基于SREBPs的泽泻活性成分及其降脂作用研究

Research on lipid-lowering effect of Alisma orientale(Sam.)Juzep.based on SREBPs

目的基于固醇调节元件结合蛋白(SREBPs)探究泽泻降脂作用。方法MTT检测泽泻(ZX)对肝细胞HL7702活力的影响;尼罗红染色观察泽泻对油酸(OA)诱导HL7702细胞内脂滴蓄积的影响;试剂盒测定细胞内总胆固醇(TC)、甘油三酯(TG)含量;荧光素酶报告基因检测泽泻及其活性成分对SREBPs转录活性的影响;Q-PCR评估泽泻对SREBPs下游靶基因的影响。结果①泽泻在0~300μg/mL浓度范围内对HL7702细胞活力无显著影响,且不同浓度的泽泻均能降低OA诱导的细胞内TC、TG含量及脂滴含量。②泽泻能够剂量依赖性抑制SREBPs转录活性,并显著抑制SREBPs下游靶基因水平。③泽泻醇A等10个活性成分可以抑制SREBPs转录活性,且能降低OA诱导的细胞内高TC、TG水平。结论泽泻能够降低OA诱导的肝细胞内脂质蓄积,其可能是通过抑制SREBPs来降低胆固醇和脂肪酸合成。

Objective To explore lipid-lowering of Alisma orientale(Sam.)Juzep.(ZX)based on sterol regulatory element binding proteins(SREBPs).Methods MTT was used to detect the effect of ZX on cell viability of HL7702.The effect of ZX on the accumulation of lipid droplets in HL7702 cells induced by oleic acid(OA)was observed by Nile red staining,and the con-tents of total cholesterol(TC)and triglyceride(TG)in cells were determined by the kit.The effect of ZX and its active compo-nents on the transcription activity of SREBPs was detected by luciferase reporter gene.Q-PCR was used to evaluate the effects of ZX on downstream target genes of SREBPs.Results 1.The activity of HL7702 cells was not significantly affected by ZX in the concentration range of 0-300μg/mL,and different concentrations of ZX reduced the contents of intracellular TC,TG and lipid droplets induced by OA.2.ZX dose-dependentially inhibited SREBPs and significantly reduced the expression of downstream target genes of SREBPs.3.The 10 active components,such as Alisol A,inhibited the transcriptional activity of SREBPs and re-duced the intracellular high TC and TG levels induced by OA.Conclusion ZX reduced lipid accumulation in hepatocytes induced by OA,possibly by inhibiting SREBPs and reducing cholesterol and fatty acid synthesis.