J. Cosmet. Sci., 64, 35–44 (January/February 2013) 35 Effect and mechanism of epigallocatechin-3-gallate (EGCG). against the hydrogen peroxide-induced oxidative damage in human dermal fi broblasts BING FENG, YUN FANG, and SHAO-MIN WEI, School of Chemical and Material Engineering, Jiangnan University, Wuxi, Jiangsu 214122 (B.F., Y.F., S.-M.W.) and R&D Center, Shanghai Jahwa United Co. Ltd., Shanghai 201702 (B.F., S.-M.W.), People’s Republic of China. Accepted for publication June 5, 2012. Synopsis This study was conducted to investigate the protective effects of epigallocatechin-3-gallate (EGCG) on hydrogen peroxide (H2O2)-induced oxidative stress injury in human dermal fi broblasts. 3-(4,5-Dimethylthi- azol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay and the use of Hoechst staining and terminal deoxynucleotidyl transferase dUTP nick end labeling for apoptosis detection indicated that the administration of H2O2 to human dermal fi broblasts caused cell damage and apoptosis. The incubation of human dermal fi broblasts with EGCG markedly inhibited the human dermal fi broblast injury induced by H2O2. The assay for 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity indicated that EGCG had a direct, concentration-dependent antioxidant activity. Treatment of human dermal fi broblasts with EGCG signifi cantly reversed the H2O2-induced decrease of superoxide dismutase (SOD) and glutathione peroxidase (GSH-px), and the inhibition of malondialdehyde (MDA) levels. These results showed that EGCG possessed antioxidant activity and was effective against H2O2-induced human dermal fi broblast injury by enhancing the activity of SOD and GSH-px, and by decreasing the MDA level. Our results suggested that EGCG should have the potential to be used further in cosmetics and in the prevention of aging-related skin injuries. INTRODUCTION Human dermal fi broblasts are the predominant cell type in the dermis and play an im- portant role in the aging process. Apoptosis of human dermal fi broblasts can decrease cell number and cell activity, leading to reduced synthesis of collagen and other extracellular matrix and fi nally to change in morphology and function of dermal layer (1–3). The clinical symptoms include many skin aging changes such as dry rough skin, loose skin, reduced elasticity, and increased wrinkles. Therefore, the study of human dermal fi broblasts apopto- sis is crucial for the research and development of personal antiaging protective products. Address all correspondence to Shao-Min Wei at weishaomin@jahwa.com.cn.