Novel peptide inhibitor of matrix Metalloproteinases-1 from pufferfish skin collagen hydrolysates and its potential Photoprotective activity via the MAPK/AP-1 signaling pathway.

Takifugu bimaculatus, a pufferfish species farmed in Fujian Province, is known for its non-toxic flesh and collagen-rich skin. We identified a novel collagen-derived matrix metalloproteinase 1 (MMP-1) inhibitory peptide, from T. bimaculatus skin with potent anti-photoaging properties. Using multistage membrane and gel filtration chromatography, we purified low-molecular-weight collagen peptides from T. bimaculatus skin (TBSCH-L). Nano-HPLC-MS/MS and virtual molecular docking screening were employed to identify peptides targeting MMP-1. Four anti-photoaging peptide sequences, GDRGFPGE, GPAGPRGA, FPGGPGAK, and RGFPGGDGAA, were identified by assessing the viability of UVB-induced L929 cells. GPAGPRGA (GP8) exhibited the highest MMP-1 inhibitory activity and cellular photoprotection. Surface plasmon resonance confirmed high-affinity binding between MMP-1 and GP8. GP8 significantly reduced intracellular reactive oxygen species (ROS) levels and enhanced superoxide dismutase activity at concentrations of 100-200 μM in UVB-exposed L929 cells. At 200 μM, GP8 significantly decreased malondialdehyde content. GP8 also accelerated migration of L929 cells, demonstrating its wound-healing potential, markedly reduced intracellular β-galactosidase levels, and downregulated phosphorylation levels of extracellular signal-regulated kinases, c-Jun N-terminal kinases, p38 proteins, and c-Jun protein expression within the MAPK/AP-1 signaling pathway, thereby lowering MMP expression in L929 cells. Exposure of zebrafish to 25-100 μM GP8 effectively mitigated UVB-induced damage, restoring up to 31.2 % of caudal fin integrity, while significantly reducing ROS levels, lipid peroxidation, and cellular apoptosis. GP8, a novel marine-derived anti-photoaging peptide, holds promise for applications in cosmetic and functional food sectors.