International Journal of Molecular Sciences (May 2015)

Chitosan Oligosaccharides Inhibit/Disaggregate Fibrils and Attenuate Amyloid β-Mediated Neurotoxicity

  • Xueling Dai,
  • Wanqi Hou,
  • Yaxuan Sun,
  • Zhaolan Gao,
  • Shigong Zhu,
  • Zhaofeng Jiang

DOI
https://doi.org/10.3390/ijms160510526
Journal volume & issue
Vol. 16, no. 5
pp. 10526 – 10536

Abstract

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Alzheimer’s disease (AD) is characterized by a large number of amyloid-β (Aβ) deposits in the brain. Therefore, inhibiting Aβ aggregation or destabilizing preformed aggregates could be a promising therapeutic target for halting/slowing the progression of AD. Chitosan oligosaccharides (COS) have previously been reported to exhibit antioxidant and neuroprotective effects. Recent study shows that COS could markedly decrease oligomeric Aβ-induced neurotoxicity and oxidative stress in rat hippocampal neurons. However, the potential mechanism that COS reduce Aβ-mediated neurotoxicity remains unclear. In the present study, our findings from circular dichroism spectroscopy, transmission electron microscope and thioflavin T fluorescence assay suggested that COS act as an inhibitor of Aβ aggregation and this effect shows dose-dependency. Moreover, data from thioflavin T assay indicated that COS could significantly inhibit fibrils formation and disrupt preformed fibrils in a dose-dependent manner. Furthermore, the addition of COS attenuated Aβ1-42-induced neurotoxicity in rat cortical neurons. Taken together, our results demonstrated for the first time that COS could inhibit Aβ1-42 fibrils formation and disaggregate preformed fibrils, suggesting that COS may have anti-Aβ fibrillogenesis and fibril-destabilizing properties. These findings highlight the potential role of COS as novel therapeutic agents for the prevention and treatment of AD.

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