Unveiling novel antioxidant peptides from silver carp (Hypophthalmichthys molitrix) bone collagen and underlying multi-dimensional mechanism by integrating in silico, in vitro, and in cellulo approaches

This work has achieved, for the first time, the unveiling of novel antioxidant peptides from silver carp bone collagen (SCBC) and their underlying multi-dimensional mechanism by integrating in silico , in vitro , and in cellulo approaches. AEDVN, EDDR, and DVEL were identified from SCBC with good DPPH · -scavenging activity (IC 50 = 0.89–2.59 mM), strong Fe 2+ -chelating ability (IC 50 = 0.98–3.72 mM), and high stability against simulated gastrointestinal digestion. The acylamino, guanidinium, and N-terminal amino groups can be their dominant redox active sites, respectively. They could form strong hydrogen bonds and electrostatic attractions with core residues (such as ARG380, ARG415, and ARG483) of Kelch domain within Keap1, thereby activating the Keap1-Nfr2-ARE antioxidant pathway. Therefore, the activities of superoxide dismutase, catalase, and glutathione peroxidase were significantly increased, resulting in the malondialdehyde reduction and cell viability improvement against H 2 O 2 -induced oxidative damage. These findings provided a cost-effective and time-saving strategy for high-value utilization of fish by-product bones as natural antioxidant sources.