Astaxanthin, a dietary carotenoid, protects retinal cells against oxidative stress in-vitro and in mice in-vivo

Abstract

We have investigated whether astaxanthin exerted neuroprotective effects in retinal ganglion cells in-vitro and in-vivo. In-vitro, retinal damage was induced by 24-h hydrogen peroxide (H2O2) exposure or serum deprivation, and cell viability was measured using a WST assay. In cultured retinal ganglion cells (RGC-5, a rat ganglion cell-line transformed using E1A virus), astaxanthin inhibited the neurotoxicity induced by H2O2 or serum deprivation, and reduced the intracellular oxidation induced by various reactive oxygen species (ROS). Furthermore, astaxanthin decreased the radical generation induced by serum deprivation in RGC-5. In mice in-vivo, astaxanthin (100 mg kg(-1), p.o., four times) reduced the retinal damage (a decrease in retinal ganglion cells and in thickness of inner plexiform layer) induced by intravitreal N-methyl-D-aspartate (NMDA) injection. Furthermore, astaxanthin reduced the expressions of 4-hydroxy-2-nonenal (4-HNE)-modified protein (indicator of lipid peroxidation) and 8-hydroxy-deoxyguanosine (8-OHdG; indicator of oxidative DNA damage). These findings indicated that astaxanthin had neuroprotective effects against retinal damage in-vitro and in-vivo, and that its protective effects may have been partly mediated via its antioxidant effects.

Stability and changes in astaxanthin ester composition from Haematococcus pluvialis during storage

“…Pre-clinical research has suggested that astaxanthin is a suitable candidate for development as a therapeutic agent for cardiovascular oxidative stress and infl ammation (Pashkow et al, 2008), because it can inhibit the formation of oxidized low-density lipoprotein (LDL) in humans (Iwamoto et al, 2000) and eliminate the lipid peroxidation caused by rofecoxib in cellular membrane models (Mason et al, 2006). Astaxanthin also has neuroprotective effects against retinal damage because of its antioxidant activity (Nakajima et al, 2008). In addition, astaxanthin has been widely used in aquatic animal feeds, as a functional human food and in cosmetics.…”

Scavenging of Hydroxyl Radicals in Aqueous Solution by Astaxanthin Encapsulated in Liposomes

“…However, there have been no reports regarding the capability of Asx to scavenge hydroxyl radical, although it was reported that Asx inhibited intracellular radical generation in cultured cells induced by treatment with Fenton's reagent. 14) Since the hydrophobicity of Asx prevents its analysis in aqueous solution, determining the capacity of Asx to react with hydroxyl radical in aqueous solution would be aided by a liposomal formulation that would allow homogeneous dispersion of the poorly water soluble Asx. Previously, we suggested that Asx penetrates through the membrane of liposomes, and the terminal rings of Asx interact with polar head groups of membrane lipids by hydrogen bonding.…”

Does squalene alter the antioxidant potential of astaxanthin and fucoxanthinol? In vitro evidence in RAW 264.7 cells, a murine macrophage

“…Unlike SQ, Ax and FuOH exerted a strong (p < 0.01) suppressive effect as indicated by the decreased DPPP levels (37.2 and 39.9 nmol/g lipid, respectively). Li et al (2013) and Nakajima et al (2008) have reported decrease in H 2 O 2 oxidative stress by Ax in ARPE-19 and RCG-5 cells respectively. Kim et al (2009) have reported suppression of lipid peroxidation by Ax in proximal tubular epithelial cells.…”

“…For instance, Lee et al (2003) and Ohgami et al (2003) have reported the antioxidant and anti-inflammatory property of Ax in lipopolysaccharide (LPS) stimulated RAW 264.7 cells. Reports of the antioxidant effect of Ax in other cell types are also available (Nakajima et al 2008, Kim et al 2009, Li et al 2013. Saw et al (2013) have moreover reported the antioxidant effect of Ax alone and in combination with EPA and DHA.…”

“…2). Nakajima et al (2008) have used similar concentrations of Ax (0.1-10 μM) to study its effect on oxidative stress in RGC-5 cells. Ohgami et al (2003) have reported the anti-inflammatory and antioxidant effects of Ax at concentrations of 12.5 μM and higher in RAW 264.7 cells.…”