Abstract: Objective To explore the mechanism of ultraviolet-induced fibroblast apoptosis and the protective effects of EGCG, a major green tea catechin, on it. Methods The apoptosis rate of fibroblasts was detected by flow cytometer. The mRNA levels of Fas and Bcl-2 were determined by reverse transcrip-tion-polymerase chain reaction (RT-PCR). Results Apoptosis peak was observed in fibroblast group either treated with ultraviolet A(UVA)or ultraviolet B(UVB), respectively. After treating with EGCG, the apoptosis rate was decreased obviously, with statistical significance (P<0.001). The mRNA level of Fas was elevated after UVA or UVB irradiation and was inhibited by EGCG treatment. The mRNA expression of Bcl-2 was decreased after UVA irradiation, but without obvious difference between the UVB group and the control group. Conclusion EGCG treatment can protect the fibroblast from apoptosis induced by UVA or UVB, with some difference in the mechanism.

Key words: Ultraviolet rays, Apoptosis, Fibroblasts, Gallic acid