MAGnesium-oral supplementation to reduce PAin in patients with severe PERipheral arterial occlusive disease: the MAG-PAPER randomised clinical trial protocol

Transdermal Magnesium for the Treatment of Peripheral Neuropathy in Chronic Kidney Disease: A Single-Arm, Open-Label Pilot Study

Introduction: Peripheral neuropathy is common in chronic kidney disease (CKD) and may be multifactorial in origin, resulting from uremia, hyperkalemia, and diabetes. Previous studies have suggested that magnesium plays a crucial role in chronic pain. Studies evaluating magnesium in neuropathy have demonstrated mixed results. Aims: To provide preliminary data on the effectiveness of transdermal magnesium in treating peripheral neuropathy related to CKD. Methods: Twenty participants with advanced CKD were enrolled from a major teaching hospital clinic in Sydney, Australia. Each participant was provided with a spray bottle containing magnesium chloride and instructed to apply five sprays to each limb affected by neuropathy daily for 12 weeks. Participants completed the Neuropathy Total Symptom Score-6 (NTSS-6) every 4 weeks during follow-up. Serum magnesium concentrations were measured at 4-week intervals. Results: Twenty participants were recruited, of which 14 completed the 12-week follow-up period. Mean age was 78.90 years, 80.00% were female and mean estimated glomerular filtration rate was 9.78 mL/min/1.73 m2. With intention to treat analysis (mean [95% confidence interval]), NTSS-6 was significantly reduced at weeks 8 (4.04 [2.43-5.65]) and 12 (4.26 [2.47-6.05]), compared with baseline (6.92 [5.29-8.55]), p < 0.05. Serum magnesium concentration did not change significantly during the study. Conclusion: This pilot study suggests that transdermal magnesium may be beneficial in reducing frequency and severity of peripheral neuropathic symptoms in patients with advanced CKD. Trial Registration: australianclinicaltrials.gov.au. Identifier: ACTRN12621000841875. Date first registered January 7, 2021.

Magnesium Citrate Increases Pain Threshold and Reduces TLR4 Concentration in the Brain

Magnesium is being investigated in various clinical conditions and has shown to be effective in some chronic pain models. However, it is not clear if oral magnesium use affects pain perception in acute pain. TLR4's (toll-like receptor) role in pain perception has emerged through its role in immune pathways and ion channels. The aim of this study is to investigate the effect of a single oral dose of magnesium citrate on pain conduction and whether with magnesium, the expression of TLR4 changes in the acute phase. Following a single dose of 66-mg/kg magnesium citrate administration to male Balb-c mice, pain perception (via hot-plate test), motor conduction (via electrophysiological recording, forelimb grip strength, rotarod and open-field tests), and emotional state (via elevated plus maze and forced swim test) were evaluated. In behavioral experiments, the control group was compared with applied magnesium for three different time groups (4, 8, 24 h). TLR4 expression was measured in four groups: control, magnesium (Mg), hot plate (HP), and Mg + HP. Hot plate latency was prolonged in the magnesium group (p < 0.0001) and electrophysiological recordings (p < 0.001) and forelimb grip strength measurement (p < 0.001) determined motor latency. Compared with the untreated hot plate group, TLR4 levels was lower in the brain (p = 0.023) and higher in the sciatic nerve (p = 0.001) in the magnesium-treated hot plate group. Consequently, the study indicated a single dose of magnesium citrate appeared to cause weakening in the transmission and perception of nociceptive pain. TLR4 may act as a regulator in magnesium's effects on pain perception.

Magnesium: The recent research and developments

Magnesium is the fourth most abundant mineral in the human body, which facilitates more than 300 enzymatic reactions. Magnesium is essential for nucleic material and protein synthesis, neuromuscular conduction, cardiac contractility, energy metabolism, and immune system function. Gastrointestinal system and kidneys closely regulate magnesium absorption and elimination to maintain adequate storage of magnesium. Magnesium deficiency has been linked to many diseases and poor health outcomes. Magnesium has also been proven to be an effective therapeutic agent in many diseases, such as bronchial asthma, cardiac arrhythmia, and pre-eclampsia.

Intracerebroventricular Coadministration of Protoxin-II and Trace Elements in Rats Enhances the Analgesic Effect of the 1.7 Voltage-Gate Sodium Channel Blocker

Pain continues to be a global unmet medical need, and the current recommendations for its management require a constant exploration of new drugs that target multiple pain mechanisms, with an improved safety profile and increased treatment adherence. Currently, the enriched distribution and localization within nociceptors of the selective channel blockers and the critical role played by sodium channels in neuronal excitability nominate isoforms as specific targets to generate innovative compounds. In the present report, we verified the hypothesis that coadministration of Protoxin-II, a selective sodium channel inhibitor, and trace elements has direct and improved antinociceptive effects. Groups of seven Wistar rats were treated intracerebroventricularly with a combination of MgCl₂, CdCl₂, and ZnCl₂ and Protoxin-II, respectively, and with Protoxin-II alone (positive) or saline (negative) for controls. Evaluations were performed by nociception assay. Coadministration of these drugs caused an increase in the maximum possible effect of up to 40% as compared with the control groups. Our findings indicate that selective channel blockers continue to be an important nociception target and that the use of trace elements may provide simple but effective means of control over sodium channel blockers' risks, potentially lowering the necessary analgesic doses, thus improving the efficacy and safety profile.

The Role of Magnesium in Neurological Disorders

Magnesium is well known for its diverse actions within the human body. From a neurological standpoint, magnesium plays an essential role in nerve transmission and neuromuscular conduction. It also functions in a protective role against excessive excitation that can lead to neuronal cell death (excitotoxicity), and has been implicated in multiple neurological disorders. Due to these important functions within the nervous system, magnesium is a mineral of intense interest for the potential prevention and treatment of neurological disorders. Current literature is reviewed for migraine, chronic pain, epilepsy, Alzheimer’s, Parkinson’s, and stroke, as well as the commonly comorbid conditions of anxiety and depression. Previous reviews and meta-analyses are used to set the scene for magnesium research across neurological conditions, while current research is reviewed in greater detail to update the literature and demonstrate the progress (or lack thereof) in the field. There is strong data to suggest a role for magnesium in migraine and depression, and emerging data to suggest a protective effect of magnesium for chronic pain, anxiety, and stroke. More research is needed on magnesium as an adjunct treatment in epilepsy, and to further clarify its role in Alzheimer’s and Parkinson’s. Overall, the mechanistic attributes of magnesium in neurological diseases connote the macromineral as a potential target for neurological disease prevention and treatment.