ABSTRACT
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 tG being increased, Pmax 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.