Fig. 3

Resveratrol and curcumin inhibit U0126-induced inhibition of Erk1/2 in primary chondrocytes. a Western blot analysis with U0126-treated chondrocytes. Serum-starved chondrocytes were pre-incubated with 10 μM resveratrol and 10 μM curcumin for 5, 10, 20, 30, 40 and 50 min, co-treated with 1 μM U0126 for 30 min and then probed (500 ng of protein per lane) for the anti-pan Erk1/2 antibody (control) and anti-phospho Erk1/2. Resveratrol and curcumin pre-treatment inhibited U0126-induced Erk1/2 inhibition in a time-dependent manner. Synthesis of pan Erk1/2 remained unaffected (a-I, II). b Serum-starved human chondrocytes were pre-incubated with equal concentrations of resveratrol and curcumin (0, 1, 2, 3, 4, 5 and 10 μM) for 4 h followed by stimulation with 1 μM U0126 for 30 min. The extracts were probed (500 ng of protein per lane) for phospho Erk1/2 by western blot analysis using antibodies to anti-pan Erk1/2 antibody (control) and anti-phospho Erk1/2. A dose-dependent activation of pErk1/2 was observed. The activation of pErk1/2 by resveratrol and curcumin is therefore dose- as well as time-dependent. Synthesis of pan Erk1/2 remained unaffected in nuclear extracts (b-I, II). Data shown are representative of three independent experiments