长波紫外线对大鼠皮肤角朊细胞的损伤及茶多酚的保护作用

目的 探讨长波紫外线（ＵＶＡ）对原代培养的大鼠皮肤角朊细胞脂质过氧化和生长状况等影响，同时探讨一种植物多酚－－茶多酚（ＴＰＰ）在此过程中所起的作用。方法 在原代培养大鼠皮肤角朊细胞基础上，经ＵＶＡ照射后，测定角朊细胞浆酶－－乳酸脱氢酶（ＬＤＨ）释放情况，脂质过氧化产物丙二醛（ＭＤＡ）、谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）水平，并测定培养细胞的存活率和细胞周期动力学。结果 ＵＶＡ可以引起体外培养的细胞膜通透性增强，胞浆酶ＬＤＨ释放增加（从８２７．５５Ｕ／Ｌ增至１３１２．４７Ｕ／Ｌ）；脂质过氧化产物ＭＤＡ水平升高，抗氧化酶ＧＳＨ－Ｐｘ水平降低；细胞存活率下降，细胞周期动力学表现为细胞增殖抑制；增殖指数（ＰＩ）从３４．２４％降至１７．９８％。天然提取物ＴＰＰ（质量浓度为０．１％）可以比较明显地抑制ＵＶＡ引起的上述损害。

Protection of tea polyphenols(TPP) from damage induced by UVA in primary cultured rat skin keratinocytes

Objective To study the effects of UVA and tea polyphenols(TPP,a kind of polyphenol substances from a special plant) on lipid peroxidation and cell kinetics in primarily cultured rat skin keratinocytes. Methods The release of cytoplasm enzyme,lactate dehydrogenase(LDH),lipid peroxidation product,malondialdehyde(MDA),and anti peroxidant,glutathione peroxidase(GSH Px),were assayed in primary cultured keratinocytes treated by UVA and TPP.Cytometry and Flow Cytometer were used to count the viable cells and the cell kinetics,too. Results UVA could obviously improve the release of LDH from 827.55 U/L to 1 312.47 U/L,increase the formation of peroxidation product MDA,decrease the level of GSH Px and reduce the survival rate of cells and the cell proliferative index(PI) from 34.24% to 17.98%.TPP could significantly protect and inhibit the damage induced by UVA. Conclusion UVA could damage skin keratinocytes,and TPP could protect keratinocytes from damage induced by UVA.The result could provide useful information in developing natural anti violet product.