Development of double emulsions loaded with Malus baccata (Linn.) polyphenols and their protective effect on dextran sulfate sodium-induced ulcerative colitis in mice

This study aimed to develop and evaluate W₁/O/W₂ double emulsions for oral delivery of Malus baccata (Linn.) polyphenols (MBP), using MBP-loaded Hohenbuehelia serotina polysaccharides-soybean protein isolate nanoparticles as stabilizers. The emulsions exhibited the typical double-emulsion core–shell structure, shear-thinning behavior and good physicochemical stability, with an apparent overall retention efficiency of 87.41% and an intestinal release rate of 69.43%. Considering structural characteristics and stability, the double emulsions (MHSG DEs) stabilized by the nanoparticles of an SPI/MBP ratio of 1:1 were selected for in vivo evaluation. In ulcerative colitis mice, MHSG DEs intervention increased the body weight by 8.96%, reduced the disease activity index by 33.33%, promoted the tight junction proteins expression by 122.70% and elevated the total short-chain fatty acids by 59.55%, accompanying with improvement of hematological parameters and modulation of gut microbiota. Although the superiorities over other interventions are not confirmed and the underlying mechanisms require further investigation, these findings indicate that MHSG DEs are a potentially promising MBP delivery system.