Underlying biochemical effects of intermittent fasting, exercise and honey on streptozotocin-induced liver damage in rats

Purpose

Derangements of liver transcriptional factors and enzymes have important implications in diabetes-induced related complications. Hence, this study which consists of two experimental phases was aimed at evaluating the possible underlying molecular mechanisms of intermittent fasting (IF), exercise starvation and honey in streptozotocin (STZ)-mediated liver damage in diabetic rats.

Methods

The diabetic rats were treated orally with distilled water (0.5 ml/kg), IF, starvation and honey at 1 g/kg body weight in the non-diabetic phase for four (4) weeks. After STZ injections, four (4) weeks of IF, exercise, starvation, and honey therapy were used as interventions prior to a biochemical evaluation of the liver.

Results

IF and exercise greatly decreased liver transcription factor (resistin, SREBP-1c), inflammatory cytokines/enzyme (TNF-α, IL-6, IL-1ß, MPO) as well as oxidative and nitrergic stress with correspondence increased liver PPAR-γ, IL-10, SOD, CAT and GSH in diabetic rats unlike starvation and honey regimen relative to diabetic controls. Furthermore, IF and exercise significantly improved hepatic glycogen synthase and decreased glycogen phosphorylase in diabetic rats compared to the diabetic control group, but starvation and honey therapy had no such influence. IF and exercise strategically reduces STZ-induced liver metabolic disorder via through modulation of liver transcriptional factors and inhibition of pro-inflammatory cytokines, oxido-nitrergic and adipokine signaling pathway.

d-ribose- l-cysteine abrogates testicular maladaptive responses induced by polychlorinated bisphenol intoxication in rats via activation of the mTOR signaling pathway mediating inhibition of apoptosis, inflammation, and oxidonitrergic flux

Male reproductive maladaptive responses are becoming a global health concern and also a social issue. Polychlorinated biphenyls (PCBs) are a member of halogenated aromatic environmental pollutants with diverse environmental matrices. This study was conducted to explore the mechanisms of PCBs-induced testicular maladaptive responses and the potential reversal effects of d-ribose- l-cysteine (DRLC) on testicular injury induced by administration of PCBs (2 mg/kg) for 30 days. DRLC (50 mg/kg) was administered orally for 15 days starting from Days 16 to 30 after the initial 15 days of treatment with PCB. All assays were carried out using established protocols. Administration of DRLC at 50 mg/kg after treatment with PCBs enhances body and testicular weights, gonadotropins (luteinizing hormone and follicle-stimulating hormone), testosterone and poor sperm quality. DRLC also reduced testicular injury score, improved spermatogenesis scoring, reduced oxidative stress biomarkers (malondialdehyde), as well as restored the reduced activities of antioxidant enzymes (glutathione peroxidase, superoxide dismutase, and catalase) and decreases pro-inflammatory response (tumor necrosis factor-alpha and NO). More so, DRLC treatment abrogates testicular DNA fragmentation and downregulated p53 and caspase 3 activities and upregulated the concentration of autophagy-related protein (mammalian target of rapamycin [mTOR] and Atg7). DRLC abates testicular deficit induced by PCBs intoxicated rats via activation of the mTOR signaling pathway mediating inhibition of apoptosis, Inflammation and oxidative flux.

Effects of methotrexate on serum testosterone level in sleep deprived male Wistar rats

BACKGROUND

Sleep deprivation has been reported to decrease testosterone levels but the mechanism remains unclear. Studies have shown that sleep deprivation increases interleukin 1 beta (IL-1β), a pro-inflammatory cytokine and that increased IL-1β levels cause reductions in Leydig cell production of testosterone. This study was therefore designed to determine the effects of methotrexate, an IL-1β blocker on serum testosterone levels in sleep deprived male Wistar rats.

METHODS

Twenty male Wistar rats were randomly assigned into four groups (n = 5); group I (Control) received the vehicle (1% tween 80 solution); group II (methotrexate) received 0.5 mg/kg body weight methotrexate; group III (SD) was sleep deprived and received the vehicle; group IV (SD+Methotrexate) was sleep deprived and received 0.5 mg/kg body weight methotrexate. Sleep deprivation was induced using the modified multiple platform technique for 14 days. Treatments were administered twice weekly by oral gavage for 14 days. Blood was collected on day 14 and serum was obtained for analyses of testosterone, LH and FSH levels. IL-1β level and histology of the testis were also determined. Data were expressed as Mean ± SEM and analysed using ANOVA. p < 0.05 was considered significant.

RESULTS

Serum testosterone levels were significantly decreased while testicular IL-1β was increased in SD and SD+Methotrexate compared with Control. FSH and LH levels were not significantly different among the groups.

CONCLUSION

Results of this study suggest that reduction in serum testosterone level in sleep deprived rats is not dependent on increased level of IL-1β.

Effects of vitamin E and melatonin on serum testosterone level in sleep deprived Wistar rats

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.