Objective:To investigate the effect of water extracts of Retro-Zuojin Pill(WERZP) on proliferation and apoptosis of human gastric carcinoma cells (SGC-7901)

and the relationship between apoptosis and bcl-2

bax expression.Methods: The cell viability was measured by MTT;the apoptotic rate was investigated by FCM and the morphology was observed by Hoechst 33258 staining.Detection of bcl-2

bax gene and protein expression of WERZP-treated gastric cancer cells were carried out with Western blot method.Results: After treatment with WERZP for 24 h

the proliferation of SGC-7901 cells was significantly inhibited(P<0.05).Inhibited cell proliferation and induced cell death were in a dose-dependent and time-dependent manner

with apoptotic rate of(4.02±1.33)

(36.10±0.23)

(55.91±0.95)

(56.50±1.55) and(60.27±3.58) % accordingly.All the concentrations except the lowest induced significant apoptosis compared with the control(P<0.01).The nucleuses were positively stained with fluorochrome Hoechst 33258.WERZP could reduce the bcl-2 gene expression and increase gene expression of bax.Conclusion: WERZP could significantly inhibit the growth of SGC-7901 cells and induce apoptosis

reduce the bcl-2 gene expression.The increased gene expression of bax may be involved in apoptosis mechanism.