Ovalbumin peptides exert bidirectional immunomodulatory activity in vivo via regulating cytokines and antioxidant capacity

The ideal immunomodulatory peptides should possess both immune-enhancing and anti-inflammatory properties. This study investigated the bidirectional immunomodulatory activity of ovalbumin peptides (OVAP) using immunocompromised and inflammatory mice models integrated with network pharmacology and molecular docking. OVAH, prepared by simultaneous hydrolysis with alkaline protease and papain, exhibited the highest degree of hydrolysis (38.44 ± 0.38%), the greatest RAW264.7 cells proliferation rate (159.71 ± 1.55%) and the lowest molecular weight (60% of fragments <500 Da). In vivo experiments, OVAP ameliorated spleen and thymus damage and atrophy in cyclophosphamide-induced immunocompromised mice by reducing lipid oxidation and enhancing total antioxidant capacity to resist oxidative stress. It also upregulated the level of immune cells (WBC, Gran, and Lymph), cytokine (IL-10, IL-6, and IFN-γ), and immunoglobulin (IgA and IgG). Simultaneously, pretreatment with OVAP effectively mitigated inflammatory response by suppressing oxidative stress and the release of inflammatory cytokines (IL-6, TNF-α and IFN-γ) in lipopolysaccharide-induced inflammatory mice. Network pharmacology analysis predicted that the core targets through which main component of OVAP (RYPILPE) exerted bidirectional immunomodulatory activity were STAT3, EGFR, TLR4, and NFKB1, involving chemokine signaling pathway, TNF signaling pathway, and PI3K-Akt signaling pathway. Molecular docking suggested the stable binding affinity between OVAP main peptide and above-mentioned targets (binging energy<−6 kcal/mol). In summary, OVAP maintained immune homeostasis through multi-component, multi-target and multi-pathway mechanisms.