Rapid screening and identification of novel dipeptidyl peptidase IV inhibitory peptides from buffalo milk.

Abstract

Background: Peptidomics combined with molecular docking is an effective alternative method for rapid screening of novel bioactive peptides in food. Buffalo milk as a potential source of dipeptidyl peptidase-IV (DPP-IV) inhibitory peptides has been less studied. Peptidomics and molecular docking methods were employed to rapidly screen new DPP-IV inhibitory peptides from buffalo milk. The screened DPP-IV inhibitory peptides were further verified using an in vitro inhibition assay and a Caco-2 cell assay.

Results: The DPP-IV inhibition rate of buffalo milk was increased from 73.40 ± 6.01% to 97.23 ± 3.18% in an in vitro digestion assay, suggesting that buffalo milk could be a promising source of DPP-IV inhibitory peptides. Subsequently, two novel peptides (GPFPIIV and FPQYL) with potential DPP-IV inhibitory activity were screened using peptidomics, molecular docking and an in vitro inhibitory assay. The IC₅₀ values for GPFPIIV and FPQYL were 0.2998 ± 0.03 and 0.1407 ± 0.01 mg mL^-1, respectively. During simulated gastrointestinal digestion in vitro, FPQYL had an excellent digestive stability of 92.13 ± 1.03%, whereas that of GPFPIIV was 59.52 ± 2.56%. In addition, GPFPIIV and FPQYL (1.00 mg mL^-1) showed significant DPP-IV inhibitory effects in a Caco-2 cell assay, with the inhibition rate increasing to 32% and 36%, respectively.

Conclusion: In summary, two new DPP-IV inhibitory peptides were screened from buffalo milk through a combination of peptidomics and molecular docking, both of which exhibited significant DPP-IV inhibitory activities. The identified peptides, GPFPIIV and FPQYL, have promising applications in diabetes management. © 2025 Society of Chemical Industry.