[Effects of Anluohuaxianwan on transforming growth factor-β1 and related signaling pathways in rats with carbon tetrachloride-induced liver fibrosis]

Abstract

Objective: The traditional Chinese medicine Anluohuaxianwan (ALHXW) has been used to treat liver fibrosis induced by chronic hepatitis B virus (HBV) infection. However, the anti-fibrosis mechanisms of ALHXW remain to be investigated. This study used a rat model of carbon tetrachloride (CCl(4))-induced liver fibrosis to explore the potential antifibrogenic mechanisms of ALHXW. Methods: Twenty-seven male Wistar rats were randomly assigned to control group, model group, and treatment group (n = 9 per group). Rats in the model and treatment group were injected intraperitoneally with 40% CCl(4)(2 ml/kg), and rats in the control group were administered saline twice a week for 6 weeks. Starting at week 4 following model construction, rats in the treatment group received daily gavages with ALHXW solution (concentration 0.15 g/ml) daily, while rats in the control and model groups were given saline for a total of 6 weeks. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured from blood samples collected at the end of weeks 3, 6 and 9. Histopathological examination of liver tissue was performed to evaluate liver fibrosis at week 9. At the same time, the mRNA expression of TGF-β1 and Smads in liver tissues was quantified by real-time reverse transcription polymerase chain reaction (RT-PCR), and TGF-β1 protein level in the liver was measured by Western blot. Inter-group comparison was performed using analysis of variance (ANOVA) when the continuous data were normally distributed and satisfied the homogeneity of variance; otherwise, nonparametric tests were used. Categorical data were compared between groups using nonparametric tests. Results: ALHXW markedly alleviated liver injury in the treatment group after 3 weeks of therapy as indicated by a significantly reduced level of ALT compared with the model group [(162.98 ± 73.14)U/L vs (322.52 ± 131.76)U/L, P = 0.047], and a 39.8% reduction in AST level compared with the model group[ (537.56 ± 306.06)U/L vs (892.98 ± 358.19)U/L, P = 0.053]. Moreover, at the end of the 6-week therapy, histopathological diagnosis showed that liver fibrosis was significantly reduced in the ALHXW-treated group compared with that in the model group (P = 0.002). The relative expression of TGF-β1 mRNA and protein in the liver were significantly lower in ALHXW-treated rats than that in model rats (1.34 ± 0.31 vs 1.78 ± 0.45, P = 0.025; 0.39 ± 0.02 vs 0.57 ± 0.04, P = 0.003). Conclusion: ALHXW treatment can reverse CCl(4)-induced liver fibrosis in rats. Its mechanisms of anti-fibrosis may occur through the inhibition of TGF-β1 synthesis and TGF-β1/Smads signaling pathway, which in turn suppress the activation of hepatic stellate cells and thereby reverses fibrosis.

Keywords: Anluohuaxianwan; Carbon tetrachloride; Hepatic cirrhosis; Rat model; Transforming growth factor β1.