Neuroprotective Effects of Anti-Aging Oriental Medicine Lycium Barbarum Against Beta-Amyloid Peptide Neurotoxicity

Exp Gerontol. Aug-Sep 2005;40(8-9):716-27. doi: 10.1016/j.exger.2005.06.010.

Abstract

As aged population dramatically increases in these decades, efforts should be made on the intervention for curing age-associated neurodegenerative diseases such as Alzheimer's disease (AD). Natural plant extracts of Lycium barbarum are well-known to exhibit anti-aging effects. We therefore hypothesized that they exhibit neuroprotective effects against toxins in aging-related neurodegenerative diseases. In this study, we aimed to investigate whether extracts from L. barbarum have neuroprotective effects against toxicity of fibrillar Abeta(1-42) and Abeta(25-35) fragments. Primary rat cortical neurons exposed to Abeta peptides resulted in apoptosis and necrosis. Pre-treatment with extract isolated from L. barbarum significantly reduced the release of lactate dehydrogenase (LDH). In addition, it attenuated Abeta peptide-activated caspases-3-like activity. The extract elicited a typical dose-dependent neuroprotective effect. Effective dosage of this extract was wider than that of a well-known western neuroprotective medicine lithium chloride (LiCl). We have further examined the underlying mechanisms of the neuroprotective effects. In agreement with other laboratories, Abeta peptides induce a rapid activation of c-Jun N-terminal kinase (JNK) by phosphorylation. Pre-treatment of aqueous extract markedly reduced the phosphorylation of JNK-1 (Thr183/Tyr185) and its substrates c-Jun-I (Ser 73) and c-Jun-II (Ser 63). Taken together, we have proved our hypothesis by showing neuroprotective effects of the extract from L. barbarum. Study on anti-aging herbal medicine like L. barbarum may open a new therapeutic window for the prevention of AD.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alzheimer Disease / metabolism
  • Alzheimer Disease / prevention & control*
  • Amyloid beta-Peptides / metabolism*
  • Animals
  • Antimanic Agents / pharmacology
  • Apoptosis / drug effects
  • Blotting, Western / methods
  • Brain / drug effects
  • Brain / metabolism*
  • Caspase 3
  • Caspases / metabolism
  • Cells, Cultured
  • DNA Fragmentation / drug effects
  • Drugs, Chinese Herbal / pharmacology*
  • Lithium Chloride / pharmacology
  • Lycium / chemistry
  • Medicine, East Asian Traditional*
  • Neurons / drug effects
  • Neurons / metabolism
  • Neuroprotective Agents / pharmacology*
  • Plant Extracts / chemistry
  • Rats
  • Rats, Sprague-Dawley

Substances

  • Amyloid beta-Peptides
  • Antimanic Agents
  • Drugs, Chinese Herbal
  • Neuroprotective Agents
  • Plant Extracts
  • lycium barbarum polysaccharide
  • Casp3 protein, rat
  • Caspase 3
  • Caspases
  • Lithium Chloride