【摘要】 目的 研究人参皂苷F1对H₂O₂诱导的HepG2细胞胆固醇代谢紊乱在其抗氧化应激中的作用机制。方法 通过1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl, DPPH）和氧化自由基吸收能力（oxygen radical absorbance capacity, ORAC）试验检测人参皂苷F1对氮氧自由基的清除作用，以400μmol/L H₂O₂诱导HepG2细胞氧化损伤，10、20和40μmol/L人参皂苷F1预处理，通过线粒体膜电位检测试剂盒（JC-1法）和胆固醇试剂盒分别检测线粒体膜电位和细胞总胆固醇水平，并采用蛋白印迹法检测胆固醇合成通路中胆固醇调节元件结合蛋白2（sterol-regulatory element binding proteins, SREBP2）和3-羟基-3-甲基戊二酸单酰辅酶A还原酶（3-hydroxy-3-methylglutaryl coenzyme A reductase, HMGCR）的蛋白表达量变化。结果 人参皂苷F1的DPPH清除率较低，远低于水溶性维生素E（6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid, Trolox）,但人参皂苷F1的ORAC能力较强，与Trolox相当；H₂O₂损伤细胞后，线粒体膜电位下降，SREBP2蛋白表达量显著下调（P<0.05）,胆固醇水平上升、HMGCR的蛋白表达显著上调（P<0.05）,10、20和40μmol/L人参皂苷F1预处理损伤细胞后，线粒体膜电位较损伤组显著提高（P<0.05）,中高浓度组SREBP2蛋白表达量显著上调（P<0.05）,胆固醇水平下降、HMGCR的蛋白表达显著下调（P<0.05）。结论 人参皂苷F1能通过抑制氧自由基、保护线粒体抵抗H₂O₂诱导的HepG2细胞氧化应激，其作用机制可能与干预SREBP2/HMGCR通路调控细胞胆固醇合成代谢有关。更多还原

【Abstract】 OBJECTIVE To investigate the inhibitory mechanisms of ginsenoside F1 on hydrogen peroxide induced cholesterol metabolism disorder and oxidative stress in HepG2 cells.METHODS 1,1-diphenyl-2-picrylhydrazyl(DPPH) and oxygen radical absorbance capacity(ORAC) tests were used to detect the scavenging effect of ginsenoside F1 on nitrogen and oxygen free radicals. HepG2 cells were treated with 400 μmol/L hydrogen peroxide and pretreated with 10, 20 and 40 μmol/L ginsenoside F1. Mitochondrial membrane potential(MMP) and total cholesterol levels were detected by JC-1 method and cholesterol kit, respectively. The protein expression levels of sterol-regulatory element binding proteins(SREBP2)and 3-hydroxy-3-methylglutaryl coenzyme A reductase(HMGCR) in cholesterol synthesis pathway were detected by Western blot.RESULTS The DPPH clearance rate of ginsenoside F1 was much lower than that of 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid(Trolox), but the ORAC capability of ginsenoside F1 was stronger, which was comparable to Trolox. The MMP and protein expression of SREBP2 were significantly decreased in injured group(P<0.05). The cholesterol and protein expression of HMGCR were significantly increased(P<0.05). Whereas, compared with the injured group, the MMP and protein expression of SREBP2 were significantly increased after 10, 20 and 40 μmol/L ginsenoside F1 pretreatment of injured cells(P<0.05). The cholesterol level and protein expression of HMGCR were significantly lower than injured group with concentration-dependent decreases(P<0.05).CONCLUSION Ginsenoside F1 can protect against hydrogen peroxide induced oxidative stress in HepG2 cells by inhibiting oxygen free radicals and protecting mitochondria. And its mechanism may be related to the intervention of SREBP2/HMGCR pathway in regulating cellular cholesterol anabolism.更多还原