The protective effects of a dietary carotenoid,astaxanthin,against light-induced retinal damage

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. © the japanese pharmacological society.