α-硫辛酸对氧化损伤大鼠肝细胞凋亡的保护作用

Protective effects of α-ipoic acid on apoptosis in rat hepatocyte with oxidative damage

目的研究α-硫辛酸（α-LA）对氧化损伤大鼠肝细胞凋亡的保护作用。方法将正常大鼠肝细胞（BRL）分为正常对照组，在含有5％胎牛血清（FBS）的DMEM培养基中培养24h；H2O2损伤组，在含有5％FBS的DMEM培养基中培养24h后，以0．2mmol／LH2O2作用1h；α-LA低、中、高剂量组，分别用含有50、100、200μmol／Ld．LA的培养液培养细胞24h后，以0．2mmol／LH2O2作用1ho测定各组谷胱甘肽过氧化物酶（GSH—Px）、超氧化物歧化酶（SOD）、丙二醛（MDA）含量、细胞凋亡率、凋亡相关蛋白Bcl-2和Bax的表达。结果与正常对照组比较，H2O2损伤组的GSH—Px和SOD活性均降低，MDA含量和细胞凋亡率升高（P〈0．05），Bcl-2蛋白表达量减少，Bax蛋白表达量增多（P〈0．05）；与H2O2损伤组相比，α-LA各剂量组的GSH—Px和SOD活性均有所升高，MDA含量和细胞凋亡率下降（P〈0．05），Bcl-2蛋白表达量增加，Bax蛋白表达量降低（P〈0．05）。结论α-LA可以通过抗氧化，上调Bcl-2的蛋白表达水平，下调Bax的蛋白表达水平，对氧化损伤引起的肝细胞凋亡起到保护作用。

Objective To investigate the protective effects of α-lipoic acid （α-LA） on apoptosis in rat hepatocyte. Methods Rat hepatocyte BRL cells were divided into normal control group：cells were incu- bated in DMEM with 5% fetal bovine serum（FBS） for 24 h; H202 exposed group：0.2 mmol/L H2O2 was added for 1 h after 24 h incubation in DMEM with 5% FBS;α-LA-low,α-LA-median, α-LA-high dose group： 0.2 mmol/L H202 was added for 1 h after 24 h incubation in DMEM with different concentration of α-LA （ 50,100,200 μmol/L）. The content of glutathione peroxidase （ GSH-Px ）, superoxide dismutase （ SOD ）, ma- londialdehyde（MDA） , apoptotic rate and expression of apoptosis related proteins Bc1-2 and Bax were detec- ted. Results Compared to normal control group, the activity of GSH-Px and SOD were lower in H202 ex- posed group, content of MDA and apoptotic rate increased and, the expression of Bcl-2 decreased while Bax protein increased. Compared to HEO2 exposed group, the activity of GSH-Px and SOD were higher in α-LA different dose groups, content of MDA and apoptotic rate decreased simultaneously. The expression of Bcl-2 increased while Bax protein reduced. Conclusion α-LA possessed protective effects on apoptosis in oxida- tive damaged rat hepatoeyte by antioxidation, up-regulating expression of Bcl-2 and down-regulating expres- sion of Bax.