PURPOSE: Long-term use of topical medication is needed for glaucoma treatment. One of the most commonly prescribed classes of hypotensive agents are prostaglandin analogs (PGs) used as both first-line monotherapy; as well as in combination therapy with other hypotensive agents. Several side effects of eye drops can be caused by preservatives. The purpose of this study was to evaluate the effects of PGs with varying concentrations of benzalkonium chloride (BAC), alternative preservatives, or no preservatives on human conjunctival fibroblast cells. METHODS: Primary human conjunctival fibroblast cells were used in these experiments. Cells were exposed to the following drugs: BAC at different concentrations, bimatoprost 0.01% (with BAC 0.02%), latanoprost 0.005% (with BAC 0.02%), tafluprost 0.0015% with/without 0.001% BAC and travoprost 0.004% (with 0.001% Polyquad) for 15 and 30 minutes. Cell cytotoxicity was evaluated by phase-contrast microscopy to monitor morphological changes of cells, Counting Kit-8 (CCK-8) assay to cell viability, and fluorescent activated cell sorting (FACS) analysis to measure apoptosis. RESULTS: BAC caused cell shrinkage and detachment from the plate in a dose-dependent manner. Morphological changes were observed in cells treated with bimatoprost 0.01% and latanoprost 0.005%. However, mild cell shrinkage was noted in cells treated with tafluprost 0.0015%, while a non-toxic effect was noted with travoprost 0.004% and preservative-free tafluprost 0.0015%. CCK-8 assay and FACS analysis showed all groups had a significantly decreased cell viability and higher apoptosis rate compared with the control group. However, travoprost 0.004% and preservative-free tafluprost 0.0015% showed lower cytotoxicity and apoptosis rate than other drugs. CONCLUSIONS: This in vitro study revealed that BAC-induced cytotoxicity is dose-dependent, although it is important to emphasize that the clinical significance of toxicity differences observed among the different PGs formulations has not yet been firmly established. Alternatively preserved or preservative-free glaucoma medications seem to be a reasonable and viable alternative to those preserved with BAC.
Apoptosis ; Cell Line ; Cell Survival/drug effects ; Conjunctiva/drug effects/*pathology ; Fibroblasts/drug effects/pathology ; Glaucoma/drug therapy/pathology ; Humans ; Preservatives, Pharmaceutical/*pharmacology ; Prostaglandins, Synthetic/*pharmacology

OBJECTIVES: Several reports demonstrated that ethanol administration impairs the DNA synthesis in rat hepatocytes. Also, it has been demonstrated that prostaglandin (PG) helps prevent membrane damage by hepatotoxic chemicals. In this study, the authors examined PG's effects on the toxicity of ethanol in the primary culture of rat regenerations. METHODS: We examined two kinds of parameters, i.e., DNA synthesis and lipid peroxidation in the primary culture of rat hepatocytes. Hepatocytes were isolated by the collagenase perfusion method. The rate of DNA synthesis was determined by pulse-labelling cultured cells with [3H]-thymidine. Incorporation of (3H)-thymidine was determined by liquid scintillation spectrophotometer. DNA content was measured by the fluorescence spectrophotometer. The lipid peroxidation was assayed with spectrophotometer. RESULTS: The results were as follows: 1) PG family (PGA1, PGD2, PGE1, PGE2, PGG2a, PGI2 & Thromboxane B2) stimulated the DNA synthesis of hepatocytes (especially PGD2 and PGE1), 2) ethanol decreased DNA synthesis by clear dose-dependent manner, 3) the combined treatment of PGD2 or PGE1, prevents the decreasing of DNA synthesis, which was induced by ethanol, 4) in ethanol treatment, lipid peroxidation was decreased significantly, but PGD2, PGE1 and PGA1 were not affected, and 5) PGD2, PGE1 and PGA1 decreased lipid peroxidation with ethanol, significantly. CONCLUSIONS: From these results, we concluded that PG could be useful for the treatment of degenerative liver disease and alcohol-induced liver disease in the assumption that further studies on the action mechanisms of PG will continue.
Animal ; Cells, Cultured ; DNA/biosynthesis ; Drug Interactions ; Ethanol/toxicity* ; Lipid Peroxidation/drug effects ; Liver/metabolism ; Liver/drug effects* ; Prostaglandins, Synthetic/pharmacology* ; Rats

BACKGROUNDLatanoprost, a prostaglandin F2alpha analog, has been shown to be an effective intraocular pressure lowering agent which acts by inducing ciliary muscle cells to synthesise matrix metalloproteinases. However, the response of ciliary melanocytes to latanoprost has never been reported. This research has investigated the ability of latanoprost to induce matrix metalloproteinase-1 expression in human ciliary melanocytes, and thereby advance the understanding of the mechanism of PGF(2alpha) in decreasing intraocular pressure.

METHODSIn vitro human ciliary melanocytes were treated for 48 hours with five different concentrations of latanoprost (100, 150, 200, 500, and 1000 nmol/L). Ciliary melanocytes treated with 0.01% ethanol (vehicle) were used as a control. The expression of matrix metalloproteinase-1 in ciliary melanocytes was determined by Western blotting and immunofluorescent staining.

RESULTSWestern blotting showed that the expression of matrix metalloproteinase-1 in ciliary melanocytes was induced by latanoprost, and the level of expression was dependent on the concentration of latanoprost in the culture medium. Immunofluorescent staining showed that matrix metalloproteinase-1 was confined to the ciliary melanocyte cytoplasm.

CONCLUSIONSLatanoprost induced the expression of matrix metalloproteinase-1 in human ciliary melanocytes in a dose-dependent manner. Ciliary melanocytes, as well as ciliary muscle cells, may also play an important role in uveoscleral outflow modulation.

Cells, Cultured ; Ciliary Body ; cytology ; drug effects ; enzymology ; Female ; Fluorescent Antibody Technique ; Humans ; Immunoblotting ; Male ; Matrix Metalloproteinase 1 ; analysis ; Melanocytes ; drug effects ; enzymology ; Prostaglandins F, Synthetic ; pharmacology