羊栖菜组分多糖对α-葡萄糖苷酶的抑制作用

为高效利用羊栖菜组分多糖(SFPSⅠ),以SFPSⅠ为原料,α-葡萄糖苷酶作为靶标,研究SFPSⅠ对α-葡萄糖苷酶的抑制作用及其结构的影响,建立具有α-葡萄糖苷酶活性的Caco-2细胞模型,并对Caco-2细胞模型上α-葡萄糖苷酶活性的抑制效果进行研究。结果表明,SFPSⅠ对α-葡萄糖苷酶有明显的抑制作用,使得α-葡萄糖苷酶活力下降一半时的抑制剂浓度,即半抑制(IC₅₀)为0.31 mg·mL^-1。SFPSⅠ对α-葡萄糖苷酶的抑制作用是一个可逆过程,抑制类型为混合型抑制。动力学分析结果表明,SFPSⅠ对α-葡萄糖苷酶的抑制常数(K_i)为0.143 μmol·L^-1。荧光测定结果表明,SFPSⅠ结合会引起α-葡萄糖苷酶三级结构的明显变化。随着SFPSⅠ浓度的升高,其对Caco-2细胞模型上α-葡萄糖苷酶抑制效果越好。本研究结果为进一步探讨和设计新型α-葡萄糖苷酶抑制剂奠定了科学基础,同时也为开发具有降血糖功能的功能性药品与保健品提供了新资源。

Inhibition of Polysaccharide Fraction of Sargassum fusiforme on the α-glucosidase

To efficienty use the Sargassum fusiforme polysaccharide(SFPS Ⅰ), studyed the inhibitory effect of the polysaccharide fraction from Sargassum fusiforme on the activity and structure of α-glucosidase while SFPS Ⅰwas as a raw material and α-glucosidase was as a target. To investigate the inhibitory effect of α-glucosidase activity on the Caco-2 cell model, a Caco-2 cell model with α-glucosidase activity was established. The results showed that SFPS Ⅰcould obviously inhibit the activity of α-glucosidase. The inhibitory concentration leadingto 50% activity lost (IC₅₀) was estimated to be 0.31 mg·mL^-1. SFPS Ⅰwas a reversible inhibitor of α-glucosidase. Lineweaver-Burk plots indicated that SFPS Ⅰwas a mixed-type inhibitor, and its inhibition constant K_i was 0.143 μmol·L^-1. Endogenous fluorescence and ANS-binding fluorescence test of α-glucosidase indicated that SFPS Ⅰcombined with the α-glucosidase caused significant changes in the structure. The higher the SFPS Ⅰconcentration, the more significant the inhibition to the α-glucosidase of Caco-2 cell model. The results of this study provide a scientific basis for the design and development of new inhibitors in the future and the new resources for further development of the hypoglycemic pharamaceutical intermediates or functional foods.