Potential health-promoting effects of astaxanthin: a high-value carotenoid mostly from microalgae.
The ketocarotenoid astaxanthin can be found in the microalgae Haematococcus pluvialis, Chlorella zofingiensis, and Chlorococcum sp., and the red yeast Phaffia rhodozyma. The microalga H. pluvialis has the highest capacity to accumulate astaxanthin up to 4-5% of cell dry weight. Astaxanthin has been attributed with extraordinary potential for protecting the organism against a wide range of diseases, and has considerable potential and promising applications in human health. Numerous studies have shown that astaxanthin has potential health-promoting effects in the prevention and treatment of various diseases, such as cancers, chronic inflammatory diseases, metabolic syndrome, diabetes, diabetic nephropathy, cardiovascular diseases, gastrointestinal diseases, liver diseases, neurodegenerative diseases, eye diseases, skin diseases, exercise-induced fatigue, male infertility, and HgCl₂-induced acute renal failure. In this article, the currently available scientific literature regarding the most significant activities of astaxanthin is reviewed.
Mol Nutr Food Res. 2011 Jan;55(1):150-65
Supplemental cellular protection by a carotenoid extends life span via Ins/IGF-1 signaling in Caenorhabditis elegans.
Astaxanthin (AX), which is produced by some marine animals, is a type of carotenoid that has antioxidative properties. In this study, we initially examined the effects of AX on the aging of a model organism C. elegans that has the conserved intracellular pathways related to mammalian longevity. The continuous treatments with AX (0.1 to 1 mM) from both the prereproductive and young adult stages extended the mean life spans by about 16-30% in the wild-type and long-lived mutant age-1 of C. elegans. In contrast, the AX-dependent life span extension was not observed even in a daf-16 null mutant. Especially, the expression of genes encoding superoxide dismutases and catalases increased in two weeks after hatching, and
the DAF-16 protein was translocated to the nucleus in the AX-exposed wild type. These results suggest that AX protects the cell organelle mitochondria and nucleus of the nematode, resulting in a life span extension via an Ins/IGF-1 signaling pathway during normal aging, at least in part.
Oxid Med Cell Longev. 2011;2011:596240
Development of a method for oral administration of hydrophobic substances to Caenorhabditis elegans: pro-longevity effects of oral supplementation with lipid-soluble antioxidants.
Methods for quantitative oral administration of various substances to Caenorhabditis elegans are needed. Previously, we succeeded in oral administration of hydrophilic substances using liposomes. However, an adequate system for delivery of hydrophobic chemicals was not available. In this study, we developed a method for oral administration of lipid-soluble substances to C. elegans. γ-cyclodextrin (γCD), which delivers hydrophobic chemicals, was used to make micro-particles of inclusion compounds that can be ingested by bacteriophagous nematodes, which do not distinguish these micro-particles from their food bacteria. Successful oral delivery of the hydrophobic fluorescent reagent 3,3›-dioctadecyloxacarbocyanine perchlorate into the intestines of C. elegans was observed. Oral administration of the hydrophobic antioxidants tocotrienol, astaxanthin, or γ-tocopherol, prolonged the nematode lifespan; tocotrienol rendered them resistant to infection with the opportunistic pathogen Legionella pneumophila. In contrast, older conventional delivery methods that involve incorporation of chemicals into the nematode growth medium or pouring chemicals onto the plate produced weaker fluorescence and no longevity effects. Our method efficiently and quantitatively delivers hydrophobic solutes to nematodes, and a minimum effective dose was estimated. In combination with our liposome method, this γCD method expands the usefulness of C. elegans for the discovery of functional food factors and for screening drug candidates.
Biogerontology. 2012 Jun;13(3):337-44
Astaxanthin attenuates the UVB-induced secretion of prostaglandin E2 and interleukin-8 in human keratinocytes by interrupting MSK1 phosphorylation in a ROS depletion-independent manner.
To elucidate the effects of redox balance regulation on cutaneous inflammation, we used the potent antioxidant astaxanthin (AX) to assess its effect on the UVB-induced secretion of PGE(2) and IL-8 in human keratinocytes and analysed its biological mechanism of action. The addition of AX (at 8 µm) to human keratinocytes even after UVB irradiation significantly down-regulated the increased secretion of PGE(2) or IL-8. Those suppressive effects were accompanied by significantly decreased expression of genes encoding COX-2 or IL-8 as well as COX-2 protein. Analysis using a specific NF-κB tanslocation inhibitor demonstrated that the UVB-stimulated secretion of PGE(2) and IL-8 was significantly abolished by its treatment prior to UVB irradiation. Western blotting of phosphorylated signalling molecules revealed that UVB irradiation (80 mJ/cm(2) ) significantly stimulated the phosphorylation of p38, ERK and JNK, which was not suppressed by treatment with AX after irradiation. In contrast, AX significantly inhibited the UVB-increased phosphorylation of mitogen- and stress-activated protein kinase (MSK)-1, NF-kBp65 or CREB even when treated postirradiation. Further, the MSK1 inhibitor H89 significantly down-regulated the increased secretion of PGE(2) and IL-8 in UVB-exposed human keratinocytes, following post-irradiation treatment. These findings suggests that AX attenuates the auto-phosphorylation of MSK1 required for its activation, which results in the decreased phosphorylation of NF-kBp65, which in turn probably leads to a deficiency of NF-kB DNA binding activity. This may be associated with the significant suppression of PGE(2) /IL-8 secretion via the down-regulated expression of COX-2 and IL-8 at the gene and/or protein levels.
Exp Dermatol. 2012 Jul;21 Suppl 1:11-7
Astaxanthin, cell membrane nutrient with diverse clinical benefits and anti-aging potential.
Astaxanthin, a xanthophyll carotenoid, is a nutrient with unique cell membrane actions and diverse clinical benefits. This molecule neutralizes free radicals or other oxidants by either accepting or donating electrons, and without being destroyed or becoming a pro-oxidant in the process. Its linear, polar-nonpolar-polar molecular layout equips it to precisely insert into the membrane and span its entire width. In this position, astaxanthin can intercept reactive molecular species within the membrane’s hydrophobic interior and along its hydrophilic boundaries. Clinically, astaxanthin has shown diverse benefits, with excellent safety and tolerability. In double-blind, randomized controlled trials (RCTs), astaxanthin lowered oxidative stress in overweight and obese subjects and in smokers. It blocked oxidative DNA damage, lowered C-reactive protein (CRP) and other inflammation biomarkers, and boosted immunity in the tuberculin skin test. Astaxanthin lowered triglycerides and raised HDL-cholesterol in another trial and improved blood flow in an experimental microcirculation model. It improved cognition in a small clinical trial and boosted proliferation and differentiation of cultured nerve stem cells. In several Japanese RCTs, astaxanthin improved visual acuity and eye accommodation. It improved reproductive performance in men and reflux symptoms in H. pylori patients. In preliminary trials it showed promise for sports performance (soccer). In cultured cells, astaxanthin protected the mitochondria against endogenous oxygen radicals, conserved their redox (antioxidant) capacity, and enhanced their energy production efficiency. The concentrations used in these cells would be attainable in humans by modest dietary intakes. Astaxanthin’s clinical success extends beyond protection against oxidative stress and inflammation, to demonstrable promise for slowing age-related functional decline.
Altern Med Rev. 2011 Dec;16(4):355-64
Cosmetic benefits of astaxanthin on humans subjects.
Two human clinical studies were performed. One was an open-label non-controlled study involving 30 healthy female subjects for 8 weeks. Significant improvements were observed by combining 6 mg per day oral supplementation and 2 ml (78.9 µM solution) per day topical application of astaxanthin. Astaxanthin derived from the microalgae, Haematococcus pluvialis showed improvements in skin wrinkle (crow›s feet at week-8), age spot size (cheek at week-8), elasticity (crow›s feet at week-8), skin texture (cheek at week-4), moisture content of corneocyte layer (cheek in 10 dry skin subjects at week-8) and corneocyte condition (cheek at week-8). It may suggest that astaxanthin derived from H. pluvialis can improve skin condition in all layers such as corneocyte layer, epidermis, basal layer and dermis by combining oral supplementation and topical treatment. Another was a randomized double-blind placebo controlled study involving 36 healthy male subjects for 6 weeks. Crow›s feet wrinkle and elasticity; and transepidermal water loss (TEWL) were improved after 6 mg of astaxanthin (the same as former study) daily supplementation. Moisture content and sebum oil level at the cheek zone showed strong tendencies for improvement. These results suggest that astaxanthin derived from Haematococcus pluvialis may improve the skin condition in not only in women but also in men.
Acta Biochim Pol. 2012;59(1):43-7
Effect of dietary astaxanthin at different stages of mammary tumor initiation in BALB/c mice.
The effects of astaxanthin on tumor growth, cardiac function and immune response in mice were studied. Female BALB/c mice were fed a control diet (diet C) for 8 weeks, 0.005% astaxathin for 8 weeks (diet A), or diet C for weeks 1-5 followed by diet A thereafter (diet CA). Mice were injected with a mammary tumor cell line on day 7 and tumor growth was measured daily. Mice fed diet A had extended tumor latency and lower tumor volume (p<0.05). Interestingly, those fed diet CA showed the fastest tumor growth. Astaxanthin feeding elevated plasma astaxanthin concentrations; there was no difference in plasma astaxanthin between mice fed CA and those fed A. Mice fed diet A, but not CA, had a higher (p<0.05) natural killer cell subpopulation and plasma interferon-gamma concentration compared to those fed diet C. Astaxanthin delayed tumor growth and modulated immune response, but only when astaxanthin was given before tumor initiation. This suggests that an adequate blood astaxanthin status is needed to protect against tumor initiation; conversely, astaxanthin supplementation after tumor initiation may be contraindicated.
Anticancer Res. 2010 Jun;30(6):2171-5
Changes in lymphocyte oxidant/antioxidant parameters after carbonyl and antioxidant exposure.
During normal B- and T-cell life, processes including activation, proliferation, signaling pathways and apoptosis are markedly dependent on ROS generation. However, these cells can also suffer the effect of oxidant overproduction. Thus, the purpose of the present study was to examine the possible pro-oxidant effects of MGO/high glucose and antioxidant effects of astaxanthin associated with vitamin C on some oxidative and antioxidant parameters of human lymphocytes in vitro. Lymphocytes from healthy subjects were treated with 20mM of glucose and 30 µM MGO followed or not by the addition of the antioxidants astaxanthin (2 µM) and vitamin C (100 µM) for up to 24h. We examined superoxide dismutase (SOD), catalase, glutathione peroxidase, glutathione reductase, and glucose-6-phosphate dehydrogenase (G6PDH) activities, GSH/GSSG ratio and total thiol and carbonyl content. Oxidative parameters included superoxide anion, hydrogen peroxide and nitric oxide production. The association of astaxanthin and vitamin C proved to be a powerful antioxidant in human lymphocytes as showed by the marked reduction in superoxide anion, and hydrogen peroxide production as well as increased GSH content, GSH/GSSG ratio, GPx and GR activities. The antioxidant association showed to be more potent than their individual application. High glucose and methylglyoxal did not promote oxidative stress in human lymphocytes, since neither the oxidative parameters nor the antioxidant defense system was altered. According to these results, new therapies with the association of astaxanthin and vitamin C may be helpful to improve the immune function of patients with exacerbated production of ROS.
Int Immunopharmacol. 2012 Dec;14(4):690-7
Dietary astaxanthin inhibits colitis and colitis-associated colon carcinogenesis in mice via modulation of the inflammatory cytokines.
Astaxanthin (AX) is one of the marine carotenoid pigments, which possess powerful biological antioxidant, anti-inflammatory and anti-cancer properties. The purpose of this study is to investigate possible inhibitory effect of AX against inflammation-related mouse colon carcinogenesis and dextran sulfate sodium (DSS)-induced colitis in male ICR mice. We conducted two different experiments. In the first experiment, we evaluated the effects of AX at three dose levels, 50, 100 and 200 ppm in diet, on colitis-associated colon carcinogenesis induced by azoxymethane (AOM)/DSS in mice. In the second, the effects of the AX (100 and 200 ppm) in diet on DSS-induced colitis were determined. We found that dietary AX significantly inhibited the occurrence of colonic mucosal ulcers, dysplastic crypts, and colonic adenocarcinoma at week 20. AX-feeding suppressed expression of inflammatory cytokines, including nuclear factor (NF)-κB, tumor necrosis factor (TNF)-α and interleukin (IL)-1β, inhibited proliferation, and induced apoptosis in the colonic adenocarcinomas. Feeding with 200 ppm AX, but not 100 ppm, significantly inhibited the development of DSS-induced colitis. AX feeding (200 ppm in diet) also lowered the protein expression of NF-κB, and the mRNA expression of inflammatory cytokines, including IL-1β, IL-6, and cyclooxygenase (COX)-2. Our results suggest that the dietary AX suppresses the colitis and colitis-related colon carcinogenesis in mice, partly through inhibition of the expression of inflammatory cytokine and proliferation. Our findings suggest that AX is one of the candidates for prevention of colitis and inflammation-associated colon carcinogenesis in humans.
Chem Biol Interact. 2011 Aug 15;193(1):79-87
Changes in cell ultrastructure and inhibition of JAK1/STAT3 signaling pathway in CBRH-7919 cells with astaxanthin.
Astaxanthin (AST), a xanthophylls carotenoid, possesses significant anticancer effects. However, to date, the molecular mechanism of anticancer remains unclear. In the present research, we studied the anticancer mechanism of AST, including the changes in cell ultrastructure, such as the mitochondrion, rough endoplasmic reticulum (RER), Golgi complex, and cytoskeleton, the inhibition of Janus kinase 1(JAK1)/transduction and the activators of the transcription-3 (STAT3) signaling pathway using rat hepatocellular carcinoma CBRH-7919 cells. Cell apoptosis was evaluated and the expressions of JAK1, STAT3, non-metastasis23-1 (nm23-1), and apoptotic gene like B-cell lymphoma/leukemia-2 (bcl-2), B-cell lymphoma-extra large (bcl-xl), proto-oncogene proteins c myc (c-myc) and bcl-2- associated X (bax) were also examined. The results showed that AST could induce cancer cell apoptosis. Under transmission electron microscope, the ultrastructure of treated cells were not clearly distinguishable, the membranes of the mitochondrion, RER, Golgi complex were broken or loosened, and the endoplasmic reticulum (ER) was degranulated. Cytoskeleton depolymerization of the microtubule system led to the collapse of extended vimentin intermediate filament bundles into short agglomerations with disordered distributions. AST inhibited the expression of STAT3, its upstream activator JAK1, and the STAT3 target antiapoptotic genes bcl-2, bcl-xl, and c-myc. Conversely, AST enhanced the expressions of nm23-1 and bax. Overall, our findings demonstrate that AST could induce the apoptosis of CBRH-7919 cells, which are involved in cell ultrastructure and the JAK1/STAT3 signaling pathway
Toxicol Mech Methods. 2012 Nov;22(9):679-86