Abstract: Objective: To investigate the effects and mechanism of curcumol (CC) on liver function and fibrosis in rats of nonalcoholic fatty liver disease (NAFLD). Methods: The rat models of nonalcoholic steatohepatitis (NASH) combined with liver fibrosis were constructed by high-fat diet. Sixty SD rats were randomly divided into blank control group, model group (NASH), NASH + Compound Biejiarangan Troche (CBT) group (positive control group), and NASH + CC groups (25, 50, 100 mg/kg) , 10 rats in each group. The percentage of liver to body weight, and the levels of high density lipoprotein (HDL), triglyceride (TG), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured. The liver fibrosis was observed by HE staining. The expressions of α-smooth muscle actin (α-SMA) and positive staining of nuclear factor κB p65 (NF-κB p65) were detected by immunohistochemistry. The expression levels of α-SMA, matrix metalloproteinase-1 (MMP-1), tissue inhibitor of metalloproteinase-1 (TIMP-1) and toll-like receptor-4 (TLR4), transforming growth factor-activated kinase-1 (TAK1), NF-κB p65 and vascular cell adhesion molecule-1 (VCAM-1) were detected by Western blot. The expression levels of interleukin (IL-6, IL-10, IL-1β) and tumor necrosis factor-α (TNF-α) were detected by enzyme linked immunosorbent assay (ELISA). Results: Compared with blank control group, the contents of HDL and IL-10 and the expression level of MMP-1 protein were decreased in model group significantly (P＜0.05), while the levels of TG, ALT and AST, the positive rate of P65, α-SMA, TIMP-1, TLR4, TAK1, NF-κB p65, VCAM-1, IL-6, TNF-α and IL-1β were increased significantly (P＜0.05). Compared with model group, the levels of HDL, IL-10 and MMP-1 protein were significantly increased after treatment with CBT and CC (P＜0.05), while the levels of TG, ALT, and AST, the positive rate of P65, α-SMA, TIMP-1, TLR4, TAK1, NF-κB p65, VCAM-1, IL-6, TNF-α and IL-1β were decreased significantly (P＜0.05). The improvement in model+high- concentration CC group was the most significant, and which in all concentration groups was lower than that in model+CBT group (P＜0.05). Conclusion: CC can reduce inflammation response and improve liver function by regulating TLR4, TAK1 and NF-κB/p65 signaling pathway, and thus alleviating liver fibrosis, showing concentration-dependence within certain range.

Key words: nonalcoholic fatty liver disease, liver fibrosis, curcumol, rat