Effects of Artemisinin Derivative on the Growth Metabolism of Tetrahymena thermophila BF5 Based on Expression of Thermokinetics

The toxic effects of artesunate and dihydroartemisinin on the growth metabolism of Tetrahymena thermophila BF5 were studied by microcalorimetry. The results showed that: (1) low concentrations of artesunate (a parts per thousand currency sign1 mg L(-1)) and dihydroartemisinin (a parts per thousand currency signaEuro parts per thousand 2 mg L(-1)) promoted the growth metabolism of T. thermophila BF5, whereas high concentrations of artesunate (1-60 mg L(-1)) and dihydroartemisinin (2-60 mg L(-1)) inhibited its growth; (2) the half inhibition concentrations IC(50) of artesunate and dihydroartemisinin were 17.5817 and 9.5089 mg L(-1), respectively. It was concluded that the inhibition of dihydroartemisinin was stronger than that of artesunate.