Effects of Bay 11-7082 and LLnL on C. crepidioides -induced iNOS expression and NO production in RAW264.7 cells. (A) iNOS reporter gene analysis. RAW264.7 cells were transfected with the indicated luciferase reporter plasmids. After transfection, the cells were incubated in a medium containing Bay 11-7082 (20 μM) or LLnL (20 μM) for 1 h and then treated with C. crepidioides (500 μg/ml) for 6 h. Thereafter, luciferase activities were measured. The activities are expressed relative to that of cells transfected with pGL3 iNOS without further treatment, which was defined as 1. LUC, luciferase. Data are mean ± SD of three independent experiments. (B) RAW264.7 cells were pretreated with Bay 11-7082 (20 μM) or LLnL (10 μM) for 1 h before stimulation with C. crepidioides (500 μg/ml) for another 6 h. The iNOS mRNA expression was determined by RT-PCR. (C) RAW264.7 cells were pretreated with the indicated concentrations of Bay 11-7082 or LLnL for 1 h before stimulation with the indicated concentrations of C. crepidioides for another 48 h. The nitrite content in the culture media was analyzed. Data are mean ± SD of triplicate cultures. C. c., C. crepidioides.