OBJECTIVETo explore the effects and the molecular mechanism of puerariae radix flavones (PRF) on acute myeloid leukemia cell line Kasumi-1 cells in vitro.

METHODSKasumi-1 cells treated by PRF for 48 hours were observed with Wright's and Hoechst 33258 dying. The apoptotic cells were analyzed by flow cytometry with AnnexinV/PI staining. The expression levels of bcl-2, Bim and Caspase-3/-8/-9 protein were assayed by Western blot and the AML1-ETO fusion gene was detected by real-time polymerase chain reaction.

RESULTSPRF could induce Kasumi-1 cells to apoptosis effectively. The proportion of apoptotic cells in 50, 200 and 500 µg/ml PRF treatment groups were (14.1 ± 0.8)%, (17.7 ± 1.3)% and (32.4 ± 1.4)%, respectively, and significantly higher than that of control \[(7.8 ± 0.7)%\]. The relative expression levels of the anti-apoptotic Bcl-2 protein were 0.85 ± 0.05, 0.62 ± 0.07 and 0.43 ± 0.05; the apoptotic Bim protein were 0.21 ± 0.06, 0.39 ± 0.04 and 0.75 ± 0.05; the caspase-3 and caspase-9 were 0.92 ± 0.04, 1.21 ± 0.07, 1.33 ± 0.04 and 0.35 ± 0.05, 0.53 ± 0.03, 0.69 ± 0.07, respectively. Compared to the blank control group, all these changes were significant (P < 0.01). Nevertheless, nearly no changes could be observed on the expression level of AML1-ETO fusion gene and caspase-8 protein.

CONCLUSIONApoptosis of Kasumi-1 cells induced by PRF might correlate to the down-regulation of Bcl-2 protein expression and the activation of caspase-3 and caspase-8 protein in the cells. It seemed that all these effects had no relationship with the AML1-ETO fusion gene.