[Study on the mechanism of Fuzheng Huayu formula against biliary fibrosis in mice].

Objective: To investigate the effect and mechanisms of Fuzheng huayu formula (FZHY) on biliary fibrosis in mice. Methods: Mdr2 gene knowout (Mdr2(-/-)) mice were randomly divided into model group, FZHY-treated group and obeticholic acid (OCA)-treated group. Wide type C57BL/6J (WT) mice of the same age were used as the control group. Mdr2(-/-) mice were treated with the corresponding drugs by gavage from the first day of the 9(th) week old. The WT and model groups were given 0.3% sodium carboxymethyl cellulose by gavage, and the mice were sacrificed at the end of 12(th) week old. The activities of serum alkaline phosphatase (ALP) and alanine aminotransferase (ALT) were detected by high-speed biochemical analyzer. H&E staining and sirius red staining were used to observe the pathological changes of liver tissues. The hepatic hydroxyproline content was determined. The hepatic expressions of Col-â and α-SMA, ductular reaction markers Epcam, CK7, CK19, and the expression of Pcna, Mki67 and Ccnd1; as well as the expression of inflammatory cytokines Ccl2, Ccl5, Tnf-α, Il10 and Cxcl4 were detected by immunohistochemical staining, western blot and qRT-PCR, respectively. Furthermore, the expression of PPARα and the phosphorylation NF-κB were detected by western blot. Results: Compared with WT mice, the serum ALT and ALP activities of Mdr2(-/-) mice were significantly increased (P<0.001). The percentage of SR positive stained area and hepatic Hyp content were significantly increased (P<0.01). The hepatic expression of Col-â and α-SMA; Epcam, CK7, CK19, Pcna, Mki67 and Ccnd1; Ccl2, Ccl5, Tnf-α, Il10 and Cxcl4 were significantly increased (P<0.01). However, both FZHY and OCA significantly reversed the elevation of these aforementioned indicators (P<0.05; P<0.01). Further study showed that the hepatic expression of PPARα in Mdr2(-/-) mice was significantly lower than that of WT mice, however the phosphorylation of NF-κB was significantly enhanced (P<0.01). The expression of PPARα in liver tissues of FZHY mice was significantly increased (P<0.05), and the NF-κB phosphorylation was significantly inhibited compared with Mdr2(-/-) mice (P<0.05). Conclusion: FZHY significantly ameliorated liver fibrosis, ductular reaction and inflammation in Mdr2(-/-) spontaneous biliary fibrosis mice, and its mechanism was related to the regulation of PPARα/NF-κB pathway.