[Study on hepatotoxicity of aqueous extracts of Polygonum multiforum in rats after 28-day oral administration-analysis on correlation of cholestasis].

OBJECTIVE: To observe the liver injury degree of SD rats after 28-day administration of aqueous extracts of Polygonum multiflorum (AEPM) and the correlation with cholestasis mechanism. METHOD: Adult SD rats were orally administered with 30, 60 g x kg(-1) of APEM once every day for 28 d. After 28 d, the general condition of rats such as weight were observed, liver function-related indicators were detected. Bile was collected to determine total bile acid output, flow rate and density and changes in major compositions. Their livers were weighed then sent for histopathological examination. RESULT: AEPM did not change the general conditions and weights of rats. From the results of the related indicators of liver function and cholestasis, AEPM did not change the contents of ALT and AST in serum, but high dose of AEPM can increase the contents of ALP, GGT and TBA in serum (P < 0.05, P < 0.01) and decrease the content of TBIL in serum (P < 0.05). And the contents of GGT in serum of low dose rats were increased (P < 0.05). The bile flow was not changed by AEPM, but bile compositions of high dose male rats were obviously changed (TG increase, TBIL decrease, TBA decrease). The weights of liver and ratio of liver of the high dose rats were increased but showed no statistical significance. Pathologic examination displayed that there were only small pieces of necrosis in livers of several rats, without any severe disease. CONCLUSION: AEPM can obviously injure bile duct epithelial cells, intervene liver cell functions and change bile compositions in rats, thus it is proved to induce cholestasis without severe liver injury.