目的：研究穿心莲内酯对人肝癌细胞株 HepG2中固醇调节元件结合蛋白（SREBP）表达及脂质代谢的影响，并探讨其作用机制。方法应用 Cell Counting Kit？8（CCK？8）试剂盒检测细胞活力；双荧光素酶报告基因实验检测穿心莲内酯对SREBP 转录活性的抑制作用；实时定量 PCR（RT？qPCR）法检测 SREBP 及其靶基因 mRNA 的表达；甘油三酯、总胆固醇（TG、TC）测定试剂盒检测 HepG2细胞中 TG、TC 的含量。结果CCK？8法结果显示穿心莲内酯在0～80μmol／L 浓度范围内对HepG2细胞活力无明显影响；穿心莲内酯能够剂量依赖性的抑制 HepG2细胞中 SREBP 的转录活性，同时浓度在20μmol／L条件下能显著下调 SREBP 靶基因 mRNA 的表达水平；此外，经穿心莲内酯体外干预后，HepG2细胞内 TG、TC 的含量明显减少。结论穿心莲内酯可能通过抑制 SREBP 的转录活性及其靶基因 mRNA 的表达，进而减少细胞内 TG、TC 的含量，起到改善肝细胞的脂质代谢作用。%ABSTRACTOBJECTIVE To explore the effects of Andrographolide on expression of SREBPs and lipid metabolism in HepG2 cellsand to study the possible mechanism.METHODS Cell viability was evaluated by Cell Counting Kit?8Dual luciferase reporter gene assay was used to test the transcription activity of SREBPThe SREBPs target genes expressions were measured by Quantitative Real?Time PCRThe intracellular triglycerideTG and total cholestero lTC contents were measured by u-sing commercially available test kits.RESULTS Andrographolide in 0 ~ 80 μmol/L concentration range has no effect on HepG2 cell activityAndrographolide could markly inhibited human SRE promoter activity in a dose?dependent mannerand the mRNA level of SREBPs target genes were significantly downregulated by Andrographolide at the dose of 35μmol/L.In ad-ditioncontents of intracellular cholesterol and triglyceride were significantly suppressed by Andrographolide treatment.CON-CLUSION These results suggested that Andrographolide might improve lipid metabolism through downregulating the mRNA levels of SREBPs target genes.
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