背景:非酒精性脂肪性肝病(NAFLD)是全球最常见的慢性肝病之一,目前尚缺乏针对特异性靶点的治疗药物.目的:研究黄连素对高脂饮食诱导的小鼠肝脏脂毒性的保护作用及其相关机制.方法:30只雄性C57BL/6J小鼠随机分为对照组、高脂饮食组和治疗组,治疗组在高脂饮食的同时每天予200 mg/kg黄连素灌胃12周.第12周末检测血清生化指标(ALT、AST、TC、TG和空腹血糖),HE染色和油红染色观察肝脏炎症损伤和脂质沉积;16S rRNA基因测序检测回盲部肠道菌群改变;ELISA法检测血清LPS和肝组织TNF-α、IL-6水平.分离、培养小鼠原代肝巨噬细胞,分别予棕榈酸、LPS和(或)黄连素处理,电子显微镜观察巨噬细胞超微结构,real-time PCR检测促炎细胞因子表达.结果:动物实验显示,黄连素能显著改善高脂饮食小鼠的肝功能、血脂、血糖以及肝脏脂质沉积、肝细胞气球样变和小叶内炎症,降低血清LPS和肝组织IL-6水平.在科分类等级,高脂饮食组小鼠回盲部拟杆菌、脱硫弧菌等减少,治疗组上述菌群失调得以恢复.体外实验中,黄连素处理能明显改善棕榈酸诱导的原代肝巨噬细胞脂质沉积,以及LPS诱导的TNF-α、IL-6表达增高.结论:黄连素能减轻小鼠NAFLD模型的肝脏脂质沉积和炎症损伤,其减轻肝脏炎症反应的作用可能与调节肠道菌群,减少LPS生成,进而抑制肝巨噬细胞炎症因子释放有关.
Background:Non-alcoholic fatty liver disease(NAFLD)is one of the most common chronic liver diseases worldwide and specific targeted therapy is still lacking up to now. Aims:To investigate the protective effect of berberine on high fat diet(HFD)-induced hepatic lipotoxicity in mice and its potential mechanisms. Methods:Thirty male C57BL/6J mice were randomly assigned to three groups,then fed either with standard diet or HFD or HFD plus berberine(200 mg/kg per day intragastrically)for 12 weeks. Serum biochemical indices including ALT,AST,TC,TG and glucose were measured at the end of the 12th week. HE staining was used to observe liver inflammation,and fatty infiltration was detected with oil red staining. Ileocecal feces was collected and the composition of gut microbiota was analyzed by 16S rRNA sequencing. Serum level of LPS and hepatic levels of TNF-α and IL-6 were detected by ELISA. In vitro,the primary hepatic macrophages of C57BL/6J mice were challenged with palmitic acid,LPS and/or berberine,respectively;the ultrastructure of macrophages was observed using electron microscope,and the proinflammatory cytokines were detected by real-time PCR. Results:In vivo,the treatment of berberine improved the liver dysfunction,hyperlipidemia and hyperglycemia in mice fed with HFD. Also,berberine significantly inhibited the HFD-induced hepatic lipid accumulation,and alleviated hepatocytes ballooning and lobular inflammatory cell infiltration;the levels of serum LPS and hepatic IL-6 were markedly decreased. 16S rRNA sequencing showed that berberine supplementation restored the abundance of Bacteroidaceae and Desulfovibrionaceae in ileocecus,which were disturbed by HFD. In vitro,berberine not only significantly reduced the palmitic acid-induced lipid accumulation in primary hepatic macrophages,but also decreased the expressions of TNF-α and IL-6 in macrophages stimulated with LPS. Conclusions:Berberine can ameliorate effectively the hepatic lipid accumulation and inflammation in mice with experimental NAFLD. The mechanism of its antiinflammatory effect might be related with regulating the gut microbiota,reducing the LPS production,and subsequently inhibiting the release of inflammatory cytokines by hepatic macrophages.