Screening and identification of novel anti-inflammatory peptides from sea cucumber gonads: In silico and in vitro analysis

This study identified three novel anti-inflammatory peptides from sea cucumber gonad hydrolysates: GDRGF, FDGPEGPRGPPGSEGRQG, and PSNLGTGLR. In vitro experiments demonstrated that these peptides, at concentrations ranging from 25 to 400 μg/mL, exhibited no cytotoxicity toward RAW264.7 macrophages and significantly promoted cell proliferation (P < 0.05). In an lipopolysaccharide (LPS)-induced inflammation model, all three peptides markedly suppressed the secretion of nitric oxide (NO) and pro-inflammatory cytokines (P < 0.05), with GDRGF exhibiting the highest NO inhibition rate of 62.89%. Molecular docking results confirmed that the three peptides interact with Toll-like receptors 2 and 4 receptors via hydrogen bonding and hydrophobic interactions. Analysis of key residues suggested that internal or C-terminal arginine (R) may enhance anti-inflammatory activity by inhibiting NO production and blocking LPS signaling pathways. This study provides an efficient screening strategy for marine-derived anti-inflammatory peptides and lays a theoretical foundation for developing anti-inflammatory functional foods from sea cucumber gonads.