Identification of a novel peptide with anti-inflammatory activity from Binglangjiang buffalo fermented milk and its potential inhibitory mechanism in lipopolysaccharide-stimulated RAW264.7 cells

Binglangjiang buffalo fermented milk (BBFM) is rich in bioactive peptides and exhibits significant immunomodulatory activity, although the specific components and effects are not well understood. In this study, we investigated the anti-inflammatory activity peptides from BBFM using peptidomics and proteomics. A total of 769 peptides were identified using LC-MS/MS, Among these, a novel peptide (GPGAPADPGRPTG (GG13)), was screened out using LPS-stimulated RAW264.7 cells. The molecular weight of peptide GG13 was 1149.56 Da, and it exhibited high in-vitro safety and thermal stability. Furthermore, ELISA and Western blot analysis showed that peptide GG13 significantly inhibited the secretion of pro-inflammatory cytokines NO and TNF-α, as well as the expression of proteins iNOS and TNF-α in LPS-stimulated RAW264.7 cells, and proteomics analysis showed that peptide GG13 significantly down-regulated the protein expression of STAT1, NOS2, COX2, and CD40. The study provides a basis for further explore the development of health fermented milk products. •A peptide with potential anti-inflammatory activity (GPGAPADPGRPTG) was discovered.•The identified peptide GG13 showed high in vitro safety and heat resistance.•Peptide GG13 suppressed iNOS and TNF-α expression in inflammatory macrophages.•Peptide GG13 anti-inflammatory mechanism involves JAK-STAT and CD40/NF-κB pathways.•Peptide GG13, which can regulate the polarization of M1-type cells, was prepared.