目的??研究来自桔梗的皂苷类单体化合物 - 桔梗皂苷 D（platycodin D， PD）对前列腺癌细胞的杀伤效应及可能 的机制。 方法??培养前列腺癌细胞株： PC3、 DU145、 LNCaP，四甲基偶唑氮（MTT）法检测 PD 对肿瘤细胞的存活率的影响； 流式细胞仪检测 PD 阻滞细胞周期的能力；蛋白免疫印迹实验检测 PD 对周期相关蛋白表达的影响。 结果??PD 杀伤前列腺癌 细胞（PC3, DU145， LNCaP）的 IC50 值均小于 30μM（PC3: 11.17μM， DU145: 26.13μM， LNCaP: 24.6μM），随处理浓度增 加，杀伤效应更为明显，呈明显剂量效应关系，其中以 PC3 细胞最为敏感。 PD 明显阻滞前列腺癌细胞周期， 10μM PD、 15μM PD 将 PC3 细胞阻滞在 G2/M 期；而将 DU145 和 LNCaP 细胞阻滞在 G0/G1 期。 PD 影响 PC3 细胞的细胞周期相关蛋白： E2F1 ， CDK2， CDK4， CDK6， CyclinD1， Cdc2， CyclinB1 蛋白表达量呈现下降趋势，与 PD 对细胞周期的阻滞作用相符合。 结论??PD 能够杀伤前列腺癌细胞，阻滞细胞周期进展，从而抑制肿瘤的发展。

Objective To evaluate the anti-tumor activity and possible mechanism(s) of Platycodin D (PD), a major saponin derived from Platycodin grandi?orum, in human prostate cancer cell lines. Methods Human prostate cancer cell lines (PC3, DU145 and LNCaP cells), and the non-malignant human prostate epithelial cell line, RWPE-1, were exposed to various concentrations of PD to evaluate its cytotoxicity in vitro (via the MTT assay). Cell cycle analysis was indicated by PI staining with ?ow cytometry. Cell cycle-related proteins levels were assessed by Western blotting. Results PD exerted cytotoxicity against three prostate cancer cell lines, PC3 cells, DU145 cells, and LNCaP cells, with half-maximal inhibitory concentrations (IC50) in the range of 11.17 to 26.13 μmol/L. The PC3 cells were the most sensitive to PD. After being treated with PD for 48 hours, the PC3 cells were arrested in the G2/ M phase, and the DU145 and LNCaP cells were arrested in the G0 /G1 phase. Western blotting analysis indicated that PD exposure decreased the levels of cell cycle-related proteins, including E2F1, CDK2, CDK4, CDK6, CyclinD1, Cdc2, CyclinB1. Conclusions PD exhibits signifcant inhibitory activities against prostate cancer cells, which provides a basis for future development of human prostate cancer chemotherapy.