Evaluation of the neuroprotective activity of Mexidol in a model of hemorrhagic stroke

Objective. To comprehensively evaluate the neuroprotective potential of Mexidol following systemic administration in various dosage forms in a model of hemorrhagic stroke. Material and methods. The study was performed on 130 outbred male rats, weighing 180—200 g and aged 7—8 weeks. All animals were divided into 3 series: Series 1 — intravenous administration of Mexidol at doses of 50 and 100 mg/kg; Series 2 — intramuscular administration at doses of 50 and 100 mg/kg; Series 3 — intragastric administration at doses of 50, 100, and 200 mg/kg. Acute hemorrhagic stroke was modeled by administering autologous blood at a volume of 0.05 ml/kg body weight into the region of the internal capsule of the right hemisphere. Mexidol administration was initiated 30 minutes after modeling acute focal stroke. Twenty-four hours after the surgery, the severity of neurological deficit was assessed using the McGraw Stroke-Index Scale modified by I.V. Gannushkina. Subsequently, the animals were euthanized, the brain was isolated, fixed in formalin, and tomography was performed. Results. Intravenous administration of Mexidol at a dose of 100 mg/kg led to a statistically significant reduction in the severity of clinical symptoms 24 hours after surgery compared to control animals. Intramuscular administration produced a similar effect at doses of 50 and 100 mg/kg, while intragastric administration did so at doses of 100 mg/kg and 200 mg/kg. Intravenous and intramuscular administration of Mexidol at doses of 50 and 100 mg/kg did not affect the size of the brain lesion in rats, whereas intragastric administration of Mexidol at a dose of 200 mg/kg led to its reduction. Conclusion. The obtained results indicate that, in cases of small intracranial hematomas (e.g., those remaining after surgical removal of the initial hematoma), Mexidol exerts a pronounced neuroprotective effect.