Purification and Characterization of Anti-Inflammatory Peptide Fractions from Enzymatic Hydrolysate of Abalone Viscera

Roughly 25% of abalone viscera generated during processing is currently discarded, resulting in substantial protein wastage and environmental contamination. In the present study, abalone viscera served as the raw material; four commercial proteases-papain, bromelain, neutral protease and trypsin-were comparatively evaluated. Among them, the neutral-protease hydrolysate of abalone viscera (AVZH) exhibited the strongest suppression of nitric oxide (NO) release from lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. Liquid chromatography with tandem mass spectrometry (LC-MS/MS) analysis ultimately led to the identification of 18 novel peptides. Integrating bioinformatic prediction with solid-phase synthesis, two sequences-GYSFTTTAER and IKKPPQDEWGTGL-were further screened and confirmed to possess excellent cytocompatibility and pronounced anti-inflammatory potency. Mechanistic investigations revealed that both peptides dose-dependently attenuated the secretion and mRNA expression of IL-1β, IL-6 and TNF-α and concurrently blocked mitogen-activated protein kinase (MAPK) signaling by down-regulating the phosphorylation of ERK, JNK and p38. These findings demonstrate that abalone viscera represent an abundant reservoir of anti-inflammatory peptides, offering both a theoretical framework and a technological roadmap for the valorisation of marine waste proteins and the development of next-generation natural anti-inflammatory agents.