Acute effects of glaucoma medications and benzalkonium chloride on pre-adipocyte proliferation and adipocyte cytotoxicity in vitro.

Purpose: To determine and compare the short-term, in vitro effect of prostaglandin analogues (PGAs), timolol, and benzalkonium chloride (BAK) on pre-adipocyte proliferation and adipocyte cytotoxicity.

Methods: For the proliferation assay, human primary subcutaneous pre-adipocytes were incubated in the presence of either bimatoprost (0.015%, 0.03%, 0.06%) travoprost (0.002%, 0.004%, 0.008%), latanoprost (0.0025%, 0.005%, 0.010%), tafluprost (0.00075%, 0.0015%, 0.003%), timolol maleate (0.25%, 0.5%, 1.0%), BAK (0.005%, 0.010%, 0.015%, 0.020%, 0.040%), or control of BAK vehicle. After 72 h in culture, cell numbers were determined by fluorescent assay with CellTiter-Blue(®) reagent. For the cytotoxity assay, mature human adipocytes were cultured for 72 h with the same test compounds and controls. Cell numbers were again determined in the same manner through fluorescence.

Results: In the proliferation assay, all four PGA medications failed to show a statistically significant difference from BAK vehicle alone (p = 0.065-0.751). Both timolol and BAK alone demonstrated near complete inhibition of pre-adipocyte proliferation at all concentrations tested (p < 0.01 for all). In the cytotoxicity assay, all four PGAs again exerted no significant effect when compared to control (p = 0.211-0.901). Timolol and BAK again displayed near complete toxicity of adipocytes at all concentrations (p < 0.01 for all).

Conclusions: All four PGAs had similar and negligible short-term effects on pre-adipocyte proliferation and adipocyte toxicity in vitro. Timolol and BAK had profound cytotoxic effects on mature adipocytes and antiproliferative effects on pre-adipocytes in vitro. Further testing is needed to determine whether similar effects are present in vivo.