Amelioration of ultraviolet-induced photokeratitis in mice treated with astaxanthin eye drops.
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PURPOSE: Ultraviolet (UV) acts as low-dose ionizing radiation. Acute UVB exposure causes photokeratitis and induces apoptosis in corneal cells. Astaxanthin (AST) is a carotenoid, present in seafood, that has potential clinical applications due to its high antioxidant activity. In the present study, we examined whether topical administration of AST has preventive and therapeutic effects on UV-photokeratitis in mice. METHODS: C57BL/6 mice were administered with AST diluted in polyethylene glycol (PEG) in instillation form (15 mul) to the right eye. Left eyes were given vehicle alone as controls. Immediately after the instillation, the mice, under anesthesia, were irradiated with UVB at a dose of 400 mJ/cm(2). Eyeballs were collected 24 h after irradiation and stained with H&E and TUNEL. In an in vitro study, mouse corneal epithelial (TKE2) cells were cultured with AST before UV exposure to quantify the UV-derived cytotoxicity. RESULTS: UVB exposure induced cell death and thinning of the corneal epithelium. However, the epithelium was morphologically well preserved after irradiation in AST-treated corneas. Irradiated corneal epithelium was significantly thicker in eyes treated with AST eye drops, compared to those treated with vehicles (p<0.01), in a doses dependent manner. Significantly fewer apoptotic cells were observed in AST-treated eyes than controls after irradiation (p<0.01). AST also reduced oxidative stress in irradiated corneas. The in vitro study showed less cytotoxicity of TKE2 cells in AST-treated cultures after UVB-irradiation (p<0.01). The cytoprotective effect increased with the dose of AST. CONCLUSIONS: Topical AST administration may be a candidate treatment to limit the damages by UV irradiation with wide clinical applications. (+info)
Role of hydroxypropyl-beta-cyclodextrin on freeze-dried and gamma-irradiated PLGA and PLGA-PEG diblock copolymer nanospheres for ophthalmic flurbiprofen delivery.
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Central corneal thickness considered an index of corneal hydration of the UVB irradiated rabbit cornea as influenced by UVB absorber.
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UVB radiation from sunlight induces an acute corneal inflammation, photokeratitis, accompanied by changes in corneal hydration. We employed a method of ultrasonic pachymetry for daily examination of central corneal thickness as an index of corneal hydration of the rabbit cornea repeatedly irradiated by UVB radiation (312 nm, daily dose of 0.25 J/cm(2) during three or four days) as influenced by UVB absorber (actinoquinol combined with hyaluronic acid) dropped on the ocular surface during irradiation. One day after the third irradiation procedure the animals were sacrificed and corneas examined immuno-histochemically for peroxynitrite formation, a marker of oxidative damage, the antioxidant aldehyde dehydrogenase 3A1 and endothelial nitric oxide synthase, an enzyme generated nitric oxide. Results show that UV absorber combined with hyaluronic acid protected the cornea against UVB-induced changes in corneal thickness and microscopical disturbances to the cornea (both seen after buffered saline application) until the fourth experimental day. These UVB doses are equivalent to a daily exposure of 2.5 hrs of the human cornea to solar UVB radiation for three consecutive days. It is suggested that actinoquinol/ hyaluronic acid drops might be helpful for the human eye in the defence against photooxidative and other oxidative processes. (+info)
Topical application of FTY720 and cyclosporin A prolong corneal graft survival in mice.
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PURPOSE: To investigate the effects of topical FTY720 and cyclosporin A (CsA) on allogeneic corneal transplantation in mice. METHODS: A total of 75 BALB/c mice received corneal grafts from C57BL/6 donors. Recipients were treated with 0.1%, 0.3%, or 0.5% FTY720 ophthalmic gel or 1% CsA eye-drops after the graft (controls received no treatment). The number of cluster of differentiation (CD)4+ T cells and CD4+CD25+forkhead box P3 (Foxp3)+ regulatory (Treg) cell phenotypes were measured by flow cytometry. Cytokine mRNA expression in corneal grafts was analyzed by real-time quantitative PCR. CD4 + T cells and cytokines in corneal samples were identified by immunohistochemical staining. RESULTS: Corneal graft survival was prolonged by treatment with topical 0.5% FTY720 (mean survival time [MST], 24.1+/-1.6 days) or 1% CsA eye-drops (MST 25.0+/-1.9 days) compared with controls (MST, 13.4+/-0.5 days; n=9, both p<0.01). Topical 0.5% FTY720 treatment significantly increased the percentages of CD4 + T (p<0.05) and Treg cells (p<0.01; n=5) in the cervical lymph nodes compared with controls. Transforming growth factor-beta1 (TGF-beta1) mRNA transcription in corneal grafts after topical 0.5% FTY720 increased (p<0.05, n=3), while interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) mRNA expression in corneal grafts treated with 1% CsA decreased (p<0.01, p<0.05, respectively). These cytokine results were paralleled by similar immunohistochemical staining. Topical 0.5% FTY720 and 1% CsA treatment reduced the infiltration of CD4+ Tcells in the grafts. CONCLUSIONS: Topical 0.5% FTY720 and 1% CsA can effectively prolong allogeneic corneal graft survival in mice. Treatment with topical 0.5% FTY720 increases the percentage of CD4+ T cells and the percentage of Treg cells in cervical lymph nodes. The 0.5% FTY720 increased TGF-beta1 mRNA expression and decreases infiltration of CD4+ T cells in corneal grafts, while topical 1% CsA down-regulated the expression of IL-2 and IFN-gamma. (+info)
Physical and chemical properties and stability of sodium cefazolin in buffered eye drops determined with HPLC method.
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The aim of the studies was to analyze the stability of 1% and 5% eye drops containing sodium cefazolin, prepared in citrate buffer of pH 6.11-6.27, which were stored at the temperature of 4 degrees C and 20 degrees C with light protection. The drops were prepared under aseptic conditions by dissolving sodium cefazolin (Biofazolin, IBA Bioton), dry injection form of the drug, in citrate buffer. The viscosity of the drops was increased using polyvinyl alcohol. The drops were preserved with phenylmercuric borate of 0.001% concentration mixed with beta-phenylethyl alcohol of 0.4% concentration in the drops. The concentration of cefazolin was determined at every three days using HPLC method. Besides, the measurements of pH, osmotic pressure and viscosity were performed as well as the organoleptic analysis of the drops (clarity, color, odor). The concentration of cefazolin in 1% drops after the 30-day-storage at the temperature of 4 degrees C, depending on their composition, decreased in the range of 2.17-6.02%. In 5% drops the decrease in cefazolin concentration was similar, i.e., after 30-day-storage at the temperature of 4 degrees C it was 1.62-6.76%. In 1% and 5% drops stored at the temperature of 20 degrees C the stability of the drops determined as the 10% degradation time of cefazolin was in the range of 9-15 days. (+info)
Influence of choroidal neovascularization and biodegradable polymeric particle size on transscleral sustained delivery of triamcinolone acetonide.
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