Marine Collagen Peptide Fraction from Lutjanus erythropterus Scales: A Multifunctional Bioactive for Intestinal Barrier Protection and Redox Modulation in Ulcerative Colitis.

Low-molecular-weight collagen peptides from food processing byproducts offer a sustainable approach to mitigating intestinal inflammation, yet their mechanistic roles remain incompletely understood. We evaluated red fish scale collagen peptides-I (LSCP-I), a <3 kDa collagen peptide fraction derived from Lutjanus erythropterus scales, in cellular and murine models of colitis. In Caco-2 cells subjected to macrophage-mediated inflammatory injury, LSCP-I (50 µg/mL) increased proliferation by 35%, enhanced migration by 40%, preserved barrier integrity, reduced reactive oxygen species (ROS) by 45%, decreased lipid peroxidation by 30%, and restored glutathione (GSH) and superoxide dismutase (SOD) activity. In mice with dextran sulfate sodium (DSS)-induced colitis, oral administration of LSCP-I at 200, 400 and 800 mg/kg/day attenuated weight loss and diarrhea, lowered intestinal permeability by 38%, enhanced colon histology, and restored the balance between pro- and anti-inflammatory cytokines. Mechanistically, LSCP-I activated the Nrf2 antioxidant pathway and partially restored gut microbiota composition. These results demonstrate that LSCP-I reinforces intestinal barrier function, restores redox homeostasis, and modulates host-microbiota interactions, establishing its potential as a functional food ingredient for the prevention and management of inflammatory bowel disease.