Efficacy of sertraline against Trypanosoma cruzi: an in vitro and in silico study.

BACKGROUND: Drug repurposing has been an interesting and cost-effective approach, especially for neglected diseases, such as Chagas disease. METHODS: In this work, we studied the activity of the antidepressant drug sertraline against Trypanosoma cruzi trypomastigotes and intracellular amastigotes of the Y and Tulahuen strains, and investigated its action mode using cell biology and in silico approaches. RESULTS: Sertraline demonstrated in vitro efficacy against intracellular amastigotes of both T. cruzi strains inside different host cells, including cardiomyocytes, with IC50 values between 1 to 10 µM, and activity against bloodstream trypomastigotes, with IC50 of 14 µM. Considering the mammalian cytotoxicity, the drug resulted in a selectivity index of 17.8. Sertraline induced a change in the mitochondrial integrity of T. cruzi, resulting in a decrease in ATP levels, but not affecting reactive oxygen levels or plasma membrane permeability. In silico approaches using chemogenomic target fishing, homology modeling and molecular docking suggested the enzyme isocitrate dehydrogenase 2 of T. cruzi (TcIDH2) as a potential target for sertraline. CONCLUSIONS: The present study demonstrated that sertraline had a lethal effect on different forms and strains of T. cruzi, by affecting the bioenergetic metabolism of the parasite. These findings provide a starting point for future experimental assays and may contribute to the development of new compounds.

Efficacy of sertraline against Trypanosoma cruzi: an in vitro and in silico study

Drug repurposing has been an interesting and cost-effective approach, especially for neglected diseases, such as Chagas disease. Methods: In this work, we studied the activity of the antidepressant drug sertraline against Trypanosoma cruzi trypomastigotes and intracellular amastigotes of the Y and Tulahuen strains, and investigated its action mode using cell biology and in silico approaches. Results: Sertraline demonstrated in vitro efficacy against intracellular amastigotes of both T. cruzi strains inside different host cells, including cardiomyocytes, with IC50 values between 1 to 10 µM, and activity against bloodstream trypomastigotes, with IC50 of 14 µM. Considering the mammalian cytotoxicity, the drug resulted in a selectivity index of 17.8. Sertraline induced a change in the mitochondrial integrity of T. cruzi, resulting in a decrease in ATP levels, but not affecting reactive oxygen levels or plasma membrane permeability. In silico approaches using chemogenomic target fishing, homology modeling and molecular docking suggested the enzyme isocitrate dehydrogenase 2 of T. cruzi (TcIDH2) as a potential target for sertraline. Conclusions: The present study demonstrated that sertraline had a lethal effect on different forms and strains of T. cruzi, by affecting the bioenergetic metabolism of the parasite. These findings provide a starting point for future experimental assays and may contribute to the development of new compounds.(AU)

Estudos farmacológicos de novos compostos semissintéticos com potencial terapêutico na doença de chagas / Pharmacological studies of new semi-synthetic compounds with therapeutic potential in Chagas disease

A doença de Chagas afeta mais de 8 milhões de pessoas nos países em desenvolvimento, e dispõe de uma terapia ultrapassada e altamente tóxica. Considerando o Brasil uma das maiores biodiversidades do mundo, compostos de sua flora podem contribuir como novos protótipos farmacêuticos. Neolignanas, isoladas da planta Nectandra leucantha, apresentaram previamente atividade anti-Trypanosoma cruzi e neste trabalho, serviram como base para a semissíntese de uma série de 24 análogos. Estudos in vitro demonstratram que 19 compostos não apresentaram citotoxicidade em células de mamífero até 200 µM. Seis compostos apresentaram atividade contra as formas tripomastigotas (CE50 8 a 76 µM) e 8 compostos contra os amastigotas intracelulares (CE50 7 a 16 µM). Estudos da relação estrutura-atividade biológica (SAR), demonstraram que a presença de pelo menos uma cadeia lateral alílica era importante para a atividade anti-T. cruzi e que o grupo fenol não era essencial. O composto 8 foi eficaz contra as duas formas do parasita e eliminou 100% das formas amastigotas no interior dos macrófagos, sendo escolhido para estudos de mecanismo de ação. O composto 8 afetou rapidamente a mitocôndria do T. cruzi,...(AU)

Chagas disease affects more than 8 million people in developing countries and the available therapy is old and highly toxic. Considering Brazil one of the biggest biodiversity in the world, compounds from the flora can contribute as new pharmaceutical prototypes. Neolignans, isolated from the plant Nectandra leucantha, previously showed anti-Trypanosoma cruzi activity and served as the basis for the semi-synthesis of a series of 24 analogues. In vitro studies demonstrated that 19 compounds caused no cytotoxicity in mammalian cells up to 200 µM. Six compounds showed activity against trypomastigote forms (IC50 8 to 76 µM) and 8 compounds against intracellular amastigotes (IC50 7 to 16 µM). Studies of the structure activity relationships (SAR) showed that the presence of at least one allylic side chain was important for anti-T. cruzi activity and that the phenol group was not essential. Compound 8 was chosen for mechanism of action studies as it was effective against both forms of the parasite and eliminated 100% of the intracellular amastigotes. Compound 8 rapidly affected the mitochondria of T. cruzi, causing an intense depolarization of the mitochondrial membrane potential, with decreasing levels of reactive oxygen species...(AU)

Efficacy of a series of alpha-pyrone derivatives against Leishmania (L.) infantum and Trypanosoma cruzi.

The neglected tropical diseases Chagas disease and leishmaniasis affect together more than 20 million people living mainly in developing countries. The mainstay of treatment is chemotherapy, however the drugs of choice, which include benznidazole and miltefosine, are toxic and have numerous side effects. Safe and effective therapies are urgently needed. Marine alpha-pyrones have been previously identified as scaffolds with potential antiprotozoan activities. In this work, using a phenotypic screen, twenty-seven examples of 3-substituted 4-hydroxy-6-methyl alpha-pyrones were synthesized and their antiparasitic efficacy evaluated against Leishmania (L.) infantum and Trypanosoma cruzi in order to evaluate structure-activity relationships within the series. The mechanism of action and the in vivo efficacy of the most selective compound against T. cruzi were evaluated using different techniques. In vitro data indicated that compounds 8, 15, 25, 26 and 28 presented IC50 values in the range between 13 and 54 µM against L. infantum intracellular amastigotes. Among them, hexanoyl substituted pyrone 8 was the most selective and potent, with a Selectivity Index (SI) > 14. Fifteen of the alpha-pyrones were effective against T. cruzi trypomastigotes, with 3-undecanoyl (11) and 3-tetradecanoyl (12) substituted pyrones being the most potent against trypomastigotes, with IC50 values of 1 and 2 µM, respectively, and SI higher than 70. Using flow cytometry and fluorescent-based assays, pyrone 12 was found to induce hyperpolarization of the mitochondrial membrane potential of T. cruzi, without affecting plasma membrane permeability. An experimental acute phase-murine model, demonstrated that in vivo dosing of 12 (30 mg/kg/day; 5 days), had no efficacy at the first parasitemia onset of T. cruzi, but reduced the second onset by 55% (p < 0.05), suggesting a delayed action in BALB/c mice. Additionally, a histopathology study demonstrated no toxic effects to the treated mice. The finding that several 3-substituted alpha-pyrones have in vitro efficacy against both L. infantum and T. cruzi, and that one analogue exhibited moderate and non-toxic in vivo efficacy against T. cruzi is encouraging, and suggests that this compound class should be explored as long-term treatments in experimental Chagas disease.

Efficacy of a series of alpha-pyrone derivatives against Leishmania (L. ) infantum and Trypanosoma cruzi

The neglected tropical diseases Chagas disease and leishmaniasis affect together more than 20 million people living mainly in developing countries. The mainstay of treatment is chemotherapy, however the drugs of choice, which include benznidazole and miltefosine, are toxic and have numerous side effects. Safe and effective therapies are urgently needed. Marine alpha-pyrones have been previously identified as scaffolds with potential antiprotozoan activities. In this work, using a phenotypic screen, twenty-seven examples of 3-substituted 4-hydroxy-6-methyl alpha-pyrones were synthesized and their antiparasitic efficacy evaluated against Leishmania (L.) infantum and Trypanosoma cruzi in order to evaluate structure-activity relationships within the series. The mechanism of action and the in vivo efficacy of the most selective compound against T. cruzi were evaluated using different techniques. In vitro data indicated that compounds 8, 15, 25, 26 and 28 presented IC50 values in the range between 13 and 54 µM against L. infantum intracellular amastigotes. Among them, hexanoyl substituted pyrone 8 was the most selective and potent, with a Selectivity Index (SI) > 14. Fifteen of the alpha-pyrones were effective against T. cruzi trypomastigotes, with 3-undecanoyl (11) and 3-tetradecanoyl (12) substituted pyrones being the most potent against trypomastigotes, with IC50 values of 1 and 2 µM, respectively, and SI higher than 70. Using flow cytometry and fluorescent-based assays, pyrone 12 was found to

As doenças tropicais negligenciadas A doença de Chagas e a leishmaniose afetam juntas mais de 20 milhões de pessoas que vivem principalmente nos países em desenvolvimento. O suporte principal do tratamento é a quimioterapia, no entanto, os medicamentos de escolha, que incluem benznidazol e miltefosina, são tóxicos e têm inúmeros efeitos colaterais. Terapias seguras e eficazes são urgentemente necessárias. As alfa-pironas marinhas foram previamente identificadas como andaimes com potenciais atividades antiprotozoárias. Neste trabalho, usando uma tela fenotípica, sintetizaram-se 27 exemplos de 4-hidroxi-6-metil alfa-pironas 3-substituídas e avaliou-se sua eficácia antiparasitária contra Leishmania (L.) infantum e Trypanosoma cruzi para avaliar a estrutura relações de atividade dentro da série. O mecanismo de ação e a eficácia in vivo do composto mais seletivo contra T. cruzi foram avaliados por diferentes técnicas. Dados in vitro indicaram que os compostos 8, 15, 25, 26 e 28 apresentaram valores de IC50 na faixa entre 13 e 54 µM contra amastigotas intracelulares de L. infantum. Entre elas, a pirona 8 substituída com hexanoílo foi a mais seletiva e potente, com um índice de seletividade (SI)> 14. Quinze das alfa-pironas foram eficazes contra as tripomastigotas de T. cruzi, com 3-undecanoil (11) e 3-tetradecanoil ( 12) pironas substituídas sendo as mais potentes contra tripomastigotas, com valores de IC50 de 1 e 2 µM, respectivamente, e SI superiores a 70. Usando citometria de fluxo e ensaios à base de fluorescência, a pirona 12 foi encontrada para

Investigation of Calcium Channel Blockers as Antiprotozoal Agents and Their Interference in the Metabolism of Leishmania (L.) infantum.

Leishmaniasis and Chagas disease are neglected parasitic diseases endemic in developing countries; efforts to find new therapies remain a priority. Calcium channel blockers (CCBs) are drugs in clinical use for hypertension and other heart pathologies. Based on previous reports about the antileishmanial activity of dihydropyridine-CCBs, this work aimed to investigate whether the in vitro anti-Leishmania infantum and anti-Trypanosoma cruzi activities of this therapeutic class would be shared by other non-dihydropyridine-CCBs. Except for amrinone, our results demonstrated antiprotozoal activity for fendiline, mibefradil, and lidoflazine, with IC50 values in a range between 2 and 16 µM and Selectivity Index between 4 and 10. Fendiline demonstrated depolarization of mitochondrial membrane potential, with increased reactive oxygen species production in amlodipine and fendiline treated Leishmania, but without plasma membrane disruption. Finally, in vitro combinations of amphotericin B, miltefosine, and pentamidine against L. infantum showed in isobolograms an additive interaction when these drugs were combined with fendiline, resulting in overall mean sum of fractional inhibitory concentrations between 0.99 and 1.10. These data demonstrated that non-dihydropyridine-CCBs present antiprotozoal activity and could be useful candidates for future in vivo efficacy studies against Leishmaniasis and Chagas' disease.

Reposicionamento de fármacos e estudo de novas combinações terapêuticas no tratamento etiológico da doença de Chagas / Repositioning of drugs and study of new therapeutic combinations in the etiological treatment of Chagas disease

Dentre as doenças parasitárias tropicais, as causadas por protozoários se apresentam como um grande desafio para a saúde pública. Conhecida também como tripanossomíase americana, a doença de Chagas é encontrada principalmente em áreas endêmicas de 21 países da América Latina, com cerca de 8-10 milhões de pessoas infectadas. A quimioterapia utiliza medicamentos de elevada toxicidade, e no Brasil, restringe-se a um único fármaco, o benznidazol. Na busca por terapias alternativas, o reposicionamento de fármacos representa uma forma promissora para introdução de novos medicamentos. O presente trabalho teve como objetivo avaliar o potencial terapêutico contra T. cruzi de fármacos aprovados clinicamente, utilizando modelos in vitro e experimentais. Dentre os 54 fármacos testados, 17 apresentaram atividade contra formas tripomastigotas, com CE50 variando entre 1,8 a 81 µM, destacando-se a sertralina como o mais efetivo e o cloxazolam como o menos efetivo. Dentre 6 fármacos escolhidos, 5 demonstraram atividade contra os amastigotas intracelulares, com CE50 entre 1,4 a 32 µM, destacando-se a sertralina como o mais efetivo e o saquinavir como o menos efetivo. Realizou-se ainda um estudo de citotoxicidade, e o índice de seletividade dos fármacos variou entre 1,2 a 17. Por meio da construção de isobologramas, realizou-se um estudo in vitro de associação terapêutica contra formas tripomastigotas entre a nitazoxanida e a sertralina, resultando em uma combinação indiferente. A efetividade in vivo da sertralina e da nitazoxanida foi verificada em modelo de camundongos Swiss; apenas a nitazoxanida reduziu em 29% a parasitemia após 5 dias consecutivos de tratamento a 50 mg/kg. Finalmente, um estudo comparativo foi desenvolvido entre a técnica de qPCR e o método de Brener por contagem em microscopia óptica. Foi observada similaridade entre ambas as técnicas para avaliação da parasitemia no modelo murino...

Among tropical parasitic diseases, those caused by protozoans represent as a major challenge to public health. Also known as American trypanosomiasis, Chagas´s disease is found mainly in endemic areas of 21 countries of Latin America, with approximately 8-10 million people infected. The chemotherapy is based in highly toxic drugs with high toxicity and, in Brazil, it is restricted to a single drug, the benznidazole. In the search for alternative therapies, the repositioning of drugs represents a promising approch for the introduction of new medicines. This study aimed the evaluation of the therapeutic potential against T. cruzi of clinically approved drugs using in vitro and experimental models. Among the 54 tested drugs, 17 showed activity against trypomastigotes, with EC50 ranging from 1.8 to 81 µM; sertraline was the most effective drug and cloxazolam the least effective. Among 6 chosen drugs, 5 demonstrated activity against intracellular amastigotes with EC50 between 1.4 to 32 µM; sertraline as the most effective and saquinavir the least one. The mammalian cytotoxicity was also evaluated and selectivity index of drugs ranged from 1.2 to 17 µM. Through the construction of isobolograms, an in vitro study of combined therapy against trypomastigotes was performed with nitazoxanide and sertraline, resulting in an indifferent combination. The in vivo efficacy of nitazoxanide and sertraline was observed in Swiss mice model; nitazoxanide reduced by 29% the parasitemia after 5 consecutive days of treatment at 50 mg/kg. Finally, a comparative study was conducted between the qPCR technique and the method of Brener by light microscopy counting. A similar result was found for both techniques when evaluating the animals parasitemia in the murine model. The repositioning of approved drugs and their therapeutic associations could contribute to more effective and less toxic treatments for neglected diseases as Chagas disease...