Investigation of the Antioxidative Potential of Meretrix Meretrix L. Derived Peptides from Simulated Gastrointestinal Digestion: in Vitro and in Silico Insights

This investigation sought to identify antioxidative peptides derived from Meretrix meretrix L. (MML) throughout simulated gastrointestinal digestion (SGD) via in vitro and in silico strategies. The study demonstrated that hydrolysates from MML captured at various SGD phases showcased robust antioxidative activity. These hydrolysates also displayed a protective role against hydrogen peroxide-induced stress in Raw 264.7 cells. Notably, hydrolysates sourced from the intestinal phase of digestion (MMLHs-I) markedly inhibited the reduction of cell viability, limited the generation of reactive oxygen species under oxidative stress conditions, and promoted the activity of key antioxidant enzymes including superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase, thus amplifying the cells' antioxidative defense system. Through nLC-MS/MS analysis, 105 peptides tracing back to 18 parent proteins were pinpointed in MMLHs-I, with 18 of these peptides previously reported in the BIOPEP-UWM database. Subsequent in silico analysis, alongside empirical antioxidant activity assays, pinpointed the peptide WLV as an exceptional antioxidative agent, demonstrating an IC50 of 0.125 mg/mL in the ABTS assay and an impressive 15.18 mu mol Trolox/mg in the ORAC assay. The outcomes highlight MML's promise as a novel source of antioxidative peptides, positioning peptide WLV as a potentially valuable addition to functional foods designed to combat oxidative stress.