Identification of antioxidant peptides from a bioactive peptide database PWDB of walnut family protein hydrolysates

This study established Walnut family Peptide DataBase (PWDB), a comprehensive peptide database containing 3894 high-confidence peptides derived from walnut family hydrolysates through LC-MS/MS (<3 kDa) coupled with advanced bioinformatic validation. Screening of PWDB identified three core antioxidant peptides-WDPFE, FDPFP, and WDPNY-with significant free radical scavenging abilities and protective effects against oxidative stress. Molecular docking simulation revealed strong interactions between these peptides and key antioxidant receptors Kelch-like ECH-associated protein 1 (Keap1), Myeloperoxidase (MPO), and Xanthine Oxidase (XO), supporting their multi-target antioxidative potential. In vitro assays using Caco-2 cells models confirmed their ability to mitigate oxidative damage in enhancing cellular viability and reducing reactive oxygen species (ROS). This study highlights walnut family as a sustainable source of bioactive peptides, providing a valuable resource for developing natural antioxidants for functional foods.