Modulation of GABA by sodium butyrate ameliorates hypothalamic inflammation in experimental model of PCOS.

Polycystic ovarian syndrome (PCOS) is a known endocrine disorder that has affected many women of childbearing age, and is accompanied by various neurodegenerative conditions. Hence, this study investigates the impact of butyrate in reversing hypothalamic-related disorder, possibly through γ aminobutyric acid (GABA) in a rat model of PCOS. Eight-week-old female Wistar rats were allotted into four groups (n = 5), which include control, butyrate, letrozole, and letrozole + butyrate groups. PCOS was induced by administering 1 mg/kg of letrozole (oral gavage) for 21 days. After confirmation of PCOS, 200 mg/kg of butyrate (oral gavage) was administered for 6 weeks. Rats with PCOS were characterized by elevated levels of plasma insulin and testosterone. Increases in plasma and hypothalamic triglyceride levels, inflammatory biomarker (SDF-1), apoptotic marker (caspase-6), and decreased plasma GnRH were observed. Additionally, a decrease in hypothalamic GABA was revealed. Nevertheless, the administration of butyrate attenuated these alterations. The present study suggests that butyrate ameliorates hypothalamic inflammation in an experimental model of PCOS, a beneficial effect that is accompanied by enhanced GABA production.

Mineralocorticoid receptor blockade attenuates hyperandrogenic metabolic dysregulation in letrozole-induced PCOS rat model.

Purpose: Polycystic ovarian syndrome (PCOS) is a metabolic syndrome associated with mineralocorticoid receptor (MR) activation, which causes infertility in women of reproductive age. Spironolactone (SPL) is a MR blocker with inconclusive effect in the treatment of PCOS. Therefore, the present study hypothesized that low dose SPL would ameliorate metabolic dysfunction associated with PCOS. Methods: Female Wistar rats (8-week-old) were divided into 3 groups namely: Control, SPL, Letrozole (LET)-treated and LET + SPL-treated groups. The control group was given vehicle (distilled water), SPL-treated group received 0.25 mg/kg, LET-treated group received 1 mg/kg of LET and LET + SPL-treated group received a combination of LET and SPL. The administrations were done by oral gavage for 21 days uninterruptedly. Biochemical parameters such as lipid profile, malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), γ-glutamyl transferase (GGT), lactate dehydrogenase (LDH), testosterone, 17-ß estradiol and glutathione peroxidase (GPx) were determined with appropriate assay methods. Results: Letrozole-treated group had a significant increase in ovarian weight, plasma and ovarian triglycerides, MDA/TNF-α, GGT/LDH and plasma testosterone while it decreased plasma 17-ß estradiol and plasma/ovarian high-density lipoproteins and GPx when compared with control group. In addition, histomorphological changes were observed in LET-treated group compared with control group. Nevertheless, administration of low dose SPL attenuated these perturbations. Conclusion: The present study therefore demonstrates that inhibition of mineralocorticoid receptor by low dose SPL ameliorates hyperandrogenic metabolic dysfunction in a rat model of PCOS. Therefore, low dose SPL is hereby suggested as a promising therapeutic agent in the management of PCOS.

Short chain fatty acid, acetate restores ovarian function in experimentally induced PCOS rat model.

BACKGROUND: Polycystic ovarian syndrome (PCOS) is pathogenically characterized with hyperandrogenism and metabolic alterations, which often result in ovarian changes and infertility in women of reproductive age. Epigenetic changes have been linked to the development of PCOS. However, the involvement of epigenetic regulator, histone deacetylase (HDAC) in PCOS-driven ovarian dysfunction is not clear. Howbeit, the present study hypothesized that acetate, an HDAC inhibitor (HDACi) would protect against ovarian dysfunction in experimentally induced PCOS. MATERIALS AND METHODS: Female Wistar rats weighing 120-150 g were randomly divided into four groups (n = 6). The groups received vehicle, sodium acetate (200 mg/kg), letrozole (1 mg/kg) and letrozole with acetate by oral gavage respectively. The administrations were done daily for 21 days. RESULTS: The rat model of PCOS had increased body weight and ovarian weight, 1-hr postload glucose and plasma insulin, testosterone and LH/FSH ratio as well as reduced insulin sensitivity and plasma 17-ß estradiol and sex hormone binding globulin. This model of PCOS in addition showed a significant increase in plasma and ovarian triglyceride, total cholesterol, TNF-α and HDAC, and ovarian malondialdehyde as well as a significant reduction in ovarian glutathione peroxidase/reduced glutathione and NrF2 with the histology of ovarian tissues showing disrupted morphology with significant increase in the number of degenerated follicles compared with control group. These alterations were however attenuated when treated with HDACi, acetate. CONCLUSION: Altogether, the present results suggest that acetate protects ovarian function with evidence of normal growing follicles and enhanced circulating 17-ß estradiol by inhibition of HDAC.

Low-dose spironolactone abates cardio-renal disorder by reduction of BAX/inflammasome expression in experimentally induced polycystic ovarian syndrome rat model.

The impact of low-dose spironolactone (LSPL) on polycystic ovarian syndrome (PCOS)-associated cardio-renal disorder is unknown. Therefore, the present study hypothesized that LSPL would ameliorate cardio-renal disorders in experimental PCOS animals. Eight-week-old female Wistar rats were allotted into three groups. The control group received vehicle (distilled water; per os (p.o.)), the letrozole (LET)-treated group designated as PCOS group received LET (1 mg/kg; p.o.), and PCOS+LSPL received LET and LSPL (0.25 mg/kg, p.o.). The treatment was done once daily for 21 days uninterrupted. The experimental PCOS rats were characterized with insulin resistance, as well as elevated testosterone and luteinizing hormone/follicle-stimulating hormone, with a significant increase in cardiac and renal lipid profile, oxidative stress, inflammatory biomarkers (nuclear factor-κB and tumor necrosis factor-α), lactate dehydrogenase and lactate content and decrease in cardiac and renal antioxidant system (glutathione peroxidase and reduced glutathione) compared with the control rats. In addition, immunohistochemical assessment of cardiac and renal tissue showed significant expression of inflammasome and B-cell lymphoma-2 associated X-protein (BAX) in animals with PCOS. Nevertheless, these perturbations were attenuated following the administration of LSPL. Collectively, the present results suggest that LSPL attenuates PCOS-associated cardio-renal disorders by reduction of oxidative stress and BAX/inflammasome expression.

Melatonin supplementation preserves testicular function by attenuating lactate production and oxidative stress in high fat diet-induced obese rat model.

Metabolic syndrome, including obesity has been documented as a critical factor in male reproductive dysfunction with subsequent reduction in male fertility. The therapeutic potential of melatonin has been demonstrated against oxidative stress-induced pathologies. Therefore, the present study investigated the effects of melatonin on testicular dysfunction associated with high fat diet (FD)-induced obese rat model, and the possible involvement of peroxisome proliferator-activated receptor-γ (PPAR-γ). Adult male Wistar rats (n = 6/group) were used: control group received vehicle (normal saline), obese group received 40% FD, melatonin-treated group received melatonin (4 mg/kg), and obese plus melatonin group received melatonin and 40% FD and the treatment lasted for 12 weeks. High fat diet caused increased body weight and testicular triglyceride, total cholesterol, malondialdehyde, γ-glutamyl transferase, lactate production and lactate/pyruvate ratio as well as decreased glutathione/glutathione peroxidase, nitric oxide and PPAR-γ and circulating testosterone. Nevertheless, all these alterations were attenuated when supplemented with melatonin. Taken together, these results demonstrates that FD-induced obesity causes testicular dysfunction. In addition, the results suggest that melatonin supplementation protects against obesity-associated testicular dysfunction and this effect is accompanied by upregulation of PPAR-γ.

Aqueous Extract of Cola nitida and Garcinia kola Synergistically Enhances Hippocampal-hypothalamic Glutamate and Na+ /K+ -ATPase Activity in Male Wistar Rats.

BACKGROUND: The incidence of cognitive decline has been proposed to rise exponentially in the coming years. Therapies targeting molecular pathways involved in the enhancement of memory and energy regulation could be a major breakthrough in the prevention or management of dementia in susceptible populations. OBJECTIVES: This study investigated the effects of aqueous extracts of Cola nitida (AECONS) and Garcinia kola (AEGAK) on glutamate level and Na+/K+-ATPase activity in the hippocampus and hypothalamus of male Wistar rats. METHODS: Adult male Wistar rats (170-200) were randomly allotted into groups (n=5/group); control (distilled water p.o.), AECONS1 (200 mg/kg), AECONS2 (400 mg/kg), AEGAK1 (200 mg/kg), AEGAK2 (400 mg/kg), AECONS1+AEGAK1 and AECONS2+AEGAK2. The extract was prepared and the administration was done daily for 6 weeks. RESULTS AND DISCUSSION: Administration of AECONS or AEGAK increased plasma, hippocampal and hypothalamic glutamate, Na+/K+-ATPase activity, NO, SOD except hippocampal glutamate in AECONS1/AEGAK1, Na+/K+-ATPase activity and SOD in AEGAK1, hypothalamic glutamate and SOD in AECONS1 when compared with control. Besides, MDA level decreased in AEGAK2 and hippocampal but not hypothalamic MDA decreased in AEGAK1 compared with control. However, concomitant administration of AECONS and AEGAK enhanced plasma, hippocampal and hypothalamic biomarkers except hypothalamic MDA level. The present study demonstrates that AECONS and AEGAK synergistically enhance hippocampal and hypothalamic glutamate and Na+/K+- ATPase activity, which are accompanied by NO and SOD-dependent antioxidant enrichment. CONCLUSION: These findings, therefore, suggest that AECONS+AEGAK could be a better therapeutic candidate in hippocampal-hypothalamic-related neurodegenerative diseases.

Acetate supplementation restores testicular function by modulating Nrf2/PPAR-γ in high fat diet-induced obesity in Wistar rats.

PURPOSE: Several studies have established impaired testicular function in obese male population, including the young males with childhood obesity, contributing to increased male infertility, which is a universal trend in the last few decades. Short chain fatty acids (SCFAs) have been recently demonstrated to inhibit progression to metabolic comorbidities. The present study therefore hypothesized that SCFAs, acetate attenuates testicular dysfunction in high fat diet (HFD)-induced obese rat model, possibly by modulating Nrf2/PPAR-γ. METHODS: Adult male Wistar rats weighing 160-190 g were randomly allotted into three groups (n = 6/group): The groups received vehicle (distilled water), 40% HFD and sodium acetate (200 mg/kg) plus 40% HFD respectively. The administration lasted for 12 weeks. RESULTS: HFD caused obesity, which is characterized with increased body weight and visceral adiposity and insulin resistance/hyperinsulinemia. In addition, it increased testicular lipid deposition, malondialdehyde, pro-inflammatory mediators, lactate/pyruvate ratio, γ-Glutamyl transferase, and circulating leptin as well as decreased testicular glutathione, nitric oxide, Nrf2, PPAR-γ and circulating follicle stimulating hormone and testosterone without a significant change in testicular lactate dehydrogenase, blood glucose and luteinizing hormone when compared to the control group. Nevertheless, administration of acetate reversed the HFD-induced alterations. CONCLUSION: The present results demonstrates that HFD causes obesity-driven testicular dysfunction, associated with testicular lipid deposition, oxidative stress, and inflammation. The study in addition suggests the restoration of testicular function in obese animals by acetate, an effect that is accompanied by elevated Nrf2/PPAR-γ.

Protective role of melatonin against adipose-hepatic metabolic comorbidities in experimentally induced obese rat model.

BACKGROUND: Adipose and hepatic metabolic dysfunctions are critical comorbidities that also aggravate insulin resistance in obese individuals. Melatonin is a low-cost agent and previous studies suggest that its use may promote metabolic health. However, its effects on some comorbidities associated with obesity are unknown. Herein, we investigated the hypothesis that melatonin supplementation would attenuate adipose-hepatic metabolic dysfunction in high fat diet (HFD)-induced obesity in male Wistar rats. MATERIALS AND METHODS: Twenty-four adult male Wistar rats (n = 6/group) were used: Control group received vehicle (normal saline), obese group received 40% high fat diet, melatonin-treated group received 4 mg/kg of melatonin, and obese plus melatonin group received 40% HFD and melatonin. The treatment lasted for 12 weeks. RESULTS: HFD caused increased food intake, body weight, insulin level, insulin resistance and plasma and liver lipid but decreased adipose lipid. In addition, HFD also increased plasma, adipose and liver malondialdehyde, IL-6, uric acid and decreased Glucose-6-phosphate dehydrogenase, glutathione, nitric oxide and circulating obestatin concentration. However, these deleterious effects except food intake were attenuated when supplemented with melatonin. CONCLUSION: Taken together, the present results indicate that HFD exposure causes adipose-hepatic metabolic disturbance in obese animals, which are accompanied by oxidative stress and inflammation. In addition, the present results suggest that melatonin supplementation attenuates adipose-hepatic metabolic dysfunction, accompanying obesity by suppression of oxidative stress/inflammation-dependent mechanism and increasing circulating obestatin.

High fructose-enriched diet synergistically exacerbates endocrine but not metabolic changes in letrozole-induced polycystic ovarian syndrome in Wistar rats.

BACKGROUND: Polycystic Ovarian Syndrome (PCOS) is a multifactorial endocrine-metabolic disorder that highly contributes to the prevalence of infertility globally. The increased consumption of refined carbohydrate, particularly fructose has been associated with pandemic metabolic disorders, including in women of reproductive age. However, the effects of high fructose consumption (FRD) on endocrine and metabolic disorders associated with PCOS are not clear. Therefore, this study investigated the effects of FRD on endocrine/metabolic changes in letrozole-induced PCOS in Wistar rats. MATERIALS AND METHODS: Twenty-eight adult female Wistar rats were randomly allotted into 4 groups and treated with vehicle, letrozole (LET; 0.5 mg/kg), FRD (D-fructose chow pellet mixture) and LET + FRD. The treatment lasted for 21days. RESULTS: Data showed a significant increase in ovarian weight, liver weight, luteinising hormone (LH), testosterone and decrease in follicle stimulating hormone as well as moderate histopathological changes in the fallopian tube, uterus and liver of animals with PCOS. FRD-treated group showed a significant increase in ovarian weight and liver weight but no significant alteration in hormonal profile or histopathological changes in uterus and fallopian tube. However, FRD significantly altered hormonal profile with consequent histopathological changes in fallopian tube and uterus but FRD did not alter ovarian/liver weight or blood glucose in animals with PCOS when compared with animals without PCOS. CONCLUSION: The present results demonstrate that FRD synergistically aggravates endocrine but not metabolic changes in PCOS, suggesting that FRD might deteriorate endocrine-related phenotypes in PCOS.

Low dose spironolactone-mediated androgen-adiponectin modulation alleviates endocrine-metabolic disturbances in letrozole-induced PCOS.

Polycystic ovarian syndrome (PCOS), is a multifactorial endocrine disorder in women of reproductive age. It usually associates with metabolic disorders (MDs), which aggravates the risk of infertility, cardiometabolic events and associated comorbidities in women with PCOS. Adiponectin, a circulating protein produced by adipocytes, which has been suggested to inversely correlate with MDs. Spironolactone, a non-selective mineralocorticoid receptor (MR) antagonist, has been in wide clinical use for several decades. Herein, we investigated the effects of low dose spironolactone (LDS) and the role of adiponectin in endocrine-metabolic disturbances in experimentally-induced PCOS rats. Eighteen female Wistar rats (160-180 g) were randomly allotted into 3 groups and treated with vehicle (p.o.), letrozole (LET; 1 mg/kg) and LET + LDS (0.25 mg/kg), once daily for 21 days, respectively. The results showed that LET-treated animals had features of PCOS, characterized by elevated plasma testosterone and prolactin, increased body weight gain and ovarian weight as well as disrupted ovarian cytoarchitecture and degenerated follicles. Additionally, elevated fasting blood glucose, 1 h-postload glucose and plasma insulin, impaired glucose tolerance, insulin resistance, reduced insulin sensitivity, increased plasma and ovarian lipid profile, plasma lipid peroxidation, TNF-α, IL-6 and decreased plasma glutathione peroxidase and glutathione content were observed. These alterations were associated with decreased circulating adiponectin and were reversed when treated with LDS. The present results suggest that LDS ameliorates endocrine-metabolic disturbances and inflammation-related comorbidities associated with LET-induced PCOS by modulating circulating androgen-adiponectin status.

Sodium butyrate arrests pancreato-hepatic synchronous uric acid and lipid dysmetabolism in high fat diet fed Wistar rats.

High fat diet (HFD) is a risk factor for metabolic syndrome which is characterized by overt glucose dysmetabolism and tissue derangement. The liver and pancreas are important metabolic tissues with anatomical proximity sharing splanchnic and mesenteric circulation but it is unclear whether, there is an associated metabolic status between the two organs in health and disease. Uric acid (UA) hypersecretion and ectopic lipid accumulation are characteristic pathophysiology of an array of non-communicable diseases. Sodium butyrate (BUT) is reputed for therapeutic roles in metabolic derangement. Therefore, the present study investigated synchrony in hepatic and pancreatic UA and lipid metabolic status in HFD-induced glucose dysregulation and probed the beneficial effects of BUT. Twenty-four female Wistar rats were treated with normal rat chow and distilled water (po) or sodium butyrate (200 mg/kg; po) or high fat diet and distilled water (po) or high fat diet and sodium butyrate. Results showed that HFD increased plasma, pancreatic and hepatic triglyceride, triglyceride-glucose index, malondialdehyde, uric acid (UA), lactate dehydrogenase but reduced glucose-6-phosphate dehydrogenase. Histological analysis revealed hepatic and pancreatic architectural derangement and cellular degeneration in HFD-fed animals. However, BUT reversed the HFD-induced systemic, pancreatic and hepatic synchronous dysmetabolism with evidence of improved histology. HFD-induced lipid and UA alterations were synchronous in the pancreas and liver. BUT elicits beneficial effects on systemic and tissue HFD-induced deleterious metabolic changes which were synchronized in pancreas and liver of rats.

Diabetic neuropathy is associated with increased pain perception, low serum beta-endorphin and increase insulin resistance among Nigerian cohorts in Ekiti State.

INTRODUCTION: There has been an increase in the global prevalence of diabetic polyneuropathy and research evidence suggests that insulin resistance plays an important role in its development and prognosis. However, there seem to be a dearth of information in understanding the likely interplay between beta endorphin, insulin resistance and pain perception especially in the setting of painful diabetic neuropathy. METHOD: This study recruited 120 volunteers divided into four groups (30 per group): group 1 healthy volunteer (control); group 2 DM type 2 without neuropathy (DM group); group 3 DM type 2 with painful neuropathy (DPN group); group 4 DM type 2 without painful neuropathy (DN). All subjects were evaluated for pain threshold and neuropathy using an ischemia-induced pain model and biothesiometer respectively. Their beta-endorphin, glycated hemoglobin, fasting plasma insulin, and HOMA values were determined and means compared using ANOVA. RESULT: Serum beta-endorphin is significantly reduced in DN and DPN (∗p < 0.001) compared with the control and DM group. Also, DPN and DN patients have significantly increased insulin resistance compared to those without neuropathy (∗p < 0.001; ∗p < 0.0001 respectively). There is a significant positive correlation between the pain threshold and beta-endorphin in all the groups except DN group. The correlation between beta-endorphin and insulin resistance was negative and significant in control and DM groups only. Suggestive that the fact that insulin resistance plays an important role in diabetes polyneuropathy, does not alone explain the chronic pain perception noticed in the DPN patients. CONCLUSION: The present study demonstrates that diabetic neuropathy patients have a poor endogenous opioid peptide system which is associated with increased pain perception and high insulin resistance. However, insulin resistance alone does not explain the chronic pain perception noticed in the DPN patients. Thus, further study is required.

Protective role of glutamine against cadmium-induced testicular dysfunction in Wistar rats: Involvement of G6PD activity.

BACKGROUND: Endocrine disruptor such as cadmium has been widely reported to cause testicular toxicity, which contributes to recent decline in male fertility worldwide. Glutamine, the most abundant amino acid in the body has been demonstrated to exert protective effects in cellular toxicity. However, its role in testicular toxicity is unknown. The present study is therefore aimed at investigating the effects of glutamine supplementation on cadmium-induced testicular toxicity, and the possible involvement of glucose-6-phosphate dehydrogenase (G6PD) activity. MATERIALS AND METHOD: Male Wistar rats weighing 160-190 g were allotted into 4 groups (n = 5/group): The groups received vehicle (distilled water; p.o.), glutamine (1gkg-1; p.o.), cadmium chloride (5mgkg-1p.o.) and Cadmium chloride plus glutamine respectively, daily for 30 days. Biochemical and histological analyses were performed with appropriate method. RESULTS: Administration of cadmium significantly decreased body weight, sperm count, motility and viability, as well as altered sperm morphology and progressivity. Cadmium also caused atrophy of the seminiferous tubule in addition to disrupted testicular architecture, lumen, Sertoli cells and spermatogonia. Similarly, serum and testicular aspartate transaminase, and malondialdehyde significantly increased, and G6PD, glutathione, nicotinamide adenine dinucleotide phosphate and nitric oxide significantly decreased with corresponding decrease in follicle stimulating hormone, luteinizing hormone and testosterone in cadmium-treated animals compared with control groups. However, supplementation with glutamine attenuated these alterations. CONCLUSION: The present study demonstrates that cadmium induces testicular dysfunction that is attributable to defective G6PD and accompanied by increased lipid peroxidation and impaired NO-dependent endothelial function. Interestingly, glutamine supplementation ameliorates cadmium-induced testicular dysfunction through enhancement of G6PD activity.

Methanolic extract of Cola nitida elicits dose-dependent diuretic, natriuretic and kaliuretic activities without causing electrolyte impairment, hepatotoxicity and nephrotoxicity in rats.

Cola nitida (Kolanut) is conventionally used in tropical Africa for the treatment of all kinds of ailments such as migraine, morning sickness, metabolic disorders etc. However, this study was designed to investigate the diuretic, natriuretic and kaliuretic activities of methanolic extract of Cola nitida (MECN) in male Wistar rats. Adult male Wistar rats were randomly allotted into control (25 ml/kg b.w.), furosemide (20 mg/kg b.w; standard), MECN1 (100 mg/kg), MECN2 (200 mg/kg), MECN3 (300 mg/kg), MECN4 (400 mg/kg), MECN5 (500 mg/kg), MECN6 (600 mg/kg) groups with n=6. The extract was prepared as previously described and the treatment lasted for 14 days. Urine volume and diuretic indices were estimated. Urine electrolytes, plasma electrolytes, plasma/renal AST/ALT, plasma creatinine and urea were assayed using flame photometry and standard colorimetric method respectively.Administration of different doses of C. nitida significantly altered body weight gain and water intake but not food intake compared with control group. There were significant increases in urine volume and urine electrolytes (Na+, K+ and Cl-), a decrease in plasma/renal ALT and AST activities, a decrease in plasma creatinine and urea concentration and no alteration in plasma electrolytes when compared with control and furosemide-treated groups. Our study suggests that MECN elicits diuretic, natriuretic, and kaliuretic activities without causing electrolyte impairment, hepatotoxicity and nephrotoxicity. These effects are dose-dependent.