杜仲叶多糖的制备及其体外活性

Separation and in vitro activity of polysaccharides from Eucommia folium leaves

【目的】分离制备杜仲叶多糖,研究其体外抗氧化和抗肿瘤活性,为杜仲叶多元化开发利用提供依据。【方法】以杜仲叶为原料,采用水提醇沉法制备杜仲叶粗多糖,以DEAE-52纤维柱色谱法进行分离纯化。测定多糖对DPPH自由基、超氧阴离子自由基、羟基自由基、ABTS自由基的清除作用;采用MTT法、LDH法和流式细胞术,检测多糖对乳腺癌MCF-7细胞生长抑制和细胞周期的影响。【结果】水提醇沉法制备的杜仲叶粗多糖经DEAE-52柱分离纯化后得到EFPs-1、EFPs-2共2个组分,其多糖质量分数分别为75.8%和84.3%。EFPs 2个组分对各自由基体系的清除能力均呈现良好的剂量依赖关系,其中EFPs-2的作用比EFPs-1强。EFPs-1对DPPH自由基、超氧阴离子、羟基自由基和ABTS自由基的半数有效浓度(EC 50)分别为3.393,5.259,3.692和2.463 mg/mL,EFPs-2的EC 50值依次为2.379,2.893,2.516和2.066 mg/mL。EFPs 2个组分对MCF-7细胞均有一定的体外生长抑制作用,其半数抑制浓度(IC 50)分别是226.23μg/mL(EFPs-1)和173.04μg/mL(EFPs-2),其中EFPs-2可使MCF-7细胞的细胞周期阻滞于G0/G1期。【结论】杜仲叶多糖具有良好的体外抗氧化和抑瘤活性。

【Objective】The polysaccharides from Eucommia folium leaves were separated and the in vitro anti-oxidation and anti-tumor activities were investigated to provide basis for diversified development and utilization of E.folium leaves.【Method】The crude polysaccharides of E.folium leaves were prepared by water extraction and alcohol precipitation methods,and then purified by DEAE-52 fiber column chromatography method.The scavenging effect of DPPH·,superoxide anion(O-·2),hydroxyl radicals(·OH)and ABTS+·were determined,and the effects on growth control and cell cycle of breast cancer MCF-7 cells were examined by MTT,LDH and flow cytometry methods.【Result】The crude polysaccharides of E.folium leaves prepared by water extract alcohol precipitation method were isolated and purified by DEAE-52 column with two components of EFPs-1 and EFPs-2,and their contents were 75.8%and 84.3%,respectively.The two components showed good dose-dependent scavenging ability in the respective basal system,and EFPs-2 was better than EFPs-1.The EC 50 of EFPs-1 for DPPH·,O-·2,·OH and ABTS+·were 3.393,5.259,3.692 and 2.463 mg/mL,respectively.The EC 50 values of EFPs-2 were 2.379,2.893,2.516 amd 2.066 mg/mL,respectively.The two components exhibited certain in vitro tumor suppression in MCF-7 cells with IC 50 of 226.23μg/mL(EFPs-1)and 173.04μg/mL(EFPs-2),respectively.EFPs-2 could block the cell cycle at G0/G1 stage.【Conclusion】The polysaccharides from E.folium leaves had good anti-oxidation and anti-tumor activity in vitro.