Lakshmi A. Dave, Maria Hayes, Leticia Mora, Shane M. Rutherfurd, Carlos A. Montoya and Paul J. Moughan* Pages 1 - 14 ( 14 )
Background: Recent in silico and in vitro studies have shown that gastrointestinal endogenous proteins (GEP) are a source of bioactive peptides. To date, however, the presence of such peptides in the lumen of the digestive tract has not been demonstrated.
Objective: We investigated the generation of GEP-derived bioactive peptides in the growing pig fed a protein-free diet.
Methods: Stomach chyme (SC) and jejunal digesta (JD) fractions from 6 growing pigs (two sampling times) were assessed for their angiotensin-I-converting enzyme (ACE-I; EC 220.127.116.11) inhibition, and antioxidant activity using the 2,2- diphenyl-1-picrylhydrazyl (DPPH) inhibition, ferric reducing antioxidant power (FRAP) and microsomal lipid peroxidation (MLP) inhibition assays.
Results: Two of the fractions prepared from JD samples inhibited ACE-I and DPPH by 81 (± 2.80)% and 94 (±0.66)%. SC fractions were found to inhibit MLP between 15-39 (±3.52-1.40)%. The study identified over 180 novel peptide sequences that were related to the determined bioactivities, including a porcine serum albumin-derived peptide (FAKTCVADE SAENCDKS), corresponding to f(7-23) of the human serum albumin peptide LVNEVTEFAKTCVADESAEN CDKSLHTLF that was previously identified from the digests of the latter GEP.
Conclusions: This study provides the first in vivo evidence for GEP as a source of bioactive peptides. These new findings help advance our knowledge of the latent bioactive role of GEP-derived peptides in mammalian nutrition and health, and their potential pharmaceutical applications.
Angiotensin-I converting enzyme (ACE-I) inhibition, antioxidant peptides, exogenous bioactive peptides, ferric reducing antioxidant power, gut non-dietary proteins, microsomal lipid peroxidation inhibition, non-dietary proteins; porcine model; serum albumin
Riddet Institute, Massey University, Private Bag 11222, Palmerston North 4442, Teagasc, The Irish Agricultural and Food Development Authority, Food BioSciences Department, Ashtown, Dublin 15, Instituto de Agroquimica y Tecnologia de Alimentos (CSIC), Avenida Agustín Escardino 7, 46980 Paterna, Valencia, Riddet Institute, Massey University, Private Bag 11222, Palmerston North 4442, Riddet Institute, Massey University, Private Bag 11222, Palmerston North 4442, Riddet Institute, Massey University, Private Bag 11222, Palmerston North 4442