Figure 2.

Flavones induce caspase-dependent apoptosis in primary human neutrophils. A, B) Neutrophils were cultured with the flavones apigenin, luteolin, and wogonin (all at 50 μM) with and without the broad spectrum caspase inhibitor Q-VD-OPh (Q-VD; 10 μM) before neutrophil viability, apoptosis, and necrosis assessment by flow cytometric analysis of annexin-V/PI binding at both 6 h (A) and 20 h (B); n ≥ 3. The presence of Q-VD-OPh dramatically inhibited the ability of flavones to induce apoptosis. C, D) Representative flow cytometry plots of annexin-V (x axis)/PI (y axis) binding are shown at 6 h for 50 μM apigenin (C) and 50 μM apigenin plus 10 μM Q-VD-OPh (D). Data are expressed as means ± se, analyzed by ANOVA with a Newman-Keuls multiple comparison test. ***P < 0.001 vs. Q-VD-OPh-treated sample.