Abstract: Objective  To investigate the effect of dihydroartemisinin on the growth and apoptosis of human gastric cancer cell line BGC-823. 
Methods  Methylthiazoletetrazolium（MTT） assay was used to determine the inhibitory rate of dihydroartemisinin with different concentrations on the proliferation of BGC-823 cells. The apoptosis rate and morphological changes of BGC-823 cells treated with dihydroartemisinin were detected by flow cytometry(FCM), fluorescence microscope, transmission electron microscope. Western-blot were used to detect the changes of Bax,Caspase-3,Caspase-8 protein levels in BGC-823 cells. 
Results  MTT assay showed that the proliferation of BGC-823 cells was markedly inhibited after treatment with dihydroartemisinin, and the inhibition rate increases with the increase of drug concentration, and with the extension of time. It has a significant dose and time dependence(P＜0.01) and IC50 was 3.4 μmol/L. The results of flow cytometry showed that with the increase of drug concentration, the apoptotic peak became more obvious and showed a dose-dependent(P＜0.01). Typical apoptotic morphology were observed in BGC-823 cells after induced by dihydroartemisinin. Western blot showed that the expressions of Bax, Caspase-3 and Caspase-8 proteins increased with the increase of dihydroartemisinin concentration. 
Conclusion  The result suggested that dihydroartemisinin could inhibit the proliferation of BGC-823 cells. Dihydroartemisinin promotes the apoptosis of BGC-823 cells by up-regulating the expression of Bax, Caspase-3 and Caspase-8.

Key words:  , stomach neoplasms, dihydroartemisinin, cell proliferation, apoptosis