Nanoencapsulation of phycocyanin peptides enhances anti‐inflammatory activity and alleviates ulcerative colitis

BACKGROUND Ulcerative colitis (UC) is a prevalent inflammatory bowel disease, and current medications have considerable side effects. Phycocyanin peptides (PCPs) have demonstrated anti‐inflammatory potential; however, their clinical application is limited by poor stability and low bioavailability. This study prepared highly active PCPs via ultrasound‐assisted enzymatic hydrolysis and used chitosan‐sodium tripolyphosphate nanoencapsulation to improve their application performance. RESULTS PCPs significantly inhibited nitric oxide release in lipopolysaccharide‐induced RAW264.7 cells. The encapsulation efficiency of phycocyanin peptide nanoparticles (PCP‐NPs) reached 91.33%, with markedly enhanced gastrointestinal stability and bioavailability. In mouse experiments, PCP‐NPs reduced the disease activity index of ulcerative colitis mice, repaired colonic injury, down‐regulated pro‐inflammatory cytokines, and up‐regulated anti‐inflammatory cytokines and intestinal tight junction proteins. Three core anti‐inflammatory peptides, YAINA, FPYTT, and YVTYA, were isolated and identified. CONCLUSION Nanoencapsulation strengthens the anti‐inflammatory activity and intestinal barrier repair capacity of PCPs, which hold promising application potential as functional food ingredients for ulcerative colitis prevention.