title: Antioxidant Peptides Identified from Ovotransferrin by the ORAC Method Did Not Show Anti-Inflammatory and Antioxidant Activities in Endothelial Cells.
abstract: Oxygen radical absorbance capacity (ORAC) is a widely used method of measuring antioxidant capacities of various antioxidant components. Surprisingly, 16 antioxidant peptides previously identified from egg protein ovotransferrin using the ORAC method did not show any anti-inflammatory and antioxidant activities in cells. After simulated gastro-intestinal digestion (GID), several peptide digests significantly reduced the expression of tumor necrosis factor-α (TNF-α)-induced pro-inflammatory intercellular cell adhesion molecule-1 (ICAM-1) by 65.7 ± 10.4% and vascular cell adhesion molecule-1 (VCAM-1) by 53.5 ± 9.6% to 61.0 ± 14.5%, but only GWNI reduced TNF-α-activated superoxide generation by 71.0 ± 12.9% when tested with dihydroethidium (DHE) assay. Mass spectrometer analysis identified two new peptides, GWN and GW, in the GWNI digest; however, only GW reduced TNF-α-induced VCAM-1 expression (64.3 ± 20.6%) significantly compared to the TNF-α treated cells. Our study suggested that ORAC lacked biological relevance in assessing bioactive peptides.
authors.affiliation: Department of Agricultural, Food and Nutritional Science, ‡Department of Obstetrics and Gynecology, §Department of Physiology, ∥Cardiovascular Research Centre and ⊥Women and Children's Health Research Institute, University of Alberta , Edmonton, Alberta T6G 2P5, Canada.
authors.forename: Forough
authors.initials: F
authors.lastname: Jahandideh
authors.affiliation: Department of Agricultural, Food and Nutritional Science, ‡Department of Obstetrics and Gynecology, §Department of Physiology, ∥Cardiovascular Research Centre and ⊥Women and Children's Health Research Institute, University of Alberta , Edmonton, Alberta T6G 2P5, Canada.
authors.forename: Subhadeep
authors.initials: S
authors.lastname: Chakrabarti
authors.affiliation: Department of Agricultural, Food and Nutritional Science, ‡Department of Obstetrics and Gynecology, §Department of Physiology, ∥Cardiovascular Research Centre and ⊥Women and Children's Health Research Institute, University of Alberta , Edmonton, Alberta T6G 2P5, Canada.
authors.forename: Sandra T
authors.initials: ST
authors.lastname: Davidge
authors.affiliation: Department of Agricultural, Food and Nutritional Science, ‡Department of Obstetrics and Gynecology, §Department of Physiology, ∥Cardiovascular Research Centre and ⊥Women and Children's Health Research Institute, University of Alberta , Edmonton, Alberta T6G 2P5, Canada.
authors.forename: Jianping
authors.initials: J
authors.lastname: Wu
mesh_terms: D000893:Anti-Inflammatory Agents / Q000737:chemistry / Q000494:pharmacology*; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D003207:Conalbumin / Q000737:chemistry*; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism; D019010:Vascular Cell Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism
chemical_list: D000893:Anti-Inflammatory Agents; D000975:Antioxidants; D010455:Peptides; D017382:Reactive Oxygen Species; D014409:Tumor Necrosis Factor-alpha; D019010:Vascular Cell Adhesion Molecule-1; D018799:Intercellular Adhesion Molecule-1; D003207:Conalbumin
keywords: anti-inflammatory; antioxidant; endothelial cells; gastro-intestinal digestion; ovotransferrin peptides