Peptides Released from Extruded Adzuki Bean Protein through Simulated Gastrointestinal Digestion Exhibit Anti-inflammatory Activity

Increasing attention has been focused
on plant-derived peptides
because of their potential bioactivities. In this study, bioactive
peptides were released from extruded adzuki bean protein by simulated
gastrointestinal digestion. A peptide (KQS-1) sequenced as KQSESHFVDAQPEQQQR
was separated and identified using ultrafiltration, pre-high-performance
liquid chromatography (HPLC), and ultraperformance liquid chromatography-tandem
mass spectrometry (UPLC-MS/MS). KQS-1 was shown to exert significant
anti-inflammatory effects in lipopolysaccharide (LPS)-induced RAW
264.7 macrophages by reducing the production of IL-1, IL-6, TNF-α,
and MCP-1 to 38.31, 6.07, 43.96, and 41.74%, respectively. The involved
signaling pathways were identified by transcriptome analysis. Overall,
5236 differentially expressed genes (DEGs) were identified. Gene ontology
(GO) functions demonstrated that DEGs were significantly related to
the NF-κB pathway. In conclusion, KQS-1 prevented the activation
and expression of NF-κB/caspase-1 by upstream and downstream
factors. These findings highlight the bioactivity of adzuki bean peptides.