Objective:To investigate the effect of artesunate(ART) on human leukemia cell line K562. Methods:Inhibition of proliferation was measured by a colorimetric MTT assay. The morphological changes of K562 were observed under a light microscope and an electron microscope. Flow cytometry assay detected the ratio of apoptosis and oncosis of K562 cell lines which were induced at three different times by three different concentrations of ART. Results:ART extract clearly inhibited the proliferation of K562. The 50% effective dose evaluated on 24h

48h

and 72h of ordinal exposure to the extract

were 65.17μg/ml

31.63μg/ml

and 10.51μg/ml

respectively

ART extract-treated cells exhibited morphological changes typical of oncosis and apoptosis. Futheremore

the ratio of apoptosis was not different from to that of oncosis. Conclusion:Artesunate can control proliferation of the K562 human leukemia cell line in two forms:oncosis and apoptosis. The ratio of oncosis and apoptosis present typical dose-dependence and time-dependence.