Protective effects of green tea polyphenols in the 6-OHDA rat model of Parkinson's disease through inhibition of ROS-NO pathway

Biol Psychiatry. 2007 Dec 15;62(12):1353-62. doi: 10.1016/j.biopsych.2007.04.020. Epub 2007 Jul 12.


Background: Nitric oxide (NO) and related pathways are thought to play an important role in the pathogenesis of Parkinson's disease (PD). Our in vitro experiments suggested that green tea polyphenols (GTP) might protect dopamine neurons through inhibition of NO and reactive oxygen species (ROS).

Methods: Immunohistochemistry, terminal deoxynucleotidyl transferase-mediated dUTP Nick End Labeling assay, electron spin resonance spin trapping, enzyme linked immunosorbent assay, and molecular biological methods were used to investigate the effects of GTP in an unilateral 6-hydroxydopamine (6-OHDA)-treated rat model of PD.

Results: GTP treatment dose-dependently protected dopaminergic neurons by preventing from midbrain and striatal 6-OHDA-induced increase in 1) both ROS and NO levels, 2) lipid peroxidation, 3) nitrite/nitrate content, 4) inducible nitric oxide synthase, and 5) protein-bound 3-nitro-tyrosine. Moreover, GTP treatment dose-dependently preserved the free radical scavenging capability of both the midbrain and the striatum.

Conclusions: These results support the in vivo protection of GTP against 6-OHDA and suggest that GTP treatment might represent a neuroprotective treatment of PD.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenergic Agents / toxicity
  • Animals
  • Antioxidants / therapeutic use*
  • Behavior, Animal
  • Disease Models, Animal
  • Flavonoids / therapeutic use*
  • In Situ Nick-End Labeling / methods
  • Lipid Peroxidation / drug effects
  • Male
  • Nitric Oxide / metabolism*
  • Oxidopamine / toxicity
  • Parkinson Disease / etiology
  • Parkinson Disease / pathology
  • Parkinson Disease / prevention & control*
  • Phenols / therapeutic use*
  • Polyphenols
  • Rats
  • Rats, Sprague-Dawley
  • Reactive Oxygen Species / metabolism*
  • Signal Transduction / drug effects
  • Signal Transduction / physiology*
  • Stereotyped Behavior / drug effects
  • Tea / chemistry
  • Thiobarbituric Acid Reactive Substances / metabolism
  • Tyrosine 3-Monooxygenase / metabolism


  • Adrenergic Agents
  • Antioxidants
  • Flavonoids
  • Phenols
  • Polyphenols
  • Reactive Oxygen Species
  • Tea
  • Thiobarbituric Acid Reactive Substances
  • Nitric Oxide
  • Oxidopamine
  • Tyrosine 3-Monooxygenase