Assessment of Toxicities of Moxifloxacin, Cefuroxime, and Levofloxacin on Corneal Endothelial Cells in Vitro
Purpose
To assess the toxic effects of moxifloxacin, cefuroxime, and levofloxacin on human corneal endothelial cells in vitro. In addition, to determine the safe intracameral concentrations for these antibiotics.
Methods
Human corneal endothelial cells (HCEn) in culture were exposed to moxifloxacin, cefuroxime, and levofloxacin at concentrations up to 2000 μg/ml. Evaluation of membrane damage was determined by ethidium homodimer-1 (EthD-1) uptake, and cell viability by intrinsic esterase activity. The inhibitory effects of the three antibiotics on the constitutive secretion of interleukin-6 (IL-6) was determined by ELISA.
Results
The acute effects (6 h) on membrane damage and cell death were dose-dependent for moxifloxacin and levofloxacin (≥500 μg/ml). For cefuroxime, membrane damage was not observed at 6 h, and slight damage was detected at 24h at concentrations ≥500 μg/ml. The half maximal inhibitory concentrations (IC50) on cell viability of moxifloxacin, levofloxacin, and cefuroxime were 487 μg/ml, 578 μg/ml, and 1600 μg/ml, respectively. The inhibitory effects of the three antibiotics on the constitutive secretion of IL-6 were observed at ≥15.6 μg/ml indicating that the antibiotics can impair the secretion of the protective cytokine even at low concentrations.
Conclusion
Moxifloxacin at >500 μg/ml causes damage of the cell membranes of corneal endothelial cells, and even higher concentrations decrease the cell viability. Considering the lower minimum inhibitory concentration for inhibiting 90% growth by moxifloxacin, we recommend intracameral moxifloxacin at ≤500 μg/ml for prophylactic use.