Effects of Coenzyme Q10 Supplementation on Inflammatory Cytokines (TNF-α, IL-6) and Oxidative Stress in Rheumatoid Arthritis Patients: A Randomized Controlled Trial

Abstract

Overproduction of proinflammatory cytokines is a main trait of rheumatoid arthritis. Coenzyme Q10 (CoQ10), an endogenous antioxidant, has shown anti-inflammatory effects in some diseases. In this study we aimed to assess the effects of CoQ10 supplementation on cytokines generation and oxidative stress in rheumatoid arthritis. In this double-blind, randomized controlled clinical trial, 44 patients with rheumatoid arthritis were recruited. Twenty two patients received 100 mg/day capsules of CoQ10 and 22 patients took placebo for 2 months. At the beginning and the end of the intervention, 7 mL of fasting blood was taken from patients to measure malondialdehyde (MDA), total antioxidant capacity (TAC), interleukin (IL)-6 and tumor necrosis factor alpha (TNF-α). At the end of the study, serum MDA significantly decreased in supplemented group (mean difference = -1.47 nmol/mL; 95% confidence interval (CI), -2.52 to -0.43; p = 0.008). CoQ10 also suppressed overexpression of TNF-α (difference in median was +1.1 in placebo vs. +0.03 in CoQ10 group; p = 0.033). There was no significant difference in TAC and IL-6 levels between groups. This study showed beneficial effects of CoQ10 supplementation on inflammatory cytokines and oxidative stress in rheumatoid arthritis patients.