[Arbutin ameliorates liver fibrosis in mice by inhibiting macrophage recruitment and regulating the Akt/NF-κB and Smad signaling pathways].

OBJECTIVE: To investigate the protective effect of arbutin against CCl4 -induced hepatic fibrosis in mice and explore the underlying mechanisms.

METHODS: Twenty-four C57BL/6 mice were randomly divided into control group, model group, and low- and high-dose arbutin treatment (25 and 50 mg/kg, respectively) groups. Mouse models of liver fibrosis were established by intraperitoneal injection of CCl4 , and arbutin was administered daily via gavage for 6 weeks. After the treatments, serum biochemical parameters of the mice were tested, and liver tissues were taken for HE staining, Sirius Red staining and immunohistochemical staining. RT-qPCR was used to detect the mRNA levels of α-SMA , Pdgfb , Col1α1 , Timp-1 , Ccl2 and Tnf-a , and Western blotting was performed to detect α-SMA protein expression in the liver tissues. In the cell experiment, the effect of arbutin treatment for 24 h on THP-1 and RAW264.7 cell migration and recruitment was examined using Transwell migration assay and DAPI staining; The changes in protein levels of Akt, p65, Smad3, p-Akt, p-p65, p-Smad3 and α-SMA in arbutintreated LX-2 cells were detected with Western blotting.

RESULTS: Arbutin treatment significantly lowered serum alanine aminotransferase and aspartate aminotransferase levels, alleviated liver tissue damage and collagen deposition, and reduced macrophage infiltration and α-SMA protein expression in the liver of the mouse models ( P < 0.05 or 0.001). Arbutin treatment also significantly reduced CCl4 -induced elevation of a-SMA , Pdgfb , Col1α1 , Timp-1 , Ccl2 and Tnf-a mRNA levels in mice ( P < 0.05). In the cell experiment, arbutin treatment obviously inhibited migration and recruitment of THP-1 and RAW264.7 cells and lowered the phosphorylation levels of Akt, p65 and Smad3 and the protein expression level of α-SMA in LX-2 cells.

CONCLUSION: Arbutin ameliorates liver inflammation and fibrosis in mice by inhibiting hepatic stellate cell activation via reducing macrophage recruitment and infiltration and suppressing activation of the Akt/NF-κB and Smad signaling pathways.