Abstract: Objective: To observe effects of different extracts of Pachyrrhizus erosus Urban (planted in Guilin region) seed on KB cell in vitro and acute toxic reaction in mice after intragastric administrate with the different extracts. Methods: The effects of the extracts on KB cell in vitro were tested by MTT. LD50 and 95% confidence limit were detected after intragastric administration with the different extracts to mice. Results: LD50 and 95% confidence limit of petroleun benzin extract are 7.314 g/kg (6.328～ 8.455 g/kg) respectively, and those of n-butanol extract are 4.223 g/kg (3.586 ～ 4.973 g/kg) respectively. The maximum tolerance of water extract is 8 g/kg. The inhibition rates to KB cell are 32.6% (p<0.01) and 16.4% (p<0.05) after 72 hours of the administration with the concentration of 80μg/ml and 40μg/ml of acetoacetate extract respectively. Conclusion: The n-butanol extract and acetoacetate extract show inhibition effect on KB cell, and the toxicity of the n-butanol extract to mice is higher whereas the toxicity of the water extract is lower compared with different groups.

Key words: Pachyrrhizus erosus Urban seed, KB cell, MTT assay, acute toxicity test