Abstract: Objective To compare the acute toxicity of different processed water extracts of Polygoni multiflori, and to provide the toxicological experimental data for the clinical safety of Polygoni multiflori. Methods Chinese Pharmacopoeia 2015 Edition and Anhui, Zhejiang, Henan, Shanghai Beijing provincial specification of Chinese materia medica was provided for preparing five processed products. They are Bean-processing, Bean juice-6 h, Stew, Steamed and Bean juice-18 h respectively. According to the classical method of acute toxicity, calculation of intragastric administration with lethal dose per kilogram of body weight (LD50), by the maximum tolerated dose (MTD) and the maximum dose (MFD), continuous observation for 14 days, compared the acute toxicity of different processed products of water extract of Polygoni multiflori. Results The Raw are able to make MTD and the other groups are able to make MFD. The main toxicity of Polygoni multiflori were diarrhea, lazy movement, unsmooth hair, and emaciation, close eyes, and trembling, dyspnea before death. The MTD of raw was 107.10 g·kg^-1·d^-1, which is equal to 1 249.50 times of 70 kg people's daily dried medicinal herb expenses. The MFD of Bean-processing, Bean juice-6 h , Stew, Steamed and Bean juice-18 h were 309.60, 328.32, 336.96, 345.60, 354.24 g·kg^-1·d^-1 respectively, which was equal to 1 806.00, 1 915.20, 1 965.60, 2 016.00 and 2 066.40 times of 70 kg people's daily dried medicinal herb expenses. Conclusion The acute toxicity of different processed products of water extract of Polygoni multiflori in mice is Raw > Bean-processing > Bean juice-6 h > Stew > Steamed > Bean juice-18 h. The hepatotoxicity of Polygoni multiflori could be reduced by processing. Different processing methods have different effects of reducing toxicity.

Key words: Polygoni multiflori, different processed products, acute toxicity, water extract