Docynia delavayi fruit polysaccharides alleviate DSS-induced ulcerative colitis via oxidative stress suppression in Drosophila model.

This study systematically investigates the polysaccharides from Docynia delavayi fruits, focusing on their extraction, composition, antioxidant capacity, and protective effects against intestinal damage using a DSS-induced ulcerative colitis (UC) Drosophila model. Employing a combination of hot water extraction and graded alcohol precipitation, distinct polysaccharide fractions (DDP-40, DDP-60, DDP-80) were obtained and characterized. The total sugar contents of DDP-40, DDP-60, and DDP-80 were 63.1%, 75.0%, and 45.0%; reducing sugar contents were 16.7%, 19.9%, and 5.7%; uronic acid contents were 6.8%, 4.6%, and 1.5%, and protein content was 2.5%, 1.3%, and 1.8%, respectively. The primary monosaccharides of D. delavayi fruit polysaccharides are galactose, arabinose and mannose. In vitro antioxidant assays revealed that DDP-60 showed stronger DPPH and ABTS radical scavenging, whereas DDP-40 had greater ferric reducing power. In a DSS-induced Drosophila model, all polysaccharide fractions significantly improved survival, mitigated gut shortening, reduced epithelial permeability, and significantly inhibited intestinal epithelial cell death and ROS accumulation. This study provided novel insights into the structure-function relationship of D. delavayi fruit polysaccharides and their protective roles in ameliorating intestinal damage, laying a theoretical foundation for their potential development as natural therapeutic agents against UC and related intestinal disorders.