Inhibition of Dipeptidyl Peptidase (DPP)-IV and α-GIucosidase Activities by Pepsin-Treated Whey Proteins

摘要

Inhibitors of the enzymes dipeptidyl peptidase (DPP)-IV and a-glucosidase are two classes of pharmacotherapeutic agents used for the treatment of type 2 diabetes. In the present study, whey protein isolate (WPI), a-lactalbumin, β-lactoglobuIin, serum albumin, and lactoferrin hydrolysates obtained by peptic digestion were investigated for their potential to serve as natural sources of DPP-IV and a-glucosidase inhibitors. Although inhibition of DPP-IV activity was observed in all pepsin-treated whey proteins studied,, the a-lactalbumin hydrolysate showed the greatest potency with an IC_(50) value of 0.036 mg/mL. Conversely, only WPI, β-lactoglobulin, and a-lactalbumin hydrolysates displayed some inhibitory activity against a-glucosidase. This study suggests that peptides generated from whey proteins may have dual beneficial effects on glycemia regulation and could be used as functional food ingredients for the management of type 2 diabetes.