Abstract: Objective To investigate the(-)-epigallocatechin-3-gallate(EGCG)photoprotection in BALB/c mouse skin damaged by chronic irradiation of different doses of ultraviolet B(UVB).Methods BLAB/c mice were pretreated with topical EGCG on the back,followed by daily irradiation with different dosages of UVB.One month later,skin samples were obtained and detected for IFN-γand IL-10 mRNA expression by RT-PCR.Results Compared with the control group,IFN-γmRNA expression in the skin of BALB/c mice was significantly decreased,while IL-10 mRNA expression was significantly increased after chronic UVB irradiation(both P<0.01),both in a dose-dependent manner.Topical application of EGCG had a significant influence(P<0.01)on the mRNA expression of IFN-γand IL-10 induced by UVB irradiation.Conclusions UVB irradiation could down-regulate IFN-γmRNA expression but up-regulate IL-10 mRNA expression in BALB/c mice skin.EGCG has a potential photo-protective effect on UVB induced local immunosuppression in BALB/c mouse skin.

Key words: Ultraviolet rays, Interferon typeⅡ, Interleukin-10, (-)-epigallocatechin-3-gallate