Abstract
Purpose:
To evaluate the cytotoxicity of antibiotics, antifungals and corticosteroids in limbal and conjunctival epithelial cells cultivated ex vivo.
Methods:
Limbal epithelial cells were obtained from corneoescleral rims and cultured in Epilife medium. Conjunctival epithelial cells were obtained from biopsy 2 mm2 x 3 mm2 at the Department of Ophthalmology of UNIFESP/EPM, and cultured in DMEM/F12 medium supplemented. The cells were incubated with amphotericin B, ciprofloxacin, chloramphenicol, dexamethasone, streptomycin, gatifloxacin, gentamicin, moxifloxacin, prednisone and tobramycin, at concentrations of 250, 125, 62.5 and 31.25 µg/mL for 4, 8, 12 and 24 hours. The drugs were diluted in BSS, and prepared without the addition of the preservative benzalkonium chloride, which was tested separately. Toxicity was estimated by cell viability assay - MTT.
Results:
Preliminary tests on limbal epithelial cells indicated that the most toxic antibiotic was gatifloxacin in most of the incubation times and concentrations tested. Ciprofloxacin presented toxicity after 8 hours of incubation and moxifloxacin after 12 hours of incubation. The drugs that were less toxic to the limbal cells were amphotericin B, streptomycin and chloramphenicol. The first tests performed in the conjunctival cells showed that after 4 hours of incubation, the most toxic antibiotic was gatifloxacin and the least toxic was gentamicin. After 8, 12, and 24 hours the antibiotics that had the higher cytotoxicity were ciprofloxacin, streptomycin and amphotericin B, at all concentrations. The antibiotic that showed less toxicity was moxifloxacin. As for corticosteroids, none of the drugs tested showed high toxicity, but dexamethasone exhibited a better profile when compared with prednisone. Benzalkonium chloride showed high toxicity in all groups, causing 100% of cells death.
Conclusions:
To the limbal epithelial cells, the fluoroquinolones tested showed greater toxicity when compared with other drugs. To conjunctival epithelial cells, among the tested fluoroquinolones, gatifloxacin and ciprofloxacin, showed higher toxicity, and moxifloxacin showed less toxicity to the conjunctival cells when compared with aminoglycosides. For both cells tested, none of the corticosteroids showed high toxicity, but dexamethasone exhibited a better profile when compared with prednisone. Additional experiments are underway to further confirm our preliminary findings.
Keywords: 422 antibiotics/antifungals/antiparasitics •
482 cornea: epithelium •
474 conjunctiva