Efficacy and molecular mechanism of Qi-Tonifying preparations in rats with liver fibrosis

Abstract

Objective To investigate the therapeutic effect and molecular mechanism of Qi-Tonifying preparations (Astragalus membranaceus and Atractylodes macrocephala) on hepatic fibrosis in rats. Methods Wistar rats (7 weeks old) were divided into normal control (n=10), model group (n=10), colchicine group (0.45 mg/kg, n=9), and Qi-Tonifying preparation group (3.6 g/kg, n=10). Corresponding drugs or normal saline were given to the rats intragastrically, once a day, for continuous 12 weeks. Western blotting was used to detect the expression of α-smooth muscle actin (α-SMA), phosphorylated extracellular signal regulated kinase 1/2 (p-ERK1/2) and phosphorylated p38 mitogen activated protease (p-p38) in the liver tissues. RT-qPCR was employed to detect the expression of monocyte chemoattractant protein-1a (MCP-1a) in the liver tissues. Immunohistochemical assay was adopted to detect the expression of matrix metalloproteinase-2 (MMP-2), MMP-9 and metalloproteinase tissue inhibitor-1 (TIMP-1) in the liver tissues. Results The results of Western blotting showed that the expression levels of α-SMA and p-ERK1/2 were significantly higher in the model group than the normal control group (P 0.05). Compared with the model group, the expression levels of α-SMA and p-p38 were decreased in the Qi-Tonifying preparation group and the colchicine group (P 0.05). These results suggested that Qi-Tonifying preparations alleviated the progression of liver fibrosis by inhibiting the expression of α-SMA, p-ERK1/2 and p-p38. RT-qPCR results showed that the expression of MCP-1a was significantly increased in the model group than the normal control group (P < 0.05), and was down-regulated in the Qi-Tonifying group and the colchicine group than the model group (P < 0.05). Qi-Tonifying preparations alleviated the progression of liver fibrosis by down-regulating MCP-1a. Immunohistochemical assay showed that MMP-2 was obviously expressed in the normal control group, and observed in the model group. Its expression was stronger in the Qi-Tonifying group and the colchicine group than the model group. The expression of MMP-9 was mildly observed in the normal group, and was up-regulated in the model group than the normal group, but down-regulated in the Qi-Tonifying group and the colchicine group when compared with the model group. Conclusion Qi-Tonifying preparations can improve liver fibrosis in rats, and may reduce the release of inflammatory cells by inhibiting MCP-1, thereby suppressing the activation of ERK1/2 and p38 signaling pathways and reducing phosphorylated p-ERK1/2, P-p38 mediated signal transmission from the cytoplasm to the nucleus, and then inhibits the expression of TIMP-1, promotes the release of MMP-2 and MMP-9, increases ECM degradation, reduces deposition, and finally, reverses liver fibrosis.

Keywords

• qi-tonifying preparations
• astragalus membranaceus
• atractylodes macrocephala
• liver fibrosis