Early abstinence of crack-cocaine is effective to attenuate oxidative stress and to improve antioxidant defences

Abstract

Rationale: Preclinical studies have shown that cocaine exposure and withdrawal are associated with cellular oxidative stress damage. However, the impact of crack-cocaine dependence on oxidative stress biomarkers remains unclear. Here, we assessed peripheral oxidative stress and antioxidant defences during two periods of crack-cocaine detoxification treatment and associated these changes with psychological morbidity.

Methods: Thirty female inpatients were recruited, and plasma samples were collected at the 4th and 18th days of abstinence; 30 healthy controls were also recruited. Plasma levels of protein carbonyl, protein thiol content, superoxide dismutase (SOD), glutathione peroxidase (GPx), reduced reduced (GSH) and total reactive antioxidant potential (TRAP) were measured by standard methods; the questionnaires Cocaine Selective Severity Assessment, Beck Depressive Inventory and the Addiction Severity Index were applied.

Results: We report higher oxidative stress damage after 4 days of detoxification, as shown by increased total thiol content and protein carbonylation when compared with control group and after 18 days of detoxification. After 18 days of treatment, we observed a recovery of the oxidative stress damage and increase of the antioxidant defences, as shown by higher levels of SOD, GPx, GSH and TRAP. There was a positive correlation between protein carbonylation and psychological variables; in contrast, there was a negative correlation between TRAP levels and clinical assessments.

Conclusions: Taken together, these results suggest that drug rehabilitation treatment was effective in decreasing oxidative damage represented by the reduction in biological markers, which are closely related to the severity of withdrawal symptoms.