title: Anti-oxidative and anti-apoptosis effects of egg white peptide, Trp-Asn-Trp-Ala-Asp, against H2O2-induced oxidative stress in human embryonic kidney 293 cells.
abstract: Peptides derived from egg white protein are well-known for their abundant species and biological properties. The aim of this study was to investigate the anti-oxidative and anti-apoptosis effects of (Trp-Asn-Trp-Ala-Asp) WNWAD, a pentapeptide derived from egg white ovomucin pepsin hydrolysates, against the oxidative stress induced by H2O2 in HEK-293 cells. Oxygen radical absorbance capacity (ORAC) results showed that WNWAD possessed extraordinary oxygen radical absorption capacity (with an ORAC value = 2.91 μM TE μM(-1)) in vitro. Then, at the cellular level, MTS assay results displayed that WNWAD dose-dependently inhibited H2O2-induced cellular oxidative stress in HEK-293 cells and fully recovered the oxidative damage induced by 400 μM H2O2 at a concentration of 1 μM. The 2',7'-dichlorofluorescein diacetate (DCFH-DA) fluorescent probe assay further proved that WNWAD inhibited cellular oxidative stress by reducing intracellular ROS accumulation in intact HEK-293 cells. In addition, scanning electron microscopy (SEM) images showed that the morphology of HEK-293 cells under H2O2 treatment displayed a cell apoptosis phenotype, while WNWAD pretreatment prevented the development of this phenotype. Furthermore, Western blot results indicated that WNWAD up-regulated the level of the anti-apoptotic protein Bcl-2 and down-regulated the levels of apoptosis executor proteins, cleaved caspase-3 and cleaved PRAP, in H2O2-induced oxidative stress in HEK-293 cells. All the above results suggested that WNWAD protected HEK-293 cells against H2O2-induced oxidative stress by inhibiting intracellular ROS accumulation and blocking the ROS activated mitochondria-mediated cell apoptosis pathway.
authors.affiliation: Laboratory of Nutrition and Functional Food, Jilin University, Changchun 130062, PR China.
authors.forename: Jingbo
authors.initials: J
authors.lastname: Liu
authors.forename: Zhifei
authors.initials: Z
authors.lastname: Chen
authors.forename: Jing
authors.initials: J
authors.lastname: He
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Ting
authors.initials: T
authors.lastname: Zhang
authors.forename: Yiqun
authors.initials: Y
authors.lastname: Jiang
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D002642:Chick Embryo; D004529:Egg White / Q000737:chemistry*; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D006861:Hydrogen Peroxide / Q000009:adverse effects; D007668:Kidney / Q000166:cytology / Q000187:drug effects* / Q000196:embryology / Q000378:metabolism; D010059:Ovomucin / Q000737:chemistry*; D018384:Oxidative Stress / Q000187:drug effects*; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D000975:Antioxidants; D010455:Peptides; D017382:Reactive Oxygen Species; D010059:Ovomucin; D006861:Hydrogen Peroxide