title: Rufloxacin-induced photosensitization in yeast.
abstract: The fluoroquinolone Rufloxacin (RFX) is active as specific inhibitor of bacterial gyrase. The adverse effects of the photosensitization induced by fluoroquinolones are well known. A predominant type II photosensitizing activity of Rufloxacin has already been demonstrated on simpler models (free nucleosides, calf thymus DNA), whereas a cooperative mechanism was corroborated on more complex ones (plasmid and fibroblast). The purpose of this study is to examine the drug photocytoxicity in another complex cellular model, a wild-type eukaryotic fast-growing microorganism whose cultivation is cheap and easily managed, Saccharomyces cerevisiae. This work represents the first report of the potential photogenotoxicity of Rufloxacin. Particular emphasis was given to DNA modifications caused in yeast by the formation of Rufloxacin photomediated toxic species, such as hydrogen peroxide and formaldehyde. Drug phototoxicity on yeast was evaluated by measuring DNA fragmentation (single/double strand breaks) using single cell gel electrophoresis assay and 8-OH-dGuo, a DNA photooxidation biomarker, by HPLC-ECD. Cellular sensitivity was also assessed by cell viability test. The extra- and intracellular RFX concentration (as well as its main photoproduct) was verified by HPLC-MS, whereas the cytotoxic species were evaluated by colorimetric assays. The results confirm the phototoxicity of Rufloxacin on yeast cell and are in agreement with those previously obtained with human fibroblast and with simpler models used recently, and provide a clear link between DNA photosensitization and overall phototoxicity.
authors.affiliation: Dipartimento di Scienze Chimiche, Università di Catania, Viale Andrea Doria 6, 95125, Catania, Italy.
authors.forename: Alfio
authors.initials: A
authors.lastname: Catalfo
authors.forename: Maria Laura
authors.initials: ML
authors.lastname: Calandra
authors.forename: Marcella
authors.initials: M
authors.lastname: Renis
authors.forename: Maria Elisabetta
authors.initials: ME
authors.lastname: Serrentino
authors.forename: Guido
authors.initials: G
authors.lastname: De Guidi
mesh_terms: D002470:Cell Survival / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D053938:DNA Fragmentation / Q000187:drug effects / Q000528:radiation effects; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D024841:Fluoroquinolones / Q000737:chemistry / Q000494:pharmacology* / Q000528:radiation effects; D005557:Formaldehyde / Q000737:chemistry / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000737:chemistry / Q000494:pharmacology; D013058:Mass Spectrometry / Q000379:methods; D015394:Molecular Structure; D017319:Photosensitizing Agents / Q000737:chemistry / Q000494:pharmacology* / Q000528:radiation effects; D015363:Quinolones / Q000737:chemistry / Q000494:pharmacology* / Q000528:radiation effects; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000187:drug effects* / Q000528:radiation effects; D012680:Sensitivity and Specificity; D014466:Ultraviolet Rays
chemical_list: D024841:Fluoroquinolones; D017319:Photosensitizing Agents; D015363:Quinolones; D005557:Formaldehyde; D006861:Hydrogen Peroxide; C060328:rufloxacin