Therapeutic effect of Jingfang Granules on CCl_4-induced liver fibrosis in mice and its mechanism

Abstract

To investigate the therapeutic effect of Jingfang Granules on carbon tetrachloride(CCl_4)-induced liver fibrosis in mice and its mechanism. Forty-nine 8-week-old male C57 BL/6 J mice were randomly divided into a blank group, a CCl_4 group, a silybin group(positive control, 100 mg·kg~(-1))+CCl_4, a Jingfang high-dose(16 g·kg~(-1)) group, a Jingfang high-dose(16 g·kg~(-1))+CCl_4 group, a Jingfang medium-dose(8 g·kg~(-1))+CCl_4 group, and a Jingfang low-dose(4 g·kg~(-1))+CCl_4 group, with 7 mice in each group. The mice in the blank group and Jingfang high-dose group were intraperitoneally injected olive oil solution, and mice in other groups were intraperitoneally injected with 10% CCl_4 olive oil solution(5 mL·kg~(-1)) to induce liver fibrosis, twice a week with an interval of 3 d, for 8 weeks. At the same time, except for the blank group and CCl_4 group, which were given deionized water, the mice in other groups were given the corresponding dose of drugs by gavage once daily for 8 weeks with the gavage volume of 10 mL·kg~(-1). All mice were fasted and freely drank for 12 h after the last administration, and then the eyeballs were removed for blood collection. The liver and spleen were collected, and the organ index was calculated. The levels of alanine aminotransferase(ALT), aspartate aminotransferase(AST), total bile acid(TBA), and triglyceride(TG) in the serum of mice were detected by an automated analyzer. Tumor necrosis factor-α(TNF-α), interleukin-6(IL-6) and interleukin-1β(IL-1β) levels were detected by enzyme-linked immunosorbent assay(ELISA). Kits were used to detect the contents of superoxide dismutase(SOD), malondialdehyde(MDA), and glutathione(GSH) in the liver tissue. Pathological changes in the liver tissue were observed by hematoxylin-eosin(HE), Masson, and Sirius red staining. Western blot was used to detect protein expressions of transforming growth factor-β(TGF-β), α-smooth muscle actin(α-SMA) and Smad4 in the liver tissue. The results indicated that Jingfang Granules significantly reduced the organ index, levels of ALT, AST, TBA,TG, TNF-α, IL-6, and IL-1β in the serum, and the content of MDA in the liver tissue of mice with CCl_4-induced liver fibrosis. Jingfang Granules also significantly increased the content of SOD and GSH in the liver tissue. Meanwhile, Jingfang Granules down-regulated the protein levels of TGF-β, α-SMA, and Smad4. Furthermore, Jingfang Granules had no significant effect on the liver tissue morphology and the above indexes in the normal mice. In conclusion, Jingfang Granules has obvious therapeutic effect on CCl_4-induced liver fibrosis, and its mechanism may be related to reducing the expression of pro-inflammatory factors, anti-oxidation, and regulating TGF-β/Smad4 signaling pathway.