title: Genotoxic effect of ciprofloxacin during photolytic decomposition monitored by the in vitro micronucleus test (MNvit) in HepG2 cells.
abstract: OBJECTIVE
  Ciprofloxacin (CIP), a broad-spectrum, second-generation fluoroquinolone, has frequently been found in hospital wastewaters and effluents of sewage treatment plants. CIP is scarcely biodegradable, has toxic effects on microorganisms and is photosensitive. The aim of this study was to assess the genotoxic potential of CIP in human HepG2 liver cells during photolysis.
  
  
  METHODS
  Photolysis of CIP was performed in aqueous solution by irradiation with an Hg lamp, and transformation products were monitored by HPLC-MS/MS and by the determination of dissolved organic carbon (DOC). The cytotoxicity and genotoxicity of CIP and of the irradiated samples were determined after 24 h of exposure using the WST-1 assay and the in vitro micronucleus (MN) test in HepG2 cells.
  
  
  RESULTS
  The concentration of CIP decreased during photolysis, whereas the content of DOC remained unchanged. CIP and its transformation products were not cytotoxic towards HepG2 cells. A concentration-dependent increase of MN frequencies was observed for the parent compound CIP (lowest observed effect level, 1.2 μmol L(-1)). Furthermore, CIP and the irradiated samples were found to be genotoxic with a significant increase relative to the parent compound after 32 min (P < 0.05). A significant reduction of genotoxicity was found after 2 h of irradiation (P < 0.05).
  
  
  CONCLUSIONS
  Photolytic decomposition of aqueous CIP leads to genotoxic transformation products. This proves that irradiated samples of CIP are able to exert heritable genotoxic effects on human liver cells in vitro. Therefore, photolysis as a technique for wastewater treatment needs to be evaluated in detail in further studies, not only for CIP but in general.
authors.affiliation: Department of Environmental Health Sciences, University Medical Centre Freiburg, Freiburg, Germany. manuel.garcia-kaeufer@uniklinik-freiburg.de
authors.forename: Manuel
authors.initials: M
authors.lastname: Garcia-Käufer
authors.forename: Tarek
authors.initials: T
authors.lastname: Haddad
authors.forename: Marlies
authors.initials: M
authors.lastname: Bergheim
authors.forename: Richard
authors.initials: R
authors.lastname: Gminski
authors.forename: Preeti
authors.initials: P
authors.lastname: Gupta
authors.forename: Nupur
authors.initials: N
authors.lastname: Mathur
authors.forename: Klaus
authors.initials: K
authors.lastname: Kümmerer
authors.forename: Volker
authors.initials: V
authors.lastname: Mersch-Sundermann
mesh_terms: D002939:Ciprofloxacin / Q000737:chemistry* / Q000633:toxicity*; D004249:DNA Damage; D004305:Dose-Response Relationship, Drug; D056945:Hep G2 Cells; D006801:Humans; D015162:Micronucleus Tests; D010782:Photolysis; D012996:Solutions
chemical_list: D012996:Solutions; D002939:Ciprofloxacin