【摘要】 目的:探讨20(S)-人参皂苷Rg3(SPG-Rg3)诱导人大细胞肺癌细胞NCI-H460凋亡及其机制。方法:MTT法测定NCI-H460细胞的增殖,依据其半数抑制浓度(IC50)将SPG-Rg3实验组分为25、50及100mg·L-1组,并设空白对照组。采用AO/EB荧光双染、免疫细胞化学染色、Rhodamine 123摄取法及Fluo-3/AM染色分别观察NCI-H460细胞的凋亡、Bcl-2及Bax蛋白的表达量、线粒体跨膜电位及细胞内游离钙离子浓度。结果:SPG-Rg3能抑制NCI-H460的生长,抑制率与浓度呈正相关(r=0.764,P<0.05),其IC50值为47.97mg·L-1;SPG-Rg3组NCI-H460细胞呈现明显凋亡改变;SPG-Rg3100mg·L-1组细胞内Bcl-2蛋白的表达量明显低于空白对照组(P<0.01);SPG-Rg3各浓度组细胞Bax蛋白的表达量均明显高于对照组(P<0.001),并随浓度的增大而增加(P<0.01);各浓度组细胞内Bax/Bcl-2比值均高于对照组,细胞内线粒体跨膜电位则均低于对照组(P<0.01),并随药物作用浓度的增加而减少,组间比较差异有显著性(P<0.01);各组细胞内游离钙离子浓度明显高于对照组(P<0.01)。结论:SPG-Rg3能够明显抑制细胞的增殖,诱导细胞凋亡。其作用机制可能是SPG-Rg3促进细胞内Bax蛋白的表达并增加Bax/Bcl-2比值,降低线粒体跨膜电位,提高细胞内游离钙离子浓度,最终经线粒体通路诱导细胞凋亡。更多还原

【Abstract】 Objective To investigate the mechanism of apoptosis of lung carcinoma cell line NCI-H460 induced by 20(S)-ginsenoside Rg3 (SPG-Rg3).Methods MTT assay was used to detect the proliferation rate of NCI-H460 cells.The cells were treated with SPG-Rg3 and divided into three groups based on IC50 value:SPG-Rg3 25 mg·L-1 group,SPG-Rg3 50 mg·L-1 group and SPG-Rg3 100 mg·L-1 group.Control group was also set up.Then the AO/EB fluorescence double-dye technique,immunocytochemistry staining,Fluo-3 staining and Rhodamine 123 uptake assay approaches were adopted to observe the apoptotic rate,expression levels of Bcl-2 and Bax proteins,concentration of cytoplasmic free Ca2+ and mitochondrial transmembrane potential of NCI-H460 cells.Results SPG-Rg3 obviously inhibited the cell proliferation,showing a positive correlation between inhibitory effect and concentration (r=0.764,P<0.05),and the IC50 was 47.97 mg·L-1.There were visible apoptotic changes observed in SPG-Rg3 groups.The protein expression level of Bcl-2 in SPG-Rg3 100 mg·L-1 group was less than that in control group(P<0.01).The protein expression levels of Bax in SPG-Rg3 groups were more than that in control group(P<0.001),and they were positively correlated with the drug dose(P<0.01).The ratios of Bax to Bcl-2 in SPG-Rg3 groups were bigger than that in control group,while the mitochondrial transmembrane potential showed an opposite situation(P<0.01) and it decreased when the drug dose increased.There were significantly differences between various groups (P<0.01).The concentrations of cytoplasmic free Ca2+ in SPG-Rg3 groups were higher than that in control group(P<0.01).Conclusion SPG-Rg3 could obviously inhibit the cell proliferation and induce the apoptosis.The mechanism is concerned with that SPG-Rg3 could up-regulate the expression level of Bax protein and increase the ratio of Bax to Bcl-2,down-regulate the mitochondrial transmembrane potential and increase the cytoplasmic free Ca2+ concentration,lead to the induction of apoptosis via mitochondrial pathway.更多还原