茶叶中表没食子儿茶素没食子酸酯抑制中波紫外线诱导HaCaT细胞氧化损伤研究

Inhibition effects of epigallocatechin gallate in tea on oxidative damage of HaCaT cells induced by ultraviolet radiation B

中文关键词:  表没食子儿茶素没食子酸酯  中波紫外线  HaCaT细胞  氧化损伤

英文关键词:epigallocatechin gallate  ultraviolet radiation B  HaCaT cell  oxidative damage

中文摘要:

      目的 研究茶叶中表没食子儿茶素没食子酸酯(EGCG)对中波紫外线(UVB)诱导的人表皮角质形成细胞(HaCaT)光损伤的保护作用。方法 用不同浓度的EGCG对HaCaT细胞进行预处理6 h, 采用60 mJ/cm2的剂量照射细胞, 用MTT法检测细胞生存率, 吸取细胞上清液检测超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH–Px)、乳酸脱氢酶(LDH)的活性和丙二醛(MDA)含量变化, 用荧光法检测细胞内ROS含量。结果 UVB辐射对HaCaT细胞造成严重损伤, 与对照组相比, 细胞活性下降21.63%; 与UVB辐射模型组相比, EGCG尤其高剂量可提高UVB照射后HaCaT细胞的存活率5.89%, 显著提高SOD、GSH–Px活性(P<0.01), 降低LDH活性 (P<0.01), 减少自由基ROS和MDA含量(P<0.01)。结论 EGCG可以减少UVB诱导HaCaT细胞的损伤和凋亡, 具有光保护作用, 其机制与增强细胞抗氧化能力和加速清除氧自由基有关。

英文摘要:

      Objective To study the photo-protective effect of epigallocatechin gallate in tea on HaCaT cells damaged from ultraviolet radiation B. Methods Sub–confluent HaCaT cells were incubated for 6 h with different doses of EGCG, and then irradiated with 60 mJ/cm2 doses of UVB. The cell viability was tested by MTT method. The activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), lactate dehydro-genase (LDH), and the level of malondialdehyde (MDA) of supernatant were detected with colorimetric me-thods. The content of ROS was measured with the fluorescence method. Results Compared with control group, the UVB irradiation could seriously damage HaCaT cell and gave rise to 21.63% cell viability decline. EGCG, especially this with the high dose, could enhance cell viability by 5.89%, increase SOD and GSH-Px activity in supernatant under UVB irradiation, and decrease LDH activity and the contents of MDA and ROS in dose–dependent manner (P<0.01). Conclusion EGCG can relieve UVB-induced oxidative damage and apoptosis of HaCaT cells, which may be the reasons that they enhance the oxidase activity and clear the oxy-radicals in cells.