Protective Effects of Oral Astaxanthin Nanopowder against Ultraviolet‐Induced Photokeratitis in Mice

Abstract

Purpose 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. Methods 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/cm2). The corneas were collected 24 hours after irradiation and stained with H&E and TUNEL. NF-κB, dihydroethidium (DHE), COX-2, p-IκB-α, TNFα, and CD45 expression were evaluated through immunohistochemistry, Western blot analysis, and qPCR. Results Corneal epithelium was significantly thicker in mice orally administered with nano-AST than in the others (p < 0.01), with significantly less NF-κB nucleus translocation (p < 0.001), and significantly fewer TUNEL cells (p < 0.01). Weaker DHE signals were detected in the nano-AST group (p < 0.05) relative to the others. Furthermore, reduced inflammation and decreased cell death in corneal tissue were observed in the nano-AST group, as indicated by a reduction in the expression of COX-2, p-IκB-α, TNFα, and CD45. Conclusions Oral administration of nano-AST demonstrated a protective effect on UV-induced photokeratitis via antioxidative, anti-inflammatory, and antiapoptotic activity.

Astaxanthin inhibits hallmarks of cancer by targeting the PI3K/NF‐κΒ/STAT3 signalling axis in oral squamous cell carcinoma models

“…38 The protective effect of nanoAXT against UV-induced photokeratitis was attributed to its antioxidant and anti-inflammatory properties. 39 Interestingly, AXTreduced gold nanoparticle was found to be cytotoxic to breast cancer cells besides exhibiting efficacy in photo-based diagnosis and therapeutic monitoring. 40 Together, these studies as well our findings support the view that nano-AXT has therapeutic potential.…”

Astaxanthin Suppresses Cigarette Smoke-Induced Emphysema through Nrf2 Activation in Mice

“…Astaxanthin has attracted attention due to its strong antioxidant properties, and there have been many reports focusing on its antioxidant activity. Astaxanthin has been shown to protect various cells from oxidative stress in vitro [31][32][33][34] and to protect the brain, eyes, salivary glands, skeletal muscle, liver, kidney, and lungs from oxidative stress in vivo [12][13][14][15][16][17][35][36][37][38][39]. These results indicate that astaxanthin is distributed throughout the body and has systemic effects.…”

“…Second, the concentration of astaxanthin (0.02% w/w) in the diet was taken from a previous study [48]. In addition, 50 mg/kg of astaxanthin was reported to be effective in mice [37]. Therefore, we decided to use the diet to contain 0.02% (w/w) astaxanthin.…”

Haematococcus pluvialis-Derived Astaxanthin Is a Potential Neuroprotective Agent against Optic Nerve Ischemia

“…Astaxanthin also protects against retinal damage by inhibiting oxidative stress [18,19]. Furthermore, astaxanthin attenuates RGC death under various stresses in a murine model [17]. Oral supplementation of astaxanthin is also reported to enhance superoxide scavenging activity in human aqueous humor [20].…”

“…Astaxanthin can decrease ROS-mediated cellular toxicity [9], and has been proven in the literature to possess anti-oxidative, anti-inflammatory, anti-diabetic, and anti-cancer effects [10][11][12][13][14][15][16]. In the eye, astaxanthin has demonstrated a protective effect on UV-induced photokeratitis via anti-oxidative, anti-inflammatory, and anti-apoptotic activity [17]. Astaxanthin also protects against retinal damage by inhibiting oxidative stress [18,19].…”