)s when incubated in the presence of hemoglobin. High worm burden reductions (WBR) were obtained with enpiroline (WBR, 82.7%; dosage, 200 mg/kg of body weight) and its threo isomers (+)-threo (WBR, 100%) and (-)-threo (WBR, 89%) and with WR7930 (WBR, 87%; dosage, 100 mg/kg) against adult S. mansoni in mice. Furthermore, excellent in vitro and in vivo antischistosomal activity was observed for two WR7930-related structures (WR29252 and WR7524). In addition, mefloquine (WBR, 81%), enpiroline (WBR, 77%), and WR7930 (WBR, 100%) showed high activities against S. haematobium harbored in mice following single oral doses of 200 mg/kg. These results provide a deeper insight into the structural features of the arylmethanols that rule antischistosomal activity. Further studies should be launched with enpiroline and WR7930.
Collapse
Affiliation(s)
- Katrin Ingram
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - William Ellis
- Department of Chemical Information, Walter Reed Army Institute of Research, Washington, DC, USA
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| |
Collapse
|
50
|
Ingram K, Schiaffo CE, Sittiwong W, Benner E, Dussault PH, Keiser J. In vitro and in vivo activity of 3-alkoxy-1,2-dioxolanes against Schistosoma mansoni. J Antimicrob Chemother 2012; 67:1979-86. [PMID: 22553141 DOI: 10.1093/jac/dks141] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
OBJECTIVES Compounds characterized by a peroxidic skeleton are an interesting starting point for antischistosomal drug discovery. Previously a series of 3-alkoxy-1,2-dioxolanes, which are chemically stable cyclic peroxides, demonstrated significant in vitro activity against Plasmodium falciparum. We aimed to evaluate the potential of these compounds against Schistosoma mansoni and elucidate the roles of iron and peroxidic groups in activity. METHODS Drugs were tested against juvenile and adult stages of S. mansoni in vitro and in vivo. Selected structures were assessed in vitro against schistosomes in the presence of additional iron sources. In addition, drugs were tested in vitro and in vivo against Echinostoma caproni, a non-blood-feeding intestinal fluke. Finally, the activity of non-peroxidic analogues was evaluated. RESULTS Three dioxolanes displayed IC₅₀s ≤ 20.1 μM against adult schistosomes and values as low as 4.2 μM against newly transformed schistosomula. Nonetheless, only moderate, non-significant worm burden reductions were observed after treatment of mice harbouring adult infections. Drugs lacked activity against juvenile schistosomes in vivo. Two selected dioxolanes showed in vitro activity against E. caproni down to concentrations of 5 mg/L, but none of the compounds revealed in vivo activity. All tested non-peroxidic analogues lacked activity in vitro against both parasites. CONCLUSIONS Selected dioxolanes presented interesting in vitro activity, but low in vivo activities have to be overcome to identify a lead candidate. Although the inactivity of non-peroxidic analogues underlines the necessity of a peroxide functional group, incubation of adult schistosomes with additional iron sources did not alter activity, supporting an iron-independent mode of activation.
Collapse
Affiliation(s)
- Katrin Ingram
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
| | | | | | | | | | | |
Collapse
|