Bioassay-guided isolation of anti-seizure principles from Semen Pharbitidis using a zebrafish pentylenetetrazol seizure model

Ethnopharmacological relevance: Semen Pharbitidis, the seeds of Pharbitis nil (Linn.) Choisy (Convolvulaceae) is a well-known traditional Chinese medicinal plant used for treating helminthiasis and epilepsy in China. Aim of the study: This study aims to identify the anti-seizure components from Semen Pharbitidis. Methods: A bioassay-guided isolation of anti-seizure compounds from Semen Pharbitidis was performed using a zebrafish pentylenetetrazol seizure model. The structures of active compounds were elucidated by high resolution mass spectrometry. The fragments of active compounds were tested for anti-seizure activity as well. Results: The bioassay-guided isolation of ethanol extract of Semen Pharbitidis led to a group of resin glucosides, namely pharbitin. One of the fragments of pharbitin, 2-methylbutyric acid, also showed anti-seizure activity. Conclusions: We provided further experimental scientific evidence to support the traditional use of Semen Pharbitidis for the treatment of epilepsy. Pharbitin was identified to be the main anti-seizure component in Semen Pharbitidis.