Abstract: In order to evaluate the antioxidant activity of peptide fractions from Moringa oleifera, peptides from Moringa oleifera leaves (MOL-P) and seeds (MOS-P) were prepared by enzymatic hydrolysis followed by fractional ethanol precipitation. A D-galactose-induced aging mouse model was established to assess the effects of administration with MOL-P and MOS-P at low and high doses (200 and 500 mg/(kg mb·d) by gavaging for 8 weeks on body mass, liver and brain indices, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities and malondialdehyde (MDA) levels in serum, liver and brain of aging mice. The results indicated that MOL-P and MOS-P could restore brain indices close to normal (P > 0.05). Compared with the model group, both of them could significantly improve GSH-Px activity in serum and SOD activity in liver (P < 0.05), and reduce MDA levels in serum, liver and brain. Low-dose MOL-P and high-dose MOS-P had the best effects on improving GSH-Px activity in serum (higher than that of the model group by 35.80% and 36.97%, respectively). MOS-P had the best effect on the improvement of liver SOD activity, at high and low doses increasing liver SOD activity by 26.08% and 34.20% compared with the model group, respectively. MOL-P and MOS-P both at high dose showed the strongest inhibitory effects on lipid peroxidation in brain tissue (MDA levels were lower than that of the model group by 41.28% and 44.95%, respectively). In addition, MOL-P was able to reduce MDA levels in serum and liver to the normal level (P > 0.05). Both MOL-P and MOS-P could effectively alleviate oxidative damage in liver caused by D-galactose as evaluated by hematoxylin-eosin (HE) staining. Therefore, the peptides from Moringa oleifera leaves and seeds can antagonize oxidative stress in vivo and have good anti-aging effects, making them potential functional ingredients in anti-aging foods.

Key words: Moringa oleifera leave, Moringa oleifera seeds, peptide, oxidative stress, anti-aging