Background: Sleep deprivation affects a significant proportion of the global population. It has been reported to induce oxidative stress in the testes and reduce serum testosterone levels. Exogenous anti-oxidants have been known to prevent damages and diseases associated with oxidative stress but there is dearth of knowledge on their effectiveness during sleep deprivation.
Aim: This study was designed to investigate the effects of two anti-oxidants; melatonin and vitamin E on serum testosterone concentration in sleep deprived male Wistar rats.
Methods: Thirty (30) male Wistar rats were used for this study. Animals were divided into six (6) groups (n = 5). Group 1 was the control, group 2 rats were sleep deprived, group 3 received vitamin E (200 mg/ kg bwt) only, group 4 rats received vitamin E and were sleep deprived, group 5 received melatonin only (10 mg/kg bwt), and group 6 rats received melatonin (10 mg/kg bwt) and were sleep deprived. Sleep deprivation was induced using the modified multiple platform technique. Body weights were taken on days 7, 14 and 21. Blood was collected at sacrifice and serum was obtained for analyses of testosterone, corticosterone and melatonin. Testicular malondialdehyde, superoxide dismutase and catalase levels were determined by the methods of Adam-Vizi and Seregi (1982), Misra and Fridovich (1972), and Sinha, (1972) respectively. Data obtained were analyzed using one way ANOVA and p < 0.05 was considered significant.
Results: Serum testosterone (nmol/l) of the sleep deprived animals (0.6 ± 0.3) reduced significantly (p < 0.05) compared with control group (3.3 ± 0.04), sleep deprived+vitamin E group (2.8 ± 0.5) and sleep deprived+melatonin group (2.0 ± 0.3). Also, melatonin+sleep deprived group had reduced testosterone compared with control. There were no significant changes in the serum corticosterone (nmol/l) and melatonin levels in all the groups compared with the sleep deprived group. However, corticosterone was increased in the sleep deprived+Vitamin E group (51.6 ± 20.5) compared with control (6.3 ± 0.6) Sleep deprived group had increased testicular malondialdehyde (MDA) (1.6 ± 0.1 unit/mg), superoxide dismutase (SOD) (3.2 ± 0.2 unit/mg), and catalasel evels (44.3 ± 1.1 unit/ mg) compared with control (0.9 ± 0.0 μmg). MDA, and catalase were significantly reduced in sleep deprived+vitamin E (1.1 ± 0.2, 2.4 ± 0.3, 39 ± 1.0 unit/ mg) compared with sleep deprived while melatonin alone had increased MDA. level (1.7 ± 0.2unit/mg) compared with control. SOD in the sleep deprived+melatonin group (2.7 ± 0.2 μ/mg) as compared with control increased (p < 0.05) while MDA and catalase levels as compared with control and sleep deprived groups showed no difference. Histological findings showed that the pathology in the testes of sleep deprived rats was ameliorated by vitamin E.
Conclusion: Vitamin E had a more potent effect than melatonin in maintaining testosterone level in sleep deprived Wistar rat.