Objective: To study effects of ethanol extract from Boschniakia rossica on proliferation and apoptosis of rat hepatic stellate cell-T6（HSC-T6） cultured in vitro.Method: HSC-T6 was cultured in vitro.The influence of B.rossica ethanol extract on HSC-T6 proliferation was detected at 12

24

36

48 h for concentrations of 0.25

0.5

0.75

1.0 g·L-1 by MTT assay.Morphological changes of HSC-T6 with drug treatment were observed by fluorescent microscope and transmission electronic microscope.Flow cytometry by double staining of Annexin V and PI was used to detect cell cycle distribution and apoptosis rate of HSC-T6.Result: ①MTT assay revealed that the Boschniakia rossica ethanol extract could inhibit HSC-T6 proliferation in dose and time dependent manner.The proliferation inhibitory ratios of B.rossica ethanol extract at concentration 0.75 g·L-1 for 12 h

24 h

36 h and 48 h were（44.58±1.42）%

（51.56±1.34）%

（63.83±0.99）% and（74.77±3.40）%

respectively.②The typical morphological changes in apoptotic HSC-T6 were observed under fluorescent microscope and transmission electronic microscope: cell surface microvilli disappeared

cell volume became smaller

cytoplasm concentrated

nuclear chromatin margined

nucleus pyknosis

karyorrhexis

blebbing.③Flow cytometry analysis showed that the HSC-T6 treated with the B.rossica ethanol extract was arrested in G0/G1 phase.The apoptosis rate increased significantly in drug treated group compared with that in the control group and positively correlated with dose increase in B.rossica ethanol extract.B.rossica ethanol extract changed cell cycle distribution

G0/G1phase cell percentage was increased from（50.33±0.80）% to（61.46±1.07）%

and apoptotic ratio was increased from（1.44±0.43）% to（14.20±0.98）%.The changes were significant compared with the controls（P<0.05）.Conclusion: B.rossica ethanol extract has significant anti-proliferation effect on HSC-T6 in vitro.B.rossica ethanol extract can induce HSC-T6 apoptosis and arrest HSC-T6 in G0/G1 phase.