Inhibitory effects of chondroitin sulfate on alpha-amylase activity: A potential hypoglycemic agent

Inhibiting the activity of the intestinal enzyme α-amylase that catalyzes the degradation of starch into glucose can control blood glucose and provide an essential way for the treatment of Type-II diabetes mellitus (T2DM). Here, we compared the structural information of chondroitin sulfate (CS) from different origins and the effects on activity of α-amylase and blood glucose have been investigated. The inhibitory effects of shark and porcine CSs against α-amylase activity is obvious with IC₅₀ values of 11.97 and 14.42 mg/ml, respectively, but the bovine CS almost no effect. From the data of fluorescence spectroscopic analyses, CSs from shark and pig quench Try fluorescence intensity of the enzyme, whereas bovine CS induces an increase. In vivo, oral administration of shark and porcine CSs efficiently suppresses postprandial blood glucose levels in normal and diabetic mice. Our study found that CSs from different sources showed different biological functions even if both molecular weight and disaccharide subunit composition are almost the same, and demonstrated that the CSs from shark and pig as α-amylase inhibitors could be regarded as a novel functional food ingredient in T2DM management.