TY - JOUR
T1 - Dipeptidyl peptidase IV inhibitory properties of a whey protein hydrolysate
T2 - Influence of fractionation, stability to simulated gastrointestinal digestion and food-drug interaction
AU - Nongonierma, Alice B.
AU - FitzGerald, Richard J.
PY - 2013/9
Y1 - 2013/9
N2 - The invitro dipeptidyl peptidase IV (DPP-IV) inhibitory activity of a whey protein hydrolysate (WPH) generated with a food-grade pancreatic enzyme preparation was studied. The 50% inhibitory concentration (IC50) value in the presence of WPH was 1.34±0.11mgmL-1. Ultrafiltration (UF) fractionation of WPH allowed enrichment in DPP-IV inhibitory peptides. The permeates generated by UF through 5 and 2kDa membranes along with the hydrophilic fraction isolated by solid-phase extraction were significantly more potent DPP-IV inhibitors than WPH. Simulated gastrointestinal digestion of WPH resulted in an increased DPP-IV inhibitory potency (IC50 value of 1.02±0.05mgmL-1). Competitive inhibition of DPP-IV was observed with WPH and all its fractions, indicating a direct interaction of the bioactive peptides therein with the active site of DPP-IV. Combinations of sitagliptin, a conventional drug-inhibitor of DPP-IV, and whey-derived peptides resulted in an additive effect on DPP-IV inhibition.
AB - The invitro dipeptidyl peptidase IV (DPP-IV) inhibitory activity of a whey protein hydrolysate (WPH) generated with a food-grade pancreatic enzyme preparation was studied. The 50% inhibitory concentration (IC50) value in the presence of WPH was 1.34±0.11mgmL-1. Ultrafiltration (UF) fractionation of WPH allowed enrichment in DPP-IV inhibitory peptides. The permeates generated by UF through 5 and 2kDa membranes along with the hydrophilic fraction isolated by solid-phase extraction were significantly more potent DPP-IV inhibitors than WPH. Simulated gastrointestinal digestion of WPH resulted in an increased DPP-IV inhibitory potency (IC50 value of 1.02±0.05mgmL-1). Competitive inhibition of DPP-IV was observed with WPH and all its fractions, indicating a direct interaction of the bioactive peptides therein with the active site of DPP-IV. Combinations of sitagliptin, a conventional drug-inhibitor of DPP-IV, and whey-derived peptides resulted in an additive effect on DPP-IV inhibition.
UR - http://www.scopus.com/inward/record.url?scp=84877836950&partnerID=8YFLogxK
U2 - 10.1016/j.idairyj.2013.03.005
DO - 10.1016/j.idairyj.2013.03.005
M3 - Article
AN - SCOPUS:84877836950
SN - 0958-6946
VL - 32
SP - 33
EP - 39
JO - International Dairy Journal
JF - International Dairy Journal
IS - 1
ER -