Fig. 3. (A) thiol levels were measured (MFI) in promastigotes using CellTracker™ fluorescent probe (1 µM). Data are the mean ± standard error of the mean (SEM) of five independent experiments. (B) Parasite viability of promastigotes untreated and treated with Sb^III (at the IC₅₀ of each isolate) in the presence or absence of L-buthionine sulfoximine (BSO). Data are the mean ± SEM of two independent experiments performed in quintuplicate. (C) ROS production after exposition to IC₅₀ Sb^III with or without BSO measured by 2′,7′-dichlorofluorescein fluorescence (MFI). Statistical analysis was performed by ANOVA followed by Tukey's post-test. Statistical significance was defined as p < 0.05. Data represent the mean ± SEM of two independent experiments performed in quintuplicate. SbS: antimony sensitive isolate; SbR: antimony resistant isolate.