Prolonged coenzyme Q10 treatment in Down syndrome patients: effect on DNA oxidation.

Oxidative stress is known to play a relevant role in Down syndrome (DS) and its effects are documented from embryonic life. Oxidative DNA damage has been shown to be significantly elevated in Down syndrome patients, and this has been indicated as an early event promoting neurodegeneration and Alzheimer type dementia. The aim of this study was to investigate the efficacy of coenzyme Q(10) (CoQ(10)) in delaying the effect of oxidative damage in these patients. In our previous study we demonstrated a mild protective effect of CoQ(10) on DNA, although the treatment was unable to modify the overall extent of oxidative damage at the patient level. Possible limitations of the previous study were: time of treatment (6 months) or spectrum of DNA lesions detected. In order to overcome these limitations we planned a continuation of the trial aimed at evaluating the effects of CoQ(10) following a prolonged treatment. Our results highlight an age-specific reduction in the percentage of cells showing the highest amount of oxidized bases, indicating a potential role of CoQ(10) in modulating DNA repair mechanisms.