蕨菜多糖的分离纯化单糖组分及免疫调节活性研究

Purification,characterization and immunomodulating activity of polysaccharides from Pteridium aquilinum (Linn.) Kuhn

目的：从蕨菜中分离纯化多糖成分，并进行相对分子质量、单糖组成和免疫调节活性研究。方法：采用热水浸提法提取蕨菜粗多糖，再经脱蛋白、DEAE Sepharose Fast Flow和Sepharose 4B凝胶柱层析得到3种均一多糖组分PLP1、PLP2和PLP3；采用高效液相凝胶渗透色谱法测定均一多糖相对分子质量；采用气相色谱分析均一多糖的单糖组分，采用MTT法和Griess法检测多糖对RAW264.7细胞生长和释放NO能力的影响。结果：PLP1、PLP2和PLP3的相对分子质量分别为6.62×10^4、4.34×10^5、1.88×10^5；PLP1含有鼠李糖、阿拉伯糖、岩藻糖、木糖、甘露糖、葡萄糖和半乳糖，PLP2含有鼠李糖、阿拉伯糖、岩藻糖、木糖、甘露糖和半乳糖，PLP3含有鼠李糖、阿拉伯糖、岩藻糖、木糖、甘露糖和半乳糖。3种多糖均可显著促进RAW264.7细胞的增殖，均具有显著增强RAW264.7细胞释放NO的能力，并呈一定的剂量效应关系。结论：PLP1、PLP2和PLP3 3个组分均为新的天然来源的均一杂多糖。3种多糖体外均能激活巨噬细胞，呈现显著的免疫调节活性。

Objective： To purify and determine the relative molecular mass, monosacchride compositions and immunomodulating activity of polysaccharides from Pteridium aquilinum （Linn.）Kuhn.Methods： The crude polysaccharide was extracted from P. aquilinum with hot water and then purified by DEAE Sepharose Fast Flow ion-exchange and Sepharose 4B gelfiltration chromatography after removing the proteins.The relative molecular mass was analyzed by high-performance gel permeation chromatography.The monosaccharide compositions were investigated by derivative gas chromatography （GC）and the immunomodulating activities were tested by MTT and Griess method.Results： Three homogenous polysaccharides PLP1, PLP2 and PLP3 were obtained from the crude polysaccharide.Their relative molecular masses were 6.62×104, 4.34×105, 1.88×105, respectively.Monosaccharide composition analysis by GC revealed that PLP1 was composed of rhamnose, arabinose, fucose, xylose, mannose, glucose, and galactose;PLP2 was composed of rhamnose, arabinose, fucose, xylose, mannose, and galactose;and PLP3 was composed of rhamnose, arabinose, fucose, xylose, mannose, and galactose, respectively.The three polysaccharides promoted the cell proliferation at the concentration of 12.5-100 μg·mL-1 and significantly induced the production of NO from RAW264.7 cells in a dose-dependent manner.Conclusion： PLP1, PLP2 and PLP3 are three new natural uniform heteropolysaccharides and all have immunomodulating activity.