BACKGROUND: Reversal of liver fibrosis is one of the key steps in the prevention and treatment of alcoholic liver disease (ALD), but the mechanism is unknown. This study was to investigate the effects of the Chinese medicine Kang Xian Fu Fang I (KXI) on prophylaxis and treatment of ALD in rats and its possible mechanism of action. 
METHODS: Eighty male Wistar rats were randomly divided into four groups: normal control; ALD model; treatment of ALD with KXI; and prophylaxis of ALD by KXI. At the end of 4, 8, 12 and 16 weeks, five rats from each group were anesthetized and their livers were removed for pathological studies using hematoxylin-eosin and Masson stain, immunohistochemical studies, and flow cytometry for matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9). Blood samples were taken for hyaluronic acid (HA) assay. 
RESULTS: Serum HA level and liver collagen content were lower in the groups given KXI for prophylaxis and treatment than in ALD model group (P<0.05). The levels of MMP-2 and MMP-9 were also decreased in the prophylaxis and treatment groups (P<0.05). Immunohistochemistry showed immunoreactive MMP-2 in endothelial cells of the hepatic artery and portal vein, sinusoidal endothelial cells, and sinusoidal cells. Immunoreactive MMP-9 occurred in the hepatic cells around the veins and sinusoidal cells. 
CONCLUSIONS: KXI can effectively inhibit or reverse the course of ALD. This may be attributable to its capacity to inhibit the expression of MMP-2 and MMP-9.