桔梗多糖对H2O2诱导PC12细胞氧化损伤的保护作用及机制研究

摘要

目的 研究桔梗多糖(PGP)对H2O2致PC12细胞氧化应激损伤的保护作用机制.方法 建立H2O2诱导PC12细胞氧化损伤模型,MTT法检测细胞存活率;比色法测定细胞内乳酸脱氢酶(LDH)、丙二醛(MDA)含量、超氧化物歧化酶(SOD)以及谷胱甘肽过氧化物酶(GSH-Px)的活性;DCFH-DA检测细胞内ROS;qPCR、Western Blot方法分别检测NOX2、p22phox和Rac mRNA和蛋白的表达.结果 与模型组相比,PGP预处理24h后,加入终浓度为600μmol/L H2O2处理2h,LDH、MDA含量和细胞内ROS减少,SOD与GSH-Px活性增强,同时,PGP下调NOX2、p22phox和Rac mRNA和蛋白的表达水平.结论 PGP对H2O2诱导的PC12细胞的氧化损伤具有保护作用,其作用机制可能与抑制NADPH氧化酶2(NOX2)过表达有关.%OBJECTIVE To determine the protective effects of Platycodon grandiflorum polysaccharide (PGP) on PC12 cells injured by H2O2 and the underlying mechanisms.METHODS The cell viability was analyzed by MTT assay, the model was established by treating PC12 cells with H2O2.The levels of LDH, MDA, SOD and GSH-Px were determined by Kits.ROS production was determined by DCFH-DA fluorescence.mRNA and proteins of NOX2, p22phox and Rac were analyzed by qPCR and Western Blot methods.RESULTS Compared with the model, treatment with PGP significantly decrease of LDH, MDA and intracellular ROS production, as well as increase activity of SOD and GSH-Px.Furthermore, PGP could down-regulate mRNA and proteins of NOX2, p22phox and Rac.CONCLUSION PGP exhibited protective effect on PC12 cells injury induced by H2O2, it may via the suppression of NOX2 activation.