Objective    To study the selective effect of artesunate (AST) on K562 cells and the normal hematopoietic stem/progenitor cells.      Methods    K562 cells and the CD34

+

hematopoietic stem/progenitor cell (HSC/HPC) from umbilical cord blood were respectively cocultured with AST of different concentrations (50

25

12.5 μg/ml). The inhibition rate of the cellular growth was measured by MTT assay. The capability of proliferation and multilineage differentiation was studied by methylcellulose assay s

ystems. Stained by anti Annexin V-FITC and PI

their apoptotic rates were examined by flow cytometer. The expressions of BCR-ABL protein were analyzed by Western blot.      Results    Artesunate had a significant inhibition and apoptosis-inducing effects on K562 cells in both time- and dose-dependent manners (P0.01). The number of CFCs was also markedly decreased (P0.01). However

the treatment of artesunate at dose of 12.5

25 μg/ml for 48 h

had little inhibition and apoptosis-inducing effects on hematopoietic stem/progenitor cells (P0.05). The number of CFCs was not affected

either. The expression of BCR-ABL protein could be down-regulated in a dose-dependent manner after 48-hour treatment of AST (P0.01).      Conclusion    The inhibition and apoptosis-inducing effects of artesunate are specific to K562 cells

while AST at dose of 12.5

25 μg/ml hardly affected HSC/HPC.