An Integrated Strategy for the Discovery, Recombinant Expression, and Biological Evaluation of Anti-Inflammatory Peptides from Rice Protein

Rice-derived anti-inflammatory peptides (AIPs) have attracted growing interest as functional food ingredients. However, their low abundance in enzymatic hydrolysates and high synthesis cost limit practical application. This study presents an integrated strategy for efficient screening and biosynthesis of AIPs. Using receptor-based screening, three peptides (PHP1, GPA1, GPD1) were identified as promising inhibitors of inflammatory targets. To address production challenges, a fusion tag system was employed to express PHP1 recombinantly in E. coli, yielding up to 28.5 ± 3 mg/L. The recombinant peptides significantly reduced pro-inflammatory cytokines (TNF-α, IL-1β, IL-6), nitric oxide, and protected RAW264.7 cells from LPS-induced damage. Mechanistically, PHP1 directly interacted with NF-κB1 (K D = 7.631 μmol/L) and significantly suppressed NF-κB1 phosphorylation. The anti-inflammatory efficacy of PHP1 was further validated in a mouse model of systemic inflammation. These findings demonstrate both the anti-inflammatory potential of PHP1 and the viability of its scalable production, supporting its application in functional food development.