Activities of antioxidant enzymes and formation of the glutathione adduct of hemoglobin (Hb ASSG) in epileptic patients with long-term antiepileptic therapy.

The activities of antioxidant enzymes (AOE) and amounts of glutathione adduct of Hb (Hb ASSG) in erythrocytes of chronic epileptic patients treated with mono or mixed therapy of phenobarbital (PB), carbamazepin (CBZ) and valproic acid (VPA), were evaluated and the results were compared with those for normal individuals. The activity of superoxide dismutase (SOD) was lowered for 40% to 60% in epileptic patients relative to normal controls. The lowest activity of SOD was found in patients treated with CBZ and PB. Activity of glutathione peroxidase (GSH-Px) was lowered comparing to the control from cca 15% in patients treated with PB to 50% in those treated with either CBZ alone or with CBZ in combination with PB. For the later two sub-groups of patients significantly lowered activities of catalase and glutathione reductase (cca 20% and 30-40%, respectively) were also characteristic. The highest amounts of Hb ASSG (cca 4% of the tota lHb) were found in hemolysates of patients with the lowest AOE levels i.e., in those treated with CBZ alone or with CBZ in combination with PB. In hemolysates of patients treated with PB, Hb ASSG represented 2.4% of the total Hb, while it was totally absent in those treated with VPA, although SOD and GSH-Px levels in erythrocytes of both of these sub-groups of patients were lowered to the same extent.