Figure 7

Detection of free DNA 3′-OH ends after incubation of Trypanossoma cruzi epimastigotes in the absence or presence of solenopsins. After cultivation for 24 h in BHI–FCS medium alone (A, BHI) or supplemented with either 0.07% TX-100 (B, TX-100) or 2.5 µM of solenopsins from Solenopsis invicta (C, INV) or S. saevissima (D, SAE), CL-Brener epimastigotes were collected, washed (3 ×) in PBS, suspended in PBS (around 2 × 10⁷ cells mL⁻¹), allowed to adhered to a poly-l-lysine embedded slide, processed through ApopTag technology, and observed under a light microscope. The obtained differential interference contrast images enable the comparison of unstained parasites with normal morphology (A), parasites with altered morphology that do not have any colour (B) that is compatible with necrosis induction, and stained parasites that also have altered morphology (C, D) that is compatible with the induction of apoptosis. Bars = 10 μm. The graphics (E) represent the mean ± SD of pixels intensity for parasites for each treatment: BHI (white bar), TX-100 (dark bar), INV (light-grey bar), SAE (dark-grey bar) from three independent experiments. Statistics: treatments were compared with Kruskal–Wallis at alpha = 0.05; the BHI/TX-100 and INV/SAE bars indicate statistically similar treatment results; an asterisk indicates values statistically different from controls. For details on analyses (e.g. p values), see the supplementary R script file.