Fig. 5.

EC₅₀ of elongation factor 2 kinase (EF2K) inhibitor for wild-type and EF2-overexpressing L. braziliensis lines (a) and effect of EF2K inhibitor on the growth of L. braziliensis lines upon Sb^III exposure (b). Parasites were incubated in M199 medium in the absence or presence of different concentrations of EF2K inhibitor (C₁₃H₁₅N₅O₃) (50 to 300 μM). For competition assay, cells were exposed to the EC₅₀ of Sb^III (7 and 14 μM for the LbWTS and EF2-overexpressing clone 9, respectively) and the EC₅₀ of EF2K inhibitor (173 and 211 μM for the LbWTS and EF2-overexpressing clone 9, respectively) independently or combined, followed by incubation for 48 h. The percentage of relative growth was determined using a Z1 Coulter Counter. Mean values ± standard deviations from three independent experiments in triplicate are shown. Statistical analysis was carried out using Student’s t-test. Statistically different values are highlighted as follows: *P < 0.05; **P < 0.01; ***P < 0.001. Pairwise comparisons (a): 100 μM: t₍₆₎ = 3.52, P = 0.0126; 150 μM: t₍₆₎ = 3.94, P = 0.0076; 200 μM: t₍₆₎ = 8.83, P = 0.0001. (b) Sb ^III  + EF2K inhibitor: t₍₄₎ = 11.72, P = 0.0003