Carboxymethyl β-cyclodextrin-loaded buffalo milk peptide nanoparticles ameliorate DSS-induced intestinal mucosal injury in mice

Buffalo milk-derived active peptides have a variety of important regulatory functions for the body, but their poor oral stability leads to low bioavailability.Herein, in vivo stability of peptides DN8 and YR9 screened from buffalo milk were enhanced using encapsulation, and the effects of these peptides on ameliorating intestinal mucosal injury in mice were investigated.The binding of peptides DN8 and YR9 to CM-CD was mainly through electrostatic adsorption and hydrogen bonding forces to form robust nanoparticles, associated with changes in O-H, C = O, and C-H bonds.The average particle size of NPs CM-CD-DN8 and CM-CD-YR9 were 75.03 nm and 41.71 nm, and the encapsulation rates were 82.513 4.617 and 90.974 0.421, respectively.NP CM-CD-DN8 and CM-CD-YR9 demonstrated stability and nonhemolytic properties at the tested concentrations in vitro, and effectively reduced the secretion of pro-inflammatory cytokines NO, IL-6, and TNF- in LPS-stimulated RAW264.7 cells.Peptides DN8 and YR9 in NPs were released in small amounts in the stomach but rapidly in the intestine.Furthermore, the NPs CM-CD-DN8 and CM-CD-YR9 were found to be effective in attenuating DSS-induced epithelial barrier injury in mice by increasing the expression of Occludin and ZO-1.This research provides insights for the development of oral food-borne active peptides with high bioavailability.