摘 要 目的：探讨冬凌草甲素（oridonin，Ori）对人多发性骨髓瘤ARH-77细胞的致凋亡作用及其可能的机制。方法：不同浓度Ori（2.5、5、10 μmol/L）作用于ARH-77细胞，MTT法检测ARH-77细胞的增殖，相差显微镜和Hoechst 33258染色观察细胞凋亡的形态学改变，流式细胞术检测ARH-77细胞的早期凋亡及线粒体膜电位（Δψm）的变化，caspase 8凋亡试剂盒检测ARH-77细胞caspase 8的活化。结果：Ori对ARH-77细胞的生长有明显的抑制作用，且呈时间和剂量依赖性。10 μmol/L Ori作用于ARH-77细胞24 h后可见细胞变小、胞质中出现空泡，并可见凋亡小体。流式细胞术结果显示，经不同浓度Ori（2.5、5、10 μmol/L）处理后，细胞早期凋亡率分别为（15.07±0.78）%、（21.00±1.49）%和（27.45±2.47）%，均高于对照组的（5.27±1.46）%（P<0.01）。不同浓度Ori（2.5、5、10 μmol/L）处理后，反映Δψm的绿色荧光细胞百分率分别为（26.80±0.75）%、（36.81±2.27）%和（49.48±1.10）%，均高于对照组的（16.96±0.50）%（P<0.01），提示ARH-77细胞凋亡有显著增加。同时，Ori处理可上调ARH-77细胞caspase 8的活性（P<0.01）。结论：冬凌草甲素能明显诱导多发性骨髓瘤ARH-77细胞的凋亡，其机制可能与激活内、外源凋亡通路有关。

Abstract Objective:To investigate the apoptosis induction effect of oridonin (Ori) on human multiple myeloma cell line ARH-77 and the possible mechanism. Methods: ARH-77 cells were treated with different concentrations of oridonin (2.5, 5 and 10 μmol/L), and then the proliferation of ARH-77 cells was detected by MTT assay. The morphological change of apoptotic ARH-77 cells was observed under phase contrast microscope and Hoechst 33258 staining. The apoptosis and the change of mitochondrial membrane potential (Δψm) of ARH-77 cells were examined by flow cytometry. The caspase 8 activity was measured by caspase-8 apoptosis kit. Results: Ori significantly inhibited the growth of ARH-77 cells in a time- and dose-dependent manner. After treatment with 10 μmol/L Ori for 24 h, ARH-77 cells became shrunk, with cytoplasm vacuoles and apoptotic bodies. Flow cytometry results revealed that the apoptotic rates of ARH-77 cells after Ori treatments (2.5, 5 and 10 μmol/L) were significantly higher than that of control group, with apoptotic rates being (15.07±0.78)%, (21.00±1.49)%, (27.45±2.47)% vs (5.27±1.46)% (P<0.01). Green fluorescence percentages of Δψm of ARH-77 cells were significantly increased in Ori-treated groups (2.5, 5 and 10 μmol/L) compared with that in control group, with percentages being (26.80±0.75)%, (36.81±2.27)%, (49.48±1.10)% vs (16.96±0.50)% (P<0.01). Meanwhile, caspase 8 activity of ARH-77 cells was significantly up-regulated by Ori treatment (P< 0.01). Conclusion: Oridonin can markedly induce apoptosis of human multiple myeloma ARH-77 cells, which might be related to extrinsic and intrinsic pathways.

广东省自然科学基金资助项目（No.7001196）