Inhibitory effect of (+)-catechin on oxidative stress-induced cell death in fibroblasts. After incubation with serum-free medium for 24 h, fibroblasts were treated for 30 min with (+)-catechin (0–400 μM) and then subjected to oxidative stress induction with 0.1 mM hydrogen peroxide (H2O2). After 24 h, cell viability was evaluated. (a) Representative microscopic images of cell death induced by oxidative stress (a) and inhibitory effect of (+)-catechin on oxidative stress-induced cell death (b). Cell viability was assessed by the MTT assay (c). Data are expressed as the mean ± SEM. *P < 0.05, **P < 0.01.