Role of petasin in the potential anti-inflammatory activity of a plant extract of petasites hybridus.
A large production of leukotrienes (LTs) can be induced in human eosinophils or neutrophils by priming with granulocyte-macrophage colony-stimulating factor and subsequent stimulation with platelet-activating factor (PAF) or the anaphylatoxin C5a. Here, we investigated the effects of a plant extract of petasites hybridus (Ze339) and its isolated active sesquiterpene ester petasin in these two in vitro cell models. Zileuton, a 5-lipoxygenase inhibitor, was used as a positive control. All compounds inhibited both cysteinyl-LT synthesis in eosinophils and LTB(4) synthesis in neutrophils. In contrast, only Ze339 and petasin, but not zileuton, abrogated PAF- and C5a-induced increases in intracellular calcium concentrations. These data suggest that Ze339 and petasin may block, compared to zileuton, earlier signalling events initiated by G protein-coupled receptors in granulocytes, perhaps at the level of or proximal to phospholipase C(beta). Taken together, petasin appears to be one major active compound of petasites hybridus extract, since it demonstrates the same inhibitory activities on calcium fluxes and subsequent LT generation in both eosinophils and neutrophils as Ze339 does.
Thomet
O A
OA
Swiss Institute of Allergy and Asthma Research (SIAF), Davos, Switzerland.
Wiesmann
U N
UN
Schapowal
A
A
Bizer
C
C
Simon
H U
HU
D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D019659:Asteraceae / Q000737:chemistry*; D002118:Calcium / Q000378:metabolism; D015936:Complement C5a / Q000378:metabolism; D003545:Cysteine / Q000378:metabolism; D004804:Eosinophils / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D006918:Hydroxyurea / Q000031:analogs & derivatives* / Q000494:pharmacology; D066298:In Vitro Techniques; D007975:Leukotriene B4 / Q000378:metabolism; D015289:Leukotrienes / Q000378:metabolism; D008264:Macrophages / Q000187:drug effects* / Q000378:metabolism; D009504:Neutrophils / Q000187:drug effects* / Q000378:metabolism; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D010972:Platelet Activating Factor / Q000378:metabolism; D012717:Sesquiterpenes / Q000494:pharmacology*; D015398:Signal Transduction
D000893:Anti-Inflammatory Agents; D000894:Anti-Inflammatory Agents, Non-Steroidal; D015289:Leukotrienes; D010936:Plant Extracts; D010972:Platelet Activating Factor; D012717:Sesquiterpenes; C112381:cysteinyl-leukotriene; D007975:Leukotriene B4; D015936:Complement C5a; C418727:petasin; D003545:Cysteine; D002118:Calcium; C063449:zileuton; D006918:Hydroxyurea