Antioxidant capacity in seminal plasma of transfusion-dependent beta-thalassemic patients

Homozygous beta-thalassemia is a haemolytic disorder with a high potential for oxidative damage, due to the high circulating iron levels. Enzymatic and non enzymatic antioxidant capacities, as well as lipoperoxide content, were investigated in seminal plasma of these patients to evaluate a possible oxidative stress.

Semen samples from 10 transfusion-dependent beta-thalassemic patients and 18 control subjects were examined. The assessment of the seminal antioxidant capacity included spectrophotometrical assays for determination of superoxide dismutase and catalase activity and of the total antioxidant status value. Furthermore, malondialdehyde level was detected as marker of lipoperoxidation.

All the beta-thalassemic patients showed high serum ferritin levels, progressive sperm motility below 50 %, and normal sperm count (median: 43 x 10 (6) sperm/ml). Increased superoxide dismutase ( p < 0.01) and catalase ( p < 0.001) activities, but unaltered total antioxidant status values, were detected in the patients' seminal plasma. Furthermore, augmented malondialdehyde levels ( p < 0.001) were measured in the patients.

Seminal antioxidant pattern of iron overloaded beta-thalassemic patients indicated the hyperactivation of the enzymatic free-radical scavengers which could be explained as a compensatory mechanism to possible high levels of reactive oxygen species. Furthermore, the increase of seminal lipoperoxidation suggested an oxidative stress in semen of these patients and it could have contributed to the impairment of sperm motility.