title: Black tea extract suppresses transformation of aryl hydrocarbon receptor induced by dioxin.
abstract: Dioxins cause various adverse effects through binding to an aryl hydrocarbon receptor (AhR) and transformation of the receptor. In this study, we investigated whether black tea extract suppresses AhR transformation. Dried black tea leaves were extracted with 75% ethanol, and the extract was pretreated to the rat liver cytosol fraction 10 min prior to addition of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Transformed AhR was detected by electrophoretic gel mobility shift assay. Black tea extract suppressed AhR transformation in a dose-dependent manner, and the IC50 value against 1 nM TCDD-induced AhR transformation was 8.9 microg/ml. The result suggests that intake of black tea has a potential to suppress the AhR transformation, leading protection from dioxin toxicity.
authors.affiliation: Laboratory of Food and Nutritional Chemistry, Faculty of Agriculture, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo 657-8501, Japan.
authors.forename: Itsuko
authors.initials: I
authors.lastname: Fukuda
authors.forename: Iwao
authors.initials: I
authors.lastname: Sakane
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Yabushita
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Sawamura
authors.forename: Kazuki
authors.initials: K
authors.lastname: Kanazawa
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Ashida
mesh_terms: D000818:Animals; D028241:Camellia sinensis; D003600:Cytosol / Q000187:drug effects / Q000502:physiology; D008099:Liver / Q000187:drug effects / Q000502:physiology; D010936:Plant Extracts / Q000494:pharmacology*; D018515:Plant Leaves; D000072317:Polychlorinated Dibenzodioxins / Q000494:pharmacology*; D051381:Rats; D018336:Receptors, Aryl Hydrocarbon / Q000096:biosynthesis* / Q000187:drug effects; D013188:Sri Lanka; D013662:Tea
chemical_list: D010936:Plant Extracts; D000072317:Polychlorinated Dibenzodioxins; D018336:Receptors, Aryl Hydrocarbon; D013662:Tea