Structure-Based Virtual Screening and In Vitro Evaluation of New Trypanosoma cruzi Cruzain Inhibitors.

Verónica Herrera-Mayorga,Benjamín Nogueda-Torres,Edgar Lara-Ramírez,Charmina Aguirre-Alvarado,Lorena Rodríguez-Páez,Francisco Reyes-Espinosa,Verónica Alcántara-Farfán,Karla Chacón-Vargas,Virgilio Bocanegra-García,Joaquín Cordero-Martínez,Gildardo Rivera

doi:10.3390/ijms20071742

Abstract

Chagas disease (CD), or American trypanosomiasis, causes more than 10,000 deaths per year in the Americas. Current medical therapy for CD has low efficacy in the chronic phase of the disease and serious adverse effects; therefore, it is necessary to search for new pharmacological treatments. In this work, the ZINC15 database was filtered using the N-acylhydrazone moiety and a subsequent structure-based virtual screening was performed using the cruzain enzyme of Trypanosoma cruzi to predict new potential cruzain inhibitors. After a rational selection process, four compounds, Z2 (ZINC9873043), Z3 (ZINC9870651), Z5 (ZINC9715287), and Z6 (ZINC9861447), were chosen to evaluate their in vitro trypanocidal activity and enzyme inhibition. Compound Z5 showed the best trypanocidal activity against epimatigote (IC50 = 36.26 ± 9.9 μM) and trypomastigote (IC50 = 166.21 ± 14.5 μM and 185.1 ± 8.5 μM on NINOA and INC-5 strains, respectively) forms of Trypanosoma cruzi. In addition, Z5 showed a better inhibitory effect on Trypanosoma cruzi proteases than S1 (STK552090, 8-chloro-N-(3-morpholinopropyl)-5H-pyrimido[5,4-b]-indol-4-amine), a known cruzain inhibitor. This study encourages the use of computational tools for the rational search for trypanocidal drugs.

Highlights

According to the World Health Organization (WHO), the Americas are one of the primary regions with a high prevalence of Chagas disease (CD)
Biological behavior did not vary between the compounds described above and the form of T. cruzi evaluated
The trypanocidal results obtained from the S1 inhibitor differ from that reported by Ferreira et al (2010) and Pinto et al (2017), because these authors indicated that the compound S1 showed IC50 values of 2.5 μM in infected mouse fibroblasts (L929) with trypomastigotes of T. cruzi of the Tulahúen strain

Summary

Introduction

According to the World Health Organization (WHO), the Americas are one of the primary regions with a high prevalence of Chagas disease (CD). The compounds S1 (STK552090, 8-chloro-N-(3-morpholinopropyl)-5H-pyrimido[5,4-b]-indol-4amine, a known Cz inhibitor), Z2, Z3, Z5 and Z6 were evaluated in vitro as potential trypanocidal agents against epimastigotes (INC-5 strain) and trypomastigotes (NINOA and INC-5 strains) of T. cruzi, using Bzn and Nfx as reference drugs. Z2 had a low activity, but Z5 showed a trypanocidal effect similar to Nfx, though it was four times less potent than Bzn. Biological behavior did not vary between the compounds described above and the form of T. cruzi evaluated. The trypanocidal results obtained from the S1 inhibitor differ from that reported by Ferreira et al (2010) and Pinto et al (2017), because these authors indicated that the compound S1 showed IC50 values of 2.5 μM in infected mouse fibroblasts (L929) with trypomastigotes of T. cruzi of the Tulahúen strain. In trypomastigotes, Z5 presented LC50 values lower than Bnz in both strains with concentrations 1.6 times lower than those present with the drug Nfx; compound Z5 is a promising structure in the search for new agents to treat Chagas disease

Enzyme Inhibition

Materials and Methods

In Vitro Evaluation

Findings

Conclusions