茵陈蒿汤通过FXR抑制TLR4/MyD88/NF-κB信号通路改善胆汁淤积性肝损伤的机制OA

Objective:To study the mechanism of Yinchenhao Tang on the improvement of cholestatic liver injury(CLI)by inhibiting toll-like receptor 4(TLR4)/myeloid differentiation factor 88(MyD88)/nuclear transcription factor-κB(NF-κB)pathway via regulating farnesol X receptor(FXR).Methods:A total of 40 Wistar male rats were randomly selected,with 10 as a blank group,and the remaining rats were subjected to the CLI model induced by alpha-naphthalene isothiocyanate(ANIT).After modeling,they were randomly divided into the model group,the ursodeoxycholic acid(0.1 g·kg-1)group and the Yinchenhao Tang(9.23 g·kg-1)group,with 10 animals in each group.Each administration group was given the corresponding drug by intragastric administration for three consecutive days.Alanine aminotransferase(ALT),aspartate aminotransferase(AST),alkaline phosphatase(ALP),γ-glutamyl transpeptidase(γ-GT),total bile acid(TBA),total bilirubin(TBil)and direct bilirubin(DBil)levels in serum were detected.Tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β),and interleukin-6(IL-6)levels in liver tissue were detected.Real-time PCR was used to detect the mRNA expression of FXR,TLR4,MyD88,NF-κB,F4/80,TNF-α,IL-1β and IL-6 in liver tissue.Western blot was used to detect protein expression of FXR,TLR4,MyD88 and NF-κB in liver tissue.The histopathological changes of the liver were observed by hematoxylin-eosin(HE)staining.Results:Compared with those in the blank group,ALT,AST,ALP,γ-GT,TBA,TBil and DBil levels in serum of rats in the model group were significantly increased(P<0.01).The levels and mRNA expression of TNF-α,IL-1β and IL-6 in liver tissue were significantly increased(P<0.01),and the mRNA and protein expressions of FXR in liver tissue were decreased(P<0.01).The mRNA and protein expressions of TLR4,MyD88 and NF-κB and the mRNA expression of F4/80 were obviously increased(P<0.05,P<0.01).Hepatic histopathology showed inflammatory cell infiltration and proliferative changes of bile duct epithelial cells.Compared with those in the model group,ALT,ALP,γ-GT,TBA,TBil and DBil levels in serum of rats in the ursodeoxycholic acid group were obviously decreased(P<0.05,P<0.01),and the levels and mRNA expression of TNF-α,IL-1β and IL-6 in liver tissue were obviously decreased(P<0.05,P<0.01).The mRNA and protein expressions of TLR4,MyD88 and NF-κB and the mRNA expression of F4/80 in liver tissue were obviously decreased(P<0.05,P<0.01).ALT,AST,ALP,γ-GT,TBA,TBil and DBil levels in the serum of rats in the Yinchenhao Tang group were obviously decreased(P<0.05,P<0.01),and the levels and mRNA expression of TNF-α,IL-1β and IL-6 in liver tissue were obviously decreased(P<0.01).The mRNA and protein expressions of FXR in liver tissue were significantly increased,and the mRNA expressions of TLR4,MyD88,NF-κB,and F4/80,as well as the protein expressions of TLR4 and NF-κB were obviously decreased(P<0.05,P<0.01).The inflammatory cell infiltration of liver tissue and the proliferation of bile duct epithelial cells decreased.Conclusion:Yinchenhao Tang has an obvious protective effect on CLI,and its mechanism may be related to regulating FXR to inhibit TLR4/MyD88/NF-κB pathway-mediated inflammatory response.