Inhibitory effect of (+)-catechin on phosphorylation of p38 and JNK induced by oxidative stress in fibroblasts. After incubation with serum-free medium for 24 h, fibroblasts were treated for 30 min with 10 μM (+)-catechin and then subjected to oxidative stress induction with 0.1 mM hydrogen peroxide (H2O2). After 1 h, cells were collected, and phosphorylation of p38 and JNK was determined by SDS-PAGE and western blotting analysis using anti-phospho p38 and anti-phospho JNK antibodies. (a) Results of western blotting for phosphorylation of (a) p38 and (b) JNK. Phosphorylation levels of p38 and JNK were normalized to those of total p38 and JNK, respectively. Data are expressed as the mean ± SEM. **P < 0.01.