黄芩苷对高脂诱导HepG2细胞脂肪沉积及SIRT1相关因子表达的影响

目的   研究黄芩苷(Baicalin, BA)对游离脂肪酸(FFA)诱导HepG2细胞脂肪沉积的影响及机制研究。方法   选用0.75 mmol/L的FFA体外诱导HepG2细胞24 h，建立体外脂肪沉积模型。将细胞分为正常组、模型组、黄芩苷低、中、高剂量组。利用油红O染色及GPO-PAP酶法检测各组细胞内甘油三酯(TG)含量的变化，ELISA法检测各组细胞上清液炎症因子TNF-α、IL-6分泌量。Western Blot检测各组细胞内沉默信息调节因子1(SIRT1)、碳水化合物应答元件结合蛋白(ChREBP)、胆固醇调节元件结合蛋白-1c(SREBP-1c)以及脂肪酸合成酶(FAS)的蛋白含量。结果   FFA诱导的HepG2细胞内脂质积聚明显，细胞内TG含量显著上升；药物干预后，3个药物组细胞内脂滴较模型组均有减少，且呈药物浓度依赖性；细胞内TG含量呈下降趋势，其中中剂量和高剂量药物组与模型组相比，差异具有统计学意义(P < 0.05)；Western Blot检测结果显示，与空白组相比，模型组SIRT1蛋白表达显著降低，SREBP-1c以及FAS的蛋白表达显著上升，与模型组相比，中、高剂量黄芩苷组细胞SIRT1蛋白表达显著上升，SREBP-1c、ChREBP以及FAS蛋白表达显著下降(P < 0.05)。结论   黄芩苷可以改善FFA诱导的HepG2细胞的脂肪沉积，减低细胞内TG的含量，其机制可能与调节SIRT1/SREBP-1c通路相关。 

Effects of Baicalin on High Fat-Induced Lipid Accumulation and SIRT1 Related Factors Expression of HepG2 Cells in vitro<\i>

OBJECTIVE To study the effects and mechanism of baicalin on high fat-induced lipid accumulation in HepG2 cells.METHODS HepG2 cells were induced in vitro with 0.75 mmol/L free fatty acid for 24 h to establish an in vitro fat deposition model.The cells were then divided into the following groups;normal group,model group,50μmol/L baicalin group,100μmol/L baicalin group and 200μmol/L baicalin group.Oil Red O staining and GPO-PAP enzymatic method were used to detect the changes of TG content in each group of cells,and enzyme-linked immunosorbent assay(ELISA)was used to detect inflammatory factors in the supernatant of each group:TNF-α,IL-6.Western Blot was used to detect the following protein content:SIRT1,ChREBP,SREBP1c,FAS Protein.RESULTS Free fatty acid induced lipid accumulation in HepG2 cells increased,the concentration of TG in cells increased significantly;after the drug intervention,the intracellular lipid droplets in the three drug groups were reduced in comparison to the model group,therefore,showing drug-concentration-dependent results;the TG concentration showed a downward trend in the drug-groups,in which,the differences between the 100μmol/L and 200μmol/L drug group and the model group were statistically significant(P<0.05).Western blot detection showed that compared with the normal group,the expression of SIRT1 protein in the model group was significantly reduced,and the protein expressions of SREBP-1c and FAS increased significantly;the SIRT1 protein expressions of the cells in the 100μmol/L baicalin group and 200μmol/L baicalin group increased significantly,while SREBP-1c,ChREBP and FAS protein expression decreased significantly(P<0.05).CONCLUSION Baicalin can reduce the lipid accumulation of HepG2 cells induced by free fatty acids and reduce the TG content in the cells.The mechanism may be related to the SIRT1/SREBP-1c pathway.