Anti-inflammatory Effect of MgSO₄ in Patients With Moderate Traumatic Brain Injury by Measurming Nucleotide-binding Oligomerization Domain-Like Receptor Pyrin Domain-containing 3 (NLRP3) Inflammasome-a Multiprotein Complex

Traumatic brain injury (TBI) remains a leading cause of mortality and long-term disability worldwide, disrupting both individual lives and healthcare systems. The pathophysiology of TBI is characterized by a biphasic process. The primary injury occurs at the moment of impact, resulting in immediate mechanical tissue disruption. This is followed by a complex cascade of cellular and molecular changes known as secondary brain injury, which develops hours to days later.

A cornerstone of this secondary injury pathway is neuroinflammation, driven by the activation of resident microglia and the infiltration of peripheral immune cells. Central to this inflammatory response is the assembly and activation of the Nucleotide-binding oligomerization domain-Like Receptor Pyrin domain-containing 3 (NLRP3) inflammasome-a multiprotein complex that triggers the maturation and release of potent pro-inflammatory cytokines, specifically interleukin-1β (IL-1β) and interleukin-18 (IL-18), accelerating neuronal apoptosis and blood-brain barrier dysfunction.

Magnesium sulfate (MgSO₄) has emerged as a promising neuroprotective candidate due to its multifaceted mechanism of action. Primarily, magnesium acts as a non-competitive antagonist of the N-methyl-D-aspartate (NMDA) receptor, thereby mitigating glutamate-mediated excitotoxicity. Emerging molecular evidence further indicates that magnesium exerts potent anti-inflammatory effects by downregulating nuclear factor kappa B (NF-κB) activation and directly inhibiting the assembly of the NLRP3 inflammasome. Consequently, evaluating the clinical and molecular efficacy of MgSO₄ in TBI patients could offer a viable therapeutic pathway to suppress secondary neuroinflammation and optimize neurological recovery.

NLRP3 Inflammasome is a multiprotein complex consisting of three core components:

• Sensor (NLRP3)
• Adaptor (ASC)
• Effector (Caspase-1)

Its activation is regulated by a two-signal framework:

• Priming (Signal 1): Activates the nuclear factor kappa B(NF-κB) pathway to produce baseline NLRP3 components and inactive proteins (Pro-IL-1β, P ro-IL-18 andPro-IL-6).
• Activation (Signal 2): Triggered by cellular stress signals (such as Ca 2+ influx, K efflux, and mitochondrial distress).

Active Caspase-1 processes cytokines into their potent active forms and triggers a inflammatory cell death.

Magnesium sulfate (MgSO₄) has emerged as a promising neuroprotective candidate.

Magnesium sulfate exerts potent anti-inflammatory effects that can inhibit NLRP3 Inflammasome activation through 4 mechanisms:

• downregulating nuclear factor kappa B (NF-κB) activation and directly inhibiting the assembly of the NLRP3 inflammasome
• preventing extracellular Ca2+ influx and intracellular release
• Reducing K Efflux
• Preserving Mitochondrial Integrity

Inclusion criteria

• Male and female patients aged 18 to 60 years.
• Sustained a closed head trauma with the study drug infusion initiated within 8 hours of the injury.
• TBI confirmed by history and clinical examination.
• Patients with moderate (GCS = 9-12) traumatic brain injury.
• Evidence of TBI confirmed by abnormalities consistent with trauma on CT scan upon admission (diffuse injury II-IV, evacuated and non-evacuated mass lesion, Marshall's CT Classification ).
• Hemodynamic stability at the time of enrollment.

Exclusion criteria

• Patient Refusal
• Prolonged and/or uncorrectable hypoxia (PaO₂ < 60 mmHg) or persistent hypotension (systolic blood pressure < 90 mmHg) at the time of randomization.
• Cardiopulmonary arrest.
• Concomitant spinal cord injury.
• Pregnant or lactating females.
• Penetrating head injury.
• Associated other extra-cranial trauma or systemic polytrauma.
• Undergoing surgical interventions during the study.
• Pre-existing severe cardiac arrhythmia, heart block, or significant myocardial damage (documented on ECG).
• Known history of chronic renal failure or abnormal baseline renal function.
• Known hypersensitivity or allergic reaction to magnesium sulfate.
• Patients on chronic steroid therapy.
• BMI>35 kg/m2.

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