Neurorescue activity, APP regulation and amyloid-beta peptide reduction by novel multi-functional brain permeable iron- chelating- antioxidants, M-30 and green tea polyphenol, EGCG

Curr Alzheimer Res. 2007 Sep;4(4):403-11. doi: 10.2174/156720507781788927.

Abstract

Accumulation of iron at sites where neurons degenerate in Parkinson's disease (PD) and Alzheimer's disease (AD) is thought to have a major role in oxidative stress induced process of neurodegeneration. The novel non-toxic lipophilic brain- permeable iron chelators, VK-28 (5- [4- (2- hydroxyethyl) piperazine-1-ylmethyl]- quinoline- 8- ol) and its multi-functional derivative, M-30 (5-[N-methyl-N-propargylaminomethyl]-8-hydroxyquinoline), as well as the main polyphenol constituent of green tea (-)-epigallocatechin-3-gallate (EGCG), which possesses iron metal chelating, radical scavenging and neuroprotective properties, offer potential therapeutic benefits for these diseases. M-30 and EGCG decreased apoptosis of human SH-SY5Y neuroblastoma cells in a neurorescue, serum deprivation model, via multiple protection mechanisms including: reduction of the pro-apoptotic proteins, Bad and Bax, reduction of apoptosis-associated Ser139 phosphorylated H2A.X and inhibition of the cleavage and activation of caspase-3. M-30 and EGCG also promoted morphological changes, resulting in axonal growth-associated protein-43 (GAP-43) implicating neuronal differentiation. Both compounds significantly reduced the levels of cellular holo-amyloid precursor protein (APP) in SH-SY5Y cells. The ability of theses novel iron chelators and EGCG to regulate APP are in line with the presence of an iron-responsive element (IRE) in the 5'-untranslated region (5'UTR) of APP. Also, EGCG reduced the levels of toxic amyloid-beta peptides in CHO cells over-expressing the APP "Swedish" mutation. The diverse molecular mechanisms and cell signaling pathways participating in the neuroprotective/neurorescue and APP regulation/processing actions of M-30 and EGCG, make these multifunctional compounds potential neuroprotective drugs for the treatment of neurodegenerative diseases, such as PD, AD, Huntington's disease and amyotrophic lateral sclerosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amyloid beta-Peptides / metabolism*
  • Amyloid beta-Protein Precursor / metabolism*
  • Animals
  • Antioxidants / chemistry
  • Antioxidants / pharmacology*
  • Apoptosis / drug effects*
  • Catechin / analogs & derivatives*
  • Catechin / chemistry
  • Catechin / pharmacology
  • Cell Line, Tumor
  • Dose-Response Relationship, Drug
  • Gene Expression Regulation, Neoplastic / drug effects
  • Humans
  • Hydroxyquinolines / chemistry
  • Hydroxyquinolines / pharmacology*
  • Mice
  • Mice, Inbred C57BL
  • Models, Biological
  • Neuroblastoma

Substances

  • 5-(N-methyl-N-propargylaminomethyl)-8-hydroxyquinoline
  • Amyloid beta-Peptides
  • Amyloid beta-Protein Precursor
  • Antioxidants
  • Hydroxyquinolines
  • Catechin
  • epigallocatechin gallate