Abstract: Objective To approach the principle of the processing method and optimize the best processed products of herba leonuri, by comparing the acute toxicity of fresh herba leonuri、dry herba leonuri and wine herba leonuri. Methods Respectively prepare the 95% alcohol extracts of fresh herba leonuri、dry herba leonuri and wine herba leonuri, and make acute toxicity study according to classic acute toxicity Methods. The bliss method is used to calculate experimental datas' LD₅₀. Results The different processed products' acute toxicity of herba leonuri from the biggest to the smallest is fresh herba leonuri、dry herba leonuri、wine herba leonuri. The fresh herba leonuri and dry herba leonuri extracts' LD₅₀ is respectively 83.089g·kg^-1 and 102.93 g·kg^-1, which is respectively equal to 145.4 times and 2 40.2 times of every people's daily dried medicinal herb expenses; 95% confidence interval is respectively 71.302~97.055g·kg^-1 and 91.862~115.140g·kg^-1, which is respectively equal to 124.8~169.9 times and 214.4~268.7 times of every people's daily dried medicinal herb expenses. The wine herba leonuri extracts' MTD is 98.0g·kg^-1, which is respectively equal to 228.7 times of every people's daily dried medicinal herb expenses. Conclusion The toxicity of herba leonuri could be decreased after processing, and the attenuation of different processed Methods is different. By the comparative study, it is beneficial to implement the normalization and standardization of cut crude drugs, and provide the safety standard and control basis for clinical medication.

Key words: Herba leonuri, Processed product, 95% alcohol extract, rats, acute toxicity