Effect of polyphenolic extract, Pycnogenol, on the level of 8-oxoguanine in children suffering from attention deficit/hyperactivity disorder

Free Radic Res. 2006 Sep;40(9):1003-10. doi: 10.1080/10715760600824902.


The purpose of this randomized, double-blind and placebo controlled study was to test the effect of polyphenolic extract of pine bark Pycnogenol (Pyc) on the level of oxidized purines represented by 8-oxo-7,8-dihydroguanine (8-oxoG) and on the total antioxidant status (TAS) in children with attention deficit/hyperactivity disorder (ADHD).We have found significantly increased damage to DNA in ADHD children when compared to controls. 8-oxoG was significantly lower after 1 month of Pyc administration in comparison to the beginning state and to placebo group. TAS in ADHD children was lower in comparison to controls. After Pyc administration, TAS was elevated but statistically significant increase was recorded after 1 month of termination of Pyc application. Improvement of DNA damage and TAS after Pyc administration is associated with the improvement of attention in ADHD children. In conclusion, Pycnogenol(R) administration reduces oxidative damage to DNA, normalizes TAS and improves attention of ADHD children. Explanation of mutual relation between oxidative damage to DNA, TAS and symptoms of ADHD and mechanism of Pyc's action needs further investigations.

Publication types

  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Adolescent
  • Antioxidants / metabolism
  • Attention Deficit Disorder with Hyperactivity / drug therapy*
  • Child
  • DNA Damage / drug effects
  • Double-Blind Method
  • Female
  • Flavonoids / administration & dosage
  • Flavonoids / isolation & purification
  • Flavonoids / therapeutic use*
  • Guanine / analogs & derivatives*
  • Guanine / antagonists & inhibitors
  • Guanine / chemistry
  • Guanine / pharmacology
  • Humans
  • Male
  • Pinus / chemistry
  • Placebos
  • Plant Bark / chemistry
  • Plant Extracts
  • Treatment Outcome


  • Antioxidants
  • Flavonoids
  • Placebos
  • Plant Extracts
  • pycnogenols
  • 8-hydroxyguanine
  • Guanine