title: Protective effects of a dietary carotenoid, astaxanthin, against light-induced retinal damage.
abstract: Dietary carotenoids exhibit various biological activities, including antioxidative activity. In particular, astaxanthin, a type of carotenoid, is well known as a powerful antioxidant. We investigated whether astaxanthin would protect against light-induced retinal damage. In an in vivo study, ddY male mice were exposed to white light at 8,000 lux for 3 h to induce retinal damage. Five days after light exposure, retinal damage was evaluated by measuring electroretinogram (ERG) amplitude and outer nuclear layer (ONL) thickness. Furthermore, expression of apoptotic cells, 8-hydroxy-deoxyguanosine (8-OHdG), was measured. In an in vitro study, retinal damage was induced by white light exposure at 2,500 lux for 24 h, and propidium iodide (PI)-positive cells was measured and intracellular reactive oxygen species (ROS) activity was examined. Astaxanthin at 100 mg/kg inhibited the retinal dysfunction in terms of ERG and ONL loss and reduced the expression of apoptotic and 8-OHdG-positive cells induced by light exposure. Furthermore, astaxanthin protected against increases of PI-positive cells and intracellular reactive oxygen species (ROS) activity in 661W cells. These findings suggest that astaxanthin has protective effects against light-induced retinal damage via the mechanism of its antioxidative effect.
authors.affiliation: Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Otsuka
authors.forename: Masamitsu
authors.initials: M
authors.lastname: Shimazawa
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Nakanishi
authors.forename: Yuta
authors.initials: Y
authors.lastname: Ohno
authors.forename: Yuki
authors.initials: Y
authors.lastname: Inoue
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Tsuruma
authors.forename: Takashi
authors.initials: T
authors.lastname: Ishibashi
authors.forename: Hideaki
authors.initials: H
authors.lastname: Hara
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D060433:Administration, Ophthalmic; D000818:Animals; D000975:Antioxidants; D017209:Apoptosis / Q000528:radiation effects; D002478:Cells, Cultured; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000378:metabolism; D004195:Disease Models, Animal; D004596:Electroretinography; D008027:Light / Q000009:adverse effects*; D008268:Macular Degeneration / Q000175:diagnosis / Q000209:etiology* / Q000473:pathology / Q000517:prevention & control*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D011419:Propidium / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D012160:Retina / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects*; D017949:Retinal Cone Photoreceptor Cells / Q000378:metabolism / Q000473:pathology; D012174:Retinitis Pigmentosa / Q000175:diagnosis / Q000209:etiology* / Q000473:pathology / Q000517:prevention & control*; D024341:Xanthophylls / Q000008:administration & dosage / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D017382:Reactive Oxygen Species; D024341:Xanthophylls; D011419:Propidium; D000080242:8-Hydroxy-2'-Deoxyguanosine; C005948:astaxanthine; D003849:Deoxyguanosine