title: Chlorhexidine markedly potentiates the oxidants scavenging abilities of Candida albicans.
abstract: The oxidant scavenging ability (OSA) of catalase-rich Candida albicans is markedly enhanced by chlorhexidine digluconate (CHX), polymyxin B, the bile salt ursodeoxycholate and by lysophosphatidylcholine, which all act as detergents facilitating the penetration of oxidants and their intracellular decomposition. Quantifications of the OSA of Candida albicans were measured by a highly sensitive luminol-dependent chemiluminescence assay and by the Thurman's assay, to quantify hydrogen peroxide (H2O2). The OSA enhancing activity by CHX depends to some extent on the media on which candida grew. The OSA of candida treated by CHX was modulated by whole human saliva, red blood cells, lysozyme, cationic peptides and by polyphenols. Concentrations of CHX, which killed over 95 % of Candida albicans cells, did not affect the cells' abilities to scavenge reactive oxygen species (ROS). The OSA of Candida cells treated by CHX is highly refractory to H2O2 (50 mM) but is strongly inhibited by hypochlorous acid, lecithin, trypan blue and by heparin. We speculate that similarly to catalase-rich red blood cells, Candida albicans and additional catalase-rich microbiota may also have the ability to scavenge oxidants and thus can protect catalase-negative anaerobes and facultative anaerobes cariogenic streptococci against peroxide and thus secure their survival in the oral cavity.
authors.affiliation: Institute for Dental Sciences, Hadassah Faculty of Dental Medicine, Hebrew University-Hadassah Medical Center, P.O.B. 12272, 91120, Jerusalem, Israel. Ginsburg@mail.huji.ac.il.
authors.forename: I
authors.initials: I
authors.lastname: Ginsburg
authors.affiliation: Institute for Dental Sciences, Hadassah Faculty of Dental Medicine, Hebrew University-Hadassah Medical Center, P.O.B. 12272, 91120, Jerusalem, Israel. erezkoren@gmail.com.
authors.forename: E
authors.initials: E
authors.lastname: Koren
authors.affiliation: Department of Prosthodontics, Hebrew University-Hadassah Faculty of Dental Medicine, Jerusalem, Israel.
authors.forename: O
authors.initials: O
authors.lastname: Feuerstein
authors.affiliation: Department of Orthodontics, Hebrew University-Hadassah Faculty of Dental Medicine, Jerusalem, Israel.
authors.forename: I P
authors.initials: IP
authors.lastname: Zogakis
authors.affiliation: Department of Orthodontics, Hebrew University-Hadassah Faculty of Dental Medicine, Jerusalem, Israel.
authors.forename: M
authors.initials: M
authors.lastname: Shalish
authors.affiliation: Institute for Dental Sciences, Hadassah Faculty of Dental Medicine, Hebrew University-Hadassah Medical Center, P.O.B. 12272, 91120, Jerusalem, Israel.
authors.forename: S
authors.initials: S
authors.lastname: Gorelik
mesh_terms: D002176:Candida albicans / Q000378:metabolism*; D002710:Chlorhexidine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D016166:Free Radical Scavengers / Q000008:administration & dosage / Q000378:metabolism*; D006801:Humans; D016877:Oxidants / Q000037:antagonists & inhibitors / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D016166:Free Radical Scavengers; D016877:Oxidants; D017382:Reactive Oxygen Species; C010882:chlorhexidine gluconate; D002710:Chlorhexidine
keywords: Catalase; Chlorhexidine; H2O2; Media; Red blood cells; Saliva