Objective: To study the effect of flavone from Galii Veri Herba et Radix (FGVL) against acute promyelocytic leukemia cell line NB4

in order to provide a new evidence for future clinical treatment for acute promyelocytic leukemia. Method: In this study

the growth of acute promyelocytic leukemia cell line NB4 at different dosages of FGVL was observed with trypan blue staining. Methyl thiazoly1 terazolium(MTT) assay was used to detect the proliferation inhibition of NB4 cells. Acridine orange ethidium bromide (AO/EB) staining was used to detect morphological changes in NB4 apoptosis. DNA agarose electrophoresis was adopted to test apoptosis. The expression of pro-and anti-apoptotic genes Bax and Bcl-2 were examined by reverse transoription-polymerase chain reaction(RT-PCR). Result: Compared with the blank group

FGVL (50

100

200 mg·L-1) could inhibit the proliferation of NB4 cells(P < 0.01);morphology analysis presented the characteristics of apoptosis

and DNA agarose electrophoresis showed the typical DNA 1adder in 24 h. Accoridng to RT-PCR experiments

compared with the blank group

FGVL could down-regulate the mRNA expression of Bcl-2 and up-regulate the mRNA expression of Bax in NB4 cells (P < 0.01)

with the positive correlation with the dosage. Conclusion: FGVL can resist acute promyelocytic leukemia NB4 cell proliferation and induce apoptosis

and its mechanism is related to the expression of Bcl-2/Bax. It provides a new possible clinical chemotherapy for acute promyelocytic leukemia.