[Progress in experimental study on inhibitory effect of traditional Chinese medicine on liver fibrosis]

Fuzheng Huayu recipe alleviates hepatic fibrosis via inhibiting TNF-α induced hepatocyte apoptosis

Background

What was the relationship of Fuzheng Huayu recipe (FZHY) inhibiting hepatocyte apoptosis and HSC activation at different stage of liver fibrosis? In order to answer this question, the study was carried out to dynamically observe FZHY’s effect on hepatocyte apoptosis and HSC activation and further explored underling mechanism of FZHY against hepatocyte apoptosis.

Methods

Mice were randomly divided into four groups: normal, model, FZHY, and N-acetylcystein (NAC) groups. Acute hepatic injury and liver fibrosis in mice were induced by CCl₄. Three days before the first CCl₄ injection, treatment with FZHY powder or NAC respectively was started. In vitro, primary hepatocytes were pretreated with FZHY medicated serum or Z-VAD-FMK and then incubated with ActD and TNF-α. Primary HSCs were treated with DNA from apoptotic hepatocytes incubated by Act D/TNF-α or FZHY medicated. Liver sections were analyzed for HE staining and immunohistochemical evaluation of apoptosis. Serum ALT and AST, Alb content and TNF-α expression in liver tissue were detected. Hyp content was assayed and collagen deposition was visualized. Expressions of α-SMA and type I collagen were analyzed by immunofluorescence and immunoblotting. Flow cytometry, immunofluorescence, and DNA ladder for hepatocyte apoptosis and immunoblotting for TNF-R1, Bcl-2 and Bax were also analyzed.

Results

Mice showed characteristic features of massive hepatocytes apoptosis in early stage of liver injury and developed severe hepatic fibrosis in later phase. FZHY treatment significantly alleviated acute liver injury and hepatocyte apoptosis, and inhibited liver fibrosis by decreasing α-SMA expression and hepatic Hyp content. In vitro, primary hepatocytes were induced by TNF-α and Act D. The anti-apoptotic effect of FZHY was generated by reducing TNFR1 expression and balancing the expressions of Bcl-2 and Bax. Meanwhile, the nuclear DNA from apoptotic hepatocytes stimulated HSC activation in a dose dependent manner, and the DNA from apoptotic hepatocytes treated with FZHY or Z-VAD-FMK reduced HSC activation and type I collagen expression.

Conclusion

These findings suggested that FZHY suppressed hepatocyte apoptosis through regulating mediators in death receptor and mitochondrial pathways, and the effect of FZHY on hepatocyte apoptosis might play an important role in inhibiting liver fibrosis.

[Effects of Chinese herbal medicine Xiaopi Pill in preventing rats from dimethylnitrosamine-induced liver fibrosis]

OBJECTIVE

To explore the intervention effects of Xiaopi Pill (XPW), a compound traditional Chinese herbal medicine, on the development progress of dimethylnitrosamine (DMN)-induced liver fibrosis in rats.

METHODS

Liver fibrosis model was established by intraperitoneal injection of 0.5% DMN 2 mL/kg thrice a week for 4 weeks. Rats were divided into control group given saline and treatment group given XPW during the 3rd week of DMN injections. Rats were sacrificed at the end of the experiment, and then liver histological changes, liver function and mRNA expression of the liver fibrosis-associated markers were observed.

RESULTS

(1) At the end of the 2nd and 4th weeks of DMN injection, serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) increased significantly in rats (P<0.01 or P<0.05); content of total bilirubin (TBil) increased significantly compared with the normal group until the end of the 4th week (P<0.05); compared with the model group after 4 weeks of DMN injection, the serum levels of ALT, AST, ALP and TBil were decreased remarkably in the XPW-treated group (P<0.01 or P<0.05). (2) The hepatic inflammation and collagen deposition in hepatic tissues increased by different degrees in experimental rats. Parts of pathological changes in the rat liver were found at the end of the 4th week, including a complete round structure of false flocculus round, meantime, the hydroxyproline content of hepatic tissue was increased significantly at the end of the 2nd and 4th weeks (P<0.05). Compared with the 4-week model group, the hepatic inflammation, collagen deposition and hydroxyproline content in hepatic tissues were alleviated dramatically (P<0.05). (3) Compared with the normal and 2nd week groups, protein expression of alpha-smooth muscle actin (α-SMA) was gradually increased, and that of the 4th week group were aggrandized significantly (P<0.01). Compared with the normal group, the mRNA expression of α-SMA, transforming growth factor-β1 (TGF-β1), tissue inhibitor of metalloproteinase-1 (TIMP-1), and heme oxygenase-1 (HO-1) was gradually increased. Further changes in above-mentioned abnormalities were found in the model rats at the end of the 4th week (P<0.01); while compared to the 4th week group, protein and mRNA levels of α-SMA and mRNA levels of TGF-β1, TIMP-1, and HO-1 were decreased significantly in the XPW group (P<0.01 or P<0.05).

CONCLUSION

Progressive DMN-induced liver fibrosis in rats can be suppressed by XPW; the mechanism may be associated with inhibition of the activated hepatic stellate cells.