[Study on the hepatoxicity of polygoni multiflori radix and polygoni multiflori rodix praeparata in rats].

OBJECTIVE: To compare the hepatoxicity of Polygoni Multiflori Radix and Polygoni Multiflori Rodix Praeparata in rats. METHODS: Water extracts of Polygoni Multiflori Radix and Polygoni Multiflori Rodix Praeparata were prepared by concentional decocting method (named as RPWE and PPWE respectively). Both in 30 days and 60 days experiments, SD rats were randomly divided into 5 groups: normal control group, RPWE high dosage group (40 mg/kg x d) and PPWE low dosage group (20 mg/kg x d), PPWE high dosage group (40 mg/kg x d) and PPEW low dosage group (20 mg/kg x d). After daily administration,the general conditions of rats were observed. At the end of the experiments, the levels of ALT and AST in plasma were detected. The liver coefficient was calculated and HE staining was used to observe the changes of liver tissue sections. RESULTS: Both in 30 days and 60 days experiments, the treatment groups rats had hypokinesia and dry fur when compared with control groups, and in a dose-dependent manner. The liver coefficients, levels of ALT and AST of plasma weren't changed significantly when conpared with control groups. The liver had varying degrees of steatosis and inflammation cell infiltration in the treatment groups rats in 60 days experiment. CONCLUSION: Oral administration of Polygoni Multiflori Radix and Polygoni Multiflori Rodix Praeparata for 60 days have hepatoxic in rats.

[Effects of extract of Polygonum multiflorum on cell cycle arrest and apoptosis of human liver cell line L02].

OBJECTIVE: To analyze the chemical constituents of Polygonum multiflorum extract which may cause human liver cell damage and to explore the mechanism. METHODS: Raw and processed Polygonum multiflorum were extracted by 70% ethanol, then raw and processed Polygonum multiflorum water-eluted material (RW and PW), 50% ethanol-eluted material (R50 and P50) and 95% ethanol-eluted material (R95 and P95) were obtained by absorbing through AB-8 macroporous resin, followed by water, 50% ethanol and 95% ethanol elution in order. The water extracts of raw and processed Polygonum multiflorum (RWE or PWE) were obtained by boiling them in water as usual. Normal human liver L02 cells were treated by different concentrations of eluted Polygonum multiflorum materials for different time, and the cell growth inhibition of each group was determined by methylthiazolyldiphenyl-tetrazolium bromide method. The chemical constituents which had a significant cytotoxicity to L02 cells were analyzed by high-performance liquid chromatography (HPLC). Morphological changes of L02 cells were observed by Giemsa staining and cell cycle distribution was observed by flow cytometry. RESULTS: It was found that 95% ethanol-eluted extracts of raw and processed Polygonum multiflorum showed significant growth inhibition on normal human liver L02 cells, while the other components showed no significant inhibition on cell growth. HPLC analysis showed that the main component in 95% ethanol-eluted extract of raw and processed Polygonum multiflorum was emodin at content of (18.53+/-2.96)% and (10.28+/-1.34)% respectively. Cell cycle analysis showed that 95% ethanol-eluted material of Polygonum multiflorum and emodin had a similar significant effect of S phase arrest and all could induce L02 cell apoptosis. CONCLUSION: The main part of Polygonum multiflorum causing liver cell damage is the 95% ethanol-eluted extract, and emodin is one of the important chemical constituents leading to liver cell damage.