Abstract: To investigate the mechanism of the antioxidant action of a peptide from naked oat globulin (PNOG) in D-galactose (D-gal) aging mice, plasma metabolomic fingerprinting of the control, aging model and PNOG-treated mice was performed using ultra-high performance liquid chromatography quadrupole-time-of-flight tandem mass spectrometry (UPLC-Q-TOF MS/MS). The potential biomarkers for the intervention effect of PNOG on aging mice and the related metabolic pathways were determined by principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) combined with variable importance in the projection (VIP) and nonparametric test. The results showed that 17 potential biomarkers in the brain of PNOG-treated mice were identified, including glycerophosphocholine, acetylcarnitine, L-carnitine, adenosine monophosphate, uric acid, S-adenosyl-L-homocysteine, and N-acetylaspartyl-glutamate. The PNOG could regulate 6 metabolic pathways in which the 17 potential biomarkers were involved in aging mice, namely glycerophospholipid metabolism, fatty acid metabolism, biosynthesis of unsaturated fatty acids, purine metabolism, cysteine and methionine metabolism and neuroactive ligand-receptor interaction; and could restore them to the normal level, thereby ameliorating metabolic disorders in aging mice. These results showed the antioxidant and anti-aging activities of PNOG, which would provide reference for further studies on the antioxidant mechanism of naked oat protein-derived peptides.

Key words: naked oat; globulin; peptide; antioxidant; aging; metabolomics