几种植物多糖降血糖活性的对比研究

Comparative Studies on the Hypoglycemic Activity of Several Plant Polysaccharides

目的:研究和对比红茶多糖(BPS)、枸杞多糖(LPS)和桑叶多糖(MPS)的成分,对比它们的降血糖效果及机理。方法:选取白琳工夫作为红茶的代表,测定红茶多糖、枸杞多糖和桑叶多糖的成分、分子质量和单糖组成。以链脲佐菌素诱导小鼠糖尿病模型,二甲双胍作为阳性对照,研究所选植物多糖提取物的降血糖效果,采用qPCR测定小鼠肝脏中相关基因表达水平和血清转氨酶水平。结果:所选红茶、枸杞和桑叶多糖提取物的绝对重均分子质量分别为8745,22410,34430 u。所选植物多糖提取物均具有降血糖的功效,红茶、枸杞和桑叶多糖的血糖下降率分别为61.6%,52.8%及53.8%。植物多糖均可提高糖酵解相关酶的活性,调节糖代谢相关基因表达,降血糖效果整体呈红茶>桑叶>枸杞的规律。结论:在试验所选剂量条件下,植物多糖提取物均未表现出肝脏毒性。红茶多糖整体降血糖效果优于桑叶多糖和枸杞多糖。

Objective:To study and compare the composition,blood sugar lowering effect and composition of BPS,LPS and MPS.Methods:Bailingongfu was selected as representatives of black tea.The composition,molecular weight and monosaccharide composition of plant polysaccharides were determined.The mice diabetes model was induced by streptozotocin,and metformin was used as a positive control to study the hypoglycemic effect of plant polysaccharides,qPCR was used to determine the expression level of related genes in mice liver,and the serum transaminase level in mice was determined.Results:The molecular weights of BPS,LPS and MPS are 8745,22410 u and 34430 u,respectively.The selected plant polysaccharides have hypoglycemic effect,the fasting blood glucose decline rates of BPS,LPS and MPS were 61.6%,52.8%and 53.8%,respectively.Plant polysaccharides can increase the activity of enzymes related to glycolysis and down-regulate the expression of Foxo1,G6Pc,PEPCK and TXNIP genes in mice.The hypoglycemic effect showed the regularity of black tea>mulberry leaf>Lycium barbarum fruit.Conclusion:Under the selected dose condition,the plant polysaccharides didn′t show hepatotoxicity.The research on the hypoglycemic effect of the selected black tea polysaccharide is better than the mulberry leaf polysaccharide and the Lycium barbarum fruit polysaccharide.