The study, published in JAMA Neurology, shows a link between low levels of blood coenzyme Q10 (CoQ10) and patients with multiple system atrophy (MSA).
The data backs recent hypotheses that CoQ10 deficiency could be linked with development of the neurodegenerative disorder, and that supplementation could be beneficial for MSA sufferers, the team said.
However, Dr Tsuji of the University of Tokyo – an author on the study – stressed that: “We need clinical trials to determine whether supplementation of coenzyme Q10 is efficacious for MSA.”
A Phase II clinical trial is planned for early next year to assess the efficacy of CoQ10 in MSA patients, he told NutraIngredients.
MSA is a progressive, difficult-to-control neurodegenerative disease, characterised by “autonomic failure in addition to various combinations of parkinsonism, cerebellar ataxia and pyramidal dysfunction.”
The study included 44 Japanese patients with MSA (average age of 64) and 39 Japanese control patients (average age 60).
The researchers compared blood samples from MSA patients with those of control subjects free of any neurodegenerative disease.
CoQ10 has properties similar to vitamins, but since it is naturally synthesized in the body it is not classed as such. With chemical structure 2,3-dimethoxy-5-methyl-6-decaprenyl-1,4-benzoquinone, it is also known as ubiquinone because of its 'ubiquitous' distribution throughout the human body.
The coenzyme is concentrated in the mitochondria - the 'power plants' of the cell - and plays a vital role in the production of chemical energy by participating in the production of adenosince triphosphate (ATP), the body's co-called 'energy currency'.
A role beyond the mitochondria is also acknowledged, with CoQ10 acting as a potent antioxidant. The coenzyme plays an important role in preserving levels of vitamin E and vitamin C.
They found plasma levels of CoQ10 were significantly lower in MSA patients, regardless of age, sex and Coenzyme Q2, polyprenyltransferase (COQ2) genotype. COQ2 is a protein coding gene which plays a part in the biosynthesis of CoQ10, Dr Tsuji explained.
Mutations in the gene lead to decreased synthesis of CoQ10, he said, citing whole genome sequence analysis which revealed allele mutations in COQ2 in two out of six families containing MSA cases.
Three MSA patients carried the heterozygous V393A variant in the COQ2 and it was found they had lower plasma levels of CoQ10 than patients not carrying the mutation.
“Our present findings indicate that plasma coQ10 levels are decreased in MSA patients even if they do not carry COQ2 mutations,” Dr Tsuji said.
However, he added that the V393A mutation could mean even lower CoQ10 production for MSA patients with the variation.
“We are sure …V393A mutation results in decreased byosynthetic activity for CoQ10 based on functional assays of the mutant COQ2 enzyme,” he said, though he conceded the sample group in the current study is too small to draw any conclusions.
The aforementioned Phase II trial will assess the efficacy of CoQ10 in MSA patients both with and without COQ2 mutations. Clinical efficacy will be determined in the two groups independently.
It is expected that high doses of CoQ10 will be needed in order to deliver sufficient amounts to the brain, he added. As such, the team has just completed a Phase I clinical trial assessing safety and pharmacokinetics of high dose CoQ10 in healthy volunteers.
The ongoing research follows other recent studies suggesting CoQ10 could increase blood flow in the brain. It is also the subject of a multi-year mouse trial looking into its effects on healthy ageing.
Source: JAMA Neurology
Published online first, doi: 10.1001/jamaneurol.2016.1325
“Plasma Coenzyme Q10 levels in patients with multiple system atrophy”
Authors: Dr Shoji Tsuji, et al