astaxanthine and Keratitis

Astaxanthin (AST) has a strong antioxidant cellular membrane chaperone protective effect. Recently, a water-soluble nanosized AST (nano-AST) form was produced, which is expected to improve the efficacy of oral intake effects. The purpose of this study was to examine whether oral nano-AST has therapeutic effects on UV-induced photokeratitis in mice.. C57BL/6 mice were administered twice with either nano-AST, AST oil, lutein, or bilberry extracts 3 hours before and shortly before UV irradiation (dose: 400 mJ/cm. Corneal epithelium was significantly thicker in mice orally administered with nano-AST than in the others (. Oral administration of nano-AST demonstrated a protective effect on UV-induced photokeratitis via antioxidative, anti-inflammatory, and antiapoptotic activity.

Topics: Administration, Oral; Animals; Keratitis; Male; Mice; Mice, Inbred C57BL; Ultraviolet Rays; Xanthophylls

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.. C57BL/6 mice were administered with AST diluted in polyethylene glycol (PEG) in instillation form (15 μl) 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/cm². 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.. 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.. Topical AST administration may be a candidate treatment to limit the damages by UV irradiation with wide clinical applications.

Topics: Administration, Ophthalmic; Animals; Antioxidants; Apoptosis; Cells, Cultured; Cornea; Cytoprotection; Dose-Response Relationship, Drug; Epithelial Cells; Epithelium, Corneal; In Situ Nick-End Labeling; Keratitis; Male; Mice; Mice, Inbred C57BL; Ophthalmic Solutions; Oxidative Stress; Ultraviolet Rays; Xanthophylls