探讨人参皂苷Rg3对人乳腺癌细胞MDA-MB-231代谢活性、凋亡和增殖的影响。

体外培养人乳腺癌细胞MDA-MB-231，分为对照组(正常培养)和Rg3处理实验组(0.4 mg/ml，0.8 mg/ml，1.6 mg/ml)，采用四甲基偶氮唑蓝(MTT)法检测各组细胞24 h内的代谢活性；采用凋亡试剂盒检测各组细胞凋亡因子caspase 3的酶活性；采用电镜观察各组细胞形态学变化；采用蛋白质印迹(Western blot)法检测细胞周期蛋白依赖性激酶2(CDK2)蛋白的表达水平。采用t检验比较两组间caspase 3酶活力和CDK2蛋白表达水平。

不同浓度Rg3处理人乳腺癌细胞MDA-MB-231后，细胞活性变弱，具有时间和浓度依赖性。凋亡试剂盒检测发现，Rg3浓度为0.4 mg/ml、0.8 mg/ml、1.6 mg/ml时分别处理细胞24 h后，caspase 3酶活力分别为(116.00±8.71)、(171.00±10.82)、(95.67±5.03)，仅Rg3浓度为0.8 mg/ml时，与对照组(105.33±7.51)比较，差异有统计学意义(t＝8.64，P<0.01)。电镜观察结果显示，0.4 mg/ml和0.8 mg/ml的Rg3处理实验组细胞出现了凋亡典型特征，1.6 mg/ml Rg3处理实验组细胞出现碎片化。Western blot结果显示，0.8 mg/ml Rg3处理实验组细胞的CDK2蛋白的表达水平(0.76±0.03)与对照组(0.89±0.07)比较显著降低(t＝2.84，P<0.05)。

浓度为0.8 mg/ml的Rg3可对人乳腺癌细胞MDA-MB-231代谢活性有明显的抑制作用，促使细胞发生凋亡，降低细胞增殖因子CDK2的表达，对细胞增殖有一定的抑制作用。

To investigate the effect of ginsenoside Rg3 on the activity, apoptosis and proliferation of human breast cancer cell line MDA-MB-231.

Human breast cancer cell line MDA-MB-231 was cultured in vitro and divided into control group (normal culture) and Rg3 treatment group (0.4 mg/ml, 0.8 mg/ml, 1.6 mg/ml). The metabolic activity of cells in each group within 24 h was detected by methyl thiazolyl terazolium (MTT) assay. Apoptosis kit was used to detect the activity of caspase 3 in each group. The morphological changes of cells in each group were observed by electron microscopy. The expression level of cyclin-dependent kinase 2 (CDK2) protein was detected by Western blot. Comparison between the enzymatic activity of caspase 3 and the protein expression levels of CDK2 was conducted using t-test.

Human breast cancer cell line MDA-MB-231 was treated with different concentrations of Rg3, and the cell activity was weakened in a time and dose dependent manner. Upon detection with the apoptosis detection kit, it was found that when the concentrations of Rg3 were 0.4 mg/ml, 0.8 mg/ml, and 1.6 mg/ml respectively, the caspase 3 enzyme activities after treating the cells for 24 hours were (116.00±8.71), (171.00±10.82), and (95.67±5.03) respectively. Only at the concentration of 0.8 mg/ml of Rg3, there was a statistically significant difference compared to the control group (105.33±7.51) (t=8.64, P<0.01). The results of electron microscopy showed that the experimental group with Rg3 concentration of 0.4 mg/ml and 0.8 mg/ml showed typical apoptotic characteristics, while the experimental group with Rg3 concentration of 1.6 mg/ml showed fragmentation. Western blot results showed that the expression level of CDK2 protein in 0.8 mg/ml Rg3 treatment group (0.76±0.03) was significantly decreased compared with that in the control group (0.89±0.07) (t=2.84, P<0.05).

Rg3 with a concentration of 0.8 mg/ml can significantly inhibit the metabolic activity of human breast cancer cell line MDA-MB-231, promote cell apoptosis, reduce the expression of cell proliferation factor CDK2, and have a certain inhibitory effect on cell proliferation.