P. acnes induced iNOS/NO and COX-2/PGE2 expressions via a ROS-dependent NF-κB cascade. (a, b) Western blot analysis of NF-κB p65 activation in the presence of P. acnes for 1 hour, pretreated with or without NAC (10 mM) in NPCs. (c–f) The activation of NF-κB p65, expression of iNOS and COX-2 (c, d), and production of NO and PGE2 (e, f) were analyzed. The NPCs were incubated with P. acnes for 1 hour (for NF-κB p65 activation) and 24 hours (for iNOS, COX-2, NO, and PGE2 expression), pretreated with or without NF-κB-specific inhibitors (BAY 11-7082, 10 μM) for 1 hour. ∗The infection + BAY 11-7082/NCA group compared with the infection group; P < 0.05. P values were analyzed by one-way ANOVA. Data are presented as the mean ± SD from three independent experiments. P-p65: phosphorylated-p65; T-p65: total-p65.