Fig. 2.

In vitro infection of host cells pretreated with resveratrol (RSV). A) Percentages of infected HeLa, Vero and L929 cells treated with RSV (for 18 h) or 25 μM Sirtinol (for 18 h) or incubated in EBSS medium (for 2 h) previous infection (indicated in the figure as “pretreatment” under the line). As controls, cells were left untreated or pre-incubated with the drug vehicle (1% DMSO for 18 h). All infections were performed for 4 h with the addition of the drug vehicle (−) or RSV at final concentrations of 4 μM (+) or 40 μM (++) (indicated in the figure as “added during infection” above the line). B) Average numbers of intracellular amastigotes per cell observed in the in vitro infection experiments using Vero, HeLa, and L929 cells pretreated with RSV or Sirtinol and with the addition of DMSO (−) or RSV at 4 μM (+) or 40 μM (++) during infection (indicated in the figure as “added during infection” above the line). As control, cells were left untreated or incubated with the drug vehicle (1% DMSO) previous to infection (indicated in the figure as “pretreatment” under the line).

All assays are expressed as the mean of three independent experiments ± SD, each performed in duplicate (∗p < 0.05, ∗∗p < 0.005). No statistical differences were observed between the controls corresponding to untreated cells and pre-incubation with DMSO. For simplicity, only the statistical analysis between DMSO control and experimental treatments are shown.