In vitro effects of preserved and unpreserved antiglaucoma drugs on apoptotic marker expression by human trabecular cells

Graefes Arch Clin Exp Ophthalmol. 2003 Dec;241(12):1037-43. doi: 10.1007/s00417-003-0777-7. Epub 2003 Nov 7.

Abstract

Background: The mechanisms of trabecular cell loss in glaucoma patients are poorly understood. In order to determine whether drug-induced apoptosis could be one of the mechanisms by which trabecular cells die in glaucoma, we evaluated the effect of benzalkonium-preserved (BAC+) or preservative-free (BAC-) antiglaucoma medications on apoptotic marker expression by cultured human trabecular meshwork (HTM) cells.

Methods: Normal and glaucomatous trabecular cell lines were treated for 15 min with antiglaucoma drugs (1/100 and 1/10 dilutions): timolol BAC+ or BAC-, betaxolol BAC+ or BAC-, latanoprost BAC+ or pure BAC. Apo2.7 expression, annexin V binding and DNA content were evaluated by flow cytometry and confocal microscopy.

Results: Results obtained in the two cell lines were similar for all tested drugs and criteria. In a 1/100 dilution, unpreserved beta-blockers had no apoptotic effect, preserved beta-blockers and latanoprost significantly increased Apo2.7 expression only, while BAC significantly increased all three apoptotic markers. When tested in a 1/10 dilution, all drugs except unpreserved timolol triggered a 2- to 3.5-fold increase in apoptotic features, whereas up to 95% of the cells underwent apoptosis upon treatment with BAC (representing a 9-fold increase over the background level).

Conclusion: At concentrations higher than those supposed to be found in the aqueous humor after instillation (1/100 dilution), unpreserved beta-blocker exhibited no proapoptotic activity on HTM cells in vitro. Benzalkonium-containing beta-blockers and prostaglandin analogue triggered mild expression of one out of three apoptotic markers, while the pro-apoptotic effect observed with BAC appeared to be largely hindered by active compounds in the preserved eyedrops.

Publication types

  • Comparative Study

MeSH terms

  • Adolescent
  • Aged
  • Annexin A5 / metabolism
  • Antihypertensive Agents / pharmacology*
  • Apoptosis*
  • Benzalkonium Compounds / pharmacology*
  • Betaxolol / pharmacology
  • Biomarkers / analysis*
  • Cells, Cultured
  • DNA / metabolism
  • Humans
  • Latanoprost
  • Male
  • Membrane Proteins / metabolism
  • Microscopy, Confocal
  • Preservatives, Pharmaceutical / pharmacology*
  • Prostaglandins F, Synthetic / pharmacology
  • Timolol / pharmacology
  • Trabecular Meshwork / cytology
  • Trabecular Meshwork / drug effects*
  • Trabecular Meshwork / metabolism

Substances

  • Annexin A5
  • Antihypertensive Agents
  • Benzalkonium Compounds
  • Biomarkers
  • Membrane Proteins
  • Preservatives, Pharmaceutical
  • Prostaglandins F, Synthetic
  • antigen 7A6
  • Latanoprost
  • Timolol
  • DNA
  • Betaxolol