Pathological effects of long-term cyanide exposure on various organs have been reported. Cyanide-induced oxidative stress contributes to the harmful effects of cyanide poisoning on various tissues. The present study was planned to investigate the effects of prolonged oral exposure to cyanide on some oxidative stress biomarkers in erythrocytes and plasma of rats. Two groups of rats received for 6 weeks either tap water or water containing 200 mg L-1 inorganic cyanide in the form of potassium cyanide. The activity of glutathione peroxidase was significantly (P<0.05) higher, whereas that of superoxide dismutase was significantly (P<0.01) lower in the erythrocytes of cyanide exposed animals, in comparison with the control values. Malondialdehyde concentration was significantly increased (P<0.01) in the erythrocyte haemolysate following cyanide exposure. However, cyanide exposure had no significant effect on erythrocyte glutathione concentrations. Indeed, the effects of cyanide exposure on the plasma levels of malondialdehyde, ferric reducing ability of plasma (FRAP) and protein carbonyls were not significant as compared to the control group. It can be concluded that prolonged cyanide poisoning significantly influenced some circulating oxidative stress biomarkers in rats. These studies may provide help for both additional explanations of the pathophysiological aspects of cyanide poisoning and supportive treatment of prolonged cyanide toxicity.

Keywords