淡黑巨藻醇提取物降血糖活性及其对小鼠肠道菌群的影响

Anti-diabetic Activity of Alcohol Extracts from Lessonia nigrescens and Its Effects on Intestinal Microflora in Mice

筛选具有降血糖活性的海藻活性物质,研究其对2型糖尿病小鼠肠道菌群的影响,为开发具有降糖作用的营养功能性食品提供依据。利用体外α-葡萄糖苷酶抑制活性和HepG2胰岛素抵抗细胞模型,对13种海藻通过分步提取法制备得到的35种海藻提取物进行筛选,并采用16S rRNA高通量测序技术分析降糖效果佳的提取物对2型糖尿病小鼠肠道菌群的影响。结果表明,35种海藻提取物中泡叶藻和淡黑巨藻55%乙醇提取物对α-葡萄糖苷酶活性抑制作用最为显著,淡黑巨藻55%乙醇提取物更能显著提高HepG2胰岛素抵抗细胞的葡萄糖消耗量,其显著增加2型糖尿病小鼠肠道内Bacteroidetes属的丰度,且使Firmicutes属细菌数量明显减少。淡黑巨藻55%醇提取物表现出显著的降血糖及调节肠道菌群的作用,具有潜在的食药用价值。

The aim of this article is to screen the seaweed active material and study the effect on intestinal flora in mice with type 2 diabetes for providing functional nutrition food with hypoglycemic effect. First,the 35 different extracts from 13 kinds of seaweeds prepared by step-by-step extraction method were screened by evaluating in vitro α-glucosidase activity and using HepG2 insulin resistance cell model. Then,the impacts of extracts with solid hypoglycemic effects on intestinal flora in type 2 diabetic mice were evaluated through 16s rRNA high-throughput sequencing. Among the 35 seaweed extracts,55%-ethanol extracts from Lessonia nigrescens and Ascophyllum nodosum showed the most significant inhibitory effects on α-glucosidase activity ;moreover,the 55%-ethanol extracts from L. nigrescens significantly increased the glucose consumption of insulin-resistant HepG2 cells,also remarkably increased the abundance of Bacteroidetes in the intestine of mice and decreased the number of Firmicutes bacteria. The 55%-ethanol extract of Lessonia nigrescens showed the most significant hypoglycemic activity and the ability to maintain the balance of intestinal microflora,which may have potential medicinal value.