雷公藤红素通过调节脂质合成及氧化降低HepG2细胞甘油三酯水平的研究

摘要

目的 探讨雷公藤红素在非酒精性脂肪肝细胞模型中对TG水平的影响,并进一步研究其背后的机制.方法 用CCK-8试剂盒确定细胞模型中雷公藤红素给药浓度, TG试剂盒测定HepG2细胞内TG水平.Western blot以及定量即时聚合酶链锁反应检测靶分子蛋白水平以及mRNA水平变化.结果 雷公藤红素400 nmol/L组,600 nmol/L组、800 nmol/L组、1000 nmol/L组的TG水平分别为(64.55±1.92) μg/mg、(64.16±2.19) μg/mg、(60.94±2.70) μg/mg、(61.45±1.61) μg/mg,较软脂酸组水平[(69.32±1.79)μg/mg]明显下降(P均＜0.05).雷公藤红素600 nmol/L组及1000 nmol/L组中,脂质合成相关的固醇调节因子结合蛋白(sterol-regulatory element-binding protein1c, SREBP-1c)及脂肪酸合成酶(fatty acid synthase, FAS)的表达显著降低,脂质氧化相关基因过氧化物酶体增殖物激活受体γ(peroxisome proliferators-activated receptor gamma, PPARγ)表达水平在600 nmol/L组以及1000 nmol/L组分别为1.11±0.09(相比正常对照组,下同)以及1.16±0.05,较软脂酸组0.86±0.07显著上调(P均＜0.05).结论 雷公藤红素能显著降低HepG2细胞内TG含量,该作用可能与下调SREBP1c以及FAS表达,上调PPARγ水平有关.%Objective To investigate the effect of celastrol on triglyceride level in model of nonalcoholic fatty liver cells, and study the underlying mechanisms. Methods CCK-8 assay was used to determine the celastrol concentration in cell model. The levels of TG in HepG2 cells were determined with TG kits. The levels of target molecular protein and mRNA were detected by using Western blot assay and quantitative real time polymerase chain reaction. Results TG levels of celastrol 400 nmol/L, 600 nmol/L, 800 nmol/L and 1000 nmol/L groups were (64.55±1.92) μg/mg, (64.16±2.19) μg/mg, (60.94±2.70) μg/mg, (61.45±1.61) μg/mg, respectively, which were significantly lower than those in palmitic acid group (69.32±1.79) μg/mg (P＜0.05). The expression levels of lipid synthesis-related sterol-regulatory element-binding protein 1c (SREBP-1c) and fatty acid synthase (FAS) were significantly decreased in 600 nmol/L group and 1000 nmol/L group, while peroxisome proliferators-activated receptor gamma (PPARγ) expression levels were significantly increased in 600 nmol/L group 1.11±0.09 and 1000 nmol/L group 1.16±0.05 compared with normal control group. The difference was significant compared with palmitic acid group 0.86±0.07 (P＜0.05). Conclusions Celastrol can significantly decrease TG content in HepG2 cells, which may be related to down-regulation of SREBP1c and FAS expression and up-regulation of PPARγ expression.