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The Effects of a Dietary Supplement Containing Astaxanthin on the Accommodation Function of the Eye in Middle-aged and Older People

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... Lower levels of nitric oxide, prostaglandin-E2 and tumor necrosis factor α in the aqueous humor in uveitis Reduce lens opacification and restore glutathione levels in animal model of steroid-induced cataracts Improve tear film breakup time and Schirmer's test scores, along with lowering reactive oxygen species levels, in dry eye disease Relieve eye fatigue in asthenopia [15][16][17][18][19][20][21][22][23][24][25][26] Largazole ...
... Asthenopia, commonly referred to as eye strain, is a frequent condition characterized by unspecific symptoms (discomfort, tearing, blurred vision, sensitivity to light, headache) which may be exacerbated by computer and display use. Astaxanthin's role in relieving eye fatigue has been extensively studied in the last years [21][22][23][24][25][26]. Nagaki et al. demonstrated in a randomized clinical trial that astaxanthin supplementation reduced eye muscle strain and improved accommodation amplitude [21]. ...
... Improvement of uncorrected visual acuity, accommodation and subjective symptoms related to visual display or terminal use were reported in healthy young adults who received oral astaxanthin either alone or in association with other substances [22,23]. Even in middle-aged and elderly people, astaxanthin improved accommodation and subjective symptoms of asthenopia such as a stiff neck or shoulders and blurred vision [24][25][26]. The mechanism for explaining the activity of astaxanthin in managing asthenopia is not completely understood; however, it may be related to the strong antioxidative effect and to the increased blood flow in the ciliary muscles, which improve the accommodative function [23,26] (Table 1). ...
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Different degrees of visual impairment lead to a decrease in patient wellbeing, which has an adverse effect on many facets of social and professional life. Eye disorders can affect several parts of the eye, most notably the retina and the cornea, and the impacted areas might share a common form of cellular damage or dysfunction (such as inflammation, oxidative stress and neuronal degeneration). Considering that marine organisms inhabit a broad variety of marine habitats, they display a great degree of chemical diversity. As a result, molecules with a marine origin are receiving more and more attention in the hopes of developing novel therapeutic approaches. For instance, fucoxanthin has been demonstrated to be effective in protecting the retina against photo-induced damage, while largazole, astaxanthin and spirulina have all shown antioxidant, anti-inflammatory and antiapoptotic activities that can be useful for the management of several ocular diseases, such as age-related macular degeneration and ocular surface disorders. The aim of this review is to analyze the scientific literature relating to the therapeutic effects on the eye of the main natural marine products, focusing on their mechanism of action and potential clinical uses for the management of ocular diseases.
... In a small clinical trial, it improved cognition and promoted the differentiation and proliferation of neural stem cells in culture [16]. Astaxanthin improved vision and eye adaptation in several randomized controlled trials in Japan [17,18]. In a double-blind, randomized controlled trials, the protective effect of astaxanthin on fertility and sperm function was evaluated. ...
... Green tea has been found to prolong the life span of different animal models. In C. elegans, daily administration of 220 μM EGCG (17) increased life expectancy by 14% [99]. In Drosophila melanogaster, the average lifespan of male flies fed on green tea extract increased by 16%, and superoxide dismutase (SOD) and catalase were correspondingly upregulated [100]. ...
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Human longevity has increased dramatically during the past century. More than 20% of the 9 billion population of the world will exceed the age of 60 in 2050. Since the last three decades, some interventions and many preclinical studies have been found to show slowing aging and increasing the healthy lifespan of organisms from yeast, flies, rodents to nonhuman primates. The interventions are classified into two groups: lifestyle modifications and pharmacological/genetic manipulations. Some genetic pathways have been characterized to have a specific role in controlling aging and lifespan. Thus, all genes in the pathways are potential antiaging targets. Currently, many antiaging compounds target the calorie-restriction mimetic, autophagy induction, and putative enhancement of cell regeneration, epigenetic modulation of gene activity such as inhibition of histone deacetylases and DNA methyltransferases, are under development. It appears evident that the exploration of new targets for these antiaging agents based on biogerontological research provides an incredible opportunity for the healthcare and pharmaceutical industries. The present review focus on the properties of slow aging and healthy life span extension of natural products from various biological resources, endogenous substances, drugs, and synthetic compounds, as well as the mechanisms of targets for antiaging evaluation. These bioactive compounds that could benefit healthy aging and the potential role of life span extension are discussed.
... As a result, the supplemented group reported improvement of both NPA and subjective symptoms, such as "stiff shoulders or neck" and blurred vision. The mechanisms underlying this efficacy may be related to the capacity of astaxanthin of determining relaxing effects on ciliary muscle, increasing blood flow in retinal capillaries and decreasing NF-kB in ciliary body [68,69]. All these activities are of great utility due to the widespread use of compact terminals, such as smartphones and tablets, which overload the accommodative system on a daily basis, thus significantly contributing to the development of eye fatigue [68]. ...
... The mechanisms underlying this efficacy may be related to the capacity of astaxanthin of determining relaxing effects on ciliary muscle, increasing blood flow in retinal capillaries and decreasing NF-kB in ciliary body [68,69]. All these activities are of great utility due to the widespread use of compact terminals, such as smartphones and tablets, which overload the accommodative system on a daily basis, thus significantly contributing to the development of eye fatigue [68]. ...
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Astaxanthin is a naturally occurring red carotenoid pigment belonging to the family of xanthophylls, and is typically found in marine environments, especially in microalgae and seafood such as salmonids, shrimps and lobsters. Due to its unique molecular structure, astaxanthin features some important biologic properties, mostly represented by strong antioxidant, anti-inflammatory and antiapoptotic activities. A growing body of evidence suggests that astaxanthin is efficacious in the prevention and treatment of several ocular diseases, ranging from the anterior to the posterior pole of the eye. Therefore, the present review aimed at providing a comprehensive evaluation of current clinical applications of astaxanthin in the management of ocular diseases. The efficacy of this carotenoid in the setting of retinal diseases, ocular surface disorders, uveitis, cataract and asthenopia is reported in numerous animal and human studies, which highlight its ability of modulating several metabolic pathways, subsequently restoring the cellular homeostatic balance. To maximize its multitarget therapeutic effects, further long-term clinical trials are warranted in order to define appropriate dosage, route of administration and exact composition of the final product.
... Astaxanthin is a red orange carotenoid found in salmon, shrimp, crab and the like, and is known for its high antioxidant potential [12]. Several studies report the effect of astaxanthin to improve accommodative ability as efficacy in the eye [9][10][11]15]. It is supposed that the improvement effect on accommodative ability of astaxanthin should be associated with its action to increase blood flow in the retinal capillaries and its inhibition of NF-B signaling pathway [12]. ...
... But most of them were conducted for subjects aged from their mid-twenties to around 40 years old before developing presbyopia. Kajita et al. reported the influence of astaxanthin on accommodative ability of aged and older subjects [15]. This study also shows that the use of multiple dietary supplements has potential to improve an accommodative ability and subjective symptoms related to asthenopia of aged and older subjects whose accommodative ability tends to decrease. ...
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Objective The study aimed to verify that ingestion of multiple dietary supplement containing lutein, astaxanthin, cyanidin-3-glucoside and docosahexaenoic acid (DHA) would improve accommodative ability of aged and older subjects who were aware of eye strain on a daily basis. Methods A randomized double-blind placebo-controlled parallel group comparison study was conducted for 48 participants aged 45 to 64 years who complained of eye strain. The subjects took multiple dietary supplement containing 10 mg of lutein, 20 mg of bilberry extract and 26.5 mg of black soybean hull extract (a total of 2.3 mg of cyanidin-3-glucoside in both extracts), 4 mg of astaxanthin, and 50 mg of DHA (test supplement) or placebo for four consecutive weeks. Near-point accommodation (NPA) and subjective symptoms were evaluated both before and after four weeks’ intake. Results The variation of the NPA of both eyes from baseline to 4 weeks’ post-intake in the test supplement group was significantly higher than in the placebo group (1.321±0.394 diopter (D) in the test supplement group and 0.108±0.336 D in the placebo group, p=0.023). The multiple dietary supplement group showed improvement in the NPA. Regarding subjective symptoms, significant improvement of “stiff shoulders or neck” and “blurred vision” was also found in the test supplement group compared to the placebo group (p<0.05). There were no safety concerns in this study. Conclusion This study shows that multiple dietary supplement containing lutein, astaxanthin, cyanidin-3-glucoside, and DHA has effect to improve accommodative ability and subjective symptoms related to eye fatigue.
... All of the studies have shown that AST reduces eye strain, as well as irritability, watery Table 13.2 Clinical studies on eye fatigue Dose: mg/day; (): number of subjects; duration Nagaki et al. (2002) 0(13), 5(13); 4 week DB-PC a Nakamura et al. (2004) 0(10), 2(12), 4(14), 12(10); 4 week DB-PC Nitta et al. (2005) 0(10), 6(10), 12(10); 4 week DB-PC Shiratori et al. (2005) 0 (19), 6(20); 4 week DB-PC Takahashi and Kajita (2005) 6(9); 2 week Open label Iwasaki and Tawara (2006) 0(10), 6(10); 2 week DB-PC, crossover Nagaki et al. (2006) 0(23), 6(25); 4 week DB-PC Kajita et al. (2009) 6(22); 4 week Open label Seya et al. (2009) 6(10); 4 week Open label Nagaki et al. (2010) 0(40), 9(42); 4 week DB-PC a DB-PC randomized double-blind placebo-controlled eyes, red eyes, stiff shoulders and back, heavy head, and headaches . 13 Clinical Applications of Haematococcus 221 ...
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... All of the studies have shown that AST reduces eye strain, as well as irritability, watery Table 13.2 Clinical studies on eye fatigue (Yamashita 2021) Dose: mg/day; (): number of subjects; duration Nagaki et al. (2002) 0 (13), 5(13); 4 week DB-PC a Nakamura et al. (2004) 0(10), 2(12), 4(14), 12(10); 4 week DB-PC Nitta et al. (2005) 0(10), 6(10), 12(10); 4 week DB-PC Shiratori et al. (2005) 0(19), 6(20); 4 week DB-PC Takahashi and Kajita (2005) 6(9); 2 week Open label Iwasaki and Tawara (2006) 0(10), 6(10); 2 week DB-PC, crossover Nagaki et al. (2006) 0(23), 6(25); 4 week DB-PC Kajita et al. (2009) 6(22); 4 week Open label Seya et al. (2009) 6(10); 4 week Open label Nagaki et al. (2010) 0(40), 9(42); 4 week DB-PC a DB-PC randomized double-blind placebo-controlled eyes, red eyes, stiff shoulders and back, heavy head, and headaches (Yamashita 2021). 13 Clinical Applications of Haematococcus 221 ...
Chapter
Haematococcus is a genus of green microalgae widely distributed in freshwater and seawater and well known for their ability to produce astaxanthin, a powerful antioxidant with diverse applications. Eight species have been assigned to this genus based on a recent genetic classification and among them Haematococcus lacustris (previously named Haematococcus pluvialis) is the most studied. This species is regarded as the most promising microalgae for the production of natural astaxanthin. It is also known for its ability to synthesize other interesting bioactive compounds with a wide range of biological activities. The present work highlights the diverse therapeutic applications of Haematococcus bioactive molecules such as antioxidant, anti-inflammation, antimicrobial, skin protection, treatment and prevention of cancer, treatment of eye and neurodegenerative diseases, and immune stimulation.KeywordsAstaxanthinAntioxidantAnti-inflammationCancer preventionNeurodegenerative diseases
... Based on the studies it is suggested that astaxanthin supplementation might be a practical and beneficial approach for eye fatigue relief. Nagaki et al. (2002) 0(13), 5(13); 4 week DB-PC Nakamura et al. (2004) 0(10), 2(12), 4(14), 12(10); 4 week DB-PC Nitta et al. (2005) 0(10), 6(10), 12(10); 4 week DB-PC Shiratori et al. (2005) 0 (19), 6(20); 4 week DB-PC Takahashi and Kajita (2005) 6(9); 2 week Open label Iwasaki and Tawara (2006) 0(10), 6(10); 2 week DB-PC, crossover Nagaki et al. (2006) 0(23), 6(25); 4 week DB-PC Kajita et al. (2009) that men have a greater sebum oil production compared to women. Thus, astaxanthin oral supplementation may help to reduce the odor related to aging by protecting the sebum oil from peroxidation. ...
Chapter
Satsuma mandarin (Citrus unshiu Marc.), a unique Japanese citrus species, is one of the foods which have most abundant β-cryptoxanthin all over the world. In this study, β-cryptoxanthin has a variety of health-promoting functions such as the body fat reducing, cosmetic (whitening), and osteoporosis prevention. β-Cryptoxanthin has also been shown in human studies to have anti-exercise fatigue and diabetes prevention actions. These multiple functions further support that β-cryptoxanthin may play a role in vitamin A function.
... Yook et al. (2015);Zhang et al. (2014a, b) Eye fatigue relief Reduces eye fatigue relieve in subjects suffering from visual display syndromeKajita et al. (2009);Kidd (2011);Nagaki et al. (2006);Serrano and Narducci (2014);Seya et al. (2009) Immune system booster Has an immunomodulating effect, strong immune system stimulator, anti-tumor, very effective for autoimmune conditions such as rheumatoid arthritisChew et al. (2010); Chew and Park (2004); Jyonouchi et al. (1995); Nir and Spiller (2002); Park et al. (2010) Cardiovascular health Improves blood lipid profiles, decreases blood pressure, offers protection from hypertension and stroke, reduces the consequences of a heart attack and vascular inflammation, reduces the area of infarction and the damage, reduces the area of infarction and the damage Fassett and Coombes (2012); Fassett and Coombes (2011); Gross and Lockwood (2005); Guerin et al. (2003); Hussein et al. (2006); Hussein et al. (2005); Iwamoto et al. (2000); Miyawaki et al. (2008) Liver health and metabolic syndrome Improves blood lipids and increases adiponectin, prevents fatty liver disease, reduces the risk of atherosclerotic plaque, inhibits progression of fatty liver disease, restores insulin-glucose balance, increases fat burning, and decreases inflammatory markers Kindlund and BioReal (2011); Kishimoto et al. (2016); Shen et al. (2014); Yilmaz et al. (2015) Diabetes and Kidneys Reduces glucose toxicity and kidney inflammation; improves pancreatic function, insulin resistance, and insulin sensitivity Naito et al. (2004); Ni et al. (2015); Savini et al. (2013); Uchiyama et al. (2002) Fertility Improves sperm parameters and fertility Comhaire et al. (2005); Donà et al. (2013); Mina et al. (2014) ...
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The worldwide annual production of lobster was 165,367 tons valued over 3.32billionin2004,butthisfigureroseupto304,000tonsin2012.Overhalfthevolumeoftheworldwidelobsterproductionhasbeenprocessedtomeettherisingglobaldemandindiversifiedlobsterproducts.Lobsterprocessinggeneratesalargeamountofbyproducts(heads,shells,livers,andeggs)whichaccountfor5070theutilizationofLPBsbyeconomicrecoveryoftheirvaluablecomponentstoproducehighvalueaddedproducts.Morethan50,000tonsofLPBsaregloballygenerated,whichcostslobsterprocessingcompaniesupwardofabout3.32 billion in 2004, but this figure rose up to 304,000 tons in 2012. Over half the volume of the worldwide lobster production has been processed to meet the rising global demand in diversified lobster products. Lobster processing generates a large amount of by-products (heads, shells, livers, and eggs) which account for 50–70% of the starting material. Continued production of these lobster processing by-products (LPBs) without corresponding process development for efficient utilization has led to disposal issues associated with costs and pollutions. This review presents the promising opportunities to maximize the utilization of LPBs by economic recovery of their valuable components to produce high value-added products. More than 50,000 tons of LPBs are globally generated, which costs lobster processing companies upward of about 7.5 million/year for disposal. This not only presents financial and environmental burdens to the lobster processors but also wastes a valuable bioresource. LPBs are rich in a range of high-value compounds such as proteins, chitin, lipids, minerals, and pigments. Extracts recovered from LPBs have been demonstrated to possess several functionalities and bioactivities, which are useful for numerous applications in water treatment, agriculture, food, nutraceutical, pharmaceutical products, and biomedicine. Although LPBs have been studied for recovery of valuable components, utilization of these materials for the large-scale production is still very limited. Extraction of lobster components using microwave, ultrasonic, and supercritical fluid extraction were found to be promising techniques that could be used for large-scale production. LPBs are rich in high-value compounds that are currently being underutilized. These compounds can be extracted for being used as functional ingredients, nutraceuticals, and pharmaceuticals in a wide range of commercial applications. The efficient utilization of LPBs would not only generate significant economic benefits but also reduce the problems of waste management associated with the lobster industry. This comprehensive review highlights the availability of the global LPBs, the key components in LPBs and their current applications, the limitations to the extraction techniques used, and the suggested emerging techniques which may be promising on an industrial scale for the maximized utilization of LPBs.
... Ponadto w Japonii przeprowadzono szczegółowe badania pod kątem korzyści zdrowotnych jakie wywołuje astaksantyna na narząd wzroku. Stwierdzono, że konsekwentne przyjmowanie astaksantyny (w ilości 6 mg/dzień) poprawia ostrość widzenia nawet u osób zdrowych [33,34]. ...
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Introduction. Carotenoids are compounds prevalent in nature, mainly in plant products. So far about 750 of these compounds have been identified. In marine raw materials there were identified more than 250 different types of carotenoids. They are responsible for the colour of both plants and animals, some of them have an essential function as a vitamin A precursor and also antioxidant properties. The analysis of the literature. Fish and crustaceans are a valuable source of carotenoids. These organisms are not able to synthesize carotenoids, however they can accumulate these compounds from forage, mainly from algae. The absorption and content of carotenoids in fish organisms depends on the species, age, physiological condition, feeding regime and environment. The distribution of carotenoids in organisms of fish and crustaceans also depends on the tissue. Conclusion. Apart from typical carotenoids, for example β-carotene, fish and crustaceans contain specific compounds such as astaxanthin and fucoxanthin. The literature shows that both astaxanthin and fucoxanthin have antioxidant activity. Astaxanthin manifests anti-inflammatory and protective activity against CVD, whereas fucoxanthin improves insulin resistance, decreases blood glucose level and reduces body weight. The detailed understanding of properties and mechanisms of carotenoid activity from fish and crustaceans have not been fully revealed yet and deserve future studies, which would enable the use of these valuable compounds in prophylaxis and therapy.
... Ponadto w Japonii przeprowadzono szczegółowe badania pod kątem korzyści zdrowotnych jakie wywołuje astaksantyna na narząd wzroku. Stwierdzono, że konsekwentne przyjmowanie astaksantyny (w ilości 6 mg/dzień) poprawia ostrość widzenia nawet u osób zdrowych [33,34]. ...
Article
Full-text available
Introduction. Carotenoids are compounds prevalent in nature, mainly in plant products. So far about 750 of these compounds have been identified. In marine raw materials there were identified more than 250 different types of carotenoids. They are responsible for the colour of both plants and animals, some of them have an essential function as a vitamin A precursor and also antioxidant properties. The analysis of the literature. Fish and crustaceans are a valuable source of carotenoids. These organisms are not able to synthesize carotenoids, however they can accumulate these compounds from forage, mainly from algae. The absorption and content of carotenoids in fish organisms depends on the species, age, physiological condition, feeding regime and environment. The distribution of carotenoids in organisms of fish and crustaceans also depends on the tissue. Conclusion. Apart from typical carotenoids, for example β-carotene, fish and crustaceans contain specific compounds such as astaxanthin and fucoxanthin. The literature shows that both astaxanthin and fucoxanthin have antioxidant activity. Astaxanthin manifests anti-inflammatory and protective activity against CVD, whereas fucoxanthin improves insulin resistance, decreases blood glucose level and reduces body weight. The detailed understanding of properties and mechanisms of carotenoid activity from fish and crustaceans have not been fully revealed yet and deserve future studies, which would enable the use of these valuable compounds in prophylaxis and therapy.
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Chapter
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Nutraceuticals offer the opportunity to prevent onset of lifestyle-associated chronic diseases due to their antioxidant, antiinflammatory, anticancer, anti-Alzheimer’s, and antiarteriosclerosis activities, among others. Therefore the food industry is increasingly focusing on the development of functional food and excipient food. Functional food can be specifically designed to modulate bioaccessibility, absorption, or transformation profile of nutraceuticals within GIT, improving their BA and consequently, their bioactivity using a suitable delivery system. Similarly, excipient food enhances the BA of bioactive compounds, such as lipophilic compounds, vitamins, and nutrients present in natural products. Many of the biologically active compounds present in foods are highly lipophilic agents that normally have low water solubility and poor oral BA. For this reason, a variety of strategies have been developed to increase absorption of lipophilic compounds using delivery systems (microemulsions, nanoemulsions, emulsions, SLNs, hydrogel beads, and liposomes), which present specific properties and materials. Also, excipient systems have been created as an alternative approach to improve intake of bioactives from natural sources, such as fruits, vegetable, cereals, and natural products. Up to date, these strategies have been mainly applied to carotenoids, phytosterols, ω-3 fatty acids, vitamins D and E, and triterpenoids. Future studies should focus on improving the physicochemical characteristics and functionality of the delivery systems, and excipient systems demonstrate their efficacy in practice and potential health effects.
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Astaxanthin (AX)‐containing preparations are increasingly popular as health food supplements. Evaluating the maximum safe daily intake of AX is important when setting dose levels for these products and currently, there are discrepancies in recommendations by different regulatory authorities. We have therefore conducted a review of approved dose levels, clinical trials of natural AX, and toxicological studies with natural and synthetic AX. Recommended or approved doses varied in different countries and ranged between 2 and 24 mg. We reviewed 87 human studies, none of which found safety concerns with natural AX supplementation, 35 with doses ≥12 mg/day. An acceptable daily intake (ADI) of 2 mg as recently proposed by European Food Safety Authority was based on a toxicological study in rats using synthetic AX. However, synthetically produced AX is chemically different from natural AX, so results with synthetic AX should not be used in assessing natural AX safety. In addition, few safety studies have been conducted in either humans or animals with synthetic AX. We therefore recommend the ADI for natural AX to be based only on studies conducted with natural AX and further studies to be conducted with synthetic AX (including human clinical trials) to establish a separate ADI for synthetic AX.
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The future fertility of cancer patients after treatment is a serious concern amongst young cancer patients. Such chemotherapeutic agents as Methotrexate (MTX), a folic acid antagonist can cause long-term or permanent gonadal toxicity in male patients. Oxidative stress is a contributing mechanism to MTX-induced testicular damage. In the past decade, several studies have investigated the use of natural antioxidant agents to prevent the side effects of MTX. Astaxanthin (AST), a red-orange xanthophyll carotenoid, owns various clinical benefits and pharmacological effects including antioxidant, anti-tumor, anti-cancer, anti-diabetic, and anti-inflammatory properties. Since there has been no study so far in the literature on the effects of AST on MTX-induced testicular dysfunction, the present study evaluated the ameliorating effect of AST against MTX-induced testicular dysfunction. Biometric and semen parameters as well as, biochemical markers of oxidative stress were measured. Compared to the control group, MTX-treated group showed a significant decrease in sperm count, motility, viability, morphology, superoxide dismutase (SOD) and catalase (CAT) activities, and a significant increase in MDA levels. Pretreatment with AST for six consecutive days before MTX administration prevented these oxidative parameters. Thus, the current results suggest that MTX seems to impair the male fertility through oxidative damage in one hand, and AST pretreatment might improve the male fertility by preventing oxidative stress-induced fertility disorders, on the other hand. However, AST pretreatment might also protect germ cells against MTX-induced oxidative stress.
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Astaxanthin is a naturally occurring carotenoid in a wide variety of living organisms such as salmon, shrimp, crab, and red snapper. Approximately 90% of the astaxanthin in krill is found in the eye. Asthenopia, or eye fatigue, is an ophthalmological condition with nonspecific symptoms such as eye pain, eye strain, blurred vision, headache, and shoulder stiffness. Symptoms often occur after reading, computer work, or other activities that involve visual display terminals (VDT). More recently, the advances of information technology (IT), software, and electronics have led to the widespread and habitual use of VDT resulting in higher visual fatigue complains and more sufferers. There is, however, no effective therapeutic approach to date. Eye fatigue is usually caused by straining the ciliary body, the eye muscle responsible for accommodation. We previously reported a randomized double-blind placebo controlled study using VDT workers (n=25 treated vs. 23 placebo). 6mg/day astaxanthin supplementation for 4-weeks significantly improved eye fatigue measuring ocular accommodation by the objective instrument and subjective individual assessment. Here we report further 4 clinical studies with the different measurements and an animal study. The same source of astaxanthin, extract derived from the microalgae Haematococcus pluvialis, was used for all of the studies. The first clinical study was performed under randomized double-blind placebo controlled cross-over conditions using 10 healthy subjects. After a 20-minute near visual task, accommodation contraction and relaxation times were extended in both the astaxanthin and placebo groups. However, accommodation relaxation time in the placebo was significantly longer than in the astaxanthin group, and accommodative contraction and relaxation times after a 10-minute rest in the placebo were also significantly longer those in the astaxanthin group. In the second study, the effects of astaxanthin on accommodative recovery derived from a rest after VDT work were studied using 10 healthy volunteers. 6mg/day astaxanthin supplementation for 2-weeks led to a significant relief in accommodative fatigue induced by 30-minutes of IT work (Nintendo Game Boy). In the third study, 22 middle-aged and elder subjects (mean age: 53.9 years) with complaints of eye strain received 6mg/day astaxanthin. Results showed that the pupillary constriction ratio at week 4 was significantly increased compared to that at week 0. The forth clinical study, using 10 healthy subjects, was performed to investigate the effects of visual fatigue on reaction times. Visual fatigue significantly increases reaction time; however 6 mg/day astaxanthin supplementation for 4-weeks was shown to significantly decrease reaction time. We also investigated the intraocular pharmacokinetics of astaxanthin in an albino rabbit. After 100mg/kg astaxanthin administration in a single dose, astaxanthin was detected in the ciliary body as well as the serum at Tmax of 24h and 9h and Cmax of 79.3ng/g and 61.3ng/ml, respectively. Based on the studies it is suggested that astaxanthin supplementation might be a practical and beneficial approach for eye fatigue relief.
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In the article the currently available scientific literature regarding the most significant activities, mechanisms action and preclinical and clinical trails of astaxanthin and other oxygenic carotinoids is reviewed. Results from experimental studies and clinical trials support the remedial properties of the astaxanthin, establishing it as an appropriate candidate for development a functional food and supplementary therapy agent promising applications in human health with the considerable medicinal potential.
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Astaxanthin is known as a "marine carotenoid" and occurs in a wide variety of living organisms such as salmon, shrimp, crab, and red snapper. Astaxanthin antioxidant activity has been reported to be more than 100 times greater than that of vitamin E against lipid peroxidation and approximately 550 times more potent than that of vitamin E for singlet oxygen quenching. Astaxanthin exhibits no pro-oxidant activity and its main site of action is on/in the cell membrane. To date, various important benefits suggested for human health include immunomodulation, anti-stress, anti-inflammation, LDL cholesterol oxidation suppression, enhanced skin health, improved semen quality, attenuation of eye fatigue, increased sports performance and endurance, limiting exercised-induced muscle damage, and the suppression of the development of lifestyle related diseases such as obesity, atherosclerosis, diabetes, hyperlipidemia and hypertension. Recently, there has been an explosive increase worldwide in both the research and demand for natural astaxanthin in human health applications. Japanese clinicians are especially using astaxanthin extracted from the microalgae, Haematococcus pluvialis, as add-on supplementation for patients who are unsatisfied with conventional medications or cannot take other medications due to serious symptoms. For example, in heart failure or overactive bladder patients, astaxanthin treatment enhances patient's daily activity levels and QOL. Other ongoing clinical trials and case studies are examining chronic diseases such as non-alcoholic steatohepatitis, diabetes, diabetic nephropathy and CVD, as well as infertility, atopic dermatitis, androgenetic alopecia, ulcerative colitis and sarcopenia. In the near future, astaxanthin's role may be stated as, "Let astaxanthin be thy medicine".
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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.
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Oxidative stress induced by hyperglycemia possibly causes the dysfunction of pancreatic β-cells and various forms of tissue damage in patients with diabetes mellitus. Astaxanthin, a carotenoid of marine microalgae, is reported as a strong anti-oxidant inhibiting lipid peroxidation and scavenging reactive oxygen species. The aim of the present study was to examine whether astaxanthin can elicit beneficial effects on the progressive destruction of pancreatic β-cells in db/db mice - a well-known obese model of type 2 diabetes. We used diabetic C57BL/KsJ-db/db mice and db/m for the control. Astaxanthin treatment was started at 6 weeks of age and its effects were evaluated at 10, 14, and 18 weeks of age by non-fasting blood glucose levels, intraperitoneal glucose tolerance test including insulin secretion, and β-cell histology. The non-fasting blood glucose level in db/db mice was significantly higher than that of db/m mice, and the higher level of blood glucose in db/db mice was significantly decreased after treatment with astaxanthin. The ability of islet cells to secrete insulin, as determined by the intraperitoneal glucose tolerance test, was preserved in the astaxanthin-treated group. Histology of the pancreas revealed no significant differences in the β-cell mass between astaxanthin-treated and -untreated db/db mice. In conclusion, these results indicate that astaxanthin can exert beneficial effects in diabetes, with preservation of β-cell function. This finding suggests that anti-oxidants may be potentially useful for reducing glucose toxicity.
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Dietary antioxidants may attenuate oxidative damage from strenuous exercise in various tissues. Beneficial effects of the antioxidant astaxanthin have been demonstrated in vitro, but not yet in vivo. We investigated the effect of dietary supplementation with astaxanthin on oxidative damage induced by strenuous exercise in mouse gastrocnemius and heart. C57BL/6 mice (7 weeks old) were divided into groups: rested control, intense exercise, and exercise with astaxanthin supplementation. After 3 weeks of exercise acclimation, both exercise groups ran on a treadmill at 28 m/min until exhaustion. Exercise-increased 4-hydroxy-2-nonenal-modified protein and 8-hydroxy-2'-deoxyguanosine in gastrocnemius and heart were blunted in the astaxanthin group. Increases in plasma creatine kinase activity, and in myeloperoxidase activity in gastrocnemius and heart, also were lessened by astaxanthin. Astaxanthin showed accumulation in gastrocnemius and heart from the 3 week supplementation. Astaxanthin can attenuate exercise-induced damage in mouse skeletal muscle and heart, including an associated neutrophil infiltration that induces further damage.
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Understanding the mechanism of accommodation is fundamental in being able to find an appropriate treatment for presbyopia. Over the last century, one universal tenet concerning accommodation is the capsular tension theory of Helmholtz. This theory states that the zonule is constantly pulling the capsule in the non-accommodated state and relaxes in the accommodated state. However, immunohistological studies have revealed important roles for elastic connective tissues (elastin, collagen, fibrillin and adhesive). And the author brought forward the "Dynamic connective tissue theory". Zonular fibers transmit the contraction of circular ciliary muscle to the capsule, resulting in centripetal movement of subcapsular connective tissues and expansion of the inter-lenticular fiber space. Throughout ones lifespan, the capsular epithelial cells produce lens fibers. And as apoptosis or necrosis does not occur, the accumulation of these fibers will gradually form a hard lens. The cause of presbyopia is mainly due to narrowed space for soft tissues and inter-fibers in the capsular bag. To find a treatment for presbyopia, quantitative analysis of accommodative power is essential. The newly developed "near triad meter" (TriIris; Hamamatsu Photonics) is useful for this approach. Maximum accommodative power can be calculated by the induced rate of miosis corresponding to an age matched standard curve. Static accommodative power was found to be half of the dynamic power. Three types of intraocular lenses (IOL) were tested for the accommodative power and 2-3D was found on aged. In the future, presbyopia research needs to proceed in two directions with investigations into accommodative IOL and biological cell control of epithelial growth in the lens.
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rights: 本文データは和漢医薬学会の許諾に基づき複製したものである We evaluated the effects of astaxanthin, a red carotenoid, on accommodation, critical flicker fusion (CFF), and pattern visual evoked potential (PVEP) in visual display terminal (VDT) workers. As controls, 13 non-VDT workers received no supplementation (Group A). Twenty-six VDT workers were randomized into 2 groups: Group B consisted of 13 subjects who received oral astaxanthin, 5 mg/day, for 4 weeks, and Group C consisted of 13 subjects who received an oral placebo, 5 mg/day, for 4 weeks. No significant difference in age was noted among the 3 groups. A double-masked study was designed in Groups B and C. Accommodation amplitude in Group A was 3.7± 1.5 diopters. Accommodation amplitudes (2.3±1.4 and 2.2±1.0 diopters) in Groups B and C before supplementation were significantly (p<0.05) lower than in Group A. Accommodation amplitude (2.8±1.6 diopters) in Group B after astaxanthin treatment was significantly (p<0.01) larger than before supplementation, while accommodation amplitude (2.3±1.1 diopters) in Group C after placebo supplementation was unchanged. The CFFs and amplitude and latency of P100 in PVEP in Group A were 45.0±4.2 Hz, 6.5±1.8μV, and 101.3±6.5 msec, respectively. The CFFs in Groups B and C before supplementation were significantly (p<0.05) lower than in Group A. The CCFs in Groups B and C did not change after supplementation. Amplitudes and latencies of P100 in PVEP in Groups B and C before supplementation were similar to those in Group A and did not change after supplementation. Findings of the present study indicated that accommodation amplitude improved after astaxanthin supplementation in VDT workers. 赤色カロチノイドの一種であるアスタキサンチンのvisual display terminal(VDT)作業者の調節力,中心フリッカー値,パターン視覚誘発電位に及ぼす影響を調べた。VDT作業を行わない13人をコントロールとした(Group A)。26人のVDT作業者を2群に無作為に分けた。Group Bはアスタキサンチン一日5mg 4週間内服した13人で,Group Cはアスタキサンチンを含有しないカプセルを4週間内服した13人とした。外見上同じカプセルでの内服投与を行った。結果:Group AはGroup B及びGroup Cと比較して,調節力,中心フリッカー値は有意に高い値であったが,パターン視覚誘発電位検査結果は,Group B,Cと有意差はなかった。Group Bでは,アスタキサンチンの投与前後で有意な調節力の改善がみられた(p<0.01)。しかし,中心フリッカー値,パターン視覚誘発電位に変化はみられなかった。Group Cでは,投与前後で,調節力,中心フリッカー値,パターン視覚誘発電位に変化はみられなかった。考察:VDT作業者では,非作業者と比べ調節力,中心フリッカー値が低下していることは以前より報告されており,今回の我々の研究でも同様の結果であった。VDT作業者で,アスタキサンチン非内服群では,調節力は投与前後で変化がなかったが,アスタキサンチンの内服群で,有意に調節力が改善した。VDT作業者の調節力の改善には,アスタキサンチンの内服が有効と考えられた。
Article
Astaxanthin (AST) is a carotenoid that is found in marine animals and vegetables. Several previous studies have demonstrated that AST exhibits a wide variety of biological activities including antioxidant, antitumor, and anti-Helicobacter pylori effects. In this study, attention was focused on the antioxidant effect of AST. The object of the present study was to investigate the efficacy of AST in endotoxin-induced uveitis (EIU) in rats. In addition, the effect of AST on endotoxin-induced nitric oxide (NO), prostaglandin E2 (PGE2), and tumor necrosis factor (TNF)-alpha production in a mouse macrophage cell line (RAW 264.7) was studied in vitro. EIU was induced in male Lewis rats by a footpad injection of lipopolysaccharide (LPS). AST or prednisolone was administered intravenously at 30 minutes before, at the same time as, or at 30 minutes after LPS treatment. The number of infiltrating cells and protein concentration in the aqueous humor collected at 24 hours after LPS treatment was determined. RAW 264.7 cells were pretreated with various concentrations of AST for 24 hours and subsequently stimulated with 10 microg/mL of LPS for 24 hours. The levels of PGE2, TNF-alpha, and NO production were determined in vivo and in vitro. AST suppressed the development of EIU in a dose-dependent fashion. The anti-inflammatory effect of 100 mg/kg AST was as strong as that of 10 mg/kg prednisolone. AST also decreased production of NO, activity of inducible nitric oxide synthase (NOS), and production of PGE2 and TNF-alpha in RAW264.7 cells in vitro in a dose-dependent manner. This study suggests that AST has a dose-dependent ocular anti-inflammatory effect, by the suppression of NO, PGE2, and TNF-alpha production, through directly blocking NOS enzyme activity.
Article
A newly developed "Near Triad Meter" is a useful tool to record the dynamics of pupils and horizontal eye movements in both eyes simultaneously with the accommodative stimuli. The responses show insufficiency or strain for accommodation. In this study the objective accommodative power (in diopters, D) is calculated by the measurement of pupillary constriction-ratio(CR) and compared in 4 age groups to find the age-related decrement of diopter values. A clearly visible accommodative target was moved back-and-forth from 50 cm to [near point + 1 D] (maximum accommodative stimulus; MAS). The speed was regulated constant for diopter movement. Pupillometry and eye tracker were recorded simultaneously with MAS in both eyes together. Three trials were done on 42 volunteers in each age group from 20-year-olds to 50-year-olds and the most reliable recording was used to measure the CR. Eighteen well-responding volunteers were selected to make the standard curves of CR by step-by-step accommodative stimuli. The mean CRs of initial tests with MAS were applied to the age-matched standard curves to calculate the maximum accommodative diopter value. The mean CRs versus MAS in each age group were 48%/7.2 D in the 20-year group, 46%/6.9 D in the 30-year group, 35%/3.6 D in the 40-year group, and 33%/3.1 D in the 50-year group. The mean values of CR were applied to age-matched standard curves to obtain the maximum accommodative power, which was 8.0 D in the 20-year group, 9.1 D in the 30-year group, 3.4 D in the 40-year group, and 4.1 D in the 50-year group. The 20- and 30-year olds showed equal power statistically, The remarkable age-dependent difference was calculated quantitatively. The dynamics of near response revealed the individual summation of accommodative power including depth of focus, and accommodative vergence objectively and quantitatively. This method is useful for understanding the quality of accommodative insufficiency and also the quantity of accommodative width, including presbyopia.
Article
Frequently used for humans as non-steroidal anti-inflammatory drug, naproxen has been known to induce ulcerative gastric lesion. The present study investigated the in vivo protective effect of astaxanthin isolated from Xanthophyllomyces dendrorhous against naproxen-induced gastric antral ulceration in rats. The oral administration of astaxanthin (1, 5, and 25 mg/kg of body weight) showed a significant protection against naproxen (80 mg/kg of body weight)-induced gastric antral ulcer and inhibited elevation of the lipid peroxide level in gastric mucosa. In addition, pretreatment of astaxanthin resulted in a significant increase in the activities of radical scavenging enzymes such as superoxide dismutase, catalase, and glutathione peroxidase. A histologic examination clearly proved that the acute gastric mucosal lesion induced by naproxen nearly disappeared after the pretreatment of astaxanthin. These results suggest that astaxanthin removes the lipid peroxides and free radicals induced by naproxen, and it may offer potential remedy of gastric ulceration.
Article
We investigated the effects of astaxanthin (AST), a carotenoid, on endotoxin-induced uveitis (EIU), and over the course of the disease measured the expression of inflammatory cytokines and chemokines in the presence or absence of AST. EIU was induced in male Lewis rats by footpad injection of lipopolysaccharide (LPS). The animals were randomly divided to 12 groups with eight animals in each. Immediately after the inoculation, AST (1, 10, or 100 mg kg(-1)) was injected intravenously. Aqueous humour was collected at 6, 12 and 24 hr after LPS inoculation and the number of infiltrating cells in the anterior chamber was counted. In addition, we assayed the concentration of protein, nitric oxide (NO), tumour necrosis factor-alpha (TNF-alpha) and prostaglandin E2 (PGE2). Immunohistochemical staining with a monoclonal antibody against activated NF-kappaB was performed in order to evaluate the effects of AST on NF-kappaB activation. Rats injected with AST showed a significant decrease in the number of infiltrating cells in the anterior chamber and additionally there was a significantly lower concentration of protein, NO, TNF-alpha and PGE2 in the aqueous humour. Moreover, even early stages of EIU were suppressed by injection of AST. The number of activated NF-kappaB-positive cells was lower in iris-ciliary bodies treated with 10 or 100 mg kg(-1) AST at 3 hr after LPS injection. These results suggest that AST reduces ocular inflammation in eyes with EIU by downregulating proinflammatory factors and by inhibiting the NF-kappaB-dependent signaling pathway.
responsible for highly potent antiperoxidative activity of the carotenoid astaxanthin
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Effects of astaxanthin on eyestrain induced by accommodative dysfunction
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Effects of astaxanthin on accommodation and asthenopiaefficacy-identification study in healthy volunteers
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Evaluation of IT ophthalmopathy using TriIRIS
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Ishikawa H, Shimizu K, Horibe M et al.: "Evaluation of IT ophthalmopathy using TriIRIS", Japan Ophthalmologists Association, Accomplishments by research group on IT ophthalmopathy and environmental factors 2002-2004: 129-134
Effects of astaxanthin on retinal capillary blood flow in normal volunteers
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Nagaki Y, Mihara Y, Takahashi J et al.: "Effects of astaxanthin on retinal capillary blood flow in normal volunteers", Journal of Clinical Therapeutics & Medicine 2005; 21: 537-542