title: Investigation of cytotoxic and genotoxic effects of the antihistaminic drug, loratadine, on human lymphocytes.
abstract: BACKGROUND
  Loratadine (LOR) is a new generation antihistamine used in the treatment of allergic disorders.
  
  
  OBJECTIVE
  The aim of this study was to evaluate the cytogenotoxic effect of LOR on human peripheral blood lymphocytes.
  
  
  METHODS
  We investigated the genotoxic effect of this drug in cultured human peripheral blood lymphocytes using sister chromatid exchange (SCE), chromosomal aberrations (CA) and micronucleus (MN) assay in culture conditions. Proliferation index (PI), mitotic index (MI) and nuclear division index (NDI) were also calculated to determine the cytotoxic/cytostatic effect. Cultures were treated with LOR at three concentrations (5, 15 and 25 µg/ml) for 48 h.
  
  
  RESULTS
  Although the MI significantly decreased at the higher concentrations (15 and 25 µg/ml) compared with negative (solvent) control, LOR indicated weaker cytotoxic potential in PI and NDI values at all the tested concentrations. LOR increased the frequencies of SCE, CA and MN in all lymphocyte cultures. However, significant increase was observed in MN at the medium and highest doses (15 and 25 µg/ml) and in CA at the medium dose (15 µg/ml) compared with negative (solvent) control culture. Our results indicate that LOR has cytotoxic and genotoxic effects on human peripheral blood lymphocyte cultures.
  
  
  CONCLUSIONS
  Although most of previously findings have shown that LOR does not reflect genotoxicity, our results indicated that it may be a genotoxic drug.
  
  
  CONCLUSIONS
  More studies are necessary to elucidate the relationship between cytotoxic, genotoxic and apoptotic effects, and to make a possible risk assessment in patients receiving therapy with this drug.
authors.affiliation: Department of Biology, Faculty of Science and Letters, Ordu University , Ordu , Turkey.
authors.forename: Seval
authors.initials: S
authors.lastname: Kontaş
authors.forename: Zülal
authors.initials: Z
authors.lastname: Atlı Şekeroğlu
mesh_terms: D000328:Adult; D018929:Cell Culture Techniques; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D005260:Female; D039563:Histamine H1 Antagonists, Non-Sedating / Q000633:toxicity*; D006801:Humans; D017336:Loratadine / Q000633:toxicity*; D008214:Lymphocytes / Q000187:drug effects* / Q000473:pathology; D008297:Male; D048629:Micronuclei, Chromosome-Defective / Q000139:chemically induced*; D008940:Mitotic Index; D015394:Molecular Structure; D012854:Sister Chromatid Exchange / Q000187:drug effects*; D055815:Young Adult
chemical_list: D039563:Histamine H1 Antagonists, Non-Sedating; D017336:Loratadine
keywords: Chromosome aberration; cytotoxicity; genotoxicity; human peripheral lymphocytes; loratadine; micronucleus; sister chromatid exchange