Fig 2. 2HF effects against wild-type or antimony-resistant promastigotes.

Wild-type or antimony-resistant L. amazonensis promastigotes were incubated in Schneider’s Drosophila medium in the absence or presence of increasing concentrations of 2HF (3–96 μM) for 24 hours. The number of parasites was determined by direct counting using a Neubauer chamber. In the control (absence of 2HF), the same volume of DMSO (0.2% v/v; solvent of 2HF) was added to the growth medium. The values are presented as the mean ± standard error of three different experiments. a) Wild-type (5 passages), b) Antimony-resistant (32 passages), c) Wild-type comparative (32 passages). The IC₅₀ was calculated via nonlinear regression using GraphPad Prism 6.0. * indicates significant difference relative to control (p < 0.05).