Objective: The total flavonoids of Broussonetia papyrifera(L.) Vent(TFBP) was investigated for its antitumor activity and induction of apoptosis in human hepatocellular carcinoma cell line HepG-2 in vitro. Method: The HepG-2 cells in logarithmic phase of growth were randomly divided into drug group and control group

with the concentration of 3

6

9

12 g·L-1 TFBP in hepatocellular carcinoma HepG-2 cells. The intervention durations was 24

48

72 h accordingly

the viability of HepG-2 cells was measured by MTT. Morphology of cell apoptosis was observed by Hoechst 33342 fluorescence staining. The cell cycle and cell apoptosis rate were detected by flow cytometry. Result: TFBP could inhibit the growth of cells and cause apoptosis significantly.The suppression was in a time-and dose-dependent manner

HepG-2 cells were treated with TFBP of 3

6

9

12 g·L-1 concentrations

the inhibition rates were 20.2%

29.44%

39.21%

43.96% at 48 h. When HepG-2 cells were treated with the concentration of 9 g·L-1 TFBP

the inhibition rate could be achieved 52.46% at 72 h

there was a significant difference compared with control group (P < 0.05) The typical apoptosis characteristics such as nuclear fragmentation and apoptotic body could be observed under the fluorescence microscope.In the same time

with the increase of drug concentration

cell apoptosis rate increased significantly(P<0.01).TFBP could reduce the cell population in G1/G0 phase and increase the cell population in G2/M phase significantly (P < 0.05).TFBP could induce a G2/M cell cycle arrest. Conclusion: TFBP has apparent inhibition and apoptosis-inducing effect on HepG-2 cells. TFBP may induce apoptosis and induce a G2/M cell cycle arrest.