Abstract: Objective To compare the acute toxicity effect of different extraction methods of Cassia Semen on normal mice and observe/evaluate the acute toxicity of Cassia Semen, so as to provide a foundation for safe and rational drug use in clinic. Methods Preparing the all-components, water extracted components, alcohol extracted components and n-butyl alcohol extracted components then ig. all-components, water extracted components and alcohol extracted components of aconite to mice and the MLD, LD₅₀ were tested respectively by the classical methods of acute toxicity. Results The MTD of alcohol extracted components was 159.6 g·kg^-1·d^-1, which was respectively equal to 774.8 times of the clinical daily dosage in 70 kg humans. The MLD of all-components was 20.0 g·kg^-1·d^-1, the MLD of water extracted components was 76.6 g·kg^-1·d^-1 and the MLD of n-butyl alcohol extracted components was 1 493.6 g·kg^-1·d^-1, which was respectively equal to 93.3 times, 357.6 times and 6 969.7 times of the clinical daily dosage in 70 kg humans. By observing, we found that poor spirit, hypokinesia, prostrate motionlessness and loose stools were the main symptoms and signs of acute toxicity caused by aconite. Conclusion The sequence of acute toxicity of different extracts from Cassia Semen is alcohol extracted components > all-components > water extracted components > n-butyl alcohol extracted components. The toxical components and mechanisms should be further researched.

Key words: Cassia Semen, mouse, acute toxicity