Parthenolide is the component of tanacetum parthenium that inhibits nitroglycerin-induced Fos activation: studies in an animal model of migraine

Tanacetum parthenium (TP) is a member of the Asteracee family long used empirically as a herbal remedy for migraine. So far, however, clinical trials have failed to prove consistently the effectiveness of TP extracts in preventing migraine attacks, probably as a consequence of the uncertainty as regards the active principle. In this study, the biological effects of different TP extracts and purified parthenolide were tested in an animal model of migraine based on the quantification of neuronal activation induced by nitroglycerin. The extract enriched in parthenolide significantly reduced nitroglycerin-induced Fos expression in the nucleus trigeminalis caudalis. Purified parthenolide inhibited nitroglycerininduced neuronal activation in additional brain nuclei and, significantly, the activity of nuclear factork B. These findings strongly suggest that parthenolide is the component responsible for the biological activity of TP as regards its antimigraine effect and provide important information for future controlled clinical trials.