Objective:To investigate the interventional effects of the Fuzheng Huayu (FZHY) formula and its partial mechanistic role on cholestatic liver fibrosis in mice.Methods:Mdr2 gene knockout (Mdr2－/ －) mice were randomly divided into a model group, FZHY group, and Obeticholic acid group. Wild-type C57BL/6J mice of the same age served as the control group. Mdr2－/ －mice were given the corresponding drugs starting from the first day of 9 weeks of age by oral gavage in each group. The control and model groups were administered 0.3% sodium carboxymethylcellulose by oral gavage and were sacrificed at 12 weeks of age for specimen collection. High-speed biochemistry analyzer was used to detect serum alkaline phosphatase and alanine aminotransferase activity in mice. Hematoxylin-eosin staining and Sirius red staining were used to observe pathological changes in liver tissues. Hydroxyproline content was measured to assess collagen in liver tissues. Immunohistochemical staining, Western blotting, and real-time fluorescence quantitative PCR were used to detect the expression of fibrosis markers Col-I and alpha-smooth muscle actin in liver tissues. The expressional condition of cholangiocyte response markers Epcam, CK7, CK19, as well as Pcna, Mki67, and Ccnd1, inflammatory related factors Ccl2, Ccl5, Tnf-α, Il10, and Cxcl4, phosphorylated peroxisome proliferator-activated receptor alpha (PPARα) and nuclear factor kappa-B (NF-κB) were determined. Comparative analysis among multiple groups was performed using one-way ANOVA. The LSD method was used for comparisons between groups. Two-tailed statistical tests were used.Results:Compared with wild-type mice, Mdr2 －/ － mice had a significant increase in serum alanine aminotransferase and alkaline phosphatase activity ( P<0.001). The percentage of Sirius red-positive staining areas and hydroxyproline content in liver tissues was significantly increased ( P<0.01). The expression of Col-I, α-smooth muscle actin, Epcam, CK7, CK19, Pcna, Mki67, and Ccnd1, and the expression of Ccl2, Ccl5, Tnf-α, Il10, and Cxcl4 were significantly increased ( P<0.01); however, both FZHY and Obeticholic acid significantly reversed the increases in these indicators ( P<0.05; P<0.01). Further results showed that compared to wild-type mice, the expression of PPARα was significantly reduced in liver tissues of Mdr2 －/ － mice, while NF-κB was significantly enhanced ( P<0.01). In contrast, compared to Mdr2-/- mice, the expression of PPARα in the liver tissues of FZHY group mice was significantly increased ( P<0.05), while NF-κB was significantly inhibited ( P<0.05). Conclusion:FZHY can significantly improve liver fibrosis, cholangiocyte response, and inflammation in Mdr2 －/ － mice with spontaneously occurring cholestatic liver fibrosis, and its mechanistic role is related to the regulation of the PPARα/NF-κB pathway.

Objective:To investigate the interventional effects of the Fuzheng Huayu (FZHY) formula and its partial mechanistic role on cholestatic liver fibrosis in mice.Methods:Mdr2 gene knockout (Mdr2－/ －) mice were randomly divided into a model group, FZHY group, and Obeticholic acid group. Wild-type C57BL/6J mice of the same age served as the control group. Mdr2－/ －mice were given the corresponding drugs starting from the first day of 9 weeks of age by oral gavage in each group. The control and model groups were administered 0.3% sodium carboxymethylcellulose by oral gavage and were sacrificed at 12 weeks of age for specimen collection. High-speed biochemistry analyzer was used to detect serum alkaline phosphatase and alanine aminotransferase activity in mice. Hematoxylin-eosin staining and Sirius red staining were used to observe pathological changes in liver tissues. Hydroxyproline content was measured to assess collagen in liver tissues. Immunohistochemical staining, Western blotting, and real-time fluorescence quantitative PCR were used to detect the expression of fibrosis markers Col-I and alpha-smooth muscle actin in liver tissues. The expressional condition of cholangiocyte response markers Epcam, CK7, CK19, as well as Pcna, Mki67, and Ccnd1, inflammatory related factors Ccl2, Ccl5, Tnf-α, Il10, and Cxcl4, phosphorylated peroxisome proliferator-activated receptor alpha (PPARα) and nuclear factor kappa-B (NF-κB) were determined. Comparative analysis among multiple groups was performed using one-way ANOVA. The LSD method was used for comparisons between groups. Two-tailed statistical tests were used.Results:Compared with wild-type mice, Mdr2 －/ － mice had a significant increase in serum alanine aminotransferase and alkaline phosphatase activity ( P<0.001). The percentage of Sirius red-positive staining areas and hydroxyproline content in liver tissues was significantly increased ( P<0.01). The expression of Col-I, α-smooth muscle actin, Epcam, CK7, CK19, Pcna, Mki67, and Ccnd1, and the expression of Ccl2, Ccl5, Tnf-α, Il10, and Cxcl4 were significantly increased ( P<0.01); however, both FZHY and Obeticholic acid significantly reversed the increases in these indicators ( P<0.05; P<0.01). Further results showed that compared to wild-type mice, the expression of PPARα was significantly reduced in liver tissues of Mdr2 －/ － mice, while NF-κB was significantly enhanced ( P<0.01). In contrast, compared to Mdr2-/- mice, the expression of PPARα in the liver tissues of FZHY group mice was significantly increased ( P<0.05), while NF-κB was significantly inhibited ( P<0.05). Conclusion:FZHY can significantly improve liver fibrosis, cholangiocyte response, and inflammation in Mdr2 －/ － mice with spontaneously occurring cholestatic liver fibrosis, and its mechanistic role is related to the regulation of the PPARα/NF-κB pathway.

The overexpression of P-glycoprotein(P-gp)and its coding gene mdrl is regarded as the classic mechanism of muhidrug resistance(MDR).Recent studies find that pregnane X receptor(PXR)can mediate the expression of P-gp.It is confirmed that PXR can also inhibit apoptosis of tumor cells.Therefore,preventing the activation of PXR specifically may be a new method to prevent MDR.