title: In vitro photochemical clastogenicity of quinolone antibacterial agents studied by a chromosomal aberration test with light irradiation.
abstract: The photochemical clastogenic potential of 12 quinolone antibacterial agents with or without light irradiation was assessed by an in vitro chromosomal aberration test using cultured CHL cells. Exposure to all test compounds, except for DK-507k, increased the incidence of cells with structural aberrations excluding gap (TA) following light irradiation. Test compounds used in the present study under light irradiation were divided into three groups based on their ED(50) values, doses inducing chromosomal aberrations in 50% of cells. The first group with ED(50) values below 30 microg/ml includes sparfloxacin (SPFX), clinafloxacin (CLFX), gemifloxacin (GMFX), lomefloxacin (LFLX), sitafloxacin (STFX), grepafloxacin (GPFX) and fleroxacin (FLRX); the second group with ED(50) values of 100 microg/ml, enoxacin (ENX) and levofloxacin (LVFX); the third group with little or no potency, moxifloxacin (MFLX), trovafloxacin (TVFX) and DK-507k. The photochemical clastogenicity of these compounds correlates well with their reported in vivo phototoxic potentials. In the chemical structure and clastogenicity relationships, substitution of a methoxy group at the C-8 position in the quinolone nucleus was confirmed to reduce not only photochemical clastogenicity, but also the clastogenic potential of quinolone antibacterial agents.
authors.affiliation: Drug Safety Research Laboratory, Daiichi Pharmaceutical Co. Ltd., 16-13 Kita-Kasai 1-Chome, Edogawa-ku, Tokyo 134-8630, Japan. itohsudk@daiichipharm.co.jp
authors.forename: Satoru
authors.initials: S
authors.lastname: Itoh
authors.forename: Shiho
authors.initials: S
authors.lastname: Nakayama
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Shimada
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000890:Anti-Infective Agents / Q000494:pharmacology*; D002869:Chromosome Aberrations; D002875:Chromosomes / Q000528:radiation effects*; D004305:Dose-Response Relationship, Drug; D024841:Fluoroquinolones; D008027:Light; D008956:Models, Chemical; D015363:Quinolones / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D015363:Quinolones