Dipeptidyl peptidase-IV inhibitory activity of Katsuobushi-derived peptides in Caco-2 cell assay and oral glucose tolerance test in ICR mice.

Dipeptidyl peptidase-IV inhibitory activity of Katsuobushi-derived peptides in Caco-2 cell assay and oral glucose tolerance test in ICR mice.

J Agric Food Chem. 2020 May 12;:

Authors: Seki E, Yamamoto A, Fujiwara Y, Yamane T, Satsu H, Ohkubo I

Abstract
Proteolytic products of bonito stock residue inhibit dipeptidyl peptidase-IV (DPP-IV). Here, we isolated, purified, and identified the components of its N5 fraction obtained after using neutral protease from Aspergillus oryzae. A 10%-ethanol eluent (N5-2 fraction) from column chromatography was sequenced, yielding 18 peptides. Of these, Glu-Val-Phe, Ala-Va-Phe, and Gly-Val-Phe were identified as novel (IC50 values for DPP-IV inhibition were 525.56, 5466.49, and 2870.87 µM , respectively), whereas Trp-Val is the primary peptide (IC50 value of 36.99 µM, 1359 unit (mL/100g-N5-2 fraction) = (yield (mg/)/100g-N5-2 fraction)/ IC50(µg/mL). Furthermore, the N5-2 fraction significantly decreased DPP-IV activity in Caco-2 intestinal epithelial cells (p<0.05). From the oral glucose tolerance test using ICR mice, the N5-2 fraction significantly attenuated the rise in serum glucose levels compared with the control (p<0.05) through cell-surface DPP-IV inhibition. We discuss the novelty, the significance and relevance of finding study as well as its broad applications of prevention with diabetes.

PMID: 32396370 [PubMed – as supplied by publisher]

Source: Industry