Repurposing Strategy of Atorvastatin against Trypanosoma cruzi: In Vitro Monotherapy and Combined Therapy with Benznidazole Exhibit Synergistic Trypanocidal Activity.

Abstract

Statins are inhibitors of cholesterol synthesis, but other biological properties, such as antimicrobial effects, have also been assigned to them, leading to their designation as pleiotropic agents. Our goal was to investigate the activity and selectivity of atorvastatin (AVA) against Trypanosoma cruzi by using in vitro models, aiming for more effective and safer therapeutic options through drug repurposing proposals for monotherapy and therapy in combination with benznidazole (BZ). Phenotypic screening was performed with different strains (Tulahuen [discrete typing unit {DTU} VI] and Y [DTU II]) and forms (intracellular forms, bloodstream trypomastigotes, and tissue-derived trypomastigotes) of the parasite. On assay of the Tulahuen strain, AVA was more active against intracellular amastigotes (selectivity index [SI] = 3). Also, against a parasite of another DTU (Y strain), this statin was more active (2.1-fold) and selective (2.4-fold) against bloodstream trypomastigotes (SI = 51) than against the intracellular forms (SI = 20). A cytomorphological approach using phalloidin-rhodamine permitted us to verify that AVA did not induced cell density reduction and that cardiac cells (CC) maintained their typical cytoarchitecture. Combinatory approaches using fixed-ratio methods showed that AVA and BZ gave synergistic interactions against both trypomastigotes and intracellular forms (mean sums of fractional inhibitory concentration indexes [∑FICIs] of 0.46 ± 0.12 and 0.48 ± 0.03, respectively). Thus, the repurposing strategy for AVA, especially in combination with BZ, which leads to a synergistic effect, is encouraging for future studies to identify novel therapeutic protocols for Chagas disease treatment.