The porcine bone collagen-derived peptides suppressed the low-grade chronic inflammation via restraining calcium-sensing receptor in RAW264.7 cells

In the current study, the anti-inflammatory capacity of porcine bone collagen peptides (PBPs) was investigated in RAW264.7 cells. During the simulated digestion process, the PBPs showed a significant inhibiting effect on the secretion of tumor necrosis factor-α (TNF-α), and nitric oxide (NO) in RAW264.7 cells. The PBPs (10 μg/mL) significantly decreased the Ca 2+ fluorescence intensity compared with the lipopolysaccharide (LPS) induced group. Furthermore, the anti-inflammatory peptide sequences were selected according to the binding property with the CaSR, among which the GPTGF (Gly-Pro-Thr-Gly-Phe) showed a significant inflammatory regulating effect and also checked to be transported in Caco-2 monolayer cells. Compared with the Cinacalcet-treated group, the GPTGF posed to suppress the CaSR and then inhibited the mRNA expressions of TNF-α, and interleukin-6 (IL-6). Generally, the PBPs were demonstrated to suppress the inflammatory response in RAW264.7 cells by inhibiting CaSR as the major pathway to exert the anti-inflammatory effect. • The anti-inflammatory stability of porcine bones peptides (PBPs) was investigated. • The potential calcium-sensing receptor (CaSR) inhibitory peptides were identified. • Peptide (GPTGF) showed high anti-inflammatory activity in RAW264.7 cells. • The GPTGF regulated the mRNA expression of inflammatory factors caused by CaSR activation.