[Inhibitory effect of acupuncture on hepatic extracellular matrix production in carbon tetrachloride-induced liver fibrosis rats].

Objective: To investigate the protective effect of acupuncture intervention on liver in carbon tetrachloride induced hepatic fibrosis rats and to reveal its impact on extracellular matrix production in the liver tissue.

Methods: A total of 46 SD rats were randomly divided into control group (n = 10), model group (n = 12), sham group (n = 12) and acupuncture group (n = 12). Hepatic fibrosis model was established by intraperitoneal injection of 50% olive oil containing CCl (1 mL/kg), 3 times in the 1st week and twice per week from the 2nd to the 6th week. During the fibrosis model establishment, acupuncture of "Taichong" (LR 3), "Qimen" (LR 14), "Ganshu" (BL 18) and "Zusanli" (ST 36) was carried out simultaneously. In the sham group, non-acupuncture points (0.5 cm left to the above-mentioned real points) were punctured. The treatment was conducted 3 times a week in the first three weeks and then twice a week for the last three weeks. Serum levels of hyaluronic acid (HA), liminin (LN) and precollagen (PC III) were determined by enzyme linked immunosorbent assay for assessing the hepatic fibrosis degree. Primary hepatic stellate cells (HSC) were separated. Western blot assay was used to detect the expression of alpha-smooth muscle actin (SMA), alpha 1 (l) collagen, fibronectin, matrix metalloproteinase (MMP)-9 (components of extracellular matrix, ECM) and tissue inhibitor of metalloprotei-nase-1 (TIMP-1, an inhibitor of MMP-9) proteins of HSC. Real-time quantitative polymerase chain reaction was used to detect the expression levels of alpha-SMA, alpha 1 (1) collagen and fibronectin genes of HSC.

Results: Compared with the control group, contents of serum HA, LN and PC III, expression levels of alpha-SMA, alpha 1 (I) collagen and fibronectin proteins and genes, and TIMP-1 protein of HSC were significantly increased in the model group (P < 0.01, P < 0.05), while MMP-9 protein (an enzyme for degradating ECM) expression level of HSC in the model group was down-regulated significantly (P < 0.01), suggesting a formation of hepatic fibrosis, impairment of the liver tissue fibrosis and imbalance of degradation of ECM. H.E. staining showed an ameliorated liver injury (disorder of hepatocyte arrangement, hepatocyte necrosis, formation of pseudolobule, etc.) in the acupuncture group in comparison with the model group. In comparison with the model group, serum HA and LN contents, expression levels of alpha-SMA, alpha 1(I) collagen and fibronectin proteins, and alpha-SMA mRNA and fibronectin mRNA of HSC were downregulated considerably in the acupuncture group (P < 0.05, P < 0.01). On the contrary, MMP-9 protein expression level of HSC was up-regulated remarkably in the acupuncture group compared with the model group (P < 0.05). No significant changes were found in all the aforementioned indexes in the sham group, and serum PC III content as well as alpha 1 (I) collagen mRNA and TIMP-1 protein expression levels of HSC in the acupuncture group compared with those in the model group (P > 0.05).

Conclusion: Acupuncture treatment can significantly relieve CCl4-induced hepatic fibrosis in hepatic fibrosis rats probably by inhibiting the synthesis and deposite of HA and LN, down-regulating expression levels of alpha-SMA, alpha 1(1) collagen and fibronectin proteins, and alpha-SMA mRNA and fibronectin mRNA of HSC as well as up-regulating MMP-9 protein expression of HSC.