In this study, we investigated the protective effects of green tea seed extract (GSE) against UVB-induced skin damage in human skin fibroblasts. GSE was first analyzed for antioxidant activity using 1,1-diphenyl-2picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging assays. Treatment of UV-irradiated fibroblast with GSE at 10～50 µg/mL significantly increased DPPH and ABTS radical scavenging activities in a dose-dependent manner. GSE treatment inhibited matrix metalloproteinase (MMP-1, MMP-3, and MMP-9) expression and MMP-1 secretion caused by UVB irradiation. Moreover, treatment with GSE significantly increased type-1 collagen expression and production. We next examined levels of antioxidative enzymes (SOD, catalase, and GPx). Reduced antioxidative enzyme activities caused by UVB irradiation were recovered by treatment with GSE at 30 µg/mL and 50 µg/mL. In conclusion, these results show that GSE has protective effects against UVB-induced skin damage in human skin fibroblasts by regulating antioxidative defense systems and MMP expression.

Keywords: green tea seed, antioxidant, photoaging, UVB, fibroblast