title: Semisynthetic flavonoid 7-O-galloylquercetin activates Nrf2 and induces Nrf2-dependent gene expression in RAW264.7 and Hepa1c1c7 cells.
abstract: The natural flavonoid quercetin is known to activate the transcription factor Nrf2, which regulates the expression of cytoprotective enzymes such as heme oxygenase-1 (HO-1) and NAD(P)H:quinone oxidoreductase 1 (NQO1). In this study, a novel semisynthetic flavonoid 7-O-galloylquercetin (or quercetin-7-gallate, 3) was prepared by direct galloylation of quercetin, and its effect on the Nrf2 pathway was examined. A luciferase reporter assay showed that 7-O-galloylquercetin, like quercetin, significantly activated transcription via the antioxidant response element in a stably transfected human AREc32 reporter cell line. In addition, 7-O-galloylquercetin caused the accumulation of Nrf2 and induced the expression of HO-1 at both the mRNA and protein levels in murine macrophage RAW264.7 cells. The induction of HO-1 by 7-O-galloylquercetin was significantly suppressed by N-acetyl-l-cysteine and SB203580, indicating the involvement of reactive oxygen species and p38 mitogen-activated protein kinase activity, respectively. HPLC/MS analyses also showed that 7-O-galloylquercetin was not degalloylated to quercetin, but it was conjugated with glucuronic acid and/or methylated in RAW264.7 cells. Furthermore, 7-O-galloylquercetin was found to increase the protein levels of Nrf2 and HO-1, and also the activity of NQO1 in murine hepatoma Hepa1c1c7 cells. Taken together, we conclude that 7-O-galloylquercetin increases Nrf2 activity and induces Nrf2-dependent gene expression in RAW264.7 and Hepa1c1c7 cells.
authors: Department of Medical Chemistry and Biochemistry, Faculty of Medicine and Dentistry, Palacký University, Hněvotínská 3, Olomouc 77515, Czech Republic; Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University, Hněvotínská 3, Olomouc 77515, Czech Republic.
authors: Lenka
authors: L
authors: Roubalová
authors: Institute of Microbiology, Laboratory of Biotransformation, Czech Academy of Sciences, Vídeňská 1083, Prague 14220, Czech Republic.
authors: David
authors: D
authors: Biedermann
authors: Regional Centre of Advanced Technologies and Materials, Department of Analytical Chemistry, Faculty of Science, Palacký University, 17. listopadu 12, Olomouc 77146, Czech Republic.
authors: Barbora
authors: B
authors: Papoušková
authors: Department of Medical Chemistry and Biochemistry, Faculty of Medicine and Dentistry, Palacký University, Hněvotínská 3, Olomouc 77515, Czech Republic.
authors: Jan
authors: J
authors: Vacek
authors: Institute of Microbiology, Laboratory of Biotransformation, Czech Academy of Sciences, Vídeňská 1083, Prague 14220, Czech Republic.
authors: Marek
authors: M
authors: Kuzma
authors: Institute of Microbiology, Laboratory of Biotransformation, Czech Academy of Sciences, Vídeňská 1083, Prague 14220, Czech Republic.
authors: Vladimír
authors: V
authors: Křen
authors: Department of Medical Chemistry and Biochemistry, Faculty of Medicine and Dentistry, Palacký University, Hněvotínská 3, Olomouc 77515, Czech Republic; Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University, Hněvotínská 3, Olomouc 77515, Czech Republic.
authors: Jitka
authors: J
authors: Ulrichová
authors: Jacqui Wood Cancer Centre, Division of Cancer Research, School of Medicine, University of Dundee, Dundee DD1 9SY, Scotland, UK.
authors: Albena T
authors: AT
authors: Dinkova-Kostova
authors: Department of Medical Chemistry and Biochemistry, Faculty of Medicine and Dentistry, Palacký University, Hněvotínská 3, Olomouc 77515, Czech Republic; Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University, Hněvotínská 3, Olomouc 77515, Czech Republic. Electronic address: vrbambv@seznam.cz.
authors: Jiří
authors: J
authors: Vrba
mesh_terms: D000818:Animals; D001711:Biotransformation / Q000187:drug effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D004790:Enzyme Induction / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects*; D017930:Genes, Reporter; D051547:Heme Oxygenase-1 / Q000096:biosynthesis; D006801:Humans; D013058:Mass Spectrometry; D055442:Metabolome / Q000187:drug effects; D051379:Mice; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000378:metabolism; D051267:NF-E2-Related Factor 2 / Q000378:metabolism*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011794:Quercetin / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D000067996:RAW 264.7 Cells; D017382:Reactive Oxygen Species / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D051267:NF-E2-Related Factor 2; D047428:Protein Kinase Inhibitors; D017382:Reactive Oxygen Species; D011794:Quercetin; D051547:Heme Oxygenase-1; D016660:NAD(P)H Dehydrogenase (Quinone); D048051:p38 Mitogen-Activated Protein Kinases
keywords: Heme oxygenase-1; Metabolism; Methyl gallate; Nrf2; Quercetin; Quercetin-7-gallate