Preparation of ovomucin glycopeptides and their immunomodulatory effects on macrophages based on metabolomics

Ovomucin glycopeptides (OVMG) are glycosylated peptides generated from the digestive degradation of chicken egg white ovomucin, yet their functional activities remain to be investigated. In this study, OVMG was prepared via simulated digestion combined with affinity chromatography. The immunomodulatory activity of OVMG was evaluated by measuring its effects on NO and TNF- α secretion in macrophages, and metabolomics analysis was applied to explore its underlying regulatory mechanism. Results showed that OVMG was non-cytotoxic at 25-800 μg/mL and promoted NO and TNF- α secretion in a dose-dependent manner at 6.25-50 μg/mL. Furthermore, the TNF- α secretion levels in macrophages stimulated with 25 and 50 μg/mL OVMG were similar to those induced by 100 ng/mL LPS. Metabolomics analysis revealed that 180 and 225 differential metabolites (DMs) were identified in the L-OVMG (6.25 μg/mL) and H-OVMG (25 μg/mL) groups, respectively, compared with the control group. These DMs primarily belonged to the classes of amino acid and its metabolites, glycerophospholipids, and fatty acids. Metabolic pathway analysis indicated that the immunomodulatory effect of OVMG might be closely associated with the remodeling of lipid, amino acid, and energy metabolism in macrophages. These findings provide a theoretical basis for developing OVMG as an immune-active component and facilitating its application in functional foods.