Fig. 4

Effects of Resveratrol/Curcumin on IL-1β-induced inhibition of MAPK pathway in human articular chondrocytes in vitro. Serum-starved human chondrocytes were pre-treated with 10 μM resveratrol and/or 10 μM curcumin alone for 12 h. Other serum-starved chondrocytes were pre-stimulated with 10 μM resveratrol and/or 10 μM curcumin alone for 4 h and then co-treated with IL-1β (10 ng/ml) or/and 1 μM U0126 for 8 h. Some cultures were left untreated and evaluated after 12 h. Equal amounts (500 ng protein per lane) of total proteins were separated by 12% SDS-PAGE and analyzed by immunoblotting with anti-pan-ERK and anti-pErk1/2 antibodies. IL-1β- or U0126-induced inhibition of pErk1/2 was blocked by curcumin and/or resveratrol (I). In contrast, western blot analysis with a pan-ERK antibody, which recognizes both the phosphorylated and non-phosphorylated forms of Erk1 and 2, confirms that these did not change in response to U0126 treatment (II). Data shown are representative of three independent experiments