Natural Antioxidant, CoQ10, as Dietary Supplement Eases Oxidative Stress in Rett Patients, Small Study Suggests

Taking coenzyme Q10 (CoQ10) — a natural antioxidant — as an oral dietary supplement can ease oxidative stress associated with symptom severity and Rett syndrome progression, a small Italian study suggests.

The study, “Effects of oral administration of common antioxidant supplements on the energy metabolism of red blood cells. Attenuation of oxidative stress-induced changes in Rett syndrome erythrocytes by CoQ10,” was published in the journal Molecular and Cellular Biochemistry.

Oxidative stress is an imbalance between the production of free radicals (that can result from energy production) and the ability of cells to detoxify. These free radicals, or reactive oxygen species (ROS), are harmful to cells and associated with a number of diseases, including Rett syndrome.

High levels of oxidative stress are a hallmark of Rett syndrome, and linked with disease severity and progression. Red blood cells, or erythrocytes — one of the first cells affected by changes in the oxidative status of the body — exhibit higher-than-normal levels of oxidative stress, and significant changes in energy state and metabolism in Rett patients.

This evidence points to oxidative stress modulation as a potential way of treating Rett syndrome.

Several reports highlight the use of erythrocytes to investigate natural or disease-associated oxidative stress, and the antioxidant properties of natural substances.

Several studies have analyzed the antioxidant properties of several dietary supplements, but the results of most are inconsistent, with differences mainly between the effects observed on cells grown in the lab and those in humans.

A team of Italian researchers has now evaluated the effects of five popular dietary antioxidant supplements — epigallocatechin gallate (EGCG), resveratrol, CoQ10, vitamin C, and vitamin E — on the energy metabolism and oxidative status of erythrocytes in 15 healthy adults.

Ten women and five men, with a median age of 41, were randomly assigned to one of the oral dietary supplements, once a day, for a month (three patients in each group).

Blood samples were taken at the beginning of the study and again after 15 and 30 days, and researchers assessed the levels of molecules associated with energy metabolism, as well as antioxidant activity in the whole blood — using the validated oxygen radical absorptive capacity (ORAC) assay.

Among the five supplements, CoQ10 was seen to be the most powerful in influencing erythrocytes’ energy state, and led to the highest, and a significant, increase in their antioxidant activity.

Data suggest that “it is possible to evaluate the protective capability of antioxidants after their absorption and distribution throughout the body, highlighting the biological relevance of the experimental approach proposed in this study,” the researchers wrote.

Having validated their approach, they conducted a pilot study into whether daily oral CoQ10 supplements (likely as capsules) could protect erythrocytes from oxidative damage in 11 girls diagnosed with Rett syndrome.

The girls, with a mean age of 11.4 (range of 2 to 19), were recruited at the Child Neurology and Psychiatry Unit, Tor Vergata University of Rome. All were given 300 mg of CoQ10 once daily for two months; four continued taking the supplements for one year.

Results showed that two months of CoQ10 supplementation partly restored energy metabolism and corrected (reverted) the oxidative damage in erythrocytes of Rett patients. No further changes were observed with longer use of the supplements.

“These data allowed us to conclude that … CoQ10 exerts an important role in the protection of erythrocytes from ROS production, contributing to the integrity and functionality of these cells,” the researchers wrote.

They also noted that, while this was a small study, its preliminary results suggest that CoQ10 dietary supplements could be used to manage Rett syndrome. Future studies are required to confirm CoQ10’s potential therapeutic effects.