知母皂苷B-Ⅱ对非酒精性脂肪性肝病的治疗作用及机制研究

Effect and mechanism of Timosaponin B-Ⅱon none alcoholic fatty liver disease in vitro and in vivo

目的用体内外实验探讨知母皂苷B-Ⅱ(TB-Ⅱ)对非酒精性脂肪性肝病(NAFLD)的治疗作用及可能的作用机制。方法体外棕榈酸(100μmol/L)处理人肝癌细胞(HepG2),同时加入不同浓度TB-Ⅱ干预24 h,检测细胞TG水平变化。将C75BL/6J小鼠随机分为正常饮食(NCD)组、高脂饮食(HFD)组、TB-Ⅱ低剂量组(HFD+LTB-Ⅱ)、TB-Ⅱ高剂量组(HFD+HTB-Ⅱ),NCD组喂以普通饲料,其余组均以高脂饲料喂养16周建立NAFLD动物模型,TB-Ⅱ低、高剂量组每天分别予50、100 mg/kgTB-Ⅱ灌胃;监测小鼠体质量、脂肪重量、生化指标及肝脏病理评估肝损伤程度,并通过实时定量PCR(RT-PCR)方法检测肝组织脂代谢相关基因变化。结果TB-Ⅱ处理后HepG2细胞TG水平下降;TB-Ⅱ治疗可使HFD小鼠体质量下降,血清转氨酶、TC、TG、LDL-C及肝组织TC和TG水平也显著下降,同时肝脏病理明显改善。其中脂质合成相关基因SREBP-1c、FAS及ACC1表达明显下降,并伴随脂肪酸β氧化关键基因CPT1、PPARα表达上调。结论TB-Ⅱ可通过调控肝细胞脂质合成及脂肪酸氧化延缓高脂诱导的NAFLD进程。

Objective To explore the effects of Timosaponin B-Ⅱ(TB-Ⅱ)on non alcoholic fatty liver disease(NAFLD)and its mechanisms.Methods In vitro,HepG2 cells were stimulated with 100μmol/L palmitate,without or with TB-Ⅱand the changes of TG level were detected.In vivo,C57BL/6J mice were fed with normal diet group(NCD),high-fat diet group(HFD),TB-Ⅱlow dose group(HFD+LTB-Ⅱ)and TB-Ⅱhigh dose group(HFD+HTB-Ⅱ).The NCD group was fed with ordinary feed,the other groups were fed with high-fat feed for 16 weeks to establish NASH animal models,and the low and high-dose groups of TB-Ⅱwere gavaged with 50 mg/kg and 100 mg/kg respectively every day.The body weight,fat weight,biochemical indexes and liver pathology of mice were monitored to evaluate the degree of liver injury,and the changes of genes related to lipid metabolism in liver tissue were detected by real-time quantitative PCR(RT-PCR).Results TG level of HepG2 cellsTB-Ⅱreduced after TB-Ⅱtreatment,TB-Ⅱtreatment can reduce the body weight of HFD mice,the levels of serum transaminase,TC,TG,LDL-C,TC and TG in liver tissue are also significantly decreased,and the liver pathology is obviously improved.but also downregulated the expression of lipogenesis-related genes(SREBP-1c,FAS and ACC),accompanied by the up-regulation of the expression of key genes CPT1 and PPARαin fatty acidβoxidation.Conclusion TB-Ⅱcould delay the process of NAFLD induced by high fat by regulating lipid synthesis and fatty acid oxidation in hepatocytes.