Model-Dependent Attenuation of Seizures by Cinnabar

Epilepsy is one of the most prevalent and severe neurological disorders, and it is inadequately controlled with currently available medications. While cinnabar (mercury(II) sulfide)—a traditional Chinese medicine—has historical application in epilepsy treatment, its therapeutic efficacy and underlying mechanisms are unclear. In this study, we find that cinnabar exerts model-dependent antiseizure efficacy in mice. Specifically, it significantly attenuates acute seizures, enhances the termination of diazepam-resistant status epilepticus, and reduces spontaneous seizures in the kainic acid (KA)-induced seizure model. Conversely, no therapeutic effect was found in the maximal electroshock-, pentylenetetrazole-, or kindling-induced seizure model. Fiber photometry revealed that cinnabar normalizes KA-induced hippocampal neurotransmission imbalances by simultaneously decreasing glutamate hyperactivity and γ-aminobutyric acid hypoactivity. Furthermore, cinnabar has neuroprotective effects and alleviates comorbid anxiety-like behaviors, while showing no alterations in motor function. Our findings suggest cinnabar's potential as a therapeutic agent for seizure management, via a mechanism associated with the reversal of the hippocampal excitatory/inhibitory imbalance.