Novel Antiphotoaging Peptides from Bovine Ligamentum Nuchae Proteins Hydrolysates: Based on Sprague–Dawley Rat Model and Molecular Docking

This study identified novel antiphotoaging peptides from bovine ligamentum nuchae proteins hydrolysates (BLPs) and clarified their molecular mechanisms in photoaging SD rats. Initially, BLPs effectively alleviated photoaging manifestations. Biochemically, BLPs significantly reduced the oxidative stress and suppressed the phosphorylation levels of p38, JNK, and ERK in the mitogen-activated protein kinase pathway. Simultaneously, BLPs dramatically downregulated the hyperactivation of the nuclear factor kappa B pathway and reduced the inflammatory cytokines accordingly (P < 0.05). Moreover, two peptide fragments with the highest antioxidant capacity in separated fractions were identified with ultraperformance liquid chromatography–tandem mass spectrometry, with the sequences of Gly-Leu-Pro-Tyr and Gly-Pro-Gly-Gly-Val-Gly-Ala-Leu. Subsequently, molecular docking revealed that the identified peptides established strong binding affinity to the four oxidation-sensitive cysteine residues in the active sites of MMP-1 mainly by hydrogen bonding and hydrophobic interactions. Collectively, this study demonstrates that BLPs exert potent photoprotection by synergistically targeting oxidative stress and MMP-1 active sites.