Epilepsy is a common nervous disorder disease affecting about 70 million worldwide population¹. Although there were more than 15 antiepileptic drugs (AED), 30% patients approximately were still suffering. A recent study carried out provided a comprehensive summary on aggression during AED treatment². It was necessary for researchers to find out alternative drugs for AED treatment. Chinese traditional medicine Cynanchum otophyllum Schneid, also called Qing Yangshen (QYS), showed a good clinical antiepileptic effects. Previous studies revealed that QYS was anticonvulsant in rodent seizure models, but therapeutic mechanisms and antiepileptic behaviors in other seizure models remained unclear. Furthermore, seizures could be elicited in a simple vertebrate system, zebrafish larvae³, but few to explore the fundamental mechanisms of epilepsy with this seizure model.

In this study, pentylenetetrazole (PTZ) was employed as a valid convulsive agent to build the epilepsy models both in zebrafish and mice. The purpose of current study was to evaluate the antiepileptic effects of pure compounds extracted from QYS and investigate the therapeutic mechanisms.

Based on the preliminary screen by locomotor behavior, the compound Otophylloside N (OtoN), a C21 steroidal glycoside, was identified which could significantly reduce the zebrafish’s swimming distance induced by PTZ. In addition, primary cortical neurons cell taken from E16 mice embryos was chosen in vitro study. OtoN could increase cell viability and intracellular LDH efflux level. Futhermore, western blot analysis revealed that the protein level of c-fos, bcl-2 and bcl-2/ bax decreased in cells and mice comparing to PTZ group. Moreover, gene expression level of these protein in zebrafish also reduced by Real Time PCR tests.

OtoN extracted from QYS showed the neuroprotecive activities not only in cells, but in vivo models (zebrafish and mice). The mechanism might refer to the apoptosis pathway. OtoN had the anticonvulsant effects and would be a promising antiepileptic drug.