Model-Dependent Attenuation of Seizures by Cinnabar

Area of Science:

• Neuroscience
• Pharmacology
• Traditional Chinese Medicine

Background:

• Epilepsy is a common neurological disorder with inadequate treatment options.
• Cinnabar (mercury(II) sulfide) has a history of use in traditional Chinese medicine for epilepsy, but its efficacy and mechanisms are not well understood.

Purpose of the Study:

• To investigate the antiseizure efficacy and underlying mechanisms of cinnabar in various epilepsy mouse models.
• To evaluate cinnabar's effects on neurotransmission, neuroprotection, and comorbid behaviors.

Main Methods:

• Administered cinnabar to mice in kainic acid (KA), maximal electroshock, pentylenetetrazole, and kindling-induced seizure models.
• Utilized fiber photometry to monitor hippocampal neurotransmission.
• Assessed neuroprotective effects and anxiety-like and motor behaviors.

Main Results:

• Cinnabar demonstrated significant antiseizure effects in the KA-induced model, attenuating acute seizures and enhancing the termination of diazepam-resistant status epilepticus.
• No therapeutic effect was observed in maximal electroshock, pentylenetetrazole, or kindling models.
• Cinnabar normalized hippocampal neurotransmission by reducing glutamate hyperactivity and gamma-aminobutyric acid (GABA) hypoactivity, provided neuroprotection, and alleviated anxiety-like behaviors without impacting motor function.

Conclusions:

• Cinnabar exhibits model-dependent antiseizure efficacy, particularly in the KA-induced epilepsy model.
• Its therapeutic mechanism involves reversing hippocampal excitatory/inhibitory imbalances.
• Cinnabar shows potential as a novel therapeutic agent for seizure management, with additional benefits for comorbid anxiety.