(A) Dose-dependent inhibition of T. cruzi intracellular multiplication and infection in cardiomyocytes by TCCYP51 inhibitors. Trypomastigotes were pre-treated with several concentrations of TCCYP51 inhibitors or mock-treated, exposed to cardiomyocyte monolayers and T. cruzi multiplication was evaluated at 72 h by determining the number of T. cruzi/cell (left panel) and the percent of infection (right panel). The data represent the mean ± standard deviation (SD) of results from triplicate samples. SD did not exceed 10% of the mean. Differences in T. cruzi per cell and % infection between trypomastigotes-mock treated (DMSO) and trypomastigotes treated with each TCCYP51 inhibitor (5–50 μM) are p<0.05 determined by the Student t test. The two most potent TCCYP51 inhibitors (21 and 22) show antiparasitic activities at ≤ 10 μM concentrations) but release cardiomyocyte monolayers at higher concentrations.
(B). Microscopic observation of the inhibition of T. cruzi multiplication by 20 μM TCCYP51 inhibitors within cardiomyocytes at 72 hr. T. cruzi pre-treated with control DMSO showed high levels of parasite multiplication, whereas cells exposed to trypanosomes pre-incubated with the inhibitors showed a dramatic decrease in the number of intracellular parasites.