辣木叶多糖的分离纯化及其体外降糖活性研究

目的研究辣木叶多糖的制备、单糖组成以及体外降糖活性。方法采用水提醇沉、Sevage法、大孔树脂-阴阳离子交换树脂联用技术得到较高纯度辣木叶粗多糖,再进一步通过二乙氨基乙基纤维素和葡聚糖凝胶柱层析分离得到2个主要多糖组分(MOs-2-a、MOs-2-b),并通过水解衍生化对其单糖组成进行分析。此外,采用HepG2细胞建立胰岛素抵抗模型,以细胞葡萄糖消耗量为指标,考察辣木叶多糖的降糖作用。结果本文采用的制备工艺可以得到较高纯度的辣木叶粗多糖(纯度为73.10%),辣木叶多糖主要由甘露糖、鼠李糖、葡萄糖及半乳糖组成,其中各单糖摩尔比为0.49:3.65:0.63:1.27。与模型组相比,辣木叶多糖组分MOs-2-a、MOs-2-b均能显著增加胰岛素抵抗HepG2细胞的葡萄糖消耗量(P0.05)。结论辣木叶多糖MOs-2-a、MOs-2-b具有良好的降糖效果,本文可以为辣木叶多糖作为功能食品发展的提供科学依据。

Isolation and purification of polysaccharides from Moringa oleifera leaves and in vitro hypoglycemic activity

Objective To investigate the preparation, monosaccharide composition and hypoglycemic activity of polysaccharides from Moringa oleifera leaves. Methods The polysaccharides were extracted by water extraction and alcohol precipitation. The deproteinization was taken by Sevage method and then purified by macroporous resin-ion exchange resin multiple techniques to obtained crude polysaccharides. Subsequently, two polysaccharides (MOs-2-a and MOs-2-b) were isolated from crude polysaccharides by diethylaminoethylcellulose and sephadex column. The monosaccharide composition was determined by derivative reaction. Besides, HepG 2 cell was utilized as the cell model to investigate the hypoglycemic activity of polysaccharides from Moringa oleifera leaves.Results High purity crude polysaccharides from Moringa oleifera leaves could be obtained through this preparation process, and the purity of crude polysaccharides was 73.10%. Moringa oleifera leaves polysaccharide was composed of mannose, rhamnose, glucose and galactose, the molar ratio of each monosaccharide was 0.49:3.65:0.63:1.27. In addition, MOs-2-a and MOs-2-b could significantly promote the glucose consumption of insulin resistance HepG 2 cells (P<0.05). Conclusion Moringa oleifera leaves polysaccharide of MOs-2-a and MOs-2-b have a good hypoglycemic effect. This research can provide the scientific basis for the development of Moringa oleifera leaves as functional food.