Combined Magnesium/Polyethylene Glycol Facilitates the Neuroprotective Effects of Magnesium in Traumatic Brain Injury at a Reduced Magnesium Dose

LncRNA ILF3-AS1 mediates oxidative stress and inflammation through miR-504-3p/HMGB1 axis in a cellular model of temporal lobe epilepsy

BACKGROUND

Temporal lobe epilepsy (TLE), a prevalent neurological disorder, is associated with hippocampal oxidative stress and inflammation. A recent study reveals that the long noncoding RNA ILF3 divergent transcript (ILF3-AS1) level is elevated in the hippocampus of TLE patients; however, the functional roles of ILF3-AS1 in TLE and underlying mechanisms deserve further investigation. Hence, this study aimed to elucidate whether ILF3-AS1 is involved in the pathogenesis of TLE by regulating oxidative stress and inflammation and to explore its underlying mechanism in vitro.

METHODS

Human hippocampal neurons were subjected to a magnesium-free (Mg2+-free) solution to establish an in vitro model of TLE. The potential binding sites between ILF3-AS1 and miRNA were predicted by TargetScan/Starbase and confirmed by dual luciferase reporter assay. Cell viability and damage were assessed by cell counting kit-8 and lactate dehydrogenase assay kits, respectively. Levels of reactive oxygen species, malondialdehyde, and superoxide dismutase were determined by commercial kits. Levels of Interleukin-6 (IL-6), IL-1β, and tumor necrosis factor-alpha were quantified by enzyme-linked immunosorbent assay. The expressions of gene and protein were determined by quantitative real-time polymerase chain reaction and Western blot analysis.

RESULTS

In Mg2+-free-treated hippocampal neurons, both ILF3-AS1 and HMGB1 were highly up-regulated, whereas miR-504-3p was down-regulated. ILF3-AS1 knockdown ameliorated Mg2+-free-induced cellular damage, oxidative stress, and inflammatory response. Bioinformatics analysis revealed that miR-504-3p was a target of ILF3-AS1 and was negatively regulated by ILF3-AS1. MiR-504-3p inhibitor blocked the protection of ILF3-AS1 knockdown against Mg2+-free-induced neuronal injury. Further analysis presented that ILF3-AS1 regulated HMGB1 expression by sponging miR-504-3p. Moreover, HMGB1 overexpression reversed the protective functions of ILF3-AS1 knockdown.

CONCLUSION

Our findings indicate that ILF3-AS1 contributes to Mg2+-free-induced hippocampal neuron injuries, oxidative stress, and inflammation by targeting the miR-504-3p/HMGB1 axis. These results provide a novel mechanistic understanding of ILF3-AS1 in TLE and suggest potential therapeutic targets for the treatment of epilepsy.

Multi-Mechanistic Approaches to the Treatment of Traumatic Brain Injury: A Review

Traumatic brain injury (TBI) is a leading cause of death and disability worldwide. Despite extensive research efforts, the majority of trialed monotherapies to date have failed to demonstrate significant benefit. It has been suggested that this is due to the complex pathophysiology of TBI, which may possibly be addressed by a combination of therapeutic interventions. In this article, we have reviewed combinations of different pharmacologic treatments, combinations of non-pharmacologic interventions, and combined pharmacologic and non-pharmacologic interventions for TBI. Both preclinical and clinical studies have been included. While promising results have been found in animal models, clinical trials of combination therapies have not yet shown clear benefit. This may possibly be due to their application without consideration of the evolving pathophysiology of TBI. Improvements of this paradigm may come from novel interventions guided by multimodal neuromonitoring and multimodal imaging techniques, as well as the application of multi-targeted non-pharmacologic and endogenous therapies. There also needs to be a greater representation of female subjects in preclinical and clinical studies.

Formulation and evaluation of magnesium sulphate nanoparticles for improved CNS penetrability

Magnesium (Mg²⁺) is the fourth most abundant cation in the human body and is involved in maintaining varieties of cellular and neurological functions. Magnesium deficiency has been associated with numerous diseases, particularly neurological disorders, and its supplementation has proven beneficial. However, magnesium therapy in neurological diseases is limited because of the inability of magnesium to cross the blood-brain barrier (BBB). The present study focuses on developing magnesium sulphate nanoparticles (MGSN) to improve blood-brain barrier permeability. MGSN was prepared by precipitation technique with probe sonication. The developed formulation was characterized by DLS, EDAX, FT-IR and quantitative and qualitative estimation of magnesium. According to the DLS report, the average size of the prepared MGSN is found to be 247 nm. The haemocompatibility assay studies revealed that the prepared MGSN are biocompatible at different concentrations. The in vitro BBB permeability assay conducted by Parallel Artificial Membrane Permeability Assay (PAMPA) using rat brain tissue revealed that the prepared MGSN exhibited enhanced BBB permeability as compared to the marketed i.v. MgSO₄ injection. The reversal effect of MGSN to digoxin-induced Na⁺/K⁺ ATPase enzyme inhibition using brain microslices confirmed that MGSN could attenuate the altered levels of Na⁺ and K⁺ and is useful in treating neurological diseases with altered expression of Na⁺/K⁺ ATPase activity.

A Mini Review on the Various Facets Effecting Brain Delivery of Magnesium and Its Role in Neurological Disorders

Magnesium is an essential cation present in the body that participates in the regulation of various vital body functions. Maintaining normal level of magnesium is essential for proper brain functions by regulating the activities of numerous neurotransmitters and their receptors. Various studies have been reported that magnesium level is found to be declined in both neurological and psychiatric diseases. Declined magnesium level in the brain initiates various cumbersome effects like excitotoxicity, altered blood-brain permeability, oxidative stress, and inflammation, which may further worsen the disease condition. Shreds of evidence from the experimental and clinical studies proved that exogenous administration of magnesium is useful for correcting disease-induced alterations in the brain. But one of the major limiting factors in the use of magnesium for treatment purposes is its poor blood-brain barrier permeability. Various approaches like the administration of its organic salts as pidolate and threonate forms, and the combination with polyethylene glycol or mannitol have been tried to improve its permeability to make magnesium as a suitable drug for different neurological disorders. These results have shown their experimental efficacy in diseased animal models, but studies regarding the safety and efficacy in human subjects are currently underway. We present a comprehensive review on the role of magnesium in the maintenance of normal functioning of the brain and various approaches for improving its BBB permeability.

'Magnesium'-the master cation-as a drug-possibilities and evidences

Magnesium (Mg²⁺) is the 2nd most abundant intracellular cation, which participates in various enzymatic reactions; there by regulating vital biological functions. Magnesium (Mg²⁺) can regulate several cations, including sodium, potassium, and calcium; it consequently maintains physiological functions like impulse conduction, blood pressure, heart rhythm, and muscle contraction. But, it doesn't get much attention in account with its functions, making it a "Forgotten cation". Like other cations, maintenance of the normal physiological level of Mg²⁺ is important. Its deficiency is associated with various diseases, which point out to the importance of Mg²⁺ as a drug. The roles of Mg²⁺ such as natural calcium antagonist, glutamate NMDA receptor blocker, vasodilator, antioxidant and anti-inflammatory agent are responsible for its therapeutic benefits. Various salts of Mg²⁺ are currently in clinical use, but their application is limited. This review collates all the possible mechanisms behind the behavior of magnesium as a drug at different disease conditions with clinical shreds of evidence.

A randomized cohort study of the efficacy of PO magnesium in the treatment of acute concussions in adolescents

INTRODUCTION/STUDY OBJECTIVE

Concussions are becoming a growing concern in society today with one out of every five adolescents being affected. This accounts for 1.6 to 3.8 million emergency department visits annually. The current standard of care involves an initial period of mental rest with symptomatic care and symptom-based return to daily activities/sports. High dose IV magnesium has been proven to be neuroprotective in severe TBI. We hypothesized that oral magnesium replacement following a concussion will decrease the overall symptomatic period allowing a quicker return to functional baseline.

METHODS

We used a randomized cohort study involving patients aged 12-18 who presented within 48 h after a concussion. Our study design had a treatment arm including acetaminophen, ondansetron, and magnesium PO and a placebo arm of acetaminophen and ondansetron. We then utilized the Post- Concussion Severity Score (PCSS) to evaluate the extent of the patient's symptoms. This score was collected immediately prior to obtaining medications, 1 h, 48 h, and 120 h after starting the study. The study relied on outpatient follow up through phone conversations, and a Sports Medicine clinic locally.

RESULTS

Our data shows that there was a statistically significant decrease in the PCSS at 48 h (p = 0.016) in the magnesium group relative to the placebo treatment arm. This study does imply that magnesium supplementation has potential benefit in treatment of concussions acutely.

CONCLUSION

Oral magnesium replacement decreases symptoms acutely following a concussion and should be provided with symptomatic management following a concussion in the emergency setting.

Does magnesium sulfate have a role in the management of severe traumatic brain injury in civilian and military populations? A systematic review and meta-analysis

INTRODUCTION

Traumatic brain injury (TBI) is a significant cause of combat morbidity. Currently, the medical management of TBI is limited to supportive critical care. Magnesium sulfate has been studied as a potentially beneficial therapeutic agent.

METHODS

A systematic review and meta-analysis was undertaken, examining the role of magnesium in the management of severe TBI in adults. The primary outcome of the study was all-cause mortality, with secondary outcomes of Glasgow Outcome Score (GOS) and GCS. EMBASE, MEDLINE, CINAHL, WHO Trial Registry and the Cochrane Library database were systematically searched, with data included until 1 February 2017. Inclusion criteria were: human study; aged >13 years; randomised controlled trial; severe TBI. Exclusion criteria were: data collected prior to 1 January 2002; magnesium commenced >24 hours postinjury; magnesium therapy for <24 hours. Statistical analysis was conducted using Stata (V.13.1).

RESULTS

The pooled results of six studies found all-cause mortality not to be significantly different in the treatment group (RR 0.84, 95% CI 0.54 to 1.33; P=0.46) with an I² value of >70%. With regard to the secondary outcomes, no significant difference in GOS scores between treatment and control was demonstrated. GCS showed a significant improvement in the treatment group.

CONCLUSIONS

The meta-analysis found a lack of evidence for magnesium pharmacotherapy in severe TBI, although the data were noted to be conflicting and significantly heterogeneous. Further study is recommended to ascertain whether a therapeutic window exists for magnesium in severe TBI.