Figure 2.

Effects of stilbene analogues and dexamethasone on the NF‐κB pathway. (A) Representative blots and quantification of total pIκBα and IκBα protein expression in A549 cells treated with various concentrations of either isorhapontigenin (ISO) or resveratrol (RES) (1–100 μM) or 1 μM dexamethasone for 1 h before stimulation with 1 ng·mL⁻¹ IL‐1β for 10 min. IL‐1β induced an increase in levels of pIκBα (B), which was not altered by the compounds (n = 4) where * represents P < 0.05 for differences from non‐stimulated cells (NS) by ANOVA followed by Bonferroni correction. However, there was a suppression of expression of IκBα by all treatments where * indicates P < 0.05 for differences between NS cells and treatments (C). Nuclear protein expression of p50 (D, F) and p65 (E, G) were increased by stimulation with 1 ng·mL⁻¹ IL‐1β for 1 h and were not altered by the compounds (n = 3) where TBP is TATA box binding protein and used as a loading control and * represents P < 0.05 for differences from NS by ANOVA followed by Bonferroni correction. A549 cells stably transfected with NF‐κB reporter gene were treated with increasing concentrations of either ISO (●) or RES () (H) or dexamethasone (I) for 1 h before stimulation with 1 ng·mL⁻¹ IL‐1β for 6 h. ISO reduced luciferase activity to nearly basal levels while RES showed minimal inhibitory effects and the maximum repression by dexamethasone was 60% (n = 5). Data are mean ± SEM.