胡柚皮黄酮对非酒精性脂肪性肝炎小鼠肝脏NLRP3炎症小体的影响

Effect of Pure Total Flavonoids from Citrus on NLRP3 Inflammasome in Mice with Non-alcoholic Steatohepatitis

目的观察胡柚皮黄酮(PTFC)对高脂高糖饮食诱导的非酒精性脂肪性肝炎(NASH)小鼠NLRP3炎症小体信号通路的影响,探讨其防治NASH的机制。方法 50只C57BL/6小鼠随机分为正常组、模型组、PTFC低、中、高剂量组,每组10只,采用高脂高糖饮食喂养16周建立NASH小鼠模型,从造模第5周起予25、50、100 mg·kg^-1·d^-1PTFC干预12周,HE及油红O染色观察肝脏组织病理学变化,生化法检测血清CHOL、TG、ALT、AST水平,Realtime-PCR检测肝组织核苷酸结合寡聚化结构域样受体3(NLRP3)、凋亡相关斑点样蛋白(ASC)、含半胱氨酸的天冬氨酸蛋白水解酶-1(Casp1)及白细胞介素(IL)-1βmRNA的表达,Western blot检测肝组织NLRP3、Casp1蛋白的表达。结果经过16周高脂高糖饮食的喂养,小鼠肝组织NAFLD活动度积分(NAS)显著升高,血清CHOL、ALT及AST水平升高,TG水平下降,肝组织NLRP3、ASC、Casp1及IL-1βmRNA表达明显增强,Casp1蛋白表达明显增加,NLRP3蛋白表达有增高趋势;经过PTFC的干预,小鼠NAS下降,血清ALT、AST水平显著下降,TG水平明显升高,肝组织NLRP3、ASC、Casp1及IL-1βmRNA表达明显减少,NLRP3及Casp1蛋白水平显著降低,以PTFC高剂量组最为明显。结论 NLRP3炎症小体信号通路激活可能参与高脂高糖诱导的小鼠NASH发生发展,PTFC可通过干预该通过防治NASH的进展。

OBJECTIVE To investigate the effect of pure total flavonoids from Citrus(PTFC) on the NLRP3 inflammasome pathway in mice with high-fat/high-fructose diet induced non-alcoholic steatohepatitis( NASH),and discuss its anti-NASH mechanism.METHODS Fifty C57 BL/6 mice were randomly divided into normal group,model group,PTFC low-dosage group,medium-dosage group and high-dosage group,10 in each group. A high-fat/high-fructose diet was given for 16 weeks to establish the NASH models,and the PTFC groups were administrated with PTFC at the dosage of 25,50,100 mg·kg^-1·d^-1 from the 5 th week,respectively.Histopathologic changes of the liver tissue were observed by HE and oil red O staining;serum CHOL,TG,ALT,AST were detected by biochemical method;the levels of NLRP3,ASC,Casp1 and IL-1β mRNA in the liver tissue were determined by Realtime-PCR;the protein expression of NLRP3 and Casp1 was detected by Western blot. RESULTS Sixteen weeks administration of high-fat/high-fructose diet induced significantly higher weight,increased NAFLD activity score( NAS) of the liver tissue,higher level of serum CHOL,ALT and AST,lower level of serum TG,increased expression of NLRP3,ASC,Casp1 and IL-1β mRNA in liver,and increased protein expression of Casp1. After PTFC administration,the mice,especially the PTFC high dosage group,exhibited( compared with the model group) marked lower NAS,decreased serum ALT and AST level,increased TG level,impaired NLRP3,ASC,Casp1 and IL-1βmRNA expression,and decreased protein expression of NLRP3 and Casp1. CONCLUSION The NLRP3 inflammasome pathway may play a key role in the development and progress of NASH in mice,and PTFC prevents the development of NASH through suppressing this pathway.