title: Cellular uptake, stability, visualization by 'Naturstoff reagent A', and multidrug resistance protein 1 gene-regulatory activity of cyanidin in human keratinocytes.
abstract: There is increasing interest in the role of anthocyanidins as potential skin protective phytochemicals. However, little is known if and to what extent anthocyanidins are taken up by the human skin. In the present study cellular uptake (as determined by HPLC), stability, and gene-regulatory activity of cyanidin were determined in human HaCaT keratinocytes in culture. Using the fluorescent dye Naturstoff reagent A cyanidin was visualized in order to determine its cellular accumulation via flow cytometry and fluorescence microscopy. Cyanidin was rapidly taken up by HaCaT cells at relatively low concentrations. Following incubation, cellular cyanidin levels decreased time-dependently most likely due to degradation into protocatechuic acid and phloroglucinol aldehyde. Confocal laser scanning microscopy data demonstrated that cyanidin was mainly present in the cytoplasm. Cellular uptake of cyanidin was accompanied by an inhibition of multidrug resistance protein 1 (involved in cellular efflux of flavonoids) mRNA-levels indicating its gene-regulatory activity. Naturstoff reagent A seems to be a promising fluorescent dye to visualize cyanidin in keratinocytes.
authors.affiliation: Institute of Human Nutrition and Food Science, Christian-Albrechts-University, Hermann-Rodewald-Strasse 6, 24118 Kiel, Germany.
authors.forename: I M A
authors.initials: IM
authors.lastname: Ernst
authors.forename: A E
authors.initials: AE
authors.lastname: Wagner
authors.forename: S
authors.initials: S
authors.lastname: Lipinski
authors.forename: S
authors.initials: S
authors.lastname: Skrbek
authors.forename: C E
authors.initials: CE
authors.lastname: Ruefer
authors.forename: C
authors.initials: C
authors.lastname: Desel
authors.forename: G
authors.initials: G
authors.lastname: Rimbach
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000037:antagonists & inhibitors / Q000502:physiology*; D000872:Anthocyanins / Q000378:metabolism* / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D004355:Drug Stability; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D015603:Keratinocytes / Q000378:metabolism*; D010860:Pigments, Biological / Q000378:metabolism / Q000494:pharmacology; D012333:RNA, Messenger / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D012869:Skin Absorption / Q000187:drug effects / Q000502:physiology*
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000872:Anthocyanins; D010860:Pigments, Biological; D012333:RNA, Messenger; C017154:cyanidin