ABSTRACT
This work reports a repurposing study of pyrazinoic acid (1) and methyl (2), ethyl (3) and 2-chloroethyl (4) ester derivatives with antimycobacterial activity, in assays against Trypanosoma cruzi. The compounds and benznidazole, the standard antitrypanosoma drug, were evaluated in concentrations ranging from 100 to 6.25 µg/mL. The results showed that compounds 2 and 3 (EC50 = 182 and 447 µM) significantly reduced the infection rate of the parasite into the mammalian cells at 100 µg/mL (p < 0.05) in a similar way to benznidazole. In addition, all the compounds also significantly reduced the number of intracellular parasites (compound 1 at 50 µg/mL, and compounds 2-4 at 100 µg/mL, p < 0.05) in comparison to the control. Compounds 1 and 2 were more effective than benznidazole at 50 µg/mL (p < 0.001). Moreover, compounds 1-4 did not show significant cytotoxicity against THP-1, J774, and HeLa cells (>1000 µM), indicating that they possess considerable selectivity against the parasites. This report represents the first study of such compounds against T. cruzi, indicating the potential of pyrazinoates as antiparasitic agents.