Gardeniae Fructus extract terminates refractory status epilepticus with a wide time window through inhibiting...

Status epilepticus (SE) is the most severe epilepsy type and exhibits a high resistance rate to the first-line therapy diazepam (DZP), which terms as refractory SE. Activated neuroinflammation is a key factor in the genesis of refractory SE. Gardeniae Fructus, a commonly used traditional Chinese herbal medicine, has been reported to exhibit anti-neuroinflammatory efficacies.

In this study we aimed to evaluate the effects of Gardenia extract (GE) in two animal models of refractory SE and explore the mechanism of GE on SE.

We identified the main components of GE using LC-MS. The pilocarpine (Salagen Tablet) and kainic acid (KA)-induced refractory SE models were established to evaluate the efficacy of GE. We used NeuN staining to observe the neuroprotective effects of GE. Then we employed network pharmacology to find potential therapeutic targets of GE. We verified the potential therapeutic mechanisms via western blot, immunohistochemistry, in vitro electrophysiological recording and pharmacological means.

We identified thirteen main compounds, and demonstrated that combining GE with DZP could effectively terminate refractory SE induced by pilocarpine or KA, with an extended therapeutic time window of up to 3 h. GE also protected against neuronal injuries caused by refractory SE. Network pharmacology analysis suggested that inflammatory high mobility group box-1 (HMGB1) is a potential therapeutic target of GE. GE could reverse the upregulated expression and translocation of HMGB1 in mice with refractory SE and directly inhibited the enhancement of hippocampal excitatory synaptic transmission mediated by HMGB1 activation. Finally, GE was effective in terminating refractory SE caused by HMGB1 activation; whereas GE could not exhibit superior terminating efficacy when HMGB1 was pharmacologically inhibited.

These findings indicated for the first time that GE can terminate refractory SE by inhibiting HMGB1-induced neuroinflammation, highlighting its potential as a promising therapeutic strategy for this neurological emergency.