Cytotoxicity studies in ophthalmology.
Ocular tissues and cells are more and more in direct contact not only with drugs but also with biomaterials, such as contact lenses, intraocular implants, corneal shields, and the cell reactivity study is an indispensable step before any clinical and human utilization. The cell toxicity may be direct, by cell membrane damaging, metabolic disturbance, or indirect by mitosis or cell differentiation blocking. In order to evaluate the unwanted effects, cell cultures are performed according to the drug or to the biomaterial to be tested: conjunctival and corneal epithelial cells, lens epithelium, ciliary processes epithelium... In this report, the cytotoxicity of three substances were evaluated on corneal cultured cells: Benzalkonium chloride (BAK), an ophthalmic preservative; Novesine (Oxybuprocaine + BAK), local anaesthetic; Neosynephrine (Phenylephrine chlorydrate), a commonly used mydriatic in ocular surgery. Results of cell counting (cell viability) are given according to curves and histograms (percentage of dead cells depending on time and doses). These data are discussed according to the different mechanisms of action of the three drugs BAK and Oxybuprocaine were found to exert a more direct cell toxicity whereas phenylephrine chloride acted indirectly by causing the sloughing of the cell monolayer.
Lapalus
P
P
Laboratory of Pharmacology, School of Medicine, Nice, France.
Ettaiche
M
M
Fredj-Reygrobellet
D
D
Jambou
D
D
Elena
P P
PP
D000779:Anesthetics, Local / Q000633:toxicity*; D000818:Animals; D001548:Benzalkonium Compounds / Q000633:toxicity*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003315:Cornea / Q000166:cytology / Q000187:drug effects*; D004848:Epithelium / Q000187:drug effects; D007928:Lethal Dose 50; D010656:Phenylephrine / Q000633:toxicity*; D011343:Procaine / Q000031:analogs & derivatives* / Q000633:toxicity; D011817:Rabbits
D000779:Anesthetics, Local; D001548:Benzalkonium Compounds; D010656:Phenylephrine; D011343:Procaine; C005298:benoxinate