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Oral Administration of Methysticin Improves Cognitive Deficits in a Mouse Model of Alzheimer's Disease

Athanassios Fragoulis, Stephanie Siegl, Markus Fendt, Sandra Jansen, Ulf Soppa, Lars-Ove Brandenburg, Thomas Pufe, Joachim Weis, Christoph Jan Wruck

Redox Biol. 2017 Aug;12:843-853.

PMID: 28448946

Abstract:

Introduction:
There is increasing evidence for the involvement of chronic inflammation and oxidative stress in the pathogenesis of Alzheimer's disease (AD). Nuclear factor erythroid 2-related factor 2 (Nrf2) is an anti-inflammatory transcription factor that regulates the oxidative stress defense. Our previous experiments demonstrated that kavalactones protect neuronal cells against Amyloid β (Aβ)-induced oxidative stress in vitro by Nrf2 pathway activation. Here, we tested an in vivo kavalactone treatment in a mouse model of AD.
Methods:
The kavalactone methysticin was administered once a week for a period of 6 months to 6 month old transgenic APP/Psen1 mice by oral gavage. Nrf2 pathway activation was measured by methysticin treatment of ARE-luciferase mice, by qPCR of Nrf2-target genes and immunohistochemical detection of Nrf2. Aβ burden was analyzed by CongoRed staining, immunofluorescent detection and ELISA. Neuroinflammation was assessed by immunohistochemical stainings for microglia and astrocytes. Pro-inflammatory cytokines in the hippocampus was determined by Luminex multi-plex assays. The hippocampal oxidative damage was detected by oxyblot technique and immunohistochemical staining against DT3 and 4-HNE. The cognitive ability of mice was evaluated using Morris water maze.
Results:
Methysticin treatment activated the Nrf2 pathway in the hippocampus and cortex of mice. The Aβ deposition in brains of methysticin-treated APP/Psen1 mice was not altered compared to untreated mice. However, methysticin treatment significantly reduced microgliosis, astrogliosis and secretion of the pro-inflammatory cytokines TNF-α and IL-17A. In addition, the oxidative damage of hippocampi from APP/Psen1 mice was reduced by methysticin treatment. Most importantly, methysticin treatment significantly attenuated the long-term memory decline of APP/Psen1 mice.
Conclusion:
In summary, these findings show that methysticin administration activates the Nrf2 pathway and reduces neuroinflammation, hippocampal oxidative damage and memory loss in a mouse model of AD. Therefore, kavalactones might be suitable candidates to serve as lead compounds for the development of a new class of neuroprotective drugs.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
AP495852-A Methysticin Methysticin 495-85-2 Price
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