title: Pacific island 'Awa (Kava) extracts, but not isolated kavalactones, promote proinflammatory responses in model mast cells.
abstract: Kava ('Awa) is a traditional water-based beverage in Pacific island communities, prepared from the ground root and stems of Piper methysticum. Kava use is associated with an ichthyotic dermatitis and delayed type hypersensitivity reactions. In the current study we collated preparative methodologies from cultural practitioners and recreational kava users in various Pacific communities. We standardized culturally informed aqueous extraction methods and prepared extracts that were subjected to basic physicochemical analysis. Mast cells exposed to these extracts displayed robust intracellular free calcium responses, and concomitant release of proinflammatory mediators. In contrast, mast cells were refractory to single or combinatorial stimulation with kavalactones, including methysticin, dihydromethysticin and kavain. Moreover, we reproduced a traditional modification of the kava preparation methodology, pre-mixing with the mucilage of Hibiscus tiliaceus, and observed its potentiating effect on the activity of aqueous extracts in mast cells. Taken together, these data indicate that water extractable active ingredients may play a role in the physiological and pathophysiological effects of kava, and suggests that mast cell activation may be a mechanistic component of kava-related skin inflammations.
authors.affiliation: Laboratory of Immunology and Signal Transduction, Department of Biology, Chaminade University, Honolulu, Hawaii 96816, USA.
authors.forename: Lori M N
authors.initials: LM
authors.lastname: Shimoda
authors.forename: Christy
authors.initials: C
authors.lastname: Park
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Stokes
authors.forename: Henry Halenani
authors.initials: HH
authors.lastname: Gomes
authors.forename: Helen
authors.initials: H
authors.lastname: Turner
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002460:Cell Line; D005260:Female; D031584:Hibiscus / Q000737:chemistry; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism*; D020901:Kava / Q000737:chemistry*; D007783:Lactones / Q000494:pharmacology*; D008297:Male; D008407:Mast Cells / Q000187:drug effects* / Q000378:metabolism; D008875:Middle Aged; D010936:Plant Extracts / Q000494:pharmacology*; D062087:Plant Mucilage / Q000737:chemistry; D051381:Rats
chemical_list: D018836:Inflammation Mediators; D007783:Lactones; D010936:Plant Extracts; D062087:Plant Mucilage; D002118:Calcium