What is "parthenolide"

Parthenolide is a sesquiterpene lactone of the germacranolide class which occurs naturally in the plant feverfew ( Tanacetum parthenium), after which it is named. It is found in highest concentration in the flowers and fruit. Feverfew is used in herbalism and is purportedly useful for a variety of aliments. Many vendors of feverfew remedies specify the content of parthenolide in their products, because it is believed to be the primary chemical constituent responsible for biological activity.

Lack of solubility in water and bioavailability limits the potential of parthenolide as a drug. Drug researchers are trying to develop synthetic analogs instead that will be absorbed to a more useful extent. It also inhibits HDAC1 protein without affecting other class I/II HDACs, which leads to sustained DNA damage response in certain cells (required for apoptosis).