Objective:To observe the anti-tumor effect of the extract rich in flavonoids of Spatholobus suberctus Dunn in vitro and in vivo.Methods:In vitro

the inhibitory effects of the extract on proliferation of human lung carcinoma cell line A549 and human colorectal adenocarcinoma cell line HT-29 were measured by MTT assay.Cell cycle were analyzed using flow cytometry.The mouse model of Lewis lung carcinoma was used to investigate the effects of the extract on tumor growth and the hematopoietic system.Results:The studies demonstrated that the extract of flavonoids of Spatholobus suberctus Dunn inhibited proliferation of A549 and HT-29

and the IC50 values on them were(70.17±12.17) μg·mL-1 and(126.81±43.00) μg·mL-1 respectively.The tumor inhibitory rate of high dose of extract on Lewis lung cancer was 31.01%.The marrow-depression was not found and the peripheral blood red cell count increase to 40.82% in high dose group compared with the control.Furthermore

the extract arrests A549 cell in S and G2/M phase

but it induces HT-29 cell cycle arrest in G2/M phase only.Conclusions:The extract rich in flavonoids of Spatholobus suberctus Dunn exists direct anti-tumor effect and the mechanism of the anti-tumor activities may be the progression inhibition of cell cycle.Moreover

this extract can stimulate red blood cell production.