Inhibition of alpha-synuclein seeded fibril formation and toxicity by herbal medicinal extracts

Mustafa T. Ardah, Simona S. Ghanem, Sara A. Abdulla, Guohua Lv, Mohamed M. Emara, Katerina E. Paleologou, Nishant N. Vaikath, Jia Hong Lu, Min Li, Konstantinos Vekrellis, David Eliezer, Omar M. A. El-Agnaf*

*Corresponding author for this work

Research output: Contribution to journalJournal articlepeer-review

23 Citations (Scopus)



Recent studies indicated that seeded fibril formation and toxicity of α-synuclein (α-syn) play a main role in the pathogenesis of certain diseases including Parkinson's disease (PD), multiple system atrophy, and dementia with Lewy bodies. Therefore, examination of compounds that abolish the process of seeding is considered a key step towards therapy of several synucleinopathies. 


Using biophysical, biochemical and cell-culture-based assays, assessment of eleven compounds, extracted from Chinese medicinal herbs, was performed in this study for their effect on α-syn fibril formation and toxicity caused by the seeding process. 


Salvianolic acid B and dihydromyricetin were the two compounds that strongly inhibited the fibril growth and neurotoxicity of α-syn. In an in-vitro cell model, these compounds decreased the insoluble phosphorylated α-syn and aggregation. Also, in primary neuronal cells, these compounds showed a reduction in α-syn aggregates. Both compounds inhibited the seeded fibril growth with dihydromyricetin having the ability to disaggregate preformed α-syn fibrils. In order to investigate the inhibitory mechanisms of these two compounds towards fibril formation, we demonstrated that salvianolic acid B binds predominantly to monomers, while dihydromyricetin binds to oligomeric species and to a lower extent to monomers. Remarkably, these two compounds stabilized the soluble non-toxic oligomers lacking β-sheet content after subjecting them to proteinase K digestion. 


Eleven compounds were tested but only two showed inhibition of α-syn aggregation, seeded fibril formation and toxicity in vitro. These findings highlight an essential beginning for development of new molecules in the field of synucleinopathies treatment.

Original languageEnglish
Article number73
JournalBMC Complementary Medicine and Therapies
Publication statusPublished - 6 Mar 2020

Scopus Subject Areas

  • Medicine(all)

User-Defined Keywords

  • Amyloid fibrils
  • Dihydromyricetin
  • Parkinson’s disease
  • Salvianolic acid B
  • Seeded fibril formation
  • α-Synuclein


Dive into the research topics of 'Inhibition of alpha-synuclein seeded fibril formation and toxicity by herbal medicinal extracts'. Together they form a unique fingerprint.

Cite this