桔梗多糖对H_2O_2诱导PC12细胞氧化损伤的保护作用及机制研究

Protective Effects and Mechanism of Polysaccharide from Platycodon Grandiflorum on Damage of PC12 Cells Induced by H_2O_2

目的研究桔梗多糖(PGP)对H_2O_2致PC12细胞氧化应激损伤的保护作用机制。方法建立H_2O_2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、p22^(phox)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 H_2O_2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、p22^(phox)和Rac mRNA和蛋白的表达水平。结论 PGP对H_2O_2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 grandiflorurn polysaccharide （PGP） on PC12 cells injured by H2 O2 and the underlying mechanisms. METHODS The cell viability was analyzed by MTT assay, the model was established by treating PC12 cells with H2 O2. 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-regu- late mRNA and proteins of NOX2, p22phox and Rac. CONCLUSION PGP exhibited protective effect on PC12 cells injury in- duced by H2 O2, it may via the suppression of NOX2 activation.