[Apoptosis-inducing effect of quercetin and kaempferol on human HL-60 cells and its mechanism].

The purpose of this study was to explore the anti-leukemia effect of quercetin and kaempferol and its mechanism. The HL-60 cells were used as the leukemia models. The inhibitory effects of quercetin and kaempferol on growth of HL-60 cells was assessed by MTT assay. The effect of quercetin and kaempferol on cell cycle in HL-60 cells was detected by flow cytometry. The cytotoxic effect of these 2 drugs was analysed by single cell electrophoresis assay. Western blot analysis was used to study the apoptotic mechanism of HL-60 cells. The results showed that the quercetin and kaempferol had a significant anti-leukemia effect in vitro. The proliferation of HL-60 cells was significantly inhibited in dose-and time-dependent manners after treating with quercetin (r = 0.77) and kaempferol (r = 0.76) respectively, and the cytotoxicity of quercetin was superior to that of kaempferol. The quercetin and kaempferol induced G(2)/M arrest and apoptosis of HL-60 cells. The quercetin and kaempferol could down-regulate the survivin expression. It is concluded that the quercetin and kaempferol have significant anti-leukemia effect in vitro. Furthermore the apoptosis-inducing effect of quercetin is stronger than that of kaempferol, both of which induce apoptosis of HL-60 cells through depressing cell growth, arresting cell cycle and inhibiting expression of survivin.