齐墩果酸诱导人肺腺癌细胞A549凋亡及其与细胞内钙离子的关系

目的通过检测齐墩果酸（oleanolic acid,OA）干预后的A549细胞的凋亡和其内钙离子浓度,探索OA对A549细胞的作用及其可能的机制。方法体外培养人肺腺癌细胞系A549。设0、10、20、40μg/ml的OA浓度干预组。选择对数生长期的细胞,在不同浓度OA干预24 h,采用Annexin V/PI流式细胞术（flowcytometry,FCM）检测各实验组细胞的凋亡情况,测定细胞的荧光强度值并计算出细胞内钙离子浓度;以曲线拟合描述细胞凋亡率与钙离子荧光强度之间的相关性。结果FCM检测显示10、20、40μg/ml OA可诱导A549细胞凋亡,凋亡率呈现浓度-效应关系;20、40μg/ml OA干预24 h,A549细胞凋亡率明显增加,与0μg/ml组比较,差异有显著性（P〈0.01）;10、20、40μg/mlOA组干预24 h,各药物干预组A549细胞内钙离子荧光强度均明显高于0μg/ml组,荧光强度随OA浓度的提高呈现增加趋势,差异有显著统计学意义（P〈0.01）;曲线拟合显示细胞凋亡率和细胞内钙离子浓度之间有明显相关性（R=0.981,P〈0.01）。结论OA具有浓度依赖地诱导人肺腺癌细胞凋亡的作用;OA诱导细胞凋亡可能与其导致细胞内钙超载有关。

Apoptosis induced by oleanolic acid and its relation to intracellular calcium of human lung adenoma A549 cells

Objective To examine the effect of Oleanolic acid （OA） on inducing apoptosis in human lung adenoma cell line A549 and to explore the mechanism of induction. Methods Human lung adenoma A549 cells were incubated and the experiment was performed as following： the apoptosis status was detected by Annexin V-FITC/PI and flow cytometry （FCM） at concentrations of 0, 10, 20 and 40μg/ml OA in 24 h; fluorescent intensity of A549 was assessed by FCM, and the level of intracellular calcium was calculated ; the relation of apoptosis and calcium fluorescent intensity was illustrated by curve fitting. Results FCM showed 10, 20 and 40μg/ml of OA could induce apoptosis in A549 cells in a concentration-dependent manner. The intervention with 20 μg/ml and 40 μg/ml OA for 24 h showed increased A549 cell apoptosis, significantly different from that in 0μg/ml group （ P 〈 0. 01 ）. Both fluorescent intensity and intracellular calcium concentrations in 10, 20 and 40 μg/ml OA groups were significantly higher than those of 0 p~g/ml group after 24 h intervention. The fluorescent intensity showed an increasing trend as concentration of OA elevated, and there was a statistically significant difference （P 〈 0.01 ）. Curve fitting showed the significant correlation of apoptosis and calcium concentration of A549 （R = 0.981, P 〈 0.01 ）. Regression equation was Y = 0.508x - 1. 627. Conclusion OA plays an important role in inducing the apoptosis of the human lung adenoma cells in a concentration-dependent manner and the apoptosis caused by OA is responsible for intracellular calcium overload of the tumor.