人参多糖对氧化应激损伤肝细胞的保护作用机制研究

目的:以氧化应激损伤模型,通过对人参中物质基础的筛选,研究其对氧化应激造成的肝细胞损伤的保护作用及其可能的作用机制的初步探讨。方法:采用浓度为25 μmol/L的过氧化氢溶液建立肝细胞损伤模型,对人参中总蛋白、总多糖、总皂苷的保护作用进行筛选。在此基础上,采用流式细胞术检测其凋亡程度、线粒体膜电位的改变,活性氧的含量变化。并采用ELISA法测肝糖原,超氧化物歧化酶(SOD)、丙二醛(MDA)、葡萄糖-6-磷酸酶(G6P)、磷酸烯醇式丙酮酸羧激酶(PEPCK)及ATP酶等指标的变化情况。结果:经过氧化氢诱导后的肝细胞,细胞活力极显著降低(P<0.01),通过对比人参中活性成分,发现人参多糖的保护作用较强,且呈现浓度依赖性;与模型组比较,人参多糖高剂量组大鼠肝细胞中MDA含量非常显著降低(P<0.001);中、高剂量组大鼠肝细胞中SOD含量显著升高(P<0.05);低剂量组大鼠肝细胞中G6P含量显著升高(P<0.05),中、高剂量组中G6P含量极显著升高(P<0.01);中剂量组大鼠肝细胞中PEPCK的含量显著升高(P<0.05),高剂量组中PEPCK的含量极显著升高(P<0.01);低、中剂量组大鼠肝细胞中ATP酶含量极显著升高(P<0.01);中、高剂量组大鼠肝细胞中肝糖原含量显著升高(P<0.05)。结论:人参多糖通过提高肝细胞中ATP酶的活力,升高线粒体膜电位来恢复肝细胞线粒体的功能,通过恢复G6P与PEPCK的含量来恢复肝脏糖异生的功能,同时通过升高SOD,降低MDA来减弱氧化应激带来的损伤,为后续研究氧化应激造成肝损伤提供一定的基础。

Mechanism of Protective Effect of Ginseng Polysaccharide on Hepatocytes Induced by Oxidative Stress

Objective:Based on the oxidative stress injury model,the protective effect of oxidative stress on hepatocyte injury and its possible mechanism were studied by screening the material basis of ginseng. Methods:A hepatocellular injury model was established by using a hydrogen peroxide solution with the concentration of 25 μmol/L to screen protective effects of total protein,total polysaccharide,total saponin in ginseng. On this basis,cytometry was used to detect the degree of apoptosis,changes in mitochondrial membrane potential,changes in reactive oxygen species,and changes in hepatic glycogen. Changes in hepatic glycogen,superoxide dismutase(SOD),malondialdehyde(MDA),glucose-6-phosphatase(G6P),phosphoenolpyruvate carboxykinase(PEPCK),and atpase were observed by ELISA. Result:After liver cells induced by hydrogen peroxide,cells viability were significantly reduced(P<0.01). By comparing the active ingredients in ginseng,it was found that the protective effect of ginseng polysaccharide was stronger and showed concentration dependence. Compared with the model group,the MDA content in the liver cells of rat for the high dose group of ginseng polysaccharide was significantly decreased(P<0.001). The SOD content in the liver cells of rat for the middle dose group and the high dose group were significantly increased(P<0.05). The content of G6P in the liver cells of rat for the low dose group was significantly increased(P<0.05),and the content of G6P in the middle dose group and the high dose group was significantly increased(P<0.01). The content of PEPCK in the liver cells of rat for the middle dose group was significantly increased(P<0.05)and the content of PEPCK in the high dose group was significantly increased(P<0.01). The atpase content in the liver cells of rat for the low dose group and the middle dose group were significantly increased(P<0.01). The content of hepatic glycogen in the liver cells of rat for middle dose group and high dose group were significantly increased(P<0.05). Conclusion:Ginseng polysaccharide restores the function of mitochondria in hepatocytes by increasing the activity of atpase in hepatocytes and increasing mitochondrial membrane potential. It restores hepatic gluconeogenesis by restoring G6P and PEPCK. At the same time,by increasing SOD and reducing MDA,the damage caused by oxidative stress is weakened. It provides a basis for the subsequent study of oxidative stress-induced liver damage.