Ultrasound-assisted enzymatic extraction improves the antiinflammatory activity of red dragon fruit peel pectin

Background/aim: Inflammatory bowel disease is a chronic inflammatory disorder characterized by excessive immune activation, primarily mediated by nitric oxide and proinflammatory cytokines. This condition encompasses ulcerative colitis and Crohn's disease, both of which significantly impair patients' quality of life and pose persistent challenges in clinical management. Pectin, a complex carbohydrate found in plant cell walls, has shown promise in reducing inflammation. Materials and methods: In this study, pectin was extracted from red dragon fruit peel using two methods: ultrasound-assisted extraction and ultrasound-assisted enzymatic extraction. The structural characteristics and antiinflammatory effects of the extracted pectin were evaluated in lipopolysaccharide-stimulated RAW 264.7 macrophages. Results: Ultrasound-assisted enzymatic extraction produced pectin with a higher yield (19.38%), a lower degree of esterification (46.51%), a reduced molecular weight (94.67 kDa), and a greater galacturonic acid content (67.51%) compared with ultrasound extraction alone. Both pectin preparations were noncytotoxic to RAW 264.7 macrophages and significantly reduced nitric oxide production and the expression of key inflammatory mediators. Structural analysis confirmed the integrity of the pectin molecules. Conclusion: These findings suggest that ultrasound-assisted enzymatic extraction enhances the physicochemical properties and antiinflammatory activity of pectin, thereby supporting its potential application in future studies targeting inflammatory bowel disease.