title: Identification of C-glycoside flavonoids as potential mutagenic compounds in kava.
abstract: Kava (Piper methysticum) extract products have been implicated in a number of severe hepatotoxicity cases. However, systematic toxicological studies regarding kava consumption have not been reported. In this study, 6 major kavalactones and different solvent fractions of kava roots, leaves, and stem peelings were evaluated for their mutagenic potential. None of the kavalactones was found to be positive in the experimental concentration ranges tested by the umu test (a sensitive test for point mutations). However, among the different solvent fractions, the n-butanol fraction of kava leaves was positive. Further investigations using bioassay-directed isolation and analysis indicated that 2 C-glycoside flavonoid compounds accounted for the positive mutagenic results. Two isolated compounds were identified as 2''-O-rhamnosylvitexin and schaftoside by NMR and MS techniques.
authors.affiliation: Natl. Center for Toxicological Research, U.S. Food and Drug Administration, 3900 NCTR Rd., Jefferson, AR 72079, USA. jjhoo@kangwon.ac.kr
authors.forename: J-W
authors.initials: JW
authors.lastname: Jhoo
authors.forename: C Y W
authors.initials: CY
authors.lastname: Ang
authors.forename: T M
authors.initials: TM
authors.lastname: Heinze
authors.forename: J
authors.initials: J
authors.lastname: Deck
authors.forename: L K
authors.initials: LK
authors.lastname: Schnackenberg
authors.forename: R D
authors.initials: RD
authors.lastname: Beger
authors.forename: K
authors.initials: K
authors.lastname: Dragull
authors.forename: C-S
authors.initials: CS
authors.lastname: Tang
mesh_terms: D000818:Animals; D001681:Biological Assay; D056486:Chemical and Drug Induced Liver Injury; D005419:Flavonoids / Q000302:isolation & purification / Q000633:toxicity*; D006027:Glycosides; D020901:Kava / Q000737:chemistry*; D009005:Monosaccharides / Q000302:isolation & purification / Q000633:toxicity*; D009152:Mutagenicity Tests; D010936:Plant Extracts / Q000633:toxicity*; D018515:Plant Leaves / Q000737:chemistry; D018517:Plant Roots / Q000737:chemistry; D018547:Plant Stems / Q000737:chemistry; D017354:Point Mutation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012486:Salmonella typhimurium / Q000187:drug effects
chemical_list: C438934:C-glycoside; D005419:Flavonoids; D006027:Glycosides; D009005:Monosaccharides; D010936:Plant Extracts