Total antioxidant capacity is significantly lower in cocaine-dependent and methamphetamine-dependent patients relative to normal controls: Results from a preliminary study.
Oxidative stress can result in damage to the brain and other organs. To protect from oxidative damage, the human body possesses molecular defense systems, based on the activity of antioxidants, and enzymatic defense systems, including the enzymes catalase (CAT), superoxide dismutase (SOD), and thutathione peroxidase (GSH-Px). Although pre-clinical research has shown that stimulant use is associated with oxidative damage, oxidative stress and the antioxidant defense systems have not been evaluated in clinical samples of stimulant-dependent patients.
This secondary analysis of data from the National Drug Abuse Treatment Clinical Trials 12-Step Facilitation for Stimulant Abusers (STAGE-12) study aimed to investigate the link between stimulant dependence and oxidative stress. Peripheral blood samples from 174 methamphetamine (n=48) and/or cocaine-dependent (n=126) participants as well as 30 normal control participants were analyzed for the enzyme activities of CAT, SOD, and GSH-Px, in the erythrocytes and the total antioxidant capacity and malondialdehye concentration in the plasma. Results showed an association of stimulant dependence with a depletion of total antioxidant capacity to 54.6 +/- 4.7%, which correlates with a reduced activity of the SOD to 71.3+/-0.03% compared with healthy control participants (100%).
Conclusions: This is the first study to evaluate oxidative stress and antioxidant defense systems in a clinical sample of stimulant-dependent patients. Consistent with pre-clinical research findings demonstrating that stimulants decrease total antioxidant activity, the present study revealed that TAC was significantly lower in both cocaine-dependent and methamphetamine-dependent patients relative to normal controls. This could, in turn, render stimulant-dependent patients at greater risk for oxidative damage to the brain and other organs. Future research to replicate and extend these findings is warranted.
Related protocols: CTN-0031, CTN-0031-A-1