Magnesium sulfate protects blood-brain barrier integrity and reduces brain edema after acute ischemic stroke in rats

The role of metal ions in stroke: current evidence and future perspectives

Metal ions play a pivotal role in maintaining optimal brain function within the human body. Nevertheless, the accumulation of these ions can result in irregularities that lead to brain damage and dysfunction. Disruptions of metal ion homeostasis can result in various pathologies, including inflammation, redox dysregulation, and blood-brain barrier (BBB) disruption. While research on metal ions has chiefly focused on neurodegenerative diseases, little attention has been given to their involvement in the onset and progression of stroke. Recent studies have identified cuproptosis and confirmed ferroptosis as significant factors in stroke pathology, underscoring the importance of metal ions in stroke pathology, including ion transport, neurotoxicity, BBB damage, and cell death. Additionally, it provides an overview of contemporary metal ion chelators and detection techniques, which may offer novel approaches to stroke treatment.

Magnesium and Cognitive Health in Adults: A Systematic Review and Meta-Analysis

Magnesium (Mg) plays a key role in neurological functioning and manifestations. However, the evidence from randomized controlled trials (RCTs) and cohorts on Mg and cognitive health among adults has not been systematically reviewed. We aimed to examine the associations of various Mg forms (supplements, dietary intake, and biomarkers) with cognitive outcomes by summarizing evidence from RCTs and cohorts. PubMed, Embase, PsycINFO, and the Cochrane Central Register of Controlled Trials were searched for relevant peer-reviewed articles published up to May 3, 2024. Three random-effects models were performed, when appropriate, to evaluate the relationship between Mg and cognitive outcomes: 1) linear meta-regression, 2) nonlinear (quadratic) meta-regression, and 3) meta-analysis using Mg variables categorized based on pre-existing recommendations. Three RCTs and 12 cohort studies were included in this systematic review. Evidence from the limited number of RCTs was insufficient to draw conclusions on the effects of Mg supplements. Cohort studies showed inconsistent dose-response relationships between dietary Mg and cognitive disorders, with high heterogeneity across populations. However, consistent U-shape associations of serum Mg with all-cause dementia and cognitive impairment were found in cohorts, suggesting an optimal serum Mg concentration of ∼0.85 mmol/L. This nonlinear association was detected in meta-regression (Pquadratic = 0.003) and in meta-analysis based on the reference interval of serum Mg (0.75-0.95 mmol/L) [<0.75 compared with 0.85 mmol/L: pooled hazard ratio (HR) = 1.43; 95% confidence interval (CI) = 1.05, 1.93; >0.95 compared with 0.85 mmol/L: pooled HR = 1.30; 95% CI = 1.03, 1.64]. More evidence from RCTs and cohorts is warranted. Future cohort studies should evaluate various Mg biomarkers and collect repeated measurements of Mg intake over time, considering different sources (diet or supplements) and factors affecting absorption (for example, calcium-to-Mg intake ratio). This systematic review was preregistered in PROSPERO (CRD42023423663).

Now that the door is open: an update on ischemic stroke pharmacotherapeutics for the neurointerventionalist

The last 10 years have seen a major shift in management of large vessel ischemic stroke with changes towards ever-expanding use of reperfusion therapies (intravenous thrombolysis and mechanical thrombectomy). These strategies 'open the door' to acute therapeutics for ischemic tissue, and we should investigate novel therapeutic approaches to enhance survival of recently reperfused brain. Key insights into new approaches have been provided through translational research models and preclinical paradigms, and through detailed research on ischemic mechanisms. Additional recent clinical trials offer exciting salvos into this new strategy of pairing reperfusion with neuroprotective therapy. This pairing strategy can be employed using drugs that have shown neuroprotective efficacy; neurointerventionalists can administer these during or immediately after reperfusion therapy. This represents a crucial moment when we emphasize reperfusion, and have the technological capability along with the clinical trial experience to lead the way in multiprong approaches to stroke treatment.

Associations between Serum Mineral Nutrients, Gut Microbiota, and Risk of Neurological, Psychiatric, and Metabolic Diseases: A Comprehensive Mendelian Randomization Study

Recent observational studies have reported associations between serum mineral nutrient levels, gut microbiota composition, and neurological, psychiatric, and metabolic diseases. However, the causal effects of mineral nutrients on gut microbiota and their causal associations with diseases remain unclear and require further investigation. This study aimed to identify the associations between serum mineral nutrients, gut microbiota, and risk of neurological, psychiatric, and metabolic diseases using Mendelian randomization (MR). We conducted an MR study using the large-scale genome-wide association study (GWAS) summary statistics of 5 serum mineral nutrients, 196 gut microbes at the phylum, order, family, and genus levels, and a variety of common neurological, psychiatric, and metabolic diseases. Initially, the independent causal associations of mineral nutrients and gut microbiota with diseases were examined by MR. Subsequently, the causal effect of mineral nutrients on gut microbiota was estimated to investigate whether specific gut microbes mediated the association between mineral nutrients and diseases. Finally, we performed sensitivity analyses to assess the robustness of the study results. After correcting for multiple testing, we identified a total of 33 causal relationships among mineral nutrients, gut microbiota, and diseases. Specifically, we found 4 causal relationships between 3 mineral nutrition traits and 3 disease traits, 15 causal associations between 14 gut microbiota traits and 6 disease traits, and 14 causal associations involving 4 mineral nutrition traits and 15 gut microbiota traits. Meanwhile, 118 suggestive associations were identified. The current study reveals multiple causal associations between serum mineral nutrients, gut microbiota, risk of neurological, psychiatric, and metabolic diseases, and potentially provides valuable insights for subsequent nutritional therapies.

[Posterior reversible encephalopathy syndrome in autoimmune disorders]

Posterior reversible encephalopathy syndrome (PRES) is characterized by nonspecific symptoms, including not only pronounced non-focal and various focal neurological signs but also specific neuroimaging features, including vasogenic edema affecting predominantly the posterior area. PRES usually develops in the setting of acute arterial hypertension. However, it is not uncommon for PRES to develop in non-hypertensive patients, including people with autoimmune disorders (multiple sclerosis, neuromyelitis optica spectrum disorder, etc). PRES could also be due to the toxic effects of drugs or other substances. The pathophysiological mechanisms of PRES include impaired autoregulation of cerebral blood flow due to acute arterial hypertension and toxic endotheliotropic effects of endogenous and exogenous factors.

Potential role of Nigella Sativa and its Constituent (Thymoquinone) in Ischemic Stroke

Ischemic stroke is one of the major causes of global mortality, which puts great demands on health systems and social welfare. Ischemic stroke is a complex pathological process involving a series of mechanisms such as ROS accumulation, Ca2+ overload, inflammation, and apoptosis. The lack of effective and widely applicable pharmacological treatments for ischemic stroke patients has led scientists to find new treatments. The use of herbal medicine, as an alternative or complementary therapy, is increasing worldwide. For centuries, our ancestors had known the remedial nature of Nigella sativa (Family Ranunculaceae) and used it in various ways, either as medicine or as food. Nowadays, N. sativa is generally utilized as a therapeutic plant all over the world. Most of the therapeutic properties of this plant are attributed to the presence of thymoquinone which is the major biological component of the essential oil. The present review describes the pharmacotherapeutic potential of N. sativa in ischemic stroke that has been carried out by various researchers. Existing literature highlights the protective effects of N. sativa as well as thymoquinone in ischemia stroke via different mechanisms including anti-oxidative stress, anti-inflammation, anti-apoptosis, neuroprotective, and vascular protective effects. These properties make N. sativa and thymoquinone promising candidates for developing potential agents for the prevention and treatment of ischemic stroke.

Natural Fatty Acid Guards against Brain Endothelial Cell Death and Microvascular Pathology following Ischemic Insult in the Presence of Acute Hyperglycemia

Ischemic stroke is worsened by the presence of sudden high blood sugar levels, even in individuals without pre-existing diabetes. This elevated glucose concentration hampers the ability of energy-starved brain cells to efficiently use it as a source of energy. Consequently, this leads to the production of abundant amounts of toxic glucose metabolites, which trigger oxidative stress in the brain milieu, particularly in the microvasculature of the brain. A prominent feature of this oxidative stress is the demise of endothelial cells, causing detrimental changes in blood vessels, including a reduction in their vascular diameter, a decreased efficiency of vessel proliferation, and the impaired integrity of tight junctions. These vascular pathologies contributed to an increase in the volume of damaged tissues (infarct), an exacerbation of brain swelling (edema), and a decline in cognitive and motor functions. In a mouse model of ischemic stroke with induced acute hyperglycemia, a naturally occurring saturated fatty acid provides protective cover to the microvasculature by preventing damage related to oxidative stress. Our current research revealed that lauric acid (LA) attenuated infarct volume and reduced brain edema by reducing endothelial cell death, enhancing vessels' diameter, promoting vascular angiogenesis, and stabilizing barrier functions. Animals administered with this natural compound showed a significant reduction in 4-HNE-positive vessels. In conclusion, natural saturated fatty acids help to preserve brain microvascular functions following ischemic insults in the presence of acute hyperglycemia.

Neuroprotective Effects of Artificial Cerebrospinal Fluid: Analysis of Brainstem Auditory-Evoked Potential Monitoring During Microvascular Decompression in 117 Consecutive Patients

BACKGROUND AND OBJECTIVES

To study the efficacy of irrigation with artificial cerebrospinal fluid (aCSF) for protection of cranial nerves during surgery; the time required for recovery of brainstem auditory-evoked potentials (BAEPs) that would reflect cochlear function was analyzed in comparison with that for saline irrigation.

METHODS

This retrospective study included 117 consecutive patients (95 women, mean age 51.5 ± 11.4 year) who underwent microvascular decompression for hemifacial spasm. During surgery, BAEPs were monitored to avoid damage to the auditory pathways. When a delayed latency of >1 ms or a decrease in amplitude of >50% was detected in BAEP wave V, surgical maneuvers were halted, and the operative field was irrigated with saline or aCSF. Saline was used for irrigation in 58 patients and aCSF in the other 59. The time required for BAEP recovery at the first halt in each patient was analyzed, and the results were compared between the groups.

RESULTS

Surgical procedures were interrupted because of BAEP latency delays or decreases in amplitude in 51 of the patients in the saline group and 54 in the aCSF group. In both groups, the latencies and amplitudes recovered significantly with time and both recovered earlier after aCSF irrigation than after saline irrigation. Hearing outcome was not significantly different between 2 groups.

CONCLUSION

aCSF is effective for protection of cochlear nerve and promotes recovery from transient dysfunction during surgery. The protective effect may be attributed to multiple factors including conditioned pH, electrolyte composition, glucose, and microelements, such as magnesium and phosphate.

Magnesium Sulfate Reduces Carrageenan-Induced Rat Paw Inflammatory Edema Via Nitric Oxide Production

Background

Magnesium is an antagonist of the N-methyl-D-aspartate receptor. This study aimed to investigate the anti-edematous effect of magnesium sulfate (MS) in different protocols of use and the possible mechanism of its action.

Methods

In a rat model of carrageenan-induced paw inflammation, the anti-edematous activity of MS was assessed with a plethysmometer. The effects of the nonselective inhibitor (L-NAME), selective inhibitor of neuronal (L-NPA) and inducible (SMT) nitric oxide synthase on the effects of MS were evaluated.

Results

MS administered systemically before or after inflammation reduced edema by 30% (5 mg/kg, P < .05) and 55% (30 mg/kg, P < .05). MS administered locally (.5 mg/paw, P < .05) significantly prevented the development of inflammatory edema by 60%. L-NAME, intraperitoneally administered before MS, potentiated (5 mg/kg, P < .05) or reduced (3 mg/kg, P < .05), while in the highest tested dose L-NPA (2 mg/kg, P < .01) and SMT (.015 mg/kg, P < .01) reduced the anti-edematous effect of MS.

Conclusions

Magnesium is a more effective anti-edematous drug in therapy than for preventing inflammatory edema. The effect of MS is achieved after systemic and local peripheral administration and when MS is administered as a single drug in a single dose. This effect is mediated at least in part via the production of nitric oxide.

Magnesium and the Brain: A Focus on Neuroinflammation and Neurodegeneration

Magnesium (Mg) is involved in the regulation of metabolism and in the maintenance of the homeostasis of all the tissues, including the brain, where it harmonizes nerve signal transmission and preserves the integrity of the blood-brain barrier. Mg deficiency contributes to systemic low-grade inflammation, the common denominator of most diseases. In particular, neuroinflammation is the hallmark of neurodegenerative disorders. Starting from a rapid overview on the role of magnesium in the brain, this narrative review provides evidences linking the derangement of magnesium balance with multiple sclerosis, Alzheimer's, and Parkinson's diseases.

Low-dose sodium-glucose cotransporter 2 inhibitor ameliorates ischemic brain injury in mice through pericyte protection without glucose-lowering effects

Antidiabetic sodium-glucose cotransporter 2 (SGLT2) inhibitors have attracted attention for their cardiorenal-protective properties beyond their glucose-lowering effect. However, their benefits in ischemic stroke remain controversial. Here we show the effects of luseogliflozin, a selective SGLT2 inhibitor, in acute ischemic stroke, using a permanent middle cerebral artery occlusion (pMCAO) model in non-diabetic mice. Pretreatment with low-dose luseogliflozin, which does not affect blood glucose levels, significantly attenuated infarct volume, blood-brain barrier disruption, and motor dysfunction after pMCAO. SGLT2 was expressed predominantly in brain pericytes and was upregulated in peri- and intra-infarct areas. Notably, luseogliflozin pretreatment reduced pericyte loss in ischemic areas. In cultured pericytes, luseogliflozin activated AMP-activated protein kinase α and increased mitochondrial transcription factor A expression and number of mitochondria, conferring resistance to oxygen-glucose deprivation. Collectively, pre-stroke inhibition of SGLT2 induces ischemic tolerance in brain pericytes independent of the glucose-lowering effect, contributing to the attenuation of ischemic brain injury.

Pre-treatment of non-diabetic mice with the SGLT2 inhibitor, luseogliflozin, reduces brain damage and neurological dysfunction following middle cerebral artery occlusion by acquiring ischemic tolerance in pericytes.

Roles of Nitric Oxide in Brain Ischemia and Reperfusion

Brain ischemia and reperfusion (I/R) is one of the most severe clinical manifestations of ischemic stroke, placing a significant burden on both individuals and society. The only FDA-approved clinical treatment for ischemic stroke is tissue plasminogen activator (t-PA), which rapidly restores cerebral blood flow but can have severe side effects. The complex pathological process of brain I/R has been well-established in the past few years, including energy metabolism disorders, cellular acidosis, doubling of the synthesis or release of excitotoxic amino acids, intracellular calcium homeostasis, free radical production, and activation of apoptotic genes. Recently, accumulating evidence has shown that NO may be strongly related to brain I/R and involved in complex pathological processes. This review focuses on the role of endogenous NO in pathological processes in brain I/R, including neuronal cell death and blood brain barrier disruption, to explore how NO impacts specific signaling cascades and contributes to brain I/R injury. Moreover, NO can rapidly react with superoxide to produce peroxynitrite, which may also mediate brain I/R injury, which is discussed here. Finally, we reveal several therapeutic approaches strongly associated with NO and discuss their potential as a clinical treatment for ischemic stroke.

Ki20227 aggravates apoptosis, inflammatory response, and oxidative stress after focal cerebral ischemia injury

The survival of microglia depends on the colony-stimulating factor-1 receptor (CSF1R) signaling pathway under physiological conditions. Ki20227 is a highly selective CSF1R inhibitor that has been shown to change the morphology of microglia. However, the effects of Ki20227 on the progression of ischemic stroke are unclear. In this study, male C57BL/6 mouse models of focal cerebral ischemic injury were established through the occlusion of the middle cerebral artery and then administered 3 mg/g Ki20227 for 3 successive days. The results revealed that the number of ionized calcium-binding adaptor molecule 1/bromodeoxyuridine double positive cells in the infarct tissue was reduced, the degree of edema was increased, neurological deficits were aggravated, infarct volume was increased, and the number of peri-infarct Nissl bodies was reduced. The number of terminal deoxynucleotidyl transferase dUTP nick-end labeling-positive cells in the peri-infarct tissue was increased. The expression levels of Bax and Cleaved caspase-3 were up-regulated. Bcl-2 expression was downregulated. The expression levels of inflammatory factors and oxidative stress-associated factors were increased. These findings suggested that Ki20227 blocked microglial proliferation and aggravated the pathological progression of ischemia/reperfusion injury in a transient middle cerebral artery occlusion model. This study was approved by the Animal Ethics Committee of Lanzhou University Second Hospital (approval No. D2020-68) on March 6, 2020.

Associations of Serum Magnesium with Brain Morphology and Subclinical Cerebrovascular Disease: The Atherosclerosis Risk in Communities-Neurocognitive Study

Circulating magnesium has been associated with a lower risk of dementia, but the physiologic effects by which magnesium may prevent neurological insults remain unclear. We studied 1466 individuals (mean age 76.2 ± 5.3, 28.8% black, 60.1% female) free of prevalent stroke, with measured serum magnesium and with available MRI scans obtained in 2011–2013, participating in the Atherosclerosis Risk in Communities Neurocognitive Study (ARIC-NCS). Cross-sectional differences in frontal, temporal, parietal, and occipital lobe volume, along with deep grey matter, total brain, and white matter hyperintensity volume across serum magnesium (categorized into quintiles and per standard deviation increases) were assessed using multiple linear regression. We also examined associations of magnesium with the prevalence of cortical, subcortical, and lacunar infarcts using multiple logistic regression. After adjusting for demographics, biomarkers, medications, and cardiometabolic risk factors, higher circulating magnesium was associated with greater total brain volume and frontal, temporal, and parietal lobe volumes (volumes 0.14 to 0.19 standard deviations higher comparing Q5 to Q1). Elevated magnesium was also associated with lower odds of subcortical infarcts (OR (95%CI): 0.44 (0.25, 0.77) comparing Q5 to Q1) and lacunar infarcts (OR (95%CI): 0.40 (0.22, 0.71) comparing Q5 to Q1). Elevated serum magnesium was cross-sectionally associated with greater brain volumes and lower odds of subclinical cerebrovascular disease, suggesting beneficial effects on pathways related to neurodegeneration and cerebrovascular damage. Further exploration through prospective analyses is needed to assess increasing circulating magnesium as a potential neuroprotective intervention.

Can magnesium sulfate prophylaxis reduce colistin nephrotoxicity?

The study aimed to investigate the role of magnesium sulfate prophylaxis in nephrotoxicity caused by colistin. Thirty Wistar Albino rats were divided into four groups: control, colistin, magnesium (Mg), and Mg+colistin. The drugs were administered to the groups for seven days. Urea-creatinine values were measured at the beginning (T0) and end (T1) of the study. Malondialdehyde (MDA) levels were measured in plasma and kidney tissue, glutathione (GSH) levels were analyzed in the erythrocyte and kidney tissues. At the end of the study, the semiquantitative score (SQS) was calculated by the histopathological examination of the kidneys. Urea values significantly decreased in Mg and Mg+colistin groups compared to the baseline (p=0.013 and p=0.001). At the time of T1, these groups had significantly lower urea values than the colistin and control groups. Creatinine value was significantly increased in the colistin group compared to baseline (p=0.005), the creatinine value in the colistin group was significantly higher than the Mg+colistin group (p=0.011). Plasma MDA levels were significantly higher in the colistin group compared to the other groups at the time of T1 (p<0.001). The Mg+colistin group had lower renal MDA levels than the colistin group. The colistin group had significantly higher renal tubular grade (p=0.035), renal affected area (p<0.001), and SQS (p=0.001) than the Mg+colistin group. The results of the study suggested that Mg sulfate may have a nephrotoxicity-reducing effect on colistin.

Can magnesium sulfate prophylaxis reduce colistin nephrotoxicity?

The study aimed to investigate the role of magnesium sulfate prophylaxis in nephrotoxicity caused by colistin. Thirty Wistar Albino rats were divided into four groups: control, colistin, magnesium (Mg), and Mg+colistin. The drugs were administered to the groups for seven days. Urea-creatinine values were measured at the beginning (T0) and end (T1) of the study. Malondialdehyde (MDA) levels were measured in plasma and kidney tissue, glutathione (GSH) levels were analyzed in the erythrocyte and kidney tissues. At the end of the study, the semiquantitative score (SQS) was calculated by the histopathological examination of the kidneys. Urea values significantly decreased in Mg and Mg+colistin groups compared to the baseline (p=0.013 and p=0.001). At the time of T1, these groups had significantly lower urea values than the colistin and control groups. Creatinine value was significantly increased in the colistin group compared to baseline (p=0.005), the creatinine value in the colistin group was significantly higher than the Mg+colistin group (p=0.011). Plasma MDA levels were significantly higher in the colistin group compared to the other groups at the time of T1 (p<0.001). The Mg+colistin group had lower renal MDA levels than the colistin group. The colistin group had significantly higher renal tubular grade (p=0.035), renal affected area (p<0.001), and SQS (p=0.001) than the Mg+colistin group. The results of the study suggested that Mg sulfate may have a nephrotoxicity-reducing effect on colistin.

Potential Therapies for Cerebral Edema After Ischemic Stroke: A Mini Review

Stroke is the leading cause of global mortality and disability. Cerebral edema and intracranial hypertension are common complications of cerebral infarction and the major causes of mortality. The formation of cerebral edema includes three stages (cytotoxic edema, ionic edema, and vasogenic edema), which involve multiple proteins and ion channels. A range of therapeutic agents that successfully target cerebral edema have been developed in animal studies, some of which have been assessed in clinical trials. Herein, we review the mechanisms of cerebral edema and the research progress of anti-edema therapies for use after ischemic stroke.

Low Serum Magnesium Levels Are Associated With Hemorrhagic Transformation After Thrombolysis in Acute Ischemic Stroke

Background: In patients with acute ischemic stroke, hemorrhagic transformation is a major complication after intravenous thrombolysis. This study aimed to investigate the relationship between serum magnesium levels and hemorrhagic transformation (HT) after thrombolytic therapy.

Methods: We retrospectively analyzed data from 242 patients who received thrombolytic therapy at the Second Affiliated Hospital of the Wenzhou Medical University in China. Baseline serum magnesium levels were measured before intravenous thrombolysis, and the occurrence of HT was evaluated using computed tomography images reviewed within 24–36 h after therapy. The relationship between serum magnesium levels and HT was examined using multivariate logistic regression, subgroup analysis, and restricted cubic spline models.

Results: Of the 242 included patients, 43 (17.8%) developed HT. Patients with HT had significant lower serum magnesium levels than those without HT (0.81 ± 0.08 vs. 0.85 ± 0.08 mmol/L, p = 0.007). Multivariable logistic regression analysis indicated that patients with higher serum magnesium levels had lower risk of HT (OR per 0.1-mmol/L increase 0.43, 95% CI 0.27–0.73, p = 0.002). However, this association did not persist when baseline levels of serum magnesium were higher than the median value (0.85 mmol/L) in subgroup analysis (OR per 0.1-mmol/L increase 0.58, 95% CI 0.14–2.51, p = 0.47). This threshold effect was also observed in the restricted cubic spline model when serum magnesium levels were above 0.88 mmol/L. No association between symptomatic HT and serum magnesium levels was observed in our study (OR per 0.1-mmol/L increase 0.52, 95% CI 0.25–1.11, p = 0.092).

Conclusions: Lower serum magnesium levels in patients with ischemic stroke are associated with an increased risk of HT after intravenous thrombolysis, but perhaps only when serum magnesium is below a certain minimal concentration.

Anti-inflammatory and Neuroprotective Agents in Clinical Trials for CNS Disease and Injury: Where Do We Go From Here?

Neurological disorders are major contributors to death and disability worldwide. The pathology of injuries and disease processes includes a cascade of events that often involve molecular and cellular components of the immune system and their interaction with cells and structures within the central nervous system. Because of this, there has been great interest in developing neuroprotective therapeutic approaches that target neuroinflammatory pathways. Several neuroprotective anti-inflammatory agents have been investigated in clinical trials for a variety of neurological diseases and injuries, but to date the results from the great majority of these trials has been disappointing. There nevertheless remains great interest in the development of neuroprotective strategies in this arena. With this in mind, the complement system is being increasingly discussed as an attractive therapeutic target for treating brain injury and neurodegenerative conditions, due to emerging data supporting a pivotal role for complement in promoting multiple downstream activities that promote neuroinflammation and degeneration. As we move forward in testing additional neuroprotective and immune-modulating agents, we believe it will be useful to review past trials and discuss potential factors that may have contributed to failure, which will assist with future agent selection and trial design, including for complement inhibitors. In this context, we also discuss inhibition of the complement system as a potential neuroprotective strategy for neuropathologies of the central nervous system.

Long-term metformin therapy improves neurobehavioral functions and antioxidative activity after cerebral ischemia/reperfusion injury in rats

Metformin (MET),an antidiabetic drug, has shown antioxidative and neuroprotective effects. In the present investigation, we aimed to study the probable effects of MET on cerebral ischemia/reperfusion in rats. Rats underwent cerebral ischemia/reperfusion and MET was administered orally at doses of 100 and 200 mg/kg for 56 days. Anxiety- and depressive-like behaviors were evaluated by elevated plus-maze or forced swimming tests, respectively. was assessed by. Cognitive functions were assessed by Y-maze continuous alternation task and morris water maze. The activity of SOD and the level of BDNF were measured in brains samples. Our results showed that administration of 200 mg/kg MET reduced the percent of brain edema (84.00 ± 2.13) in comparison with the ischemic animals (91.25 ± 2.25) (p < 0.05). Administration of 200 mg/kg MET in ischemic animals improved anxiety-like behavior by increasing the percentage of the open arms entries (46.51 ± 3.13) and the percentage of the open arms time (32.70 ± 2.49) in comparison with the cerebral ischemia group (26.35 ± 7.02 and 15.32 ± 5.78, respectively) (all p < 0.001). MET treatment (200 mg/kg) increased the cognition index of correct alternations (90.20 ± 4.95) in comparison with the cerebral ischemia group (59.50 ± 8.01) (p < 0.05). MET at the both doses reduced escape latency compared to the cerebral ischemia animals (all p < 0.05). In addition, 200 mg/kg MET increased the time spent in the target quadrant (16.06 ± 0.58) in comparison with the ischemic animals (9.84 ± 0.92) (p < 0.001) and the both doses of the drug increased the number of crossing (5.42 ± 0.36 and 6.5 ± 0.42, respectively) compared to the cerebral ischemia group (3.75 ± 0.31) (p < 0.05 and p < 0.001, respectively). Moreover, 200 mg/kg MET reduced the immobility time (47.50 ± 9.00) in comparison with the cerebral ischemia group (93.43 ± 8.28) (p < 0.001). Furthermore, the both doses of MET increased the BDNF levels (4590 ± 197.6 and 4767 ± 44.10, respectively) in comparison with the ischemic animals (3807 ± 42.56) (p < 0.01 and p < 0.001, respectively). Also, the both doses of the drug increased the SOD activity of brain (52.67 ± 0.33 and 55.00 ± 0.57, respectively) compared to the ischemic animals (49.33 ± 0.33) (p < 0.01 and p < 0.001, respectively). Based on our data, long-term MET therapy may improve behavioral disorders following cerebral ischemia/reperfusion and can be considered as a novel therapeutic approach for the treatment of brain ischemic conditions.

Magnesium Increases the Protective Effect of Citicoline on Aluminum Chloride-induced Cognitive Impairment

Objective

Alzheimer's disease is a popular neurodegenerative disorder which is growing in the elderly people. Exposure to environmental pollutant like aluminum could trigger or accelerate its involved mechanisms like tau phosphorylation. The current study will evaluate the effect of alone or co-administration of Citicoline or/and magnesium on the aluminum chloride induced memory impairment.

Methods

Male albino mice were randomly divided into different groups (n = 7). Memory impairment was induced via orally administration of 300 mg/kg Aluminum Chloride for 28 days. Based on respective group, animals received 100, 250, 500 mg/kg of Citicoline or 50, 100, 150 mg/kg of Magnesium sulfate (MgSO4), intraperitoneally. In co-administration, 50 mg/kg of MgSO4 injected concomitantly with 100, 250, or 500 mg/kg of Citicoline. Rivastigmine (2 mg/kg intraperitoneally) was used as a positive control. Memory was evaluated using the Object Recognition Task (ORT) and Passive Avoidance Test (PAT).

Results

The studied doses of Citicoline or MgSO4 when administered individually showed significant increase in the discrimination index in ORT and latency time in the PAT compared to the Aluminium chloride (AlCl3) treated group. Concomitant injection of 50 mg/kg MgSO4 with the different doses of Citicoline strongly increased the above indices values in comparison to each alone.

Conclusion

The findings show, individual administration of Citicoline or MgSO4 inverted the AlCl3-induced memory impairment in a dose independent manner. The addition of MgSO4 to the Citicoline showed a synergistic effect in the PAT and likely additive effect in the ORT.