银杏叶提取物抗氧化及其抗胰岛RIN-mβ细胞凋亡的作用

Effects of EGb761 on the antioxygen and cell apoptosis induced by H_2O_2 in RIN-m beta cells

目的:探讨银杏叶提取物(EGb761)的抗氧化及其抗过氧化氢(hydrogen peroxide,H2O2)诱导的胰岛RIN-mβ细胞凋亡的作用。方法:以500μmol/L H2O2作用于胰岛RIN-mβ细胞6 h建立凋亡模型;采用荧光探针DCFH-DA法进行活性氧检测细胞内氧自由基(reactive oxygen species,ROS)的变化,NO测试试剂盒检测细胞NO释放的变化,Annexin V-PI双染色法流式细胞术分析细胞凋亡情况。结果:经H2O2损伤诱导凋亡后,细胞存活率降低,凋亡率增加,细胞产生NO减少,活性氧ROS增多。与阴性对照组相比,EGb761能清除ROS,增加NO,改善凋亡情况,且作用呈剂量依赖性。结论:EGb761对β细胞凋亡有显著保护作用,其机制可能与其清除氧自由基等作用有关。

Aim： To investigate the effects of Ginkgo biloba extract （ EGb761 ） upon hydrogen peroxide （H2O2） induced apoptosis in RIN-m beta-cells. Methods： The apoptotic model was made by H2O2 exposed for six hours with a concentration of 500 μmol/L. EGb761 and quercefin（Que） respectively pretreated the RIN-m beta-cells for 10 hours which would suppose to act as ROS cleaner to scavenge oxidative damage produced by H2O2, The cytotoxicity was measured by cell counting-8 kit （CCK-8）. The pro- duction of nitric oxide （NO） was assayed with NO assay kit, and peroxide levels were determined using dichlorofluorescein diacetate assay kit （DCFH/DA）. AnnexinV- PI double staining of flow cytometry were used to quanfitively detect the effect of EGb761 on the apoptosis of RIN-m beta-cells induced by H2O2. Results： Compared to normal control group, after exposed to 500μmoL/L H2O2 for 6 hours, the apoptosis level increased and cell survival levels were decreased considerably（ P 〈 0. 001 ）. 100 μmL EGb761 or 100 μmol/L Que can scavenge the excessive ROS （P 〈 0. 01 ,compared with H2O2 group）. Pretreated with EGb761 or Que, the apoptosis level decreased and the NO increased considerably. Condusion： EGb761 can decrease cell apoptosis through scavenging of the excessive ROS, increasing NO releasing in RIN-m beta-cells.