Identification of C-glycoside Flavonoids as Potential Mutagenic Compounds in Kava

• Published in: Journal of food science Vol. 72; no. 2; pp. C120 - C125
• Main Authors: Jhoo, J.-W, Ang, C.Y.W, Heinze, T.M, Deck, J, Schnackenberg, L.K, Beger, R.D, Dragull, K, Tang, C.-S
• Format: Journal Article
• Language: English
• Published: Malden, USA Blackwell Publishing Inc 01.03.2007; Institute of Food Technologists; Wiley Subscription Services, Inc
• Subjects: Animals; bioassays; Biological and medical sciences; Biological Assay; Chemical and Drug Induced Liver Injury; flavonoid; Flavonoids - isolation & purification; Flavonoids - toxicity; Flowers & plants; Food industries; Food science; Fundamental and applied biological sciences. Psychology; glycoflavonoids; hepatotoxicity; kava; Kava - chemistry; kavalactones; lactones; leaves; Monosaccharides - isolation & purification; Monosaccharides - toxicity; mutagenicity; Mutagenicity Tests; Piper methysticum; plant extracts; Plant Extracts - toxicity; Plant Leaves - chemistry; Plant Roots - chemistry; Plant Stems - chemistry; Point Mutation; Rats; Rats, Sprague-Dawley; roots; Salmonella typhimurium - drug effects; Solvents; stems; Polyphenol; flavonoid,kava,kavalactones,mutagenicity; Dicotyledones; Angiospermae; Piperaceae; Spermatophyta; Glycoside; Identification; Piper methysticum; Flavonoid
• ISSN: 0022-1147; 1750-3841
• DOI: 10.1111/j.1750-3841.2007.00278.x

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.