Fuzheng Huayu inhibits carbon tetrachloride-induced liver fibrosis in mice through activating hepatic NK cells

Aim of the study: Fuzheng Huayu (FZHY) is a Chinese compound herbal preparation which consists of six Chinese herbs. This study examines the preventative effects of FZHY on liver fibrosis induced by carbon tetrachloride (CCl4) and explores its possible mechanisms of action. Materials and methods: Liver fibrosis was induced in male C57BL/6N mice by injecting a 10% CCl4 solution intraperitoneal twice a week for six weeks. After 6 weeks of treatment, serum ALT and AST assay, liver tissue histological examination and immunostaining were carried out to examine the liver function and fibrosis degree. The expression levels of alpha-smooth muscle actin (SMA) were measured by quantitative real-time PCR and western blot. Hepatic natural killer (NK) cells were isolated from liver and evaluated by FACS. Results: Upon pathological examination, the FZHY-treated mice showed significantly reduced liver damage. The expression of alpha-SMA increased markedly upon treatment with CCl4 and the increase was reversed by FZHY treatment. FZHY treatment also enhanced the activation of hepatic NK cells and the production of interferon-gamma (IFN-gamma). The protective effects of FZHY were reversed in the mice that were depleted of NK cells by anti-ASGM-1 Ab treatment. Conclusions: FZHY can efficiently inhibit CCl4-induced liver fibrosis. Furthermore, the depletion of NK cells attenuates the protective effects of FZHY. We conclude that FZHY could be an effective drug for liver fibrosis, and its mechanism of action involves the activation of hepatic NK cells. (C) 2012 Elsevier Ireland Ltd. All rights reserved.