The Protective Effects of a Dietary Carotenoid, Astaxanthin, Against Light-Induced Retinal Damage

Abstract

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.

Protective Effects of Antiplacental Growth Factor Antibody Against Light-Induced Retinal Damage in Mice

“…Light exposure was performed as previously described. 14,[28][29][30] Mice were adapted to dark conditions 24 hours prior to light exposure by covering with a completely black box, and they had free access to food and water. Mice pupils were dilated via administration of 1% cyclopentolate hydrochloride eye drops (Santen Pharmaceuticals Co., Ltd., Osaka, Japan) 30 minutes prior to exposure to light.…”

Antioxidation and anti-ageing activities of different stereoisomeric astaxanthin in vitro and in vivo

“…The presence of hydroxyl and carbonyl functional groups in ketocarotenoids makes AST excellent antioxidants (Dose et al, 2016;Liu & Osawa, 2007). The high antioxidant power of AST has been shown to have beneficial effects on various diseases related to oxidative damage, such as obesity (Kimura et al, 2014), hypertension (Sasaki, Kobara, Higashino, Giddings, & Yamamoto, 2011), cancer and macular degeneration (Otsuka et al, 2013). Hence, AST has attracted great interest due to its antioxidant capacity and its possible role in reducing the risk of certain diseases.…”

A role of Heat Shock Protein 70 in Photoreceptor Cell Death: Potential as a Novel Therapeutic Target in Retinal Degeneration

“…Therefore, protection of photoreceptor cells may be a useful therapeutic strategy for RDs. Some of the candidate therapeutic agents for RDs are listed in Table []; these agents include therapeutic agents against the early stage of photoreceptor cell death (antioxidants, ROS scavengers, Ca 2+ antagonists and calpain inhibitors), therapeutic agents against the late stage of photoreceptor cell death (cathepsin inhibitors and caspase inhibitors), and HSP70 inducers.…”