Abstract: In recent years, antioxidant peptides with high safety and potent antioxidant capacity have become a hot research field. The aim of this study was to investigate the effects of egg white-derived bioactive peptides WNWAD (Trp-Asn-Trp- Ala-Asp), WNW (Trp-Asn-Trp), WAD (Trp-Ala-Asp) and WN (Trp-Asn) on the survival rate, reactive oxygen species (ROS) content, antioxidative enzyme activities and interleukin-8 (IL-8) level in HEK293 cells under oxidative stress induced by H2O2. MTS assay results showed that all four peptides significantly dose-dependently inhibited H2O2-induced cellular oxidative stress in HEK-293 cells and increased the survival rate increased from (48.0 ± 2.4)% to (99.7 ± 1.8)%, (69.4 ± 3.2)%, (78.9 ± 5.1)%, and (72.1 ± 3.6)% at 1.0 μmol/L concentration, respectively. These changes were statistically significant (P < 0.01). 2’,7’-Dichlorofluorescin diacetate (DCFH-DA) fluorescent probe assay proved that all these peptides inhibited oxidative stress by reducing intracellular ROS accumulation in HEK293 cells. They dose-dependently increased the activity of total superoxide dismutase (T-SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) in HEK293 cells. In addition, the results of enzyme-linked immune sorbent assay (ELISA) showed that WNWAD and WN up-regulated IL-8 secretion (P < 0.05). All the above results showed that the egg white-derived peptides play a positive role in protecting HEK293 cells against H2O2-induced oxidative stress and improving antioxidant capacity in HEK293 cells.

Key words: egg white-derived peptide, HEK293 cell, reactive oxygen species content, antioxidant enzyme system, cytokines