白花丹醌对人急性早幼粒细胞白血病细胞的体外效应

根据作者已往的临床经验，中草药白花丹对急性早幼粒细胞白血病（APL）治疗有效，但至今尚无关于白花丹对APL疗效方面的系统研究。本研究的目的是通过NB4细胞体外观察白花丹提取物白花丹醌（plumbagin）对细胞增殖及凋亡的影响。采用MTT比色法检测白花丹醌对NB4细胞增殖抑制作用；用光学显微镜及透射电镜观察细胞形态改变；DNA凝胶电泳及annexin V／PI双染实验测定检测细胞凋亡；DNAPI染色法检测细胞亚二倍体峰及细胞周期。结果显示：白花丹醌在2-15μmol/L浓度范围内能够显著抑制NB4细胞的增殖，且呈剂量依赖性效应关系（P〈0．01）；在光学显微镜及透射电镜下可见典型的细胞凋亡形态变化；白花丹醌诱导细胞出现DNA梯形条带，annexin V^＋／PI^-凋亡细胞及亚二倍体峰，细胞周期阻滞于G2／M期，凋亡细胞比例与白花丹醌呈剂量依赖性效应关系（P〈0．05）。结论：本研究首次证实白花丹醌能够抑制APL细胞系NB4的增殖、诱导细胞凋亡及阻滞细胞周期进程。

Effects of Plumbagin on the Human Acute Promyelocytic Leukemia Cells In Vitro

According to previous clinical experiences of the authors, plumbago zeylanica was effective against acute promyelocytic leukemia (APL). However, its effectiveness has never been proven experimentally or unequivocally clinically. This study was aimed to investigate the effects of plumbagin on the proliferation, cell cycle and apoptosis of APL cell line NB4 Cells. Cell inhibitory rates were detected by MTT colorimetric assay; morphologic changes were observed under light microscope and transmission electron microscope; apoptosis-inducing effects were determined by DNA gel electrophoresis, annexin V/PI double-stained and PI single-stained flow cytometry. The results demonstrated that 2-15 micromol/L plumbagin inhibited the proliferation of NB4 cells in a dose-dependent manner. The morphologic changes of cell apoptosis, such as chromsome condensation and apoptotic body formation, were observed by light microscope and transmission electron microscope. Cell cycle analysis showed that NB4 cells were blocked in G2/M phase of cell cycle. And plumbagin induced annexin V+/PI- cell increase and DNA fragmentation. There was a correlation between cell apoptosis rates and the concentrations of plumbagin in dose-dependent manner (P < 0.05). It is concluded that for the first time the present study shows that plumbagin can inhibit cell proliferation, block cell cycle and induce apoptosis of APL cell line NB4 cells.