A potential neuroprotective role for magnesium in neurological disease has been appreciated for almost three decades, yet translation to the clinical arena has proven elusive. Accumulating experimental evidence continues to suggest that magnesium plays a critical role in a number of neurological conditions including headache, stress, alcohol/drug intoxication, acute brain injury, seizures, Parkinson's disease and Alzheimer's disease. Simple administration of a magnesium salt in these conditions has not always been therapeutically successful, with a number of studies showing poor penetration of serum magnesium across the blood brain barrier. Several studies have since demonstrated that using a carrier such as polyethylene glycol can address this, simultaneously reducing the dose of magnesium required to achieve the desired central effects while at the same time attenuating deleterious peripheral effects. Alternatively, administering a more permeable magnesium salt, such as magnesium threonate, is seen as the preferred option in more chronic neurological conditions, with positive results having been achieved in experimental models of Alzheimer's disease. Irrespective of the approach, improved central penetration of a magnesium compound that avoids peripheral side effects of high magnesium dosages is clearly a desirable outcome, and should now be investigated in animal models that accurately mimic the complex human condition.

Magnesium (Mg) is relatively stable in the intracellular compartment, although decreases linearly with advancing age. This begs the question as to whether Mg could be used as biomarker of aging. A biomarker of aging is a biological parameter of an organism that, in the absence of disease, better predicts functional capability at a later age than the chronological age. Bone and muscle Mg content might be useful biomarkers, but the need for biopsies and the heterogeneous distribution of Mg in bones and muscles strongly limit the application of these methods in clinical practice. Similar considerations can be made for urinary Mg assessment, particularly after a loading test. Markers of Mg in blood seem fairly unreliable as biomarkers of aging since they are strongly dependent upon renal function, do not reflect the intracellular Mg status, and, in some investigations, are within normal ranges although other Mg parameters are not. Other investigations (e.g. nuclear magnetic resonance with fluorescent probes) seem to be promising, but their availability remains limited.

The aim of this study was to determine the relationship between serum magnesium (Mg) concentrations in middle-aged and older men, and the occurrence of selected metabolic and hormonal disorders. The study involved a total of 313 men aged 50-75 years, and who underwent standard anthropometric measurements. Also determined were blood serum Mg, lipid parameters - total cholesterol (TCh), high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglyceride (TG) and carbohydrate metabolism parameters - glucose, insulin (I). In men with a normal total testosterone (TT) concentration, serum Mg was significantly higher compared to patients with a total testosterone deficiency. The subjects with metabolic syndrome had lower serum Mg compared to patients without metabolic syndrome. Serum Mg concentration in type 2 diabetes mellitus was lower compared to men without diabetes. In patients with arterial hypertension, serum Mg concentration was lower than in patients without hypertension. Statistically significant negative correlations were found for the relationships between Mg concentration and body mass index, waist-to-hip ratio, abdominal circumference, arterial blood pressure. Statistically significant, positive correlations were found for the relationships between Mg concentration and TT, TCh, LDL concentrations. The lower serum Mg level may be conducive to the development of total testosterone deficiency, arterial hypertension, diabetes, and therefore metabolic syndrome.

Abnormal serum sodium levels are frequently observed among patients with aneurysmal subarachnoid hemorrhage (SAH) and may worsen cerebral edema or mass effect. Low serum potassium levels (hypokalemia) are also common among patients with aneurysmal SAH and are associated with prolonged QT interval and ventricular arrhythmia. Recent meta-analysis suggests that MgSO4 infusion improves the clinical outcome in patients after aneurysmal SAH; however, MgSO4 infusion may theoretically exacerbate electrolyte disturbance. We retrospectively reviewed the prospectively collected demographic and laboratory data of 100 patients after aneurysmal subarachnoid SAH in a neurosurgical center in Hong Kong. 51 patients had daily magnesium sulfate infusion for 14 days (Group 1) and 49 patients were managed similarly, without magnesium sulfate infusion (Group 2). Days of hypernatremia (mean+/-SD) were 2.0+/-2.7 for group 1 and 2.0+/-2.5 for group 2, p = 0.999; days of hyponatremia (mean+/-SD) were 2.7+/-3.1 for group 1 and 2.0+/-2.9 for group 2, p = 0.230; days of hypokalemia (mean+/-SD) were 4.5+/-3.1 for group 1 and 4.5+/-3.2 for group 2, p = 0.819. Hyperkalemia was uncommon in both groups. There was also no statistically significant difference between the two groups when the data were re-analyzed as severe hyponatremia, severe hypokalemia and severe hyperkalemia. Magnesium sulfate infusion was safe and did not seem to exacerbate the duration of electrolyte disturbance associated with aneurysmal subarachnoid hemorrhage.

Disturbances in magnesium homeostasis, often linked to altered expression and/or function of magnesium channels, have been implicated in a plethora of diseases. This review focuses on magnesium transporter 1 (MAGT1), as recently described changes in this gene have further extended our understanding of the role of magnesium in human health and disease. The identification of genetic changes and their functional consequences in patients with immunodeficiency revealed that magnesium and MAGT1 are key molecular players for T cell-mediated immune responses. This led to the description of XMEN (X-linked immunodeficiency with magnesium defect, Epstein Barr Virus infection, and neoplasia) syndrome, for which Mg2+ supplementation has been shown to be beneficial. Similarly, the identification of a copy-number variation (CNV) leading to dysfunctional MAGT1 in a family with atypical ATRX syndrome and skin abnormalities, suggested that the MAGT1 defect could be responsible for the cutaneous problems. On the other hand, recent genetic investigations question the previously proposed role for MAGT1 in intellectual disability. Understanding the molecular basis of the involvement of magnesium and its channels in human pathogenesis will improve opportunities for Mg2+ therapies in the clinic.

The present study investigated associations between environmental exposure to magnesium (Mg) and the levels of oxidative stress parameters and selected cytokines, and the antioxidant defense system in the seminal plasma of fertile males. The study population consisted of 57 healthy, non-smoking, fertile men from the southern region of Poland. Based on the median magnesium levels in seminal plasma, subjects were divided into two groups: those with low (Mg-L) and high (Mg-H) magnesium concentrations. Differences were not observed between the Mg-L and Mg-H groups as regards semen volume, pH, count, motility, or morphology of sperm cells. In the Mg-H group, cholesterol levels were significantly higher (77%) compared with the Mg-L group: however, γ-glutamyltranspeptidase activity was significantly lower (21%). The values of total oxidant status were significantly different between the two groups, with 78% higher values observed in the Mg-H group compared with the Mg-L group, whereas malondialdehyde levels did not differ significantly. The values for total antioxidant capacity and uric acid levels were significantly lower in the Mg-H group compared with the Mg-L group (14% and 17%, respectively). However, levels of bilirubin, albumin, thiol groups and α-tocopherol were significantly higher in the Mg-H group (71%, 44%, 35% and 47%, respectively). No associations between Mg levels in the seminal plasma of fertile males and standard semen parameters were found. However, Mg levels may be associated with altered function of the non-enzymatic antioxidant system.

Various sources of drinking water, with varying levels of total hardness, and calcium and magnesium concentrations, are used by populations in different regions. The use of water purifiers can compound the problem of maintaining the desired levels of hardness. An inverse relationship between various conditions, including cardiovascular disease, and hard water has been reported. Until this study, investigation of the hardness of drinking water from different sources, and serum magnesium and calcium in normal subjects from the Surat district, had not been undertaken. This study was performed to assess the concentrations of calcium and magnesium, and total hardness in filtered and non-filtered water and the relationship with serum magnesium and calcium levels in normal subjects consuming such water. Three water samples were collected, at 15-day intervals, from 12 urban and rural areas of Surat; and also 10 different brands of bottled water. Samples were analyzed for total hardness and calcium by complexometric and EDTA methods respectively. Magnesium concentrations were obtained by subtraction of the calcium concentration from total hardness. Serum samples from healthy individuals were analyzed for magnesium and calcium using calmagite and arsenazo methods respectively. The independent t-test was used to establish significance at a level of 95%. A p-value <0.05 was considered significant. Mean total hardness, and calcium and magnesium concentrations in non-filtered, rural tube-well water were much higher than in filtered water from the same area, and the magnesium concentrations were significantly higher (p = 0.038). Filtered urban municipal had lower hardness and concentrations of calcium and magnesium (p = 0.01) compared to corresponding non-filtered water. Significantly lower levels were observed in bottled water compared to rural and urban sources of water. Serum magnesium was significantly lower in the population who were consuming filtered water compared to those drinking non-filtered water (p<0.05). No such difference was observed for serum calcium. Hypomagnesemia correlates with lower magnesium concentrations in drinking water (both rural tube-well and urban municipal waters), which can be attributed to the use of water purifiers. Assuming that a person consumes two liters of drinking water per day, it is estimated that there is an average loss of 160 mg (79%) of magnesium from total waterborne magnesium levels as a result of the filtration of both rural and urban water supplies. Bottled water is too hardness as in calcium and magnesium concentrations.

A large section of the North American population is not meeting recommended intakes for magnesium (Mg). Supplementation and consumption of Mg-fortified foods are ways to increase intake. Currently, information on Mg bioavailability from different compounds and their efficacy in improving Mg status is scant. This study compared the relative ability of inorganic and organic Mg compounds to preserve the Mg status of rats when fed at amounts insufficient to retain optimal Mg status. Male Sprague-Dawley rats (n=12/diet group) were fed one of eight test diets supplemented with phytic acid (5 g/kg diet) and low levels of Mg (155 mg elemental Mg/kg diet) from Mg oxide, Mg sulphate, Mg chloride, Mg citrate, Mg gluconate, Mg orotate, Mg malate or ethylenediaminetetraacetic acid disodium Mg salt for five weeks. Rats were also fed three control diets that did not contain added phytic acid but were supplemented with 500 (NMgO, normal), 155 (LMgO, low) or 80 (DMgO, deficient) mg of Mg per kg diet as Mg oxide. Mg concentrations in femur, serum and urine showed a graded decrease in rats fed the control diets with lower Mg. Mg concentrations did not differ (P≥0.05) between rats fed the different test diets. Addition of phytic acid to the diet did not affect the Mg status of the rats. The results indicate that any differences in the Mg bioavailability of the compounds were small and physiologically irrelevant.

The goal of this review is to bring to the attention of the readership of Magnesium Research another facet of the importance of magnesium, i.e. magnesium-based biomaterials. A concise history of biomaterials and magnesium are thus presented. In addition, historical and current, clinical magnesium-based applications are presented.

Calcium (Ca(2+)) and magnesium (Mg(2+)) are important metal elements that regulate a variety of cellular processes such as proliferation, migration, and apoptosis, in cancer cells. Among the ionic channels mediating intracellular entry, the transient receptor potential melastatin type 7 (TRPM7) channel is of particular interest, it being a non-selective, cationic channel mediating both Ca(2+) and Mg(2+) influx. TRPM7 is highly expressed in a number of human cancer tissues and cell lines. In this review, we summarise current knowledge on the physiological role of the dual function TRPM7 chanzyme, the potential application of TRPM7 as a diagnostic and prognostic marker of cancer progression with respect to clinical and pathological characteristics, and the molecular mechanisms implicated in cancerogenesis that specifically involve Ca(2+) and Mg(2+) influx through TRPM7 or kinase activity and interaction with cytoskeletal proteins.