In vitro effects of NSAIDS and paracetamol on oxidative stress-related parameters of human erythrocytes.

In vitro effects of widely used nonsteroidal antiinflammatory drugs (NSAIDs) and paracetamol were studied on oxidative stress-related parameters of human red blood cells (RBC). Membrane lipid integrity, activity of erythrocyte antioxidant enzymes; i.e. glutathione S-transferase (GST), selenium dependent-glutathione peroxidase (Se-GPx), and catalase (CAT), and hemolytic/stabilizing action of the drugs on erythrocyte membrane were assessed. Diclofenac, indomethacin and paracetamol at the therapeutic and higher concentrations, and dipyrone at the high concentration exerted a statistically significant inhibition on H2O2 forced erythrocytic membrane lipid peroxidation (EMLP). Increased hemolysis was observed by Na-salicylate, naproxen and ketorolac at therapeutic and higher concentrations, and by diclofenac and tiaprofenic acid at high concentrations, while the others seemed to stabilize the membrane at the same conditions. Na-salicylate inhibited GST activity at the therapeutic dose, however activated the same enzyme at high concentrations. Naproxen, tiaprofenic acid and piroxicam caused a decrease in GST activity at therapeutic doses. Paracetamol caused an activation at a high dose. Tiaprofenic acid, ketorolac, naproxen and piroxicam caused a significant Se-GPx inhibition. Erythrocyte CAT activity was increased by Na-salicylate, acemetacin, and tenoxicam at the therapeutic, and by dipyrone at the high concentration. Our results suggest that NSAIDs and paracetamol may be involved in oxidative/antioxidative processes of human erythrocytes. Also, the in vitro EMLP method can be considered as a simple test for evaluating possible antioxidant potency of chemicals.