In vivo effects of non-steroidal antiinflammatory drugs on oxidative stress-related parameters of human erythrocytes

In this study, we evaluated the effects of commonly used non-steroidal anti -inflammatory drugs (NSAIDs) on oxidative stress and anti-oxidant system. S ixteen healthy volunteers and 35 patients diagnosed as one of musculoskelet al disorders were included in the study. Patients were treated with one of the three NSAIDs (i.e. naproxen, tiaprofenic acid, acemetacin) or paracetam ol for 15 days. Erythrocyte glutathione S-transferase, erythrocyte and plas ma glutathione peroxidase, and erythrocyte catalase (CAT) activities and pl asma malondialdehyde level as lipid peroxidation index were detected in the blood samples of the patients, at the beginning of the study (0 week), aft er treatment for 15 days (2nd week), and at the end of 1 week-washout perio d (3rd week). The most affected enzyme by NSAIDs war; erythrocyte catalase, which tended to increase at the end of 2 weeks treatment, and decrease at the end of 1 week-washout period. In the groups treated with acemetacin, na proxen and tiaprofenic acid, plasma malondialdehyde levels were decreased a t some extent, but at the end of washout period a rebound increase was obse rved in acemetacin group. Our results suggest that NSAIDs have different influences on oxidative stre ss and anti-oxidant system related parameters. These effects seem to be rel ated with the mechanisms of some of the adverse effects, which are not well understood yet. Further studies with larger groups are needed to illuminat e the relationship between adverse effects of NSAIDs and the effects of the se drugs on anti-oxidant system, and to clarify their mechanisms of therape utic action, as well.