Diosgenin alleviates alcohol-mediated escalation of social defeat stress and the neurobiological sequalae

RATIONALE

Emerging evidence indicates that persistent alcohol consumption escalates psychosocial trauma achieved by social defeat stress (SDS)-induced neurobiological changes and behavioral outcomes. Treatment with compounds with neuroprotective functions is believed to reverse ethanol (EtOH)-aggravated SDS-induced behavioral impairments.

OBJECTIVES

We investigated the outcomes of diosgenin treatment, a phytosteroidal sapogenin in mice co-exposed to repeated SDS and EtOH administration.

METHODS

During a period of 14 days, SDS male mice were repeatedly administered EtOH (20%, 10 mL/kg) orally from days 8-14 (n = 9). Within days 1-14, SDS mice fed with EtOH were simultaneously treated with diosgenin (25 and 50 mg/kg) or fluoxetine (10 mg/kg) by oral gavage. Locomotor, cognitive-, depressive-, and anxiety-like behaviors were assessed. Adrenal weight, serum glucose, and corticosterone levels were assayed. Brain markers of oxido-inflammatory, neurochemical levels, monoamine oxidase-B, and acetylcholinesterase activities were measured in the striatum, prefrontal cortex, and hippocampus.

RESULTS

The anxiety-like behavior, depression, low stress resilience, social, and spatial/non-spatial memory decline exhibited by SDS mice exposed to repeated EtOH administration were alleviated by diosgenin (25 and 50 mg/kg) and fluoxetine, illustrated by increased dopamine and serotonin concentrations and reduced monoamine oxidase-B and acetylcholinesterase activities in the prefrontal cortex, hippocampus, and striatum. Diosgenin attenuated SDS + EtOH interaction induced corticosterone release and adrenal hypertrophy, accompanied by reduced TNF-α, IL-6, malondialdehyde, and nitrite levels in the striatum, prefrontal cortex, and hippocampus. Diosgenin increased glutathione, superoxide dismutase, and catalase levels in SDS + EtOH-exposed mice.

CONCLUSIONS

Our data suggest that diosgenin reverses SDS + EtOH interaction-induced behavioral changes via normalization of hypothalamic-pituitary-adrenal axis, neurochemical neurotransmissions, and inhibition of oxidative and inflammatory mediators in mice brains.

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.

Ginkgo biloba supplement abates lead-induced endothelial and testicular dysfunction in Wistar rats via up-regulation of Bcl-2 protein expression, pituitary-testicular hormones and down-regulation of oxido-inflammatory reactions

BACKGROUND

Apoptotic and oxido-inflammatory pathways have been found to be up-regulated in lead acetate poisoning which has been associated to endothelial and testicular dysfunctions. It is yet uncertain, nevertheless, if treatment with Ginkgo biloba supplements (GBS), a flavonoid-rich natural product can lessen the adverse effects of lead on endothelial and testicular functions. This study investigated the impact of Ginkgo biloba supplementation on lead-induced endothelial and testicular dysfunctions.

METHODS

The animals were treated with GBS (50 mg/kg and 100 mg/kg orally) for 14 days following oral exposure to lead acetate (25 mg/kg) for 14 days. After euthanasia, blood samples, epididymal sperm, testes, and aorta were collected. The quantities of the hormones (testosterone, follicle stimulating hormone (FSH) and luteinizing hormone (LH), as well as the anti-apoptotic, oxidative, nitrergic, inflammatory markers, were then determined using immunohistochemistry, ELISA, and conventional biochemical methods.

RESULTS

GBS reduced lead-induced oxidative stress by increasing the levels of the antioxidant enzymes catalase (CAT), glutathione (GSH), and superoxide dismutase (SOD), while lowering malondialdehyde (MDA) in endothelium and testicular cells. Normal testicular weight was restored by GBS which also decreased endothelial endothelin-I and increased nitrite levels. TNF-α and IL-6 were decreased while Bcl-2 protein expression was enhanced. Lead-induced alterations in reproductive hormones (FSH, LH, and testosterone) were also restored to normal.

CONCLUSION

According to our result, using Ginkgo biloba supplement prevented lead from causing endothelial and testicular dysfunction by raising pituitary-testicular hormone levels, boosting Bcl-2 protein expression and lowering oxidative and inflammatory stress in the endothelium and testes.

Co-administration of metformin and/or glibenclamide with losartan reverse NG-nitro-l-arginine-methyl ester-streptozotocin-induced hypertensive diabetes and haemodynamic sequelae in rats

Over the years, there have been opinions on whether to reduced blood pressure (BP) to a different levels in patients with diabetes mellitus. Hence, this study investigated the efficacy of the co-administration of losartan (angiotensin receptor blocking antihypertensive agent) with metformin and/or glibenclamide (antidiabetic agents) on hypertensive-diabetic experimental rats induced by N^G-nitro-l-arginine-methyl-ester hydrochloride (l-NAME), and streptozotocin (STZ). STZ (45 mg/kg, i.p.)-induced diabetic rats combined with l-NAME (40 mg/kg, p.o.)-induced hypertension were allotted into different groups. Group 1 received distilled water (10 mL/kg) and served as normal control, group 2 comprised hypertensive diabetic rats with distilled water, groups 3-5 were hypertensive-diabetic rats but received combination treatments of losartan + metformin, losartan + glibenclamide, and losartan + metformin + glibenclamide daily for 8 weeks, respectively. Our finding revealed no changes in the body weights, but there was a significant increase in fasting blood sugar levels in l-NAME - STZ-induced hypertensive-diabetes, which were lowered by losartan + metformin, losartan + glibenclamide, and losartan + metformin + glibenclamide treatments. Moreover, the increased systolic-BP, mean arterial pressure but not diastolic-BP and heart rate by l-NAME + STZ were attenuated more significantly by losartan + metformin + glibenclamide between weeks 2-8 relative to hypertensive-diabetic control. l-NAME + STZ-induced elevated levels of lactate dehydrogenase and creatinine kinase, were differentially reversed by losartan + metformin, losartan + glibenclamide, and losartan + metformin + glibenclamide. However, l-NAME + STZ-induced decreased nitrite level was significantly restored by all treatments, suggesting increased nitrergic transmission. Additionally, l-NAME + STZ-induced degeneration of pancreatic islet and myocardial cells were dramatically alleviated by losartan + metformin + glibenclamide treatments. Our findings suggest hyperglycemia with raised systolic-BP should be managed with losartan combined with both metformin and glibenclamide than single combination of losartan with antidiabetics.

Antihypertensive and antihyperglycemic effects of combinations of losartan with metformin and/or glibenclamide in desoxycorticosterone acetate and streptozotocin-induced hypertensive diabetic rats

BACKGROUND

Hypertension is a medical condition that often comorbidly exist in patients with type II diabetes. Therefore, it is very important to manage both conditions simultaneously to mitigate the complications and mortality connected with this comorbidity. Hence, this study investigated the antihypertensive and antihyperglycemic effects of combinations of losartan (LOS) with metformin (MET) and/or glibenclamide (GLB) in hypertensive diabetic rats. Hypertensive diabetic state was induced with desoxycorticosterone acetate (DOCA) and streptozotocin (STZ) in adult Wistar rats. The rats were divided into 5 groups (n = 5): control group (group 1), hypertensive diabetic (HD) control (group 2), treatment groups receiving LOS + MET (group 3), LOS + GLB (group 4), and LOS + MET + GLB (group 5). Group 1 comprised healthy rats while groups 2-5 were HD rats. The rats were treated orally once daily for 8 weeks. Fasted blood glucose (FBS) level, haemodynamic parameters, and some biochemical indices were thereafter assessed.

RESULTS

FBS level and blood pressure measurements were significantly (P < 0.05) increased following induction by DOCA/STZ. The drug treatment combinations, particularly combination of LOS + MET + GLB, significantly (P < 0.05) reduced the induced hyperglycemia and remarkably decreased systolic blood pressure and heart rate. There was significant (P < 0.05) reduction in raised lactate dehydrogenase and creatinine kinase levels by all drug treatment combinations except LOS + GLB.

CONCLUSIONS

Our findings suggest that LOS combinations with MET and/or GLB exhibited significant antidiabetic and antihypertensive effects against DOCA/STZ-induced hypertensive diabetic state in rats.

Polycythemia, Thrombocythemia, and Hyperfibrinogenemia are Associated With Streptozotocin-induced Diabetes and Salt-induced Hypertension in Male Wistar Rats

Background: Diabetes mellitus and anaemia are frequently reported to be associated with polycythemia in several studies. Furthermore, some studies also have linked polycythemia with hypertension. However, whether hypertension and diabetes comorbidity had polycythemia/erythrocytosis, thrombocythemia, or hyperfibrinogenemia is unknown. Objectives: This study investigated the incidence of polycythemia, thrombocythemia, and hyperfibrinogenemia in diabetic and hypertensive male Wistar rats. Methods: Thirty male Wistar rats were categorized into five groups, each with six animals: negative control (zero-salt diet), positive control (standard salt diet – 0.3% salt), high salt diet – 8% salt (HSD only), Streptozotocin (STZ)-induced diabetes fed with normal salt diet (STZ only), and high salt diet with STZ-induced diabetes (HSD+STZ). Hematological variables and fibrinogen concentration were measured after a 4-week experimental period. One-way ANOVA was used for statistical analysis and a P<0.05 was considered significant. Results: The heart rate and mean arterial pressure increased significantly in the HSD, STZ, and HSD+STZ groups, suggesting salt-induced hypertension. Compared to the controls, the STZ and HSD +STZ groups had significantly higher hematocrit, platelet estimate, and fibrinogen concentration. The STZ and HSD+STZ groups had a shorter clotting period, which correlated with higher platelet counts and fibrinogen levels. Compared to the controls, the HSD group had a lower platelet count and fibrinogen concentration, as well as a longer clotting time. Conclusion: This study suggests that polycythemia, thrombocythemia, and hyperfibrinogenemia are potential risk factors for hypertension in people with diabetes mellitus.

Taurine, an essential β-amino acid insulates against ketamine-induced experimental psychosis by enhancement of cholinergic neurotransmission, inhibition of oxidative/nitrergic imbalances, and suppression of COX-2/iNOS immunoreactions in mice

Cholinergic, oxidative, nitrergic alterations, and neuroinflammation are some key neuropathological features common in schizophrenia disease. They involve complex biological processes that alter normal behavior. The present treatments used in the management of the disorder remain ineffective together with some serious side effects as one of their setbacks. Taurine is a naturally occurring essential β-amino acid reported to elicit antipsychotic property in first episode psychosis in clinical setting, thus require preclinical investigation. Hence, we set out to investigate the effects of taurine in the prevention and reversal of ketamine-induced psychotic-like behaviors and the associated putative neurobiological mechanisms underlying its effects. Adult male Swiss mice were sheared into three separate cohorts of experiments (n = 7): drug alone, preventive and reversal studies. Treatments consisted of saline (10 mL/kg/p.o./day), taurine (50 and 100 mg/kg/p.o./day) and risperidone (0.5 mg/kg/p.o./day) with concomitant ketamine (20 mg/kg/i.p./day) injections between days 8-14, or 14 days entirely. Behavioral hyperactivity, despair, cognitive impairment, and catalepsy were measured. Brain oxidative/nitrergic imbalance, immunoreactivity (COX-2 and iNOS), and cholinergic markers were determined in the striatum, prefrontal-cortex, and hippocampus. Taurine abates ketamine-mediated psychotic-like episodes without cataleptogenic potential. Taurine attenuated ketamine-induced decrease in glutathione, superoxide-dismutase and catalase levels in the striatum, prefrontal-cortex and hippocampus. Also, taurine prevented and reversed ketamine-mediated elevation of malondialdehyde, nitrite contents, acetylcholinesterase activity, and suppressed COX-2 and iNOS expressions in a brain-region dependent manner. Conclusively, taurine insulates against ketamine-mediated psychotic phenotype by normalizing brain central cholinergic neurotransmissions, oxidative, nitrergic and suppression of immunoreactive proteins in mice brains.

Up-regulation of B-cell lymphoma factor-2 expression, inhibition of oxidative stress and down-regulation of pro-inflammatory cytokines are involved in the protective effect of cabbage (Brassica oleracea) juice in lead-induced endothelial dysfunction in rats

BACKGROUND

Oxido-inflammatory stress and dysregulation of nitric oxide (NO) system has been implicated in lead toxicity. Cabbage is an antioxidant-rich household vegetable with plethora of therapeutic potentials. The present study investigated the anti-oxido-inflammatory activity of cabbage in lead-induced endothelial dysfunction.

METHODS

Twenty (20) male Wistar rats were selected into four groups (n = 5) and treated with distilled water (1 mL/100 g b.wt), lead acetate (25 mg/kg b.wt), cabbage juice (1 mL/100 g b.wt) and lead acetate (25 mg/kg b.wt) plus cabbage juice (1 mL/100 g b.wt) respectively. Treatment was done orally for 28 days, thereafter, oxidative stress (SOD, CAT, GSH, and MDA), inflammatory (TNF-α and IL-6) and apoptotic (Bcl-2) markers were assayed using standard biochemical assays as well as histoarchitectural study of the endothelium.

RESULTS

The results showed that they were significant increase in MDA, ET-1, TNF-α and IL-6 while SOD, GSH, CAT, NO and Bcl-2 protein expression were decreased in Lead exposed animals. Endothelial histoarchitecture was also altered. Following Cabbage juice treatment, MDA, ET-I, TNF-α and IL-6 were down-regulated while SOD, GSH, CAT, NO and Bcl-2 protein expression were up-regulated. Histoarchitecture was significantly recovered.

CONCLUSION

The study suggests that cabbage juice could mitigates Lead-induced endothelial dysfunction by modulating oxido-inflammatory and anti-apoptotic mediators.

DATA AVAILABILITY

All data are available upon request.

COVID-19 pandemic: the implications of the natural history, challenges of diagnosis and management for care in sub-Saharan Africa

BACKGROUND

Coronavirus disease (COVID-19) is a severe acute respiratory infection which has afflicted virtually almost all nations of the earth. It is highly transmissible and represents one of the most serious pandemics in recent times, with the capacity to overwhelm any healthcare system and cause morbidity and fatality.

MAIN CONTENT

The diagnosis of this disease is daunting and challenging as it is dependent on emerging clinical symptomatology that continues to increase and change very rapidly. The definitive test is the very expensive and scarce polymerase chain reaction (PCR) viral identification technique. The management has remained largely supportive and empirical, as there are no officially approved therapeutic agents, vaccines or antiviral medications for the management of the disease. Severe cases often require intensive care facilities and personnel. Yet there is paucity of facilities including the personnel required for diagnosis and treatment of COVID-19 in sub-Saharan Africa (SSA). It is against this backdrop that a review of key published reports on the pandemic in SSA and globally is made, as understanding the natural history of a disease and the documented responses to diagnosis and management is usually a key public health strategy for designing and improving as appropriate, relevant interventions. Lead findings were that responses by most nations of SSA were adhoc, paucity of public health awareness strategies and absence of legislations that would help enforce preventive measures, as well as limited facilities (including personal protective equipment) and institutional capacities to deliver needed interventions.

CONCLUSION

COVID-19 is real and has overwhelmed global health care system especially low-income countries of the sub-Sahara such as Nigeria. Suggestions for improvement of healthcare policies and programs to contain the current pandemic and to respond more optimally in case of future pandemics are made herein.