The Potential Neuroprotective Effects of Extracts from Oat Seedlings against Alzheimer's Disease

Nutrients. 2022 Oct 2;14(19):4103. doi: 10.3390/nu14194103.

Abstract

The physiological or dietary advantages of germinated grains have been the subject of numerous discussions over the past decade. Around 23 million tons of oats are consumed globally, making up a sizeable portion of the global grain market. Oat seedlings contain more protein, beta-glucan, free amino acids, and phenolic compounds than seeds. The progressive neurodegenerative disorder of Alzheimer's is accompanied by worsening memory and cognitive function. A key indicator of this disorder is the unusual buildup of amyloid-beta protein (or Aβ) in human brains. In this context, oat seedling extract (OSE) has been identified as a new therapeutic candidate for AD, due to its antioxidant activity and AD-specific mechanism of action. This study directly investigated how OSE affected AD and its impacts by examining the cognitive function and exploring the inflammatory response mechanism. The dried oat seedlings were grounded finely with a grinder, inserted with 50% fermented ethanol 10 times (w/v), and extracted by stirring for 10 h at 45 °C. After filtering the extract by 0.22 um filter, some of it was used for UHPLC analysis. The results indicated that the treatment with OSE protects against Aβ25-35-induced cytotoxicity in BV2 cells. Tg-5Xfad AD mice had strong deposition of Aβ throughout their brains, while WT mice did not exhibit any such deposition within their brains. A drastic reduction was observed in terms of numbers, as well as the size, of Aβ plaques within Tg-5Xfad AD mice exposed to OSE. This study indicated OSE's neuroprotective impacts against neurodegeneration, synaptic dysfunction, and neuroinflammation induced by amyloid-beta. Our results suggest that OSE acts as a neuroprotective agent to combat AD-specific apoptotic cell death, neuroinflammation, amyloid-beta accumulation, as well as synaptic dysfunction in AD mice's brains. Furthermore, the study indicated that OSE treatment affects JNK/ERK/p38 MAPK signaling, with considerable inhibition in p-JNK, p-p38, and p-ERK levels seen in the brain of OSE-treated Tg-5Xfad AD mice.

Keywords: Alzheimer’s disease; BACE1; OSE; β-amyloid.

MeSH terms

  • Alzheimer Disease* / metabolism
  • Amino Acids / therapeutic use
  • Amyloid beta-Peptides / metabolism
  • Animals
  • Antioxidants / pharmacology
  • Antioxidants / therapeutic use
  • Avena
  • Disease Models, Animal
  • Ethanol
  • Humans
  • Mice
  • Mice, Transgenic
  • Neuroprotective Agents* / pharmacology
  • Neuroprotective Agents* / therapeutic use
  • Seedlings / metabolism
  • beta-Glucans* / therapeutic use
  • p38 Mitogen-Activated Protein Kinases

Substances

  • Amino Acids
  • Amyloid beta-Peptides
  • Antioxidants
  • Neuroprotective Agents
  • beta-Glucans
  • Ethanol
  • p38 Mitogen-Activated Protein Kinases