Anti-emetic principles of Inula linariaefolia flowers and Forsythia suspensa fruits.

The anti-emetic effects of 40 extracts made from 12 traditional Chinese herbal drugs were examined. Ten extracts inhibited emesis induced by copper sulfate pentahydrate; all were administered orally, and one extract inhibited emesis induced by apomorphine hydrochloride given to leopard and ranid frogs. Taraxasteryl palmitate and acetate, bigelovin and dihydrobigelovin were isolated from the CHCl(3) extract of Inula linariaefolia flowers, and identified as the active antiemetic agents when emesis was induced by copper sulfate. In addition, chlorogenic acid was isolated from the MeOH extract as an anti-emetic principle for the emesis induced by apomorphine hydrochloride. Rengyol, phillyrin and rutin were isolated from the MeOH extract of Forsythia suspensa fruits and identified as the inhibitors of emesis induced by copper sulfate pentahydrate.