In vitro trypanocidal activity of DB745B and other novel arylimidamides against Trypanosoma cruzi.

OBJECTIVES As part of a search for new therapeutic opportunities to treat chagasic patients, in vitro efficacy studies were performed to characterize the activity of five novel arylimidamides (AIAs) against Trypanosoma cruzi. METHODS The trypanocidal effect against T. cruzi was evaluated by light microscopy through the determination of IC₅₀ values. Cytotoxicity was determined by MTT assays against mouse cardiomyocytes. RESULTS Our data demonstrated the trypanocidal efficacy of these new compounds against bloodstream trypomastigotes and intracellular amastigotes, exhibiting IC₅₀ values ranging from 0.015 to 2.5 and 0.02 to0.2 μM, respectively. One of the compounds, DB745B, was also highly active against a broad panel of isolates, including those naturally resistant to benznidazole. DB745B showed higher in vitro efficacy than the reference drugs used to treat patients (benznidazole IC₅₀= 12.94 μM) and to prevent blood bank infection (gentian violet IC₅₀= 30.6 μM). CONCLUSIONS AIAs represent promising new chemical entities against T. cruzi and are also potential trypanocidal agents to prevent transfusion-associated Chagas' disease.