Identification and molecular mechanism of the anti-inflammatory effect of sea cucumber peptides: Network pharmacology, molecular docking and animal experiments.

Ulcerative colitis (UC) is a chronic inflammatory bowel disease for which there is currently no efficacious therapeutic drug with fewer side effects. Therefore, the development of approaches for the prevention of UC from natural food sources is urgently needed. In this study, mice were pre-fed with sea cucumber peptides prior to dextran sodium sulfate (DSS) induction. Results showed that sea cucumber peptides decreased pro-inflammatory cytokine (IL-4 and IL-10) levels and remissions of main clinic symptoms in a dose-dependent manner. The composition of peptides was identified, and the anti-inflammatory molecular mechanism was evaluated by silico prediction. The molecular weight of the peptides was 243-1800 Da and composed of 3-18 amino acid residues. Online activity assessment and molecular docking prediction revealed that tripeptides of FGI, FLI, FLL, GFL, GFM, IGF and LDF exhibited strong anti-inflammatory activity. Particularly, LDF showed the highest potency, with a binding energy of -5.37 kJ/mol. Network pharmacology analysis of UC related diseases indicated that active peptides interact with colitis disease targets, primarily proto-oncogene tyrosine-protein kinase Src (SRC), E3 ubiquitin-protein ligase XIAP (XIAP) and angiotensin-converting enzyme (ACE). The results suggest that sea cucumber peptides have potential as a novel nutraceutical option for colitis relief.