RESUMO
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.
Assuntos
Flavonoides/toxicidade , Kava/química , Monossacarídeos/toxicidade , Testes de Mutagenicidade , Extratos Vegetais/toxicidade , Animais , Bioensaio , Doença Hepática Induzida por Substâncias e Drogas , Flavonoides/isolamento & purificação , Glicosídeos , Monossacarídeos/isolamento & purificação , Folhas de Planta/química , Raízes de Plantas/química , Caules de Planta/química , Mutação Puntual , Ratos , Ratos Sprague-Dawley , Salmonella typhimurium/efeitos dos fármacosRESUMO
Broiler breast and leg meats in sealed bags were cooked in an 88°C water bath to an internal temperature of 81 °C. Product was cooled and stored at 4°C for 0 or 3 d. Samples were reheated to 60°C in a 163°C oven. No significant differences were found by the thiobarbituric acid reactive substances test between control and reheated portions, regardless of muscle type or storage time after cooking. The reheating practice made negligible contribution to oxidative changes of precooked chicken meat.