Fig. 1.

Magnolin inhibits NF-κB transactivation activity. a Chemical structure of magnolin. b RSK2 mediates IκBα phosphorylation at Ser32. RSK2^+/+ and RSK2^−/− MEFs were used to visualize the phosphorylation of IκBα induced by EGF stimulation using the specific antibodies as indicated. c Magnolin inhibits EGF-induced IκBα phosphorylation at Ser32. JB6 Cl41 (1 × 10⁶) cells were seeded, starved, and treated with magnolin in the presence or absence of EGF. The specific protein levels were visualized by Western blotting using the specific antibodies as indicated. b–c β-actin was used as an internal control to verify equal protein loading. d–e Magnolin inhibits EGF-induced NF-κB transactivation activity. JB6 Cl41 cells stably expressing NF-κB luciferase reporter plasmid were seeded, cultured, starved, and stimulated with EGF and the indicated doses of magnolin (d), or treated with the indicated doses of magnolin under normal culture conditions for 24 h (e). Firefly luciferase activity was measured as described in “Materials and Methods”. b–e Data are presented as the mean ± S.D. of values from triplicate experiments, and statistical significance was determined using the Student’s t-test (*, p < 0.05)