Protective effect of melatonin on the oxidative stress caused by diabetes and forced swimming exercise on rat brain tissue

Abstract

Objective: The objective of the present study is to examine how melatonin supplementation affects lipid peroxidation in the brain tissue of diabetic rats subjected to acute swimming exercise. Material and Methods: The study was carried out on 80 Spraque-Dawley type adult male rats, which were equally allocated to 8 groups: Group 1, general control; Group 2, melatonin-supplemented control; Group 3, melatonin-supplemented diabetic control; Group 4, swimming control; Group 5, melatonin-supplemented swimming; Group 6, melatonin-supplemented diabetic swimming; Group 7, diabetic swimming; and Group 8, diabetic control. The animals were injected with 40 mg/kg subcutaneous streptozotocin (STZ). The same dose was repeated after 24 hours. The rats were supplemented with 3 mg/kg/day intraperitoneal (ip) melatonin for 4 weeks. Brain tissue samples were collected from the animals, which were decapitated at the end of the study, to determine malondialdehyde (MDA) (nmol/gram/protein) and glutathione (GSH) (mg/dL/gram protein) levels. Results: The highest MDA values in brain tissue were in Group 7 and 8. Groups 3 and 6 had the highest brain GSH values. Brain GSH values in Group 2 were lower than the values in Groups 3 and 6, but higher than those in all other groups. The lowest GSH values in brain tissue were established in Groups 7 and 8. Conclusion: Results of the present study indicate that the oxidative stress caused by diabetes and acute swimming exercise in rat brain tissue can be offset by melatonin supplementation. © 2012 by Türkiye Klinikleri.