title: Comparative study of topical anti-allergic eye drops on human conjunctiva-derived cells: responses to histamine and IFN gamma and toxicological profiles.
abstract: BACKGROUND
  The purpose of the study was to compare toxic effects and responses to histamine and IFN gamma associated with the use of some widely used anti-allergic eye drops commercially available today.
  
  
  METHODS
  For dynamic studies, the Wong-Kilbourne cell line was stimulated for 24 h with histamine or IFN gamma in the presence or absence of anti-allergic eye drops. Supernatants of histamine-stimulated cells were evaluated for the production of IL-6 and IL-8 by ELISA, while the expression of ICAM-1 was evaluated by flow cytometry on IFN gamma-stimulated cells. Toxicological assays were performed using cold light cytofluorometry: viability and apoptosis as well as reactive oxygen species (ROS) and O2(.)- production were assessed using neutral red, Hoechst/propidium iodide, H(2)-DCFDA and hydroethidine tests, respectively.
  
  
  RESULTS
  Antihistamines reduced IL-6 release and presented dose-dependent inhibitory effects on IL-8 production. None of the eye drops decreased the basal or IFN gamma-stimulated expression of ICAM-1. Conversely, eye drops preserved with benzalkonium chloride (BAC) induced even higher ICAM-1 expression levels on IFN gamma-stimulated cells than did IFN gamma alone, whereas unpreserved drugs had no effect. Toxicological assays confirmed the pivotal role of BAC in proportionally reducing cell viability while increasing apoptosis and oxidative stress.
  
  
  CONCLUSIONS
  The ability of topical ocular anti-H(1) drugs to significantly reduce the production of IL-6 and IL-8 argues that they may help treat the inflammatory processes occurring in allergic ocular surface disorders. Nevertheless, preserved ophthalmic formulations may enhance epithelial conjunctival expression of ICAM-1 in the presence of a low inflammatory stimulus, such as IFN gamma, and displayed toxic as well as pro-oxidative effects on these cells. Therefore, BAC used as preservative might in part interfere with the potential anti-inflammatory properties of the active compound by modulating the immuno-inflammatory response of epithelial conjunctival cells.
authors.affiliation: U598, INSERM, Cordeliers Biomedical Institute, 15 rue de l'école de médecine, 75006, Paris, France.
authors.forename: Aude
authors.initials: A
authors.lastname: Pauly
authors.forename: Françoise
authors.initials: F
authors.lastname: Brignole-Baudouin
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Guenoun
authors.forename: Luisa
authors.initials: L
authors.lastname: Riancho
authors.forename: Patrice
authors.initials: P
authors.lastname: Rat
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Warnet
authors.forename: Christophe
authors.initials: C
authors.lastname: Baudouin
mesh_terms: D000287:Administration, Topical; D018926:Anti-Allergic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D003228:Conjunctiva / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism; D005434:Flow Cytometry; D006632:Histamine / Q000494:pharmacology*; D006634:Histamine H1 Antagonists / Q000494:pharmacology; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D007371:Interferon-gamma / Q000494:pharmacology*; D015850:Interleukin-6 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D009883:Ophthalmic Solutions / Q000494:pharmacology; D010545:Peroxides / Q000378:metabolism; D011310:Preservatives, Pharmaceutical / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D018926:Anti-Allergic Agents; D006634:Histamine H1 Antagonists; D015850:Interleukin-6; D016209:Interleukin-8; D009883:Ophthalmic Solutions; D010545:Peroxides; D011310:Preservatives, Pharmaceutical; D017382:Reactive Oxygen Species; D018799:Intercellular Adhesion Molecule-1; D006632:Histamine; D007371:Interferon-gamma