穿心莲内酯对HepG2细胞ACAT活性和基因表达的影响

Effect of Andrographolide on the activity and gene expression of acyl-CoA:cholesterol acyltransferase in HepG2 cells

目的探讨穿心莲内酯(andrographolide,AP)在Hep G2细胞中对胆固醇酰基转移酶(ACAT)活性和基因表达的影响。方法使用MTT法确定穿心莲内酯对Hep G2细胞生长无明显抑制的剂量。在此无毒剂量下展开实验,分别使用高效液相色谱法、荧光检测法和RT-q PCR技术测定细胞胆固醇含量、ACAT酶活性以及ACAT基因表达。结果 AP(质量浓度分别为40、80μg/m L)可以显著降低游离胆固醇(FC)和酯化胆固醇(CE)含量,明显抑制ACAT酶活性和ACAT2 mRNA表达。结论穿心莲内酯具有一定的抗动脉粥样硬化作用,其机制可能是通过下调肝脏中ACAT2 mRNA表达来降低ACAT活性。

Objective To investigate the effect of Andrographolide（ AP） on the activity and gene expression of acyl-Co A： cholesterol acyltransferase（ ACAT） in Hep G2 cells. Methods The growth inhibition concentration of AP on Hep G2 was determined by MTT. HPLC,fluorescence assay and RT-q PCR were used to measure the content of cholesterol,ACAT activity and ACAT gene expression in Hep G2 cells,respectively. Results AP at 40 and 80 μg / mL obviously reduced the contents of free cholesterol（ FC） and cholesterol esters（ CE）,ACAT activity and ACAT2 mRNA expression in a dose-dependent manner.Conclusion AP may reduce ACAT activity via down-regulation of ACAT2 mRNA expression,which provides a new evidence for anti-atherosclerosis effects of AP.