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

Abstract

Inhibitors of the enzymes dipeptidyl peptidase (DPP)-IV and α-glucosidase are two classes of pharmacotherapeutic agents used for the treatment of type 2 diabetes. In the present study, whey protein isolate (WPI), α-lactalbumin, β-lactoglobulin, serum albumin, and lactoferrin hydrolysates obtained by peptic digestion were investigated for their potential to serve as natural sources of DPP-IV and α-glucosidase inhibitors. Although inhibition of DPP-IV activity was observed in all pepsin-treated whey proteins studied, the α-lactalbumin hydrolysate showed the greatest potency with an IC50 value of 0.036 mg/mL. Conversely, only WPI, β-lactoglobulin, and α-lactalbumin hydrolysates displayed some inhibitory activity against α-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.

Sorghum condensed tannins encapsulated in kafirin microparticles as a nutraceutical for inhibition of amylases during digestion to attenuate hyperglycaemia

“…IC 50 is defined as the concentration of inhibitor required to inhibit 50% of enzyme activity (Lacroix & Li-Chan, 2013). Alpha-glucosidase and α-amylase activities were assayed (as described) in the presence SCT alone and acarbose at various concentrations.…”

Whey proteins have beneficial effects on intestinal enteroendocrine cells stimulating cell growth and increasing the production and secretion of incretin hormones

“…The pharmacological efficacy of GLP-1 and GIP mimetics as therapeutics for the treatment of T2DM is well established (Green & Flatt, 2007). Inhibition of Dipeptidyl peptidase-4 (DPP-IV), an enzyme responsible for the short half-life of these incretin hormones (Flatt, Bailey, & Green, 2008) is also of interest, as is the inhibition of the carbohydrate-hydrolysing enzyme alpha-glucosidase (Lacroix & Li-Chan, 2013). Recent studies have found that peptides derived from whey hydrolysates have inhibitory activity against DPP-IV and alpha-glucosidase.…”

“…Recent studies have found that peptides derived from whey hydrolysates have inhibitory activity against DPP-IV and alpha-glucosidase. This includes hydrolysates of beta-lactoglobulin (Silveira, Martínez-Maqueda, Recio, & Hernández-Ledesma, 2013;Uchida, Ohshiba, & Mogami, 2011), alpha-lactalbumin (Lacroix & Li-Chan, 2013) and lactoferrin (Nongonierma & FitzGerald, 2013). Interestingly, only protein hydrolysates derived from meat or egg albumin (Cordier-Bussat et al, 1998;Gevrey et al, 2004) have been found to elicit an increase in GLP-1 secretion in vitro.…”

Inhibition of dipeptidyl peptidase IV (DPP-IV) by tryptophan containing dipeptides

“…Individual milk protein hydrolysates generated with -lactoglobulin (-Lg) 14,[16][17][18] α-lactalbumin (α-La) 18 , bovine serum albumin (BSA) 18 and lactoferrin (LF) 11,18 have also been identified as potent DPP-IV inhibitors.…”