黄芩汤对非酒精性脂肪肝炎大鼠的作用及机制研究

目的:研究黄芩汤对非酒精性脂肪肝炎(non-alcoholic steatohepatitis，NASH)的作用及机制。方法:将大鼠随机分为空白组、模型组、阳性对照组(多烯磷脂胆碱，8 mg·kg^-1)、黄芩汤低、中、高剂量组(5，10，20 g·kg^-1)，采用高脂饮食饲喂12周造模。灌胃给药5周后，检测各组大鼠血脂、肝功能及炎性因子水平;HE染色观察肝脏组织病理变化;RT-PCR和Western Blot法检测肝组织Toll样受体2(TLR2)、髓样分化因子88(MyD88)、核因子κB p65(NF-κB p65)、白介素6(IL-6)、维甲酸相关核孤儿受体γt(RORγt)、IL-23和IL-17 mRNA和蛋白表达;免疫组化法检测肝组织中NF-κB p65表达。结果:与空白组比较，模型组大鼠血脂、肝功能和炎性因子水平明显异常(P<0.01)。肝组织出现脂肪变性及炎性浸润;肝组织中TLR2、MyD88、NF-κB p65、IL-6、RORγt、IL-23和IL-17 mRNA和蛋白表达明显升高(P<0.01);NF-κB p65阳性细胞表达明显提升(P<0.01)。与模型组比较，黄芩汤组大鼠血脂、肝功能和炎性因子水平得到明显恢复(P<0.05，P<0.01);肝组织脂肪变性和炎性浸润得到纠正;上述蛋白mRNA和蛋白表达均明显降低(P<0.05，P<0.01);NF-κB p65阳性细胞表达明显降低(P<0.01)。结论:黄芩汤可能通过抑制TLR2/MyD88/NF-κB信号通路和IL-23/IL-17轴治疗NASH。

Study on the effect and mechanism of Huangqin Decoction in non-alcoholic steatohepatitis rats

OBJECTIVE To study the effect and mechanism of Huangqin Decoction on the non-alcoholic steatohepatitis (NASH) in rats.METHODS The experimental groups were fed with high-fat diet for 12 weeks to develop an animal model for NASH. The rats were randomly divided into six groups,including normal,model,polyene lecithin choline-treated (8 mg·kg^-1),Huangqin Decoction-treated (low-dose,5 g·kg^-1),Huangqin Decoction-treated (medium-dose,10 g·kg^-1) and Huangqin Decoction-treated (high-dose,20 g·kg^-1). After 5 weeks of oral administration,the levels of blood lipid,liver function and inflammatory factors were detected. Meanwhile,the pathological changes of liver tissues were analyzed by HE staining. RT-PCR and western blot were used to analyse the expression of toll-like receptor 2 (TLR2),myeloid differentiation factor 88 (MyD88),nuclear factor kappa-B p65 (NF-κB p65),interleukin 6 (IL-6),retinoid-related orphan nuclear receptor γt (RORγt),IL-23 and IL-17. Then the expression level of NF-κB p65 in liver tissue was detected by immunohistochemical staining.RESULTS Compared with the normal group,the blood lipid profiles,liver function and the level of inflammatory cytokines in the model group were abnormal (P<0.01). The liver tissue in the model group showed severe steatosis with inflammatory infiltration. The mRNA and protein expressions of TLR2,MyD88,NF-κB p65,IL-6,RORγt,IL-23 and IL-17 in the model group were significantly increased (P<0.01); the expression of NF-κB p65 positive cells in the the model group was significantly increased (P<0.01). Compared with the model group,the blood lipid profiles,liver function and the level of inflammatory cytokines were obviously recovered in Huangqin Decoction groups (P<0.05,P<0.01). Liver tissue steatosis and inflammatory infiltration in Huangqin Decoction groups were corrected. The mRNA and protein expressions level in Huangqin Decoction groups were significantly decreased (P<0.05,P<0.01),and the expression of NF-κB p65 positive cells in Huangqin Decoction groups was significantly increased (P<0.01).CONCLUSION Huangqin Decoction might treat NASH through the TLR2/MyD88/NF-κB signaling pathway and IL-23/IL-17 axis.