Potential mechanisms mediating the protective effects of a peptide from walnut (Juglans mandshurica Maxim.) against hydrogen peroxide induced neurotoxicity in PC12 cells

Food Funct. 2019 Jun 19;10(6):3491-3501. doi: 10.1039/c8fo02557f.

Abstract

Amelioration of oxidative stress has been the main approach to improve neurodegenerative disorders. In the present study, a walnut peptide with a strong capacity of scavenging reactive oxygen species (ROS) was purified and identified as EVSGPGLSPN by SEC, RP-HPLC, and HPLC-MS/MS. Treatment with EVSGPGLSPN could significantly (P < 0.05) reduce ROS generation, and increase cell viability, and superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-px) activities in a dose-dependent manner in hydrogen peroxide induced PC12 cells. Western blot and immunofluorescence analysis showed that EVSGPGLSPN suppressed the expression of IKKβ and p65 to inhibit NF-κB pathway activation, attenuating the neurotoxic cascade by overexpression of IL-1β and TNF-α. Moreover, EVSGPGLSPN inhibited apoptosis by suppressing the expression of cytochrome C, caspase-9, caspase-3, and PARP. Additionally, it also up-regulated the expression of p-CREB and synaptophysin in oxidatively damaged PC12 cells. Thus, EVSGPGLSPN may protect against hydrogen peroxide induced neurotoxicity by enhancing the activity of antioxidant enzymes and blocking the NF-κB/caspase pathways.

MeSH terms

  • Animals
  • Antioxidants / metabolism
  • Apoptosis / drug effects
  • Caspases / genetics
  • Caspases / metabolism
  • Catalase / genetics
  • Catalase / metabolism
  • Hydrogen Peroxide / toxicity*
  • Juglans / chemistry*
  • NF-kappa B / genetics
  • NF-kappa B / metabolism
  • Neurons / cytology
  • Neurons / drug effects*
  • Neurons / metabolism
  • Oxidative Stress / drug effects
  • PC12 Cells
  • Peptides / pharmacology*
  • Plant Extracts / pharmacology*
  • Protective Agents / pharmacology*
  • Rats
  • Reactive Oxygen Species / metabolism
  • Superoxide Dismutase / genetics
  • Superoxide Dismutase / metabolism

Substances

  • Antioxidants
  • NF-kappa B
  • Peptides
  • Plant Extracts
  • Protective Agents
  • Reactive Oxygen Species
  • Hydrogen Peroxide
  • Catalase
  • Superoxide Dismutase
  • Caspases