加杨芽鳞提取物的抗肿瘤作用研究

Anticancer Effect of Bud Scale Extract Prepared from Populus Canadensis

[目的]建立杨树芽鳞提取物(PBE)的制备方法,研究其抗肿瘤活性并探讨其作用机制。[方法]采集加杨芽鳞,提取醇溶性成分PBE。以顺铂为阳性对照,通过酸性磷酸酶法检测PBE对体外培养肿瘤细胞的抑制作用,并进行腹腔接种腹水型肝癌H22细胞的荷瘤小鼠抗癌实验。在光镜与电镜下观察癌细胞的形态学改变。以流式细胞仪和荧光显微镜分析细胞凋亡状况。[结果]PBE对肿瘤细胞系BEL鄄7402、CNE、NCI鄄H460、S180的增殖均有明显抑制作用,IC50分别为8、6、4和12μg/ml,最小有效剂量分别为0.4、0.5、0.8和1.0μg/ml。与顺铂不同的是,PBE对人正常肝细胞L02未见明显抑制作用。体内实验显示PBE可延长荷瘤小鼠的生存期。在PBE作用下癌细胞出现明显形态学变化,包括分裂相细胞减少、细胞表面微绒毛样突起明显增多、细胞连接消失、胞质内积累大量囊泡等。细胞凋亡率未发生明显变化。[结论]PBE对多种肿瘤细胞有显著抑制和杀伤作用。其作用机理可能与改变膜限区室结构、影响细胞表面分子表达、影响微丝系统有关,而非与凋亡途径活化有关。

To establish a method of preparing poplar bud-scale extract (PBE) and to study its anticancer activities and mechanisms.Bud scales of Populus Canadensis were collected and extracted with ethanol to obtain PBE.Various cultured cancer cell lines were used for in vitro test.Inhibition of cell proliferation was assayed using the acid phosphatase method.Cisplatin was used as positive control. Anticancer experiment was done on mice inoculated i.p.with the H22 liver cancer cells.Morphological changes were studied by light and electron microscopes. Apoptosis was analyzed with FACS and fluorescent microscope.PBE inhibited proliferation of BEL-7402,CNE,NCI-H460 and S180 cancer cell lines with IC50 of 8,6,4 and 12μg/ml respectively.The minimum effective dose on the above cell lines was 0.4, 0.5, 0.8 and 1.0μg/ml respectively. Contrary to cisplatin, which strongly inhibited the proliferation of the normal human liver L02 cells, no apparent inhibition by PBE was observed on the L02 cells.In vivo test showed that PBE could prolong the life spans of tumor-bearing mice. PBE treated cancer cells showed significant morphological changes, including decrease of mitogenetic cells, increase of microvilli on cell surface, diminish of cell junctions, and accumulation of large amount of cytoplasmic vesicles. No apparent variations in apoptosis rate were observed.[Conclusion] PBE has inhibitory and cytotoxic effects on various cancer cell lines.The anticancer mechanisms of PBE may involve changes of the membrane-bound compartments,variation of the expression of cell surface molecules,and modification of the microfilament system.However,activation of the apoptosis pathway is not involved.