辣木叶黄酮对肝癌HepG2细胞脂质代谢的影响及机制探究

Effects of flavonoids from moringa oleifera leaves on lipid metabolism in HepG2 cells and its mechanism

目的探究辣木叶黄酮对肝癌HepG2细胞脂质代谢的影响及其潜在作用机制。方法构建脂质沉积肝癌HepG2细胞模型,用辣木叶黄酮(终浓度1、2、5及10μg/ml)处理细胞;细胞计数(cell counting kit,CCK)-8实验检测细胞活力;油红O染色检测细胞内脂滴染色情况;采用试剂盒检测细胞中活性氧(reactive oxygen species,ROS)和三磷酸腺苷(adenosine triphosphate,ATP)表达;实时荧光定量聚合酶链式反应法检测脂质代谢相关基因[低密度脂蛋白受体(low-density lipoprotein receptor,LDLR)]、固醇调节原件结合蛋白(sterol regulatory element binding protein,SREBP)-1c、小凹蛋白(caveolin,CAV)1及乙酰辅酶A胆固醇乙酰转移酶(acetyl-coenzyme A acetyltransferase,ACAT)1表达;免疫印迹法检测核因子E2相关因子(nuclearfactor-E2-related factor,Nrf)2/血红素加氧酶(hemeoxygenase-1,HO)-1信号通路相关蛋白表达水平。结果选取1、2及5μg/ml辣木叶黄酮处理细胞进行实验。与模型组相比,辣木叶黄酮处理组HepG2细胞中ROS、SREBP-1c及ACAT1水平明显降低,ATP、LDLR、CAV1水平及Nrf2、HO-1蛋白表达明显升高,且呈剂量依赖性,差异有统计学意义(P<0.05)。抑制Nrf2/HO-1信号通路可逆转辣木叶黄酮对脂质代谢相关基因表达的调控作用。结论辣木叶黄酮能够改善脂质沉积HepG2细胞的氧化应激和脂质代谢水平,可能是通过激活Nrf2/HO-1信号通路来实现的。

Objective To investigate the effects of flavonoids from moringa oleifera leaf on lipid metabolism in HepG2 cells and its potential mechanism.Methods HepG2 cell model with lipid deposition was constructed,and the cells were treated with moringa leaf flavonoids(final concentration 1,2,5,10μg/ml).Cell counting kit(CCK-8)assay was used to detect cell viability.Oil red O staining was used to detect intracellular lipid droplet staining.The expression of reactive oxygen species(ROS)and adenosine triphosphate(ATP)were detected by the kit.The expression of lipid metabolism-related genes[low-density lipoprotein receptor(LDLR),sterol regulatory component binding protein-1C(SREBP-1C),caveolin-1(CAV1)and acetyl coenzyme a acetyltransferase 1(ACAT1)]were detected by quantitative real time polymerase chain reaction.The expression levels of nuclearfactor-E2-relatedfactor(Nrf)2/hemeoxygenase(HO)-1 signaling pathway were detected by western blot.Results The cells treated with 1,2,5μg/ml of moringa leaf flavonoids were selected for the experiment.Compared with model group,the levels of ROS,SREBP-1c and ACAT1 in HepG2 cells in moringa leaf flavonoids treatment group were significantly decreased,while the levels of ATP,LDLR,CAV1 and Nrf2 and HO-1 protein expressions were significantly increased in a dose-dependent manner,with statistically significant differences(P<0.05).Inhibition of Nrf2/HO-1 signaling pathway reversed the regulatory effect of moringa leaf flavonoids on lipid metabolism related genes expression.Conclusion Moringa oleifera leaf flavonoids can improve oxidative stress and lipid metabolism in lipid-deposited HepG2 cells,possibly through activation of Nrf2/HO-1 signaling pathway.