To study the photo-protection effect of cranberry on HaCaT cells damaged by ultraviolet radiation B (UVB). HaCaT cells were first incubated for six hours with three different doses of cranberry juice, and then irradiated with 60 mJ/cm2 dose of UVB. The cell viability was detected by the MTT method. The level of malondialdehyde (MDA), hydroxyproline (Hyp) and the activites of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), lactate dehydrogenase (LDH) of supernatants were determined with the colorimetric methods. The content of intra-cellular reactive oxygen species (ROS) was tested with the fluorescence method. Compared with the control group, the UVB irradiation could seriously damage HaCaT cells, which lead to 29.54%decline in cell viability and obvious decrease in SOD and GSH-Px activities (P<0.01). Importantly, compared with the UVB model group, cranberry could obviously enhance cell viability (P<0.05 or P<0.01), increase SOD, GSH-Px activities and Hyp content, decrease LDH activity and the contents of MDA and ROS in supernatants under UVB irradiation in dose-dependent manner (P<0.01 or P<0.05), which lead to the decreased rate in cell damage and apoptosis. In conclusion , cranberry could relieve UVB-induced oxidative damage and apoptosis of HaCaT cells and exhibit the photo-protection effect , which might be the reasons that cranberryefficiently enhanced the oxidase activity , cleared the oxy-radicals and stimulated the collagen synthesis in cells.%研究蔓越莓对中波紫外线(UVB)诱导的人表皮角质形成细胞(HaCaT)光损伤的保护作用.用3个不同剂量的蔓越莓果汁预处理HaCaT细胞6 h,采用60 mJ/cm2强度UVB照射细胞;然后用MTT法检测细胞的生存率,吸取细胞上清液采用比色法检测丙二醛(MDA)、羟脯氨酸(Hyp)的含量和超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、乳酸脱氢酶(LDH)的活性变化,用荧光法检测细胞内活性氧自由基(ROS)含量,用倒置显微镜和流式细胞仪观察检测细胞凋亡状况.UVB辐射对HaCaT细胞造成比较严重的损伤; 相比于空白对照组,UVB辐射模型组HaCaT细胞活性下降了29.54%,SOD和GSH-Px活性极显著降低(P<0.01);相比于模型组,蔓越莓各剂量组可显著提高UVB照射后HaCaT细胞的活力(P<0.05或P<0.01),提高SOD和GSH-Px活性(P<0.01),减少MDA和ROS含量(P<0.05或P<0.01),并且降低LDH活性和增加Hyp含量(P<0.01),呈剂量依赖关系,从而降低UVB所导致的细胞损伤及凋亡率升高.蔓越莓可以明显减少UVB诱导HaCaT细胞的氧化损伤和凋亡,具有显著的光保护功效,其作用机制与增强细胞抗氧化能力、加速清除氧自由基以及促进胶原蛋白合成有关.
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