没食子酸-卵磷脂复合物诱导氧化应激增强辐射对A549细胞增殖的抑制作用

Inhibitory effect of irradiation enhanced by gallic acid-lecithin complex-induced oxidative stress on proliferation of A549 cells

目的:探讨没食子酸-卵磷脂复合物(GA-LC)对X射线照射所致肺癌A549细胞增殖的抑制作用,阐明其可能的作用机制。方法:A549细胞分为不同浓度(0、0.05、0.10、0.15、0.20、0.25、0.30和0.35 g·L^(-1))GA-LC组,CCK-8法检测各组A549细胞增殖活性,并确定GA-LC的半抑制浓度(IC50)值。A549细胞分为对照组、GA-LC组、4 Gy X射线照射组和GA-LC+4 Gy X射线照射组,CCK-8法检测各组细胞增殖活性,流式细胞术检测各组细胞中活性氧(ROS)和线粒体膜电位(MMP)水平及细胞凋亡率,线粒体绿色荧光探针Mito-Tracker染色检测各组细胞中线粒体膜通透性。结果:与0 g·L^(-1)GA-LC组比较,0.15、0.20、0.25、0.30和0.35 g·L^(-1)GA-LC组细胞增殖活性明显降低(P<0.05),GA-LC对A549细胞的IC50值为0.1711 g·L^(-1)。与对照组比较,GA-LC组、4 Gy X射线照射组和GA-LC+4 Gy X射线照射组细胞增殖活性和MMP水平明显降低(P<0.05或P<0.01),GA-LC组和GA-LC+4 Gy X射线照射组ROS水平和细胞凋亡率明显升高(P<0.05或P<0.01);与GA-LC组比较,GA-LC+4 Gy X射线照射组细胞MMP水平明显降低(P<0.01),ROS水平和细胞凋亡率明显升高(P<0.05);与4 Gy X射线照射组比较,GA-LC+4 Gy X射线照射组细胞增殖活性和MMP明显降低(P<0.05),ROS水平和细胞凋亡率明显升高(P<0.05或P<0.01)。线粒体绿色荧光探针Mito-Tracker染色,线粒体荧光显微镜下可见绿色荧光,与对照组比较,GA-LC组、4 Gy X射线照射组和GA-LC+4 Gy X射线照射组细胞中绿色荧光强度增加,且GA-LC+4 Gy X射线照射组细胞中绿色荧光强度增加最明显,表明线粒体膜通透性增加。结论:GA-LC可以增强X射线照射对肺癌A549细胞增殖的抑制作用,其机制与诱导氧化应激进而促进线粒体通透性增加、MMP降低和诱导细胞凋亡有关。

Objective:To discuss the inhibitory effect of gallic acid-lecithin complex(GA-LC)on the proliferation of the lung cancer A549 cells induced by X-ray irradiation,and to clarify its possible mechanism.Methods:The A549 cells were divided into different concentrations(0,0.05,0.10,0.15,0.20,0.25,0.30,and 0.35 g·L^(-1))of GA-LC groups.CCK-8 assay was used to detect the proliferation activities of A549 cells in various groups,and the half-inhibitory concentration(IC50)value of GA-LC was determined.The A549 cells were divided into control group,GA-LC group,4 Gy X-ray irradiation group,and GA-LC+4 Gy X-ray irradiation group.CCK-8 assay was used to detect the proliferation activities of cells in various groups;flow cytometry was used to detect the reactive oxygen species(ROS)levels,mitochondrial membrane potential(MMP)levels and apoptotic rates of cells in various groups;the mitochondrial green fluorescence probe Mito-tracker was used to detect the permeability of mitochondrial membrane.Results:Compared with 0 g·L^(-1)GA-LC group,the proliferation activities of the cells in 0.15,0.20,0.25,0.30 and 0.35 g·L^(-1)GA-LC groups were significantly decreased(P<0.05),and the IC50 value of GA-LC to the A549 cells was 0.1711 g·L^(-1).Compared with control group,the proliferation activities and MMP levels of the cells in GA-LC group,4 Gy X-ray irradiation group,and GA-LC+4 Gy X-ray irradiation group were significantly decreased(P<0.05 or P<0.01),while the ROS levels and apoptotic rates of the cells in GA-LC group and GA-LC+4 Gy X-ray irradiation group were significantly increased(P<0.05 or P<0.01).Compared with GA-LC group,the MMP level of the cells in GA-LC+4 Gy X-ray irradiation group was decreased(P<0.01),while the ROS level and apoptotic rate of the cells in GA-LC+4 Gy X-ray irradiation group were significantly increased(P<0.05);compared with 4 Gy X-ray irradiation group,the proliferation activity and MMP level of the cells in GA-LC+4 Gy X-ray irradiation group were decreased(P<0.05),while the ROS level and apoptotic rate of the cells in GA-LC+4 Gy X-ray irradiation group were significantly increased(P<0.05 or P<0.01).The mitochondrial fluorescence probe Mito-tracker staining results showed that the green fluorescence could be observed under fluorescence microscope;compared with control group,the green fluorescence intensities in the cells in GA-LC group,4 Gy X-ray irradiation group,and GA-LC+4 Gy X irradiation group were increased,and the green fluorescence intensity in the cells in GA-LC+4 Gy X-ray irradiation group was the most obvious,demonstrating that the mitochondrial membrane permeability was increased.Conclusion:GA-LC can enhance the inhibitory effect of X-ray irradiation on the proliferation activity of the lung cancer A549 cells,and its mechanism is related to the induction of oxidative stress,thereby increasing the mitochondrial permeability,decreasing the MMP and inducing the apoptosis.