P.<unk>  is believed to contain the sesquiterpene esters petasin, isopetasin, and neopetasin, which are believed to help alleviate migraine symptoms. Petasin may inhibit inflammatory functions through regulation of phospholipase Cβ. Petasin has also been shown to block eosinophil cationic protein, an important step in the adaptive immune response system. Isopetasin operates by blocking intracellular signaling molecules in pathways involving Arachidonate 5-lipoxygenase in turn leading to the reduction of leukotriene synthesis. Petasin's structure The anti-allergic effects of butterbur are believed to come from Bakkenolide B a terpinoid found in the leaves of the plant. Bakkenolide was shown to have efficacy in mast cell degranulation and inhibiting gene inductions of inducible nitric oxide synthase and cyclooxyrgenase 2. It is unclear if retail preparations of butterbur contain Bakkenolide due to non-standardization of preparation, and which parts of the plants are included.
Petasites hybridus
Piedraia hortae
Antihecticum poterii
Craniopagus parasiticus
Cedecea davisae
Hydnocarpus wightianus
Capillaria philippinensis
Cerbera odollam