A bioassay for inhibition of serotonin release from bovine platelets.

A bioassay was developed to study agents capable of inhibiting the release of serotonin from bovine blood platelets. It is a simple, inexpensive, and reproducible high-throughput bioassay suitable for quality control of feverfew, Tanacetum parthenium, a crude drug with proven migraine prophylactic activity that is being considered for governmental registration and regulation. The bioassay, which requires no experimental animals or human subjects, was used to assess the in vitro activity of T. parthenium samples grown from seed obtained from 10 different regions of Europe. The activity was found to vary significantly within and between samples, with no geographical correlation. Serotonin release inhibition was shown to be significantly correlated with the content of the germacranolide sesquiterpene lactone, parthenolide, although other sesquiterpene lactones from this plant and other members of the Asteraceae were also shown to be active. The activities of six other species of Tanacetum, as well as of Artemisia absinthium (wormwood) and Zingiber officinale (ginger), and two commercial drugs for migraine prophylaxis, verapamil hydrochloride and propranolol hydrochloride, were also assessed. The relevance of the bovine platelet serotonin release inhibition bioassay to antimigraine research is discussed.