Protective effects of epicatechin derivatives on the UV light-induced skin cell damages

Abstract

It has been known that green tea and its components possess the significant chemopreventive effects against chemical carcinogens- and photo-caused skin tumor formation. In this study, the protective effects of green tea epicatechins (EC, EGC, ECG, EGCG) on the UV-induced skin damage (photoaging) were studied in guinea pig, hairless mouse and human dermal fibroblast culture. The UVB-induced lipid peroxidation and erythema were significantly reduced in the epicatechins-treated group. EGCG showed the strongest effect among tested. Amount of lipid peroxides produced in control and EGCG treated group were 838±144 and 286±57 nmol/mg protein 18 hours after UV-irradiation, respectively. The erythema relative index of the control and the EGCG treated group was 223±25 and 124±22 at 16 hours after UV-irradiation, respectively. EGCG treatment reduced UVA-induced skin damage (roughness and sagginess) and protected from the decrease of dermal collagen in hairless mouse skin. EGCG treatment blocked the UV-induced increase of collagenase secretion and collagenase mRNA levels in fibroblast culture. The nuclear transcription factors NF-kB and AP-1 binding activities were also inhibited by EGCG treatment.