title: Sodium ascorbate kills Candida albicans in vitro via iron-catalyzed Fenton reaction: importance of oxygenation and metabolism.
abstract: Ascorbate can inhibit growth and even decrease viability of various microbial species including Candida albicans. However the optimum conditions and the mechanism of action are unclear. Materials/methodology: Candida albicans shaken for 90 min in a buffered solution of ascorbate (90 mM) gave a 5-log reduction of cell viability, while there was no killing without shaking, in growth media with different carbon sources or at 4°C. Killing was inhibited by the iron chelator 2,2'-bipyridyl. Hydroxyphenyl fluorescein probe showed the intracellular generation of hydroxyl radicals.
  
  
  
  Ascorbate-mediated killing of C. albicans depends on oxygenation and metabolism, involves iron-catalyzed generation of hydroxyl radicals via Fenton reaction and depletion of intracellular NADH. Ascorbate could serve as a component of a topical antifungal therapy.
authors.affiliation: Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA 02114, USA.|Department of Dermatology, Harvard Medical School, Boston, MA 02115, USA.|Department of Dermatology, Venerology & Dermato-Oncology, Semmelweis University, Budapest 1085, Hungary.
authors.forename: Pinar
authors.initials: P
authors.lastname: Avci
authors.affiliation: Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA 02114, USA.|Department of Biosciences & Oral Diagnosis, Institute of Science & Technology, Universidade Estadual Paulista (UNESP), São José dos Campos, São Paulo 12245-000, Brazil.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Freire
authors.affiliation: Department of Dermatology, Venerology & Dermato-Oncology, Semmelweis University, Budapest 1085, Hungary.
authors.forename: Andras
authors.initials: A
authors.lastname: Banvolgyi
authors.affiliation: Infectious Diseases Division, Warren Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI 02912, USA.
authors.forename: Eleftherios
authors.initials: E
authors.lastname: Mylonakis
authors.affiliation: Department of Dermatology, Venerology & Dermato-Oncology, Semmelweis University, Budapest 1085, Hungary.
authors.forename: Norbert M
authors.initials: NM
authors.lastname: Wikonkal
authors.affiliation: Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA 02114, USA.|Department of Dermatology, Harvard Medical School, Boston, MA 02115, USA.|Harvard-MIT Division of Health Sciences & Technology, Cambridge, MA 02139, USA.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Hamblin
mesh_terms: D000935:Antifungal Agents / Q000737:chemistry / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000737:chemistry / Q000494:pharmacology*; D002176:Candida albicans / Q000737:chemistry / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000737:chemistry; D017665:Hydroxyl Radical / Q000378:metabolism; D007501:Iron / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D009243:NAD / Q000378:metabolism; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism
chemical_list: D000935:Antifungal Agents; C045076:Fenton's reagent; D009243:NAD; D017665:Hydroxyl Radical; D006861:Hydrogen Peroxide; D007501:Iron; D001205:Ascorbic Acid; D010100:Oxygen
keywords: Candida albicans; ascorbate; hydroxyl radicals; oxidative stress; vitamin C