目的 观察氧化苦参碱诱导人结肠腺癌细胞株SW620凋亡的作用并探讨其可能机制。方法 采用MTT法检测氧化苦参碱对SW620细胞的增殖抑制作用；Hoechst33258荧光染色检测氧化苦参碱对SW620细胞凋亡的影响；流式细胞仪检测氧化苦参碱对SW620细胞周期的影响；实时定量PCR法检测细胞内p16、cyclinD1及CDK4基因表达水平；免疫印迹法检测细胞内p16、CyclinD1及CDK4蛋白表达水平。结果 氧化苦参碱抑制SW620细胞增殖作用呈剂量依赖性，其作用24 h的IC₅₀为4.02 μmol/L；与对照组相比，苦参碱处理后的SW620细胞G₁期比例明显增高，G₂期细胞比例下降（P<0.05）；氧化苦参碱作用后SW620细胞p16基因和蛋白水平升高（P<0.05），cyclinD1及CDK4基因和蛋白表达水平显著降低（P<0.01）。结论 氧化苦参碱在体外能抑制SW620细胞的增殖，诱导细胞在G₁期阻滞，其诱导作用与其调控p16、cyclinD1及CDK4基因和蛋白表达有关。

Objective To explore the antitumor effect of oxymatrine and detect the mechanism involved. Methods The Anti- proliferative effects of oxymatrine in human colon adenocarcinoma SW620 cells were assessed using MTT assay. SW620 cells treated with oxymatrine were assessed with Hoechst 33258 staining and cell cycle distribution assay was performed by flow cytometry. The quantitative real-time PCR assay was used to evaluate the expression of p16, cell cycle-related cyclinD1 and CDK4 mRNA at the genetic level. To investigate the molecular mechanisms underlying alterations in cell apoptosis, the proteins p16, cell cycle-related cyclinD1, and CDK4 were determined by Western blotting analysis. Results Oxymatrine could significantly inhibit the growth of SW620 cells compared with the control group, the IC₅₀ was 4.02 μmol/L. Its anticancer activity was related to the alteration in expression of p16, cyclinD1, and CDK4 (P < 0.05, 0.01). Conclusion These results suggest that oxymatrine produces the obvious antitumor effects on SW620 cells in vitro, induces the cell arrest in G₁ phase which is related to the regulation on the protein expression of p16, cyclinD1, and CDK4.

国家自然科学基金青年基金资助项目（81001701）；广东省中医药局建设中医药强省科研项目（20131106）