Abstract

Rhynchophylline (RIN) is a significant active component isolated from the Chinese herbal medicine Uncaria rhynchophylla. Several studies have demonstrated that RIN has a significant anticonvulsant effect in many types of epilepsy models in vivo. However, the mechanisms of the anticonvulsant effect remain elusive. Using combined methods of behavioral testing, immunofluorescence and electrophysiological recordings, we characterized the anticonvulsant effect of RIN in a pilocarpine-induced status epilepticus (SE) rat model of temporal lobe epilepsy (TLE) and investigated the underlying cellular mechanisms. In one set of experiments, rats received RIN treatment prior to pilocarpine injection. In a second set of experiments, rats received RIN treatment following the onset of stage 3 seizures. Pretreatment and posttreatment with RIN effectively reduced the seizure severity in the acute phase of TLE. Furthermore, RIN protected medial entorhinal cortex (mEC) layer III neurons from neuronal death and terminated spontaneous epileptiform discharge of mEC layer II neurons in SE-experienced rats. Whole-cell voltage-clamp recordings indicated that RIN inhibited neuronal hyperexcitability via inhibition of the persistent sodium current (INaP) and NMDA receptor current. Immunofluorescence experiments also demonstrated that RIN rectified the pilocarpine-induced upregulation of Nav1.6 and NR2B protein expression. In conclusion, our results identified RIN as an anticonvulsant agent that inhibited ictal discharge via INap and NMDA receptor current inhibition.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.