Studies during the past few years have indicated an inhibitory effect of green tea or tea polyphenols on tumorigenesis in animal and even in human.The purpose of this study was to observe the possible effects of tea polyphenols on skin cell growth and on apoptosis in rat priary cultured keratinocytes and fibroblasts.The release of a cell plasma enzyma enzyme(LDH),lipid peroxidation products (MDA production),and GSH-Px(glutathione peroxidase)into the medium in cultrued cells was determined after treatment with tea polyphenols in a primary culture of skin cells,The percentage of cells in each cell cycle phase and in apoptosis were assayed by flow cytometry(FCM),Tea polyphenols may have a beneficial effect on skin cells at concentrations from 0.05% to 0.1%,showing a dose-dependent decrease in LDH,MDA(malondialdehyde)production,and a significant dose -de -pendent increase in GSH-Px and cell number,These effects were more obvious after exposure for 24h than after 12h,The results indicate that tea polyphenols may stabliize and protect the cell membrane against the release of cell plasma enzyme LDH,and its anti-peroxidation effect is also important for cell growth,FCM analysis revealed that treatment with 0.01% to 0.1% tea polyphenols dereased the percentage of cells in the G1/G0(quiescent)phase from 81.32%to 74.38%,and increased the percentage of cells in S and G2/M phase from 9.87% to 15.26%,and from 6.51% to 10.36%,respectively,Tea polyphenols also increased the value of PI(proliferation index) from 18.17 to 25.62,At the same time it decreased the percentage of apoptosis from 27.10% to 17.97%,which indicates that green tea stimulates cell growth and inhibits the occureeence of apoptosis,Our results indicate that tea polyphenols are effective anti-oxidants and also inhibit apoptosis ,which may improve the proliferative capacity of primary skin cells in vitro.

完成机构：[1]SchoolofPublicHealth,ShanghaiMedialuniversity,Shanghai200032 [2]DepartmentofScienceResearch,ShanghaiJiahuaCo.Ltd.,Shanghai200082,China

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