Therapeutic effects of coenzyme Q10 (CoQ10) and reduced CoQ10 in the MPTP model of Parkinsonism

Coenzyme Q₁₀ (CoQ₁₀) is a promising agent for neuroprotection in neurodegenerative diseases. We tested the effects of various doses of two formulations of CoQ₁₀ in food and found that administration in the diet resulted in significant protection against loss of dopamine (DA), which was accompanied by a marked increase in plasma concentrations of CoQ₁₀. We further investigated the neuroprotective effects of CoQ₁₀, reduced CoQ₁₀ (ubiquinol), and CoQ₁₀ emulsions in the (MPTP) model of Parkinson's disease (PD). We found neuroprotection against MPTP induced loss of DA using both CoQ₁₀, and reduced CoQ₁₀, which produced the largest increases in plasma concentrations. Lastly, we administered CoQ₁₀ in the diet to test its effects in a chronic MPTP model induced by administration of MPTP by Alzet pump for 1 month. We found neuroprotective effects against DA depletion, loss of tyrosine hydroxylase neurons and induction of alpha-synuclein inclusions in the substantia nigra pars compacta. The finding that CoQ₁₀ is effective in a chronic dosing model of MPTP toxicity, is of particular interest, as this may be more relevant to PD. These results provide further evidence that administration of CoQ₁₀ is a promising therapeutic strategy for the treatment of PD.