Repositioning FDA Drugs as Potential Cruzain Inhibitors from Trypanosoma cruzi: Virtual Screening, In Vitro and In Vivo Studies.

Isidro Palos,Benjamin Nogueda-Torres,Gildardo Rivera,Muhammad Kashif,Edgar E Lara-Ramirez,Carlos Garcia-Perez,Virgilio Bocanegra-Garcia,Julio Cesar Lopez-Cedillo

doi:10.3390/molecules22061015

Isidro Palos, Benjamin Nogueda-Torres + Show 6 more

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https://doi.org/10.3390/molecules22061015

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Abstract

Chagas disease (CD) is a neglected disease caused by the parasite Trypanosoma cruzi, which affects underdeveloped countries. The current drugs of choice are nifurtimox and benznidazole, but both have severe adverse effects and less effectivity in chronic infections; therefore, the need to discover new drugs is essential. A computer-guided drug repositioning method was applied to identify potential FDA drugs (approved and withdrawn) as cruzain (Cz) inhibitors and trypanocidal effects were confirmed by in vitro and in vivo studies. 3180 FDA drugs were virtually screened using a structure-based approach. From a first molecular docking analysis, a set of 33 compounds with the best binding energies were selected. Subsequent consensus affinity binding, ligand amino acid contact clustering analysis, and ranked position were used to choose four known pharmacological compounds to be tested in vitro. Mouse blood samples infected with trypomastigotes from INC-5 and NINOA strains were used to test the trypanocidal effect of four selected compounds. Among these drugs, one fibrate antilipemic (etofyllin clofibrate) and three β-lactam antibiotics (piperacillin, cefoperazone, and flucloxacillin) showed better trypanocidal effects (LC50 range 15.8–26.1 μg/mL) in comparison with benznidazole and nifurtimox (LC50 range 33.1–46.7 μg/mL). A short-term in vivo evaluation of these compounds showed a reduction of parasitemia in infected mice (range 90–60%) at 6 h, but this was low compared to benznidazole (50%). This work suggests that four known FDA drugs could be used to design and obtain new trypanocidal agents.

Highlights

Chagas disease (CD) is a neglected parasitic disease caused by the protozoan Trypanosoma cruzi.It represents a public health threat for under-developed countries in Latin America, where 350 million people are at risk for transmission and about 8 million are infected worldwide [1].Molecules 2017, 22, 1015; doi:10.3390/molecules22061015 www.mdpi.com/journal/moleculesThe infective pathway in human beings is with the bite of the haematophagous triatomine vector, which excretes trypomastigote infective forms near the bite site, allowing parasite penetration into the exposed tissue
We report a computational drug virtual screening protocol to identify Food and Drug Administration (FDA)
INC-5 strains, three compounds were less effective in comparison with benznidazole; piperacillin showed a decrease of parasitemia close to 70% at 6 h (Figure 4A). These results suggest that piperacillin and etofyllin clofibrate could be potential Cz inhibitors, but further confirmatory enzyme inhibition analyses are necessary

Summary

Introduction

Chagas disease (CD) is a neglected parasitic disease caused by the protozoan Trypanosoma cruzi.It represents a public health threat for under-developed countries in Latin America, where 350 million people are at risk for transmission and about 8 million are infected worldwide [1].Molecules 2017, 22, 1015; doi:10.3390/molecules22061015 www.mdpi.com/journal/moleculesThe infective pathway in human beings is with the bite of the haematophagous triatomine vector, which excretes trypomastigote infective forms near the bite site, allowing parasite penetration into the exposed tissue. Chagas disease (CD) is a neglected parasitic disease caused by the protozoan Trypanosoma cruzi. It represents a public health threat for under-developed countries in Latin America, where 350 million people are at risk for transmission and about 8 million are infected worldwide [1]. During cell infection the trypomastigotes transform into reproductive amastigote forms, disrupting cells and allowing tissue dissemination of new trypomastigotes, causing a generalized invasion [2]. The parasite employs essential proteins to reach the intracellular environment of the host cell. Aside from its pathogenic role, is that this protein has no human homologue; as a result, Cz is an attractive drug target for developing new inhibitors

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