Erythritol attenuates testicular dysfunction in diabetic rat via suppression of oxidative stress, inflammation and apoptosis

Hyperglycemia -induced oxidative stress and inflammation have been closely associated with diabetes complications including testicular dysfunction. Conversely, reducing blood glucose and/or use of antioxidant have been associated with reduced diabetes complications. The present study investigated the effect of erythritol (which has both antioxidant and blood glucose lowering function) on diabetes -induced testicular dysfunction in rats. Thirty male Wistar rats (170-200g) were randomly divided into 5 groups: 1) control; 2) erythritol; 3) diabetic; 4) diabetic + erythritol 1000 mg/kg; and 5) diabetic + metformin 300 mg/kg. After 8 weeks of treatment period, blood sample, testes and epididymis were collected for reproductive hormones, biochemical and histological examinations, and sperm analysis respectively. There was a significant (p < 0.05) decrease in sperm count, sperm motility, sperm morphology and serum reproductive hormones (Follicle stimulating hormone (FSH), Leutinizing hormone (LH), testosterone and gonadotropin releasing hormone (GnRH)) of diabetes rat compared to control. Also, diabetes rat showed increase in sperm and testicular malonaldehyde (MDA) and decrease in sperm and testicular superoxide dismutase (SOD) activity and glutathione (GSH) level. Further, diabetes rat showed reduced testicular weight, decreased testicular 17β-HSD and 3β-HSD activity and testicular histo-architectural alteration which were accompanied by decrease testicular vascular endothelial growth factor (VEGF) and concomitant increase in testicular myeloperoxidase activity and level of caspase 3. The present results indicates that induction of diabetes in rat causes reduction in the level of reproductive hormones (Testosterone, LH and FSH) as well as sperm and testicular oxidative stress causing abnormal sperm parameters, and biochemical and histo-architectural alterations in the testes of rats. In addition, the present results suggest that erythritol administration reduced blood glucose and ameliorated hyperglycemia -induced oxidative stress -mediated alterations in both sperm and testes of diabetes rat. Further, the present study suggests that erythritol improved testicular oxidative stress, inflammation and apoptosis by up-regulating VEGF.

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.

Spironolactone reversed hepato-ovarian triglyceride accumulation caused by letrozole-induced polycystic ovarian syndrome: tissue uric acid-a familiar foe

Polycystic ovarian syndrome (PCOS) is a complex endocrine disease among women of reproductive age and is one of the main causes of infertility. Non-alcoholic fatty liver disease (NAFLD), the most prominent chronic liver disease in adults, is characterized by excess hepatic triglyceride (TG) accumulation. PCOS women have increased risk of NAFLD and uric acid has been documented to have a positive correlation with subclinical tissue damage and might be the link in the cystic. Spironolactone (SPL) is a mineralocorticoid receptor (MR) blocker that has been in wide clinical use for some decades. In this research, we investigated the effects of SPL on ovarian and hepatic tissue damage in experimental PCOS rats induced by letrozole (LET). A total of eighteen adult female Wistar rats were used for this study and the animals divided into 3 groups are treated with vehicle, LET (1 mg/kg), and LET+SPL (SPL; 0.25 mg/kg), p.o. once daily respectively for 21 uninterrupted days. Results showed that LET treatment induced features of PCOS characterized by increased plasma testosterone (T) and luteinizing hormone (LH) together with increased body weight. Abnormal ovarian and hepatic histomorphological changes were also observed with elevated uric acid (UA) and TG accumulation in both tissues respectively. Treatment with SPL however attenuated the elevated testosterone in the LET-induced PCOS model accompanied with a reversal in the observed ovarian and hepatic UA, TG accumulation, and altered histomorphological changes. Taken together, spironolactone reversed the PCOS-induced ovarian and hepatic tissue damage by suppressing tissue UA and TG accumulation.

Drospirenone-containing contraceptive exerts positive effects on cardiac uric acid and PAI-1 but not GSK-3: Improved safety profiles in contraception?

The use of combined oral contraceptives (COC) have been associated with increased risk of adverse cardiovascular events and elevated cardiac and circulating plasminogen activator inhibitor-1 (PAI-1) and glycogen synthase kinase-3 (GSK-3) have been implicated in these events. Contraceptives containing drospirenone, a progestin with anti-androgenic actions may have a positive or neutral effect on cardiac PAI-1 and GSK-3 levels. Studies on the favorable effects of oral contraceptives containing drospirenone when compared with other androgenic contraceptives have not been fully elucidated. We therefore sought to compare the effect of a contraceptive containing ethinyl estradiol and drospirenone (DSP) with a contraceptive containing ethinyl estradiol and levonorgestrel (LVG) on cardiac uric acid (UA), PAI-1, GSK-3 and some hematological parameters. Ten weeks old female Wistar rats were divided into three groups; control (CON), LVG or DSP treated rats. The treatment lasted for 8 weeks. Results showed that LVG and not DSP treatment led to increase in plasma and cardiac tissue UA, plasma and cardiac PAI-1 as well as granulocyte-lymphocyte ratio (GLR) and platelet-lymphocyte ratio (PLR). However, the DSP treatment affected the circulating GSK-3. Taken together, the findings showed that LVG and not DSP affected cardiac UA and PAI-1. These results suggest that COC containing drospirenone appears to have positive effects on cardiac UA and PAI-1 levels but do not affect GSK-3, hence, COC containing drospirenone may be a better and safer means of contraception compared to androgenic contraceptives.

Oral hormonal therapy with ethinylestradiol–levonorgestrel improves insulin resistance, obesity, and glycogen synthase kinase-3 independent of circulating mineralocorticoid in estrogen-deficient rats

Estrogen deficiency has been associated with increased incidence of cardiovascular diseases , and recent clinical trials of standard formulations of hormonal therapies have not demonstrated consistent beneficial effects. Estrogen–progestin therapy has been used as exogenous estrogen to normalize depressed estrogen level during menopause. Ovariectomized rodents mimic an estrogen-deficient state in that they develop cardiometabolic dysfunction, including insulin resistance (IR). We therefore hypothesized that hormonal therapy with combined oral contraceptive steroids, ethinylestradiol–levonorgestrel (EEL), improves IR, obesity, and glycogen synthase kinase-3 (GSK-3) through reduction of circulating mineralocorticoid in ovariectomized rats. Twelve-week-old female Wistar rats were divided into 4 groups: sham-operated (SHM) and ovariectomized (OVX) rats were treated with or without EEL (1.0 μg ethinylestradiol and 5.0 μg levonorgestrel) daily for 8 weeks. Results showed that OVX or SHM + EEL treated rats had increased HOMA-IR (homeostatic model assessment of IR), 1 h postload glucose, HOMA-β, triglycerides (TG), total cholesterol (TC), TC/HDL cholesterol, TG/HDL cholesterol, plasma insulin, GSK-3, corticosterone, and aldosterone. On the other hand, OVX + EEL treatment ameliorated all these effects except that of aldosterone. Taken together, the results demonstrate that oral hormonal replacement with EEL improves IR and pancreatic β-cell function and suppresses GSK-3 and glucocorticoid independent of circulating aldosterone, suggesting a positive cardiometabolic effect of oral EEL therapy in estrogen-deficient rats.