目的 探討18α-甘草次酸對游離脂肪酸（FFAs）致HepG2細(xì)胞脂毒性的保護(hù)作用及經(jīng)線粒體途徑調(diào)節(jié)的分子機(jī)制。方法 給予1 mmol/L FFAs，油酸（OA）-棕櫚酸（PA）（2：1）建立體外HepG2細(xì)胞脂肪變性模型，細(xì)胞分為對照組、模型組和18α-甘草次酸低、中、高劑量（10、20、40 μmol/L）組，陽性藥（凋亡抑制劑Z-VAD-FMK，10 μmol/L）組，采用MTT法檢測細(xì)胞活力，用Hoechst33258染色法觀察細(xì)胞凋亡；免疫熒光染色法觀察Bax蛋白激活情況；Western blotting檢測細(xì)胞色素C在線粒體和胞漿的分布情況；Caspase-3酶活檢測試劑盒測定細(xì)胞內(nèi)Caspase-3活性。結(jié)果 18α-甘草次酸能保護(hù)FFAs致HepG2細(xì)胞活力下降，減少HepG2細(xì)胞脂性凋亡數(shù)量；18α-甘草次酸能下調(diào)Bax蛋白激活，減少細(xì)胞色素C的釋放，從而阻止Caspase-3活性的增高，且呈劑量相關(guān)性。結(jié)論 18α-甘草次酸對FFAs致HepG2細(xì)胞的脂毒性中存在保護(hù)作用，其作用機(jī)制與抑制線粒體凋亡通路有關(guān)。

Objective To investigate the protective effect of 18α-glycyrrhetic acid on lipotoxicity in HepG2 cells induced by free fatty acids (FFAs) and its potential cellular pathway. Methods The HepG2 cell steatosis model in vitro were incubated with 1 mmol/L FFAs, oleic acid (OA)-palmitic acid (PA) (2:1). The HepG2 cells were randomly divided into control group, model group, 18α-glycyrrhetic acid 10, 20, and 40 μmol/L groups, Z-VAD-FMK group. Cell viability was assessed by MTT method. Cell apoptosis was determined by Hoechst 33258. Bax activation was detected by immuno fluorescence staining. Mitochondrial dysfunction was analyzed by detecting cytochrome C release by Western blotting method. Caspase-3 enzyme activity was determined by Caspase-3 enzyme activity kit. Results 18α-Glycyrrhetic acid could protect the decrease of HepG2 cell activity and reduce the number of lipid apoptosis in HepG2. 18α-Glycyrrhetic acid could reduce the activation of Bax protein and decrease the release of cytochrome C. Thus, 18α-glycyrrhetic acid could decrease the Caspase-3 enzyme activity, and they were dose-dependent. Conclusion 18α-Glycyrrhetic acid has the protection of lipotoxicity in HepG2 cells induced by FFAs, and its mechanism may be related to inhibition of mitochondrial apoptosis pathway.

R966

四川省科技廳科技支撐計(jì)劃（2014SZ0140）；成都中醫(yī)藥大學(xué)?；鹳Y助項(xiàng)目（ZRYB201003）