Effect of quercetin on proliferation and apoptosis of human nasopharyngeal carcinoma HEN1 cells.

The effect of quercetin (Que) on proliferation and apoptosis of human nasopharyngeal carcinoma HEN1 cells was investigated. Inhibition rate of quercetin on HEN1 was assayed by MTT method, apoptosis by flow cytometry (FCM), and the caspase-3 expression of each group by colorimetry set respectively. Quercetin inhibited HEN1 cells in in a dose-(r=0.709, P<0.01) and time-dependent manner (r=0.703, P<0.01). The ratio of apoptotic and necrosis cells was increased in the cells treated with quercetin. Cell cycle was specifically arrested in G(2)/M phase. Apoptosis cusp was revealed by FCM. The activity of caspase-3 was significantly up-regulated in 5 groups treated with quecetin as compared with control group (P<0.05). It was concluded that the growth inhibition of quercetin was highly related to cell cycle arrest at the G(2)/M phase and induction of caspase-dependent apoptosis in human nasopharyngeal carcinoma HEN1 cells.