目的 探讨大黄不同炮制品对四膜虫毒性的差异。方法 采用微量量热仪考察大黄不同炮制品对四膜虫生物热活性参数的影响。结果 大黄不同炮制品对四膜虫生长有不同程度的抑制作用，其作用强度顺序为生大黄＞酒大黄＞熟大黄＞大黄炭；对四膜虫生长的抑制毒性表现为：随着抑制率的增大，传代时间（t_G）延长，最大热功率（P_max）逐渐降低，达最大热功率时间（t_max）逐渐延后；四模虫整个生长过程的产热量不同程度地减少，以生大黄减少的最为明显。结论 大黄经炮制后，有明显的减毒作用，四膜虫生物热活性研究可用于中药毒性的早期筛选。

Objective To explore the toxicity difference of various processed rhubarb products on Tetrahymena thermophila BF5. Methods The effects of various processed-rhubarb products on parameter of bio-heat activity in T. thermophila BF5 were invastigated by a TAM air isothermal microcalorimeter. Results Various processed rhubarb products had different inhibition on the growth of T. thermophila BF5 in different degrees. The order of intensity was crude rhubarb > alcohol-processed rhubarb > steamed rhubarb > carbonized rhubarb. The inhibition on the growth of T. thermophila BF5 was with the phenomenon of t_G being increased, P_max being lowered down, and t_max being delayed. The heat production during the growth of T. thermophila BF5s was reduced in varying degrees, and the reducing of crude rhubarb was the most obvious. Conclusion It could be concluded that the processed rhubarb could attenuate the toxicity significantly. The study on the bio-heat activity of T. thermophila BF5 is suitable for the early screening on toxicity of Chinese materia medica.

国家科技部“十一五”科技支撑计划（2006BAI08B03）