Protective effects of (-)-epigallocatechin-3-gallate on UVA- and UVB-induced skin damage

It has been known that green tea and its components possess significant che mopreventive effects against chemical carcinogens and photo-caused skin tum or formation. In this study, the protective effects of (-)-epigallocatechin -3-gallate (EGCG), a major green tea catechin, on the ultraviolet (UV)-indu ced skin damage (photoaging) were studied in guinea pigs, hairless mice and human dermal fibroblast cultures. The lipid peroxidation was significantly reduced in the EGCG-treated group. The amount of lipid peroxides produced in the control and EGCG treated group were 838 +/- 144 and 286 +/- 57 nmol/ mg at 18 h after UV irradiation, respectively. UVB-induced erythema was als o significantly reduced in the EGCG treated group. The erythema relative in dex of the control and the EGCG treated group were 311 +/- 45 and 191 +/- 4 9 at 16 h after UV irradiation, respectively. EGCG treatment reduced UVA-in duced skin damage (roughness and sagginess) and protected from the decrease of dermal collagen in hairless mouse skin. EGCG treatment blocked the UV-i nduced increase of collagen secretion and collagenase mRNA level in fibrobl ast culture. The nuclear transcription factors NF-kappaB and AP-1 binding a ctivities were also inhibited by EGCG treatment. Copyright (C) 2001 S. Karg er AG, Basel.