Rice Protein Peptides\nAmeliorate DSS-Induced Cognitive\nImpairment and Depressive Behavior in Mice by Modulating Phenylalanine\nMetabolism and the BDNF/TRKB/CREB Pathway

Rice\nprotein peptide (RPP) has been reported to alleviate the symptoms\nof dextran sulfate sodium (DSS)-induced colitis, but its potential\nprotective effect and fundamental neurobiological mechanisms against\nDSS-induced inflammatory bowel disease (IBD), coupled with depression\nand cognitive impairment, remain unclear. In this study, RPP treatment\nin DSS-induced mice inhibited decreases in body weight and colon length\nand improved intestinal barrier function and behavioral performance.\nRPP treatment enhanced phenylalanine and tyrosine metabolism in the\nbrains of mice, and it upregulated metabolites such as l-dopa,\nphenylethylamine, and 3,4-dihydroxyphenylacetate. Additionally, RPP\ntreatment enhanced the brain-derived neurotrophic factor (BDNF) by\nupregulating the BDNF/TrkB/CREB signaling pathway. Spearman’s\ncorrelation analysis revealed that the phenylalanine and tyrosine\ncontents in the brain were significantly negatively correlated with\nthe BDNF/TrkB/CREB signaling pathway and behavioral performance. In\nconclusion, this study suggested that RPP may serve as a unique nutritional\nstrategy for preventing IBD and its associated cognitive impairment\nand depression symptoms.