title: Free radical scavenging and antioxidant activity of betanin: electron spin resonance spectroscopy studies and studies in cultured cells.
abstract: Betanin is a red pigment present in red beetroot. Recently, potential health benefits of betanin-rich beetroot have been suggested. However, little is known regarding the free radical scavenging and antioxidant activity of betanin. Electron spin resonance spectroscopy (ESR) and spin trapping techniques were applied to evaluate the ability of betanin to scavenge hydroxyl, superoxide, 2,2 diphenyl-1-picrylhydrazyl (DPPH), and galvinoxyl free radicals. In addition, we tested in cultured cells the ability of betanin to prevent DNA damage and to induce the transcription factor Nrf2 (nuclear factor (erythroid-derived 2)-like 2) as well as its down-stream target heme oxygenase1 (HO-1), paraoxonase1 (PON1) and glutathione (GSH). Betanin dose-dependently scavenged DPPH-, galvinoxyl-, superoxide-, and hydroxyl-radicals in the ESR and spin trapping studies and prevented hydrogen peroxide induced DNA damage as determined by the Comet assay. Furthermore, betanin treatment induced the transcription factor Nrf2 and resulted in an increase of HO-1 protein levels, PON1-transactivation and cellular GSH. Present data suggest that betanin is both a free radical scavenger and an inducer of antioxidant defense mechanism in cultured cells.
authors.affiliation: Institute of Human Nutrition and Food Science, University of Kiel, Germany.
authors.forename: Tuba
authors.initials: T
authors.lastname: Esatbeyoglu
authors.affiliation: Institute of Human Nutrition and Food Science, University of Kiel, Germany.
authors.forename: Anika E
authors.initials: AE
authors.lastname: Wagner
authors.affiliation: Department of Plant Sciences, Faculty of Natural Sciences, University of Tabriz, Iran.
authors.forename: Rouhollah
authors.initials: R
authors.lastname: Motafakkerazad
authors.affiliation: Institute of Science and Engineering, Faculty of Natural System, Bioengineering Course, Kanazawa University, Kanazawa, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Nakajima
authors.affiliation: Institute of Science and Engineering, Faculty of Natural System, Bioengineering Course, Kanazawa University, Kanazawa, Japan.
authors.forename: Seiichi
authors.initials: S
authors.lastname: Matsugo
authors.affiliation: Institute of Human Nutrition and Food Science, University of Kiel, Germany. Electronic address: rimbach@foodsci.uni-kiel.de.
authors.forename: Gerald
authors.initials: G
authors.lastname: Rimbach
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D050859:Betacyanins / Q000494:pharmacology*; D045744:Cell Line, Tumor; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D004797:Enzyme-Linked Immunosorbent Assay; D016166:Free Radical Scavengers / Q000494:pharmacology*; D006801:Humans
chemical_list: D000975:Antioxidants; D050859:Betacyanins; D016166:Free Radical Scavengers; C020228:betanin
keywords: Beetroot; Betanin; ESR; Heme oxygenase 1; Nrf2; Paraoxonase 1