Antioxidant Synergetic Effect Between the Peptides Derived from the Egg White Pentapeptide Trp-Asn-Trp-Ala-Asp

When foods are intaken together, the antioxidant activity of mixtures may present synergistic, additive, or antagonistic interactions. The aim of this study was to investigate the oxygen radical absorbance capacity (ORAC) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonicacid) diammonium salt (ABTS) radical scavenging activity of (Trp-Asn-Trp-Ala-Asp) WNWAD, a pentapeptide derived from egg white ovomucin pepsin hydrolysates, and its fragments as well as the effect of WNWAD on cellular antioxidant enzymes activities. The ORAC assays demonstrated that combined group (WN + WAD) significantly improved the antioxidant activities, while combined group (WNW + AD) decreased the antioxidant activities. The ABTS assays showed peptide fragments (WNW, WN, WAD) and its mixture (WNW + AD, WN + WAD) have lower EC50 than antioxidant peptide WNWAD in ABTS assay. Various combinations of peptide were found to have synergistic interaction, and synergistic interaction exhibited certain dose-dependently interactions. At cellular level, the activities of SOD, GSH-Px, CAT were higher while the level of MDA, LDH release were lower in the peroxide + peptide-treated group when compared to the peroxide exposed group. Results in this study imply the importance of exploiting synergism interactions in the development of new functional food.