Purpose: Oxidative stress (OS) is associated with several chronic complications and diseases. The use of coenzyme Q10 (CoQ10) as an adjuvant treatment with routine clinical therapy against metabolic diseases has shown to be beneficial. However, the impact of CoQ10 as a preventive agent against OS has not been systematically investigated.
Methods: A systematic literature search was performed using the PubMed, SCOPUS, EMBASE, and Cochrane Library databases to identify randomized clinical trials evaluating the efficacy of CoQ10 supplementation on OS parameters. Standard mean differences and 95% confidence intervals were calculated for net changes in OS parameters using a random-effects model.
Results: Seventeen randomized clinical trials met the eligibility criteria to be included in the meta-analysis. Overall, CoQ10 supplementation was associated with a statistically significant decrease in malondialdehyde (MDA) (SMD - 0.94; 95% CI - 1.46, - 0.41; I2 = 87.7%) and a significant increase in total antioxidant capacity (TAC) (SMD 0.67; 95% CI 0.28, 1.07; I2 = 74.9%) and superoxide dismutase (SOD) activity (SMD 0.40; 95% CI 1.12, 0.67; I2 = 9.6%). The meta-analysis found no statistically significant impact of CoQ10 supplementation on nitric oxide (NO) (SMD - 1.40; 95% CI - 0.12, 1.93; I2 = 92.6%), glutathione (GSH) levels (SMD 0.41; 95% CI - 0.09, 0.91; I2 = 70.0%), catalase (CAT) activity (SMD 0.36; 95% CI - 0.46, 1.18; I2 = 90.0%), or glutathione peroxidase (GPx) activities (SMD - 1.40; 95% CI: - 0.12, 1.93; I2 = 92.6%).
Conclusion: CoQ10 supplementation, in the tested range of doses, was shown to reduce MDA concentrations, and increase TAC and antioxidant defense system enzymes. However, there were no significant effects of CoQ10 on NO, GSH concentrations, or CAT activity.
Keywords: Coenzyme Q10; Glutathione peroxidase; Malondialdehyde; Oxidative stress.