人参皂苷Rg3对食管癌细胞放射增敏作用的初步研究

目的 探讨人参皂苷Rg3（简称Rg3）对食管癌EC109细胞的放射增敏作用。方法采用四甲基偶氮唑盐比色法观察不同浓度的Rg3（10、20、50、100、200、400、600mmol/L）作用EC109细胞24、48及72h的细胞存活率，克隆形成实验及单击多靶模型计算10mmol/L Rg3预处理24h经0、1、3、6和9Gy X射线照射后的辐射增敏比（SER）。根据实验设计分为对照组、单纯照射组及Rg3+照射组，流式细胞仪及Foci焦点形成实验分别检测3组经8Gy X射线照射48h的细胞凋亡率和DNA分子损伤情况。结果在10～600mmol/L范围内，Rg3可降低EC109细胞的存活率，呈剂量和时间依赖性；10mmol/L Rg3处理EC109细胞的SER为1.28。Rg3+照射组的凋亡率为（62.33±4.60）%，高于对照组的（6.46±1.23）%和单纯照射组的（30.68±3.55）%，差异有统计学意义（P＜0.05）；Rg3+照射组的Foci焦点细胞数为（64±12）个，亦高于对照组的（6±3）个和单纯照射组的（32±6）个，差异有统计学意义（P＜0.05）。结论Rg3对食管癌EC109细胞有放射增敏作用，能够抑制细胞活性并诱导细胞凋亡与DNA分子损伤。

A preliminary study on radiosensitization effect of ginsenoside Rg3 on esophageal carcinoma cells

Objective To investigate the radiosensitivity enhancement of ginsenoside Rg3 on esophageal carcinoma EC109 cells. Methods The survival rates of EC109 cells at 24, 48 and 72h after treatment with different concentrations （ 10, 20, 50, 100, 200, 400, 600mmol/L） of Rg3 were determined by MTT in vitro. The cloning formation assay and multi-target single-hit model were employed to calculate the sensitization enhancement ratio （ SER） after pretreatment of 10 mmol/L Rg3 following irradiation of 0, 1, 3, 6 and 9Gy. According to the experimental protocol, the following experiments were carried out in control group, irradiation group and Rg3＋irradiation group. The apoptosis rate and DNA damage were evaluated by flow cytometry and Foci focus formation assay in the 3 groups after 48h irradiation of 8Gy X-ray. Results The Rg3 ranging from 10 to 600mmol/L could reduce the survival rates of EC109 cells in a dose-and time-dependent manner. The SER of 10mmol/L Rg3 for EC109 cells was 1. 28. The apoptosis rate of Rg3＋irradia-tion group was （62. 33±4. 60）%, higher than （6. 46±1. 23）% of control group and （30. 68±3. 55）% of irradiation group with signifi-cant difference（ P〈0. 05） . The number of Foci-positive cells in Rg3＋irradiation group was 64 ± 12, higher than 6 ± 3 of control group and 32±6 of irradiation group with significant difference （P〈0. 05）. Conclusion Rg3 can exert radiosensitizing effect on esophageal carcinoma EC109 cells, inhibite cell activity and induce cell apoptosis and DNA damage.