玉竹高异黄酮抑制人肺癌细胞A549增殖的作用及机制

Anti-proliferation Effect of Homoisoflavonoids Extracted from Polygonati Odorati Rhizoma on A549 Cells

目的:以人肺癌A549细胞为研究对象,探讨玉竹中提取的高异黄酮对A549细胞增殖的抑制作用及其作用机制。方法:从玉竹中提取高异黄酮,作用于肺癌细胞A549;噻唑蓝(MTT)比色法观察高异黄酮12.5,25,50,100 mg·L^(-1)作用于A549细胞6,12,24 h对细胞存活率的影响。通过流式细胞仪检测细胞凋亡及周期变化,并通过蛋白免疫印迹法(Western blot)分析与细胞凋亡相关半胱氨酸天冬氨酸蛋白酶-3(Caspase-3),B细胞淋巴瘤(白血病)-2(Bcl-2),Bcl-2对抗杀伤性蛋白(Bak)和与细胞周期相关的磷酸化周期素依赖激酶2(p-Cdc 2),细胞周期蛋白依赖性激酶2(Cdc 2)及p38蛋白表达。结果:与空白组比较,高异黄酮呈剂量和时间依赖性抑制A549细胞的增殖(P<0.05,P<0.01),高异黄酮对A549细胞处理12 h后,细胞周期阻滞于G2/M期(P<0.05);与空白组比较,25,50,100 mg·L^(-1)高异黄酮可显著促进凋亡蛋白Caspase-3和Bak表达,抑制Bcl-2表达(P<0.01),可显著促进细胞周期蛋白p-Cdc 2和p38表达,抑制Cdc 2表达(P<0.01)。结论:玉竹中提取的高异黄酮对A549细胞增殖具有抑制作用,能使A549细胞阻滞于细胞周期G2/M期,其机制与线粒体介导的细胞凋亡和p38 MAPK通路相关。

Objective： To study the anti-proliferation effect of homoisoflavonoids extracted from Polygonati Odorati Rhizoma on human lung cancer A549 cells. Method： Ethanol was used as the solvent to extract homoisoflavonoids from Polygonati Odorati Rhizoma; methylthiazolyldiphenyl-tetrazolium bromide （MTT） method was used to observe the proliferation inhibition rates of lung cancer A549 cells after being treated with homoisoflavonoids （12.5, 25, 50, 100 mg·L^-1） for 6, 12, 24 h. Apoptotic rate and cell cycles were analyzed through flow cytometer （FCM）. And Western blot analysis was used to detect the expressions of apoptosis-related （Caspase-3, the Bcl-2, Bak） and cell cycle-related （p-Cdc, Cdc 2, p38） protein. Result： Compared with normal group, A549 cells treated by homoisoflavonoids extracted from Polygonati Odorati Rhizoma were observed as typical apoptotic cells. The results of MTT and FCM showed that homoisoflavonoids could significantly inhibit tumor cell proliferation and induce apoptosis of A549 in a dose and time-dependent manner（P〈0.05, P〈0.01）. And the cell number in G2/M period was increased after being treated with homoisoflavonoids for 12 h （P〈0.05）. Compared with normal group, the cells treated with 25, 50, 100 mg·L^-1 homoisoflavonoids, Caspase-3 and Bak were up-regulated, while Bcl-2 was down-regulated significantly （P〈0.01）; p-Cdc 2 and p38 were up-regulated, while Cdc 2 was down-regulated （P〈0.01）. Conclusion： Homoisoflavonoids extracted from Polygonati Odorati Rhizoma can promote the apoptosis of A549 cells and increase the proportion of cells in G2/M. The antitumor mechanism of homoisoflavonoids is related to mitochondria-mediated apoptosis and p38 MAPK pathway.