Evaluation of Coenzyme Q10 Redox Status as a Biomarker of Oxidative Stress

Abstract

The article examines the role of ubiquinone as a redox molecule whose functions consist in electron transport in the mitochondrial respiratory chain and regeneration of endogenous antioxidants. Changes in electron redox pathways cause uncontrolled release of reactive oxygen species, which leads to oxidative stress and development of pathologies. The objective of the study was to determine the content of coenzyme Q10 and its redox status in the human body as a biomarker of oxidative stress in various pathologies. This was achieved by assessing and consolidating data on changes in concentrations of the oxidized, reduced ubiquinone forms and total ubiquinone in various pathologies. Total serum ubiquinone was reduced in patients with chronic heart failure (0.68 μmol/L) compared with the control group (0.97 μmol/L). The redox status, expressed as the [ubiquinol]/ [ubiquinone] concentration ratio, decreased in patients with coronary heart disease (0.49 ± 0.34), diabetes (0.26 ± 0.16) compared with the healthy subjects (1.23–1.41). A negative correlation with malonic dialdehyde was observed. The authors analysed the possibility of assessing the efficacy of statin therapy by plasma ubiquinone concentration in patients. Patients with hyperlipidemia who received statins showed a statistically significant reduction in ubiquinol concentration after taking the drug (from 0.81 to 0.46 μg/mL) and the [ubiquinone]/[total ubiquinone] ratio (from 11 to 10 %), which confirms the potential mechanism of statinassociated muscle injury development. Thus, coenzyme Q10 redox status, as well as the concentrations of oxidized, reduced and total ubiquinone can be effective biomarkers of oxidative stress in cardiovascular diseases, diabetes, as well as an important indicator in evaluating the efficacy of hyperlipidemia treatment.