矢车菊素-3-O-葡萄糖苷对H_2O_2诱导细胞氧化损伤的保护作用

目的:研究矢车菊素-3-O-葡萄糖苷(C3G)对人胚肾HEK-293细胞氧化损伤的保护作用。方法:通过检测细胞活力、活性氧(ROS)水平和丙二醛(MDA)水平考察C3G对氧化损伤细胞的影响,并采用Western blot法和q RTPCR检测Nrf2和Keap1的蛋白表达量和m RNA表达量变化。结果表明:C3G预处理氧化应激细胞后,细胞活力显著高于H_2O_2损伤组(p <0.05),并呈浓度依赖性提高; H_2O_2损伤组的DCF荧光强于对照组,ROS相对含量增加到近2倍,1.25、5、20μmol/L C3G预处理后细胞荧光强度逐渐减弱,ROS相对量呈浓度依赖性降低; C3G预处理后细胞MDA水平呈浓度依赖性降低; 1.25、5、20μmol/L C3G处理后,Nrf2的m RNA表达和蛋白表达量均呈浓度依赖性上调,Keap1蛋白表达量显著低于H_2O_2损伤组(p <0.05),5和20μmol/L C3G对Keap1的m RNA下调作用明显。结论:矢车菊素-3-O-葡萄糖苷对HEK-293细胞有保护作用,可降低细胞ROS和MDA水平,其作用机制可能是通过激活Nrf2/Keap1信号通路以抵抗H_2O_2导致的细胞氧化损伤。

Protective Effects of Cyanidin-3-O-glucoside on H_2O_2-induced Oxidative Damage in Cells

Objective: To investigate the inhibitive effect of Cyanidin-3-O-glucoside (C3G) on oxidative stress in human embryonic kidney cells (HEK-293). Methods: Cell viability,MDA level and the level of intracellular reactive oxygen species (ROS) were investigated.Quantitative real-time PCR and Western blotting were used to detect the expression of Nrf2 and Kelch-like ECH associated protein 1 (Keap1).Results: After pretreatment with C3G,the cell viability was significantly higher than that of the injury group and increased in a concentration-dependent manner (p < 0.05). The fluorescence intensity of oxidative DCF in injured group was increased compared with control group,and the ROS content of injured group was twice greater then control group. The fluorescence intensity of cells which pretreated with C3G was gradually weakened. The ROS content of C3G group decreased in a concentration-dependent manner.After pretreatment of C3G,the MDA levels decreased in a concentration-dependent manner. Furthermore,the protein and m RNA expressions of Nrf2 were significantly enhanced by 1.25,5 and 20 μmol/L of C3G (p < 0.05).The protein expression of Keap1 was significantly lower than that of injury group,and the m RNA expression of Keap1 was significantly down-regulated by 5 and 20 μmol/L of C3G. Conclusion: These results demonstrated that C3G protect HEK-293 cells against H2O2-induced oxidative stress through reducing intracellular ROS and MDA,as well as activating Nrf2/Keap1 signaling pathway.