FIG 8.

Effects of resveratrol (Rv) on nitric oxide (NO) and cytokine production by murine peritoneal macrophages. Shown are uninfected (10⁵) (A) and L. amazonensis-infected macrophages (Leish) (B) at a 10:1 ratio, stimulated with IFN-γ or left unstimulated; these were incubated in the presence or absence of 100 μM Rv. NO production was evaluated after 48 h of treatment by the Griess method. The results from four independent experiments performed in triplicate are shown as the nitrite concentration means ± SEM. *, P < 0.05 and **, P < 0.001 compared to cells treated with IFN-γ alone. (C) Scavenger effect analysis was performed in a cell-free system by incubating SNAP solution (1 mM) as the NO donor with 100 μM Rv. Rutin (1 mM), an NO scavenger, was used as a positive control, and RPMI medium served as the negative control. The nitrite levels were determined by the Griess method. The data represent the means ± SEM from three independent experiments. ***, P < 0.0001. (D to G) The production of TNF-α (D and E) and TGF-β (F and G) was determined by specific ELISA after 48 h of treatment. The data represent the averages ± SEM from 3 experiments in triplicate. *, P < 0.05; **, P < 0.01; ***, P < 0.0001.