Clinical Investigation of French Maritime Pine Bark Extract on Attention-Deficit Hyperactivity Disorder as compared to Methylphenidate and Placebo: Part 2: Oxidative Stress and Immunological Modulation

Abstract

Objectives: To evaluate the effect of French Maritime Pine Bark Extract (PBE; Pycnogenol®) on immune, oxidative stress and neurochemical biomarkers in paediatric Attention-Deficit Hyperactivity Disorder (ADHD) as compared to methylphenidate (MPH) and placebo. Results: Paediatric ADHD patients (n = 88, 70 % male, mean age 10.1 years) were randomised (placebo (n = 30), PBE (n = 32) and MPH (n = 26)) receiving 20 mg/day if < 30 kg or 40 mg/day if ≥ 30 kg PBE, or 20 mg/day if < 30 kg or 30 mg/day if ≥ 30 kg MPH for 10 weeks. In the oxidative stress pathway, catalase (CAT) activity was nominally significant different in the PBE group with a p-value of 0.025 whereas the immunity biomarkers IgA and IgG2 were nominally significant different after MPH treatment with a p-value of 0.028 and 0.017 respectively, compared to baseline. Serum Neuropeptide Y (NPY) levels and weight were significantly lower after 10-weeks MPH. Conclusions: Loss of appetite and weight loss was observed for MPH, whereas no differences in NPY concentrations and a significant weight gain, which is to be an expected physiological process in this age group, was noticed for PBE. Firm evidence that PBE increases antioxidant levels, reduces oxidative damage and improves immune status in general as compared to placebo or MPH could not be obtained.

Keywords

• ADHD
• French Maritime Pine Bark Extract
• Methylphenidate
• Oxidative stress
• Immunity
• Polyphenols