Antioxidant properties of astaxanthin and its application in nutrition and medicine

 Astaxanthin, an oxygenated derivative of carotenoids, can effectively quench reactive oxygen species and has high nutritional and medicinal value. Astaxanthin was isolated from the shells of shrimps and crabs in the 1930s, and its physiological functions were not widely recognized until the 1980s. Since then, many scholars have proved through animal and clinical experiments that astaxanthin can inhibit tumorigenesis, enhance immune function, prevent cardiovascular disease and other physiological functions [2][9], and has a broad application prospect.

 

As the most abundant astaxanthin in nature, the astaxanthin content of Rhodococcus aurantium can reach 3.0% by dry weight or even higher, which is regarded as a natural astaxanthin ui concentrate. Moreover, astaxanthin from red algae has advantages in terms of function and safety that cannot be matched by astaxanthin from other sources.         Therefore, it is considered to be the best biological source of natural astaxanthin.

 

Scholars at home and abroad have conducted a large number of studies on the antioxidant properties of natural astaxanthin and its potential role in the human body [1][9]. In this paper, we summarize the current status of astaxanthin research and application in food and medicine in light of the research progress in this field at home and abroad in recent years, further elucidate some of the authors' views and prospects for future work, and provide certain suggestions and theoretical basis for astaxanthin application in nutrition and medicine.

 

1 Antioxidant effects of astaxanthin

1.1 Structure, properties and distribution

Astaxanthin is an oxygenated derivative of carotenoids, belonging to the ketocarotenoids, known as 3, 3' - dihydroxy -4, 4' - diketone - , p ' - carotene, the molecular formula for the C40H52 O4 o Astaxanthin is insoluble in water, soluble in chloroform, acetone, benzene and carbon disulfide and other organic solvents Its structure is shown in Figure 1.

Fig.1 The structure of astaxanthin

 

1.2 Antioxidant effects

Biological oxidation is a basic physiological and biochemical process in every cell of an organism, and is very important in maintaining normal metabolism. Bio-oxidation process will produce oxygen radicals and reactive oxygen species such as H2O2, but excessive reactive oxygen species will lead to oxidative damage. Reactive oxygen species are highly unstable and can cause a variety of cellular injuries such as oxidation of amino acids, degradation of proteins and DNA damage. Oxygen free radicals also attack unsaturated fatty acids on cell membranes, and oxidized fatty acids can generate more fatty acid radicals through chain reactions. The presence of too many free radicals disrupts the balance between free radicals and antioxidants in living organisms, and is an important factor leading to rheumatoid arthritis, heart disease, Parkinson's syndrome, many types of cancers, and shock[2] o

In general, dietary antioxidants are helpful in the prevention of many diseases, and carotenoids and their derivatives are effective biological antioxidants. They can absorb the active energy of mono-linear oxygen through their long-chain conjugated olefin structure, thus preventing mono-linear oxygen from causing oxidative damage to other molecules or tissues; and they can also block the free-radical chain reaction triggered by the degradation of unsaturated fatty acids, thus reducing or preventing the generation of free radicals. It can also block the free radical chain reaction triggered by the degradation of unsaturated fatty acids, thus reducing or preventing the generation of free radicals.

 

Astaxanthin is a chain-breaking antioxidant with strong antioxidant effects. o Lee et al. compared the effects of five carotenoids and their derivatives, namely lutein, zeaxanthin, lycopene, iso-zeaxanthin, and astaxanthin, which have different numbers of conjugated double bonds, on the quenching of reactive oxygen species in the photo-oxidation of soybean oil. o Lee et al. found that this effect increased with the number of conjugated double bonds, and that the effect was strongest in the case of astaxanthin. o Lee et al. used heme proteins containing ferrous ions as free radical producers and linoleic acid as the acceptor. The ED50 of free radical scavenging of carotenoids and their derivatives and tocopherol (VE) was measured by the thiobarbituric acid method using heme proteins containing ferrous ions as the free radical generators and linoleic acid as the acceptor (see Table 1). Astaxanthin was found to be the most potent scavenger of free radicals, and the presence and number of hydroxyl and ketone groups in carotenoids and their derivatives were found to be very important for the scavenging of free radicals[4] . o Similar results were obtained from experiments on rat erythrocyte membranes and liver mitochondria. The antioxidant property of astaxanthin is more than 100 times stronger than that of a-tocopherol, which is why it is called ui super VE. Liu Ziyi et al. compared astaxanthin extracted from shrimp shells with a-tocopherol in preventing peroxidation of mouse liver homogenates and showed that the antioxidant effect of astaxanthin was more than a thousand times stronger than that of a-tocopherol [5]. The antioxidant effect of astaxanthin was more than a thousand times stronger than that of a-tocopherol[5] . Astaxanthin is also effective in preventing the peroxidation of phospholipids and other lipids[6] o

 

2 Astaxanthin and Health

2.1 Combating cancer

Nishino [10] found that astaxanthin has strong anticarcinogenic effects by studying the anticarcinogenic effects of natural carotenoids and their derivatives. o Gradelet et al. investigated the effects of carotenoids such as astaxanthin on the hepatic carcinogenicity induced by aflatoxin B1 (AFB1) [11 ]: rats were fed with carotenoids, lycopene (300mg/kg) and excess VA, intraperitoneally injected with AFB1, and also injected with 3- methylcholanthrene (6 20mg/kg bw). In rats fed with -carotene, lycopene (300 mg/kg) and excess VA, and injected intraperitoneally with AFB1 and 3-methylcholanthrene (6 20 mg/kg bw), astaxanthin, B-carotene and 3-methylcholanthrene were found to be highly effective in decreasing the number and size of hepatocellular carcinoma foci, while lycopene and excess VA were ineffective. This is because astaxanthin reduces AFB1-induced single-strand breaks in DNA in vivo, decreases the binding of AFB1 to hepatic DNA and plasma plasma albumin, and facilitates the in vitro metabolism of AFB1 to the less toxic aflatoxin M1. o Feeding astaxanthin for 3-4 w to rats with lung tumors induced by diethylnitrosamine (DEN) or a-nitropropropropane significantly reduces the size and number of lung tumor foci[27] . The results of this study are summarized in the following table.

 

Feeding astaxanthin to experimental rats and mice significantly inhibited chemical-induced carcinogenesis at the initial stage, and had antiproliferative and immune-enhancing effects on epithelial cells exposed to carcinogens, and there was also a dose effect. The incidence of various oral cancers in mice fed carcinogens and supplemented with astaxanthin was much lower than that in the control group, and the incidence of colon cancer was significantly lower in the astaxanthin group (p<0.01)[7] o Dietary supplementation with astaxanthin inhibited the growth of breast tumors by more than 50 %, which greatly reduced the incidence of breast cancer, a more significant effect than that of carotene and carotenoids, both of which have been shown to be effective in reducing breast cancer. Dietary supplementation with astaxanthin has been shown to inhibit the growth of breast tumors by more than 50 %, thus significantly reducing the incidence of breast cancer, a function that is stronger than that of carotenoids and keratins [8]. o The enlargement of the prostate gland is mainly caused by the enzyme 5-a-reductase, which is inhibited by astaxanthin; therefore, supplementation with astaxanthin has been regarded as an effective means of preventing prostatic hyperplasia and prostate cancer. The anticancer activity of astaxanthin is closely related to its induction of cell gap junc- tion communication, which plays an important role in regulating the normal proliferation and differentiation of cells as well as the stability of tissues. Currently, the inhibition or disruption of cell gap junc- tion communication is considered to be an important mechanism of carcinogenesis [9].

 

2.2 Enhancement of immunity

Jyonouchi et al. investigated the immunomodulatory effects of astaxanthin and carotenoids on mouse lymphocytes in vitro in a tissue culture system, and showed that the immunomodulatory effects of carotenoids and their derivatives were not related to the presence or absence of VA activity, and that astaxanthin showed a stronger effect[12] . o In vitro experiments have shown that astaxanthin significantly promotes antibody production in the response of mouse splenocytes to thymus-dependent antigen (TD-Ag), and enhances humoral immune responses dependent on T-specific antigens. - Ag) in mouse splenocytes, and enhances the humoral immune response to T-specific antigens. In vitro studies on human blood cells also showed that astaxanthin and carotenoids significantly promoted antibody production and increased the number of IgG- and IgM-secreting cells in response to TD-Ag stimulation. 1994 Jyonouchi et al. investigated the effect of astaxanthin on immunoglobulin production by peripheral blood mononuclear cells in vitro, using blood samples from adult volunteers and full-term newborn infants (umbilical cord blood). In 1994, Jyonouchi et al. used blood samples from adult volunteers and full-term newborns (umbilical cord blood) to study the effect of astaxanthin on immunoglobulin production by peripheral blood mononuclear cells in vitro.

 

2.3 Photoprotection

Upon exposure to bright light, especially UV light, cell membranes and tissues are damaged by mono-linear oxygen, free radicals and photo-oxidation. In nature, carotenoids play an important role in protection against UV oxidation, and their presence can be detected in tissues exposed to direct sunlight[39] . Astaxanthin is more effective in preventing UV oxidation of lipids than carotenoids and lutein[13] . UV damage to the eyes and skin has been widely recognized, and the UV-protective properties of astaxanthin are therefore important for the maintenance of eye and skin health.

 

The leading causes of visual impairment and even blindness are age-related macular degeneration (AMD) and senile cataracts, both of which are associated with photo-oxidative processes within the eye. Epidemiologic studies have shown that oxidation increases the risk of AMD. Dietary supplementation with carotenoids, particularly lutein and zeaxanthin, can reduce the incidence of cataracts and AMD. Lutein and zeaxanthin are mainly concentrated in the retinal macula, and astaxanthin is structurally similar to lutein and zeaxanthin, but astaxanthin has stronger antioxidant and UV-protective effects. Astaxanthin has not been isolated from the human eye, but animal studies have demonstrated that it can cross the blood-brain barrier and deposit in the retina in the same way as lutein[14] . Astaxanthin-fed mice showed much less retinal damage and faster recovery than control mice. Therefore, it can be inferred that astaxanthin has a photoprotective effect on the eye and prevents the oxidation of retinal tissues, thus maintaining the health of the eye.

Skin burns, oxidizes, becomes inflamed, immunosuppressed and even cancerous when exposed to bright light. Preclinical studies have shown that adequate dietary intake of antioxidants such as β-carotene, as well as tocopherols and ascorbic acid, can reduce these injuries[15] o Astaxanthin protects salmon skin from UV oxidation.        In vitro experiments have also demonstrated that astaxanthin is more resistant to photo-oxidation than beta-carotene and lutein [13][38] o These findings suggest that astaxanthin has great potential as a food photoprotectant.

 

2.4 Prevention of cardiovascular diseases

 Clinical studies have shown that oxidation of low-density lipoproteins (LDL) is an important cause of atherosclerosis, while high-density lipoproteins (HDL) are negatively correlated with the risk of coronary heart disease, and high levels of HDL prevent atherosclerosis. o Supplementation with antioxidants can reduce the risk of atherosclerosis. LDL is usually present in a non-oxidized state, and oxidation of LDL accelerates the onset of atherosclerosis[16] . o Supplementation with antioxidants reduces the risk of atherosclerosis, and epidemiologic and clinical data suggest that dietary antioxidants can prevent cardiovascular disease[17] .

In human blood, astaxanthin is carried by very low density lipoprotein (VLDL), LDL, and HDL-cholesterol, and in vitro and clinical trials have demonstrated that oral administration of 3.6mg of astaxanthin per day for 2 weeks in humans prevents oxidation of LDL-cholesterol [30]. o Astaxanthin has been shown to have a significant HDL- and LDL-lowering effect in animal studies [18], thereby preventing cardiovascular diseases such as atherosclerosis, coronary heart disease, and ischemic brain damage. 18], thus preventing cardiovascular diseases such as atherosclerosis, coronary heart disease and ischemic brain injury.

 

2.5 Maintaining the health of the central nervous system

The central nervous system (including the brain, spinal cord, and peripheral nerves), which is rich in unsaturated fatty acids, lipids, and iron, is highly metabolically active and susceptible to oxidative damage, leading to the development of many neurological disorders. There is extensive research and clinical evidence that oxidative stress is a major cause or at least contributes to the development of neurological disorders, including Huntington's syndrome, Parkinson's syndrome, and lateral sclerosis of muscular dystrophy (ALS), etc. Consumption of foods high in antioxidants reduces the risk of these disorders[19 21] o

Experiments in mice fed natural astaxanthin have shown that astaxanthin crosses the blood-brain barrier and produces antioxidant activity outside the barrier[14] o Thus, oral administration of astaxanthin is an effective way to prevent and treat neurological diseases such as Parkinson's syndrome.

 

2.6 Anti-inflammatory effects

In inflammatory conditions, such as Crohn's disease, phagocytes release toxic reactive oxygen species and phagocytosis at the site of inflammation (intestinal mucosa and intestinal lumen), disrupting the original balance between free radicals and antioxidants, resulting in decreased levels of antioxidants, oxidation products, and increased levels of lipid peroxidation[22] . o Studies have demonstrated that there is a direct correlation between the release of reactive oxygen species and phagocytosis at the site of inflammation (intestinal mucosa and intestinal lumen). o Reactive oxygen species can also exacerbate inflammation associated with asthma[24] and training-induced muscle injury[25] . o Studies have shown that oxidants are directly related to the inflammatory stimulation of endothelial cells[23] o Reactive oxygen species can also exacerbate inflammation associated with asthma[24] and training-induced muscle damage[25] .

Kurashige showed that astaxanthin reduced foot swelling in mice, while VE did not[26] o In 1999, Benned sen's study found that astaxanthin prevented Helicobacter pylorio ulcers and reduced gastritis[27] o Mara investigated the effects of an astaxanthin product from red algae, Astafactor, on human health and compared its effects with 26 other well-known anti-inflammatory drugs[28]. o Mara has also shown that Astafactor is an important anti-inflammatory drug for human health, and that it is not an anti-inflammatory drug. The Mara study investigated the effects of the red chlorella astaxanthin product (Astafactor) on human health and compared its effects with 26 other well-known anti-inflammatory drugs[28] . The results showed that acute and chronic patients taking astaxanthin experienced an 85% improvement in health status, and that astaxanthin was as effective or more effective than 92% of the anti-inflammatory drugs in the survey; astaxanthin was as effective or better than 76% of the 62 over-the-counter (OTC) anti-inflammatory drugs, including aspirin. These results suggest that the anti-inflammatory effects of astaxanthin may make it useful as a nutritional and nutraceutical food for the treatment and prevention of diseases caused by inflammation.

Benned sen et al. showed that feeding astaxanthin-rich red algae algal powder to mice can significantly reduce the attachment of Helicobacter pylori to the stomach and infection[31] , for this reason, astaxanthin has been developed as an oral astaxanthin as an anti-gastric infection preparation.        Astaxanthin ester also has the role of anti-infective drugs, and can enhance the efficacy of the latter when taken together with aspirin[32] o

 

2.7 Delayed aging, cell protection

In mitochondria, the chain oxidation reaction generates the energy needed by the cell, but also produces a large number of free radicals, which must be removed in order to ensure the normal function of the mitochondria. Oxidative damage to mitochondria accelerates cellular aging, which is the main cause of aging. Astaxanthin can prevent the peroxidation of rat liver mitochondria in vitro, and its efficiency is more than 100 times that of VE[26] , which shows that astaxanthin protects mitochondria and has anti-aging properties. The strong protective effect of astaxanthin on cell membranes is mainly due to its antioxidant ability in and on the surface of the membrane, because the polyolefin chain and terminal ring structure of astaxanthin increase the rigidity of the cell membrane and change the permeability of the cell membrane. Antioxidants, especially carotenoids and their derivatives, are important for cellular health, not only because they prevent the oxidation of intracellular substances, but also because they play an important role in regulating gene expression and inducing cell-to-cell messaging. o In 2002, Kistler's study demonstrated that astaxanthin modulates the CYP gene in murine hepatocytes, but to date, there is no evidence of such modulation of the gene in humans [1]. There is no evidence to date that astaxanthin has such a regulatory effect on human genes[33] . Carotenoids and their derivatives are active inducers of information transfer in cell gap junctions. Gap junctions are responsible for the exchange of information necessary for the regulation of cell growth and, more importantly, for inhibiting the spread of cancer cells[9] o

 

3 Development prospects of natural astaxanthin

3.1 Advantages of natural astaxanthin

Currently, astaxanthin can be produced in two ways: synthetically and biologically. Astaxanthin is more difficult to synthesize, and there are significant differences in structure, function, application and safety of synthetic astaxanthin compared with natural astaxanthin.

Structurally, astaxanthin has three conformations: 3S, 3' S, 3R, 3s R, and 3R, 3 S. Synthetic astaxanthin is a mixture of these three conformations, with 3R, 3 S being the dominant one, which is very different from that of natural astaxanthin. Physiologically, natural astaxanthin has a higher stability and antioxidant activity than synthetic astaxanthin. In terms of physiological functions, natural astaxanthin has higher stability and antioxidant activity than synthetic astaxanthin. In terms of application, natural astaxanthin has better bioabsorption than synthetic astaxanthin, and synthetic astaxanthin cannot be converted to its natural conformation in animals.

 

There are three main sources of natural astaxanthin: waste from the fish processing industry, Phaffia rhodozyma and microalgae. The astaxanthin content in waste products is low and the cost of extraction is high, making it unsuitable for large-scale production. The content of astaxanthin in natural S. rhodozyma is only 0.15% and 0.40%.

The astaxanthin content in red algae can be up to 3.0% or even higher than that in red yeast, which is 1000 4000 times higher than that in salmon meat. 3.0% or even higher, compared with the content in red hair yeast is much higher than that in salmon meat 1000 4000 times, so the rainy red chlorella is regarded as natural astaxanthin uc concentrate ", is the best biological source of natural astaxanthin A large number of studies have proved that the rate of accumulation of astaxanthin and the total amount of astaxanthin in the rainy red chlorella is higher than that of other living organisms, and rainy red chlorella astaxanthin and its lipid ratio ( most of the monoester and a small part of the diester and a small amount of free astaxanthin) is very similar to that of animals, this is through the chemicalization of free astaxanthin. Moreover, the ratio of astaxanthin and its lipids (most of the monoesters, a small portion of diesters and a small amount of free astaxanthin) contained in Rhodococcus rabiotis is very similar to that of astaxanthin in animals, which is an advantage not possessed by chemically synthesized astaxanthin or astaxanthin extracted from yeasts, such as the red hair yeast.        In addition, the 3S,3s S configuration of astaxanthin in Rhodococcus pyrenoidus was dominant, which was basically the same as that of astaxanthin in animals.

 

3.2 Safety of natural astaxanthin

The safety of astaxanthin from Rhodococcus aureus has been recognized in many countries. The results of animal and human experiments showed that no deaths or abnormalities were observed in male and female mice at oral doses of up to 10.4 18.0 mg/g of E. rainbowii powder[34] o No harmful effects were observed in rats fed 400 μg/g of astaxanthin for 41 days[35] o A Japanese patent study showed that human consumption of 14.4 mg/day astaxanthin for 2 w did not have any pathogenic effects, and as the dose of astaxanthin increased, the serum levels of astaxanthin in the serum did not show any adverse effects[36] o A study in a Japanese patent study showed that human consumption of E. rainbowii powder for 2 w did not have any pathogenic effects. A Japanese patent study showed that a dose of 14.4 mg of astaxanthin per day for 2 w in humans was not associated with any pathogenic effects, and the rate of oxidation of serum LDL was significantly reduced with increasing doses of astaxanthin[36] . In vitro studies have also not found any mutagenic effects of E. rainbowii powder. 1999 study by Aquasearch showed that 33 healthy adults were given daily astaxanthin supplementation with E. rainbowii powder in two dosage groups of high (19.25 mg) and low (3.85 mg) doses for a period of 29 d. The volunteers were carefully monitored for weight, skin color and skin texture. After detailed monitoring of the volunteers' body weight, skin color, blood pressure, near and distance vision, comprehension, eye health, as well as ear, nose, throat, mouth, teeth, chest, lungs and reflexes, and comprehensive analysis of blood and urine samples, the results showed that oral intake of natural astaxanthin-rich red algae algal powder did not have any pathogenic effects or toxic side effects on human beings[37] , and other research results also proved that the oral intake of natural astaxanthin-rich red algae algal powder did not have any pathogenic effects or toxic side effects on human beings[38] . The results of other studies also proved that astaxanthin from R. rainbowii is safe [29]. o

 

3.3 Prospects for natural astaxanthin applications

The regulation of chemically synthesized astaxanthin is becoming more and more stringent around the world, and the U.S. Food and Drug Administration (FDA) has banned chemically synthesized astaxanthin from entering the health food market. Natural astaxanthin has a much higher absorption effect and bioefficacy than synthetic astaxanthin at the same concentration, so natural astaxanthin is increasingly favored by people.

A large number of studies have proved that natural astaxanthin has potential physiological regulation effects in the human body, which makes it a promising application in nutrition and medicine, especially in the production of functional health drugs. Based on the strong antioxidant property of astaxanthin and its potential role in human body, it can be inferred that astaxanthin supplementation is expected to be an effective way to regulate body functions and maintain human health.  Aquasearch's red algae products have been approved by the U.S. FDA, allowing them to enter the market as a new dietary ingredient.

 

As the best biological raw material for the production of natural astaxanthin in nature, Rhodococcus rainieri has attracted widespread attention in related fields both at home and abroad, and its cultivation and development technology has been improved day by day, so the application of astaxanthin from Rhodococcus rainieri in nutrition and medicine undoubtedly has a broad prospect for development.

 

References:

[1] Guerin M, Huntley M E, Olaizola M. Haematococcus astaxanthin:applications for human health and nutrition [J]. Trends Biotechnol,2003,21(5):210.

[2] Halliwell B, Gutteridge J M C. Oxygen toxicity, oxygen radicals,transitionmetalsanddisease[J].BiochemJ, 1984,219:1.

[3] Lee S H, Min D B. Effects of quenching mechanism and kinetics of carotenoidsinchlorophyll-sensitizedphoto-oxidationofsoybeanoil[J].JAgric Food Chem, 1990, 38(8):1630.

[4] Miki W. Biochemical functions and activities of animal carotenoids [J].Pure & Appl Chem, 1991, 63(1): 141.

[5] Liu ZY, Shen QG. Bioactivity of astaxanthin and prospects for its development and application[J]. Chinese Marine Drugs, 1997, 63(3): 46.

[6] Naguib Y MA.Antioxidants activities of astaxanthin and related carotenoids [J]. JAgric Food Chem, 2000, 48:1150.

[7] TanakaT, Kawamori T,OhnishiM, et al. Suppression of azomethane-inducedratscoloncarcinogenesisbydietaryadministrationofnaturally occurring xanthophylls astaxanthin and canthaxanthin during the ostinitiationphase J].Carcinogenesis,1995,16:2957.

[8] Chew B P, Park J, Wong M W, et al. A comparison of the anticancer activities of dietary -carotene,canthaxanthin in mice in vivo [J].Anticancer Res, 1999 Anticancer Res, 1999,19:1849.

[9] Jyonouchi H,Gross M, et al. Antitumor activity of astaxanthin and its mode of action [J].Nutr Cancer, 2000, 36:59.

[10] WANG Jufang, WU Zhenqiang, et al. Physiological functions and applications of astaxanthin [J]. Food and Fermentation Industry, 2000, 26(2): 66.

[11] Astorg P, Gradelet S, Berges R, et al. Modulation of aflatoxin B1carcinogenicity, genotoxicity and metabolism in rat liver by dietary carotenoids. evidenceforaprotectiveeffectofCYPT1Ainducers[J].Nutr Cancer, 1997,29(1):60.

[12] Jyonouchi H, Zhang L, Gross M, et al. Immunomodulating action of carotenoids:enhancement of in vivo and in vitro antibody production to T-dependent antigens[J].Nutr Cancer, 1994,21(1):47.

[13] O'Connor, IO'Brien, N. Modulation of UVA light-induced oxidative stressbybeta-carotene,luteinandastaxanthininculturedfibroblast[J]. Dermatol Sci, 1998, 16:226.

[14] Tso M,O M, Lam T T. Method of retarding and ameliorating central nervous system and eye demage [P]. U.S Patent# 5527533, 1996.

[15] Lee S H, Min D B. Carotenoid supplement reduces erythema in human

skin after simulated solar radiation exposure [J]. Proc Soc Exp Biol Med, 2000, 223:170.

[16] Frei B. Cardiovascular disease and nutrient antioxidants: role of low-density lipoprotein oxidation [J].Crit Rev FoodSci Nutr, 1995,35:83.

[17] KrithevskySB. -Carotene,carotenoidsandthepreventionofcoronary heat disease [J].JNutr, 1999, 129: 5.

[18] MurilloE.Effectsofastaxanthin onhighdensitylipoproteininrats[J].Arch Latinoam Nutr, 1992, 42: 409.

[19] BorlonganC.Free radical damage and oxidative stress in Huntington's disease [J]. J FlaMed Assoc, 1996, 83: 335.

[20] De Rijk M. Huisman MV, Büller HR . Dietary antioxidants and Parkinson disease. the Rotterdam Study[J]. Arch Neurol, 1997, 54:762.

[21] Ferrante R. Bogdanov MB. Evidence of increased oxidative damage in bothsporadicandfamilialamyotrophiclateralscerosis [J].JNeurochem,1997, 69: 2064.

[22] Aghdassi,Allard JP.Breath alkanes as a marker of oxidative stress in different clinical condition [J].FreeRadic Biol Med, 2000,28:880.

[23] Aw TY.Molecular and cellular responses to oxidative stress and changes in oxidation-reduction imbalance in the intestine [J].Am J Clin Nutr,1999, 70:557.

[24] GreeneL.Asthma and oxidant stress: nutritional, environmental, and genetic risk factors [J]. JAm Coll Nutr, 1995, 14: 317.

[25] Dekkers J, Roberfroid N. The role of antioxidant vitamins and enzymes in the prevention of exercise-induced muscle damage [J]. Sports Med,1996, 21:213.

[26] KurashigeM. Inhibition of oxidative injury of biological membranes by astaxanthin [J]. Physiol Chem Phys Med NMR, 1990, 22:27.

[27] Bennedsen M, Wang X, Willen R, et al. Treatment of H. pylori infected micewithantioxidantastaxanthinreducesgastricinflammation,b material

load and modulates cytokine release by splenocytes [J]. ImmunolLett,1999, 70:185.

[28] Mera Pharmaceuticals.Haemotococcus pluvials and astaxanthin safety for human health consumption [R]. Technical Report TR, 3005.001. 1999.

[29] Lignell A. Medicament for improvement of duration of muscle function or treatment of muscle disorders or diseases [P].Patent Sweden:991251, 1999.

[30] Jyonouch H, Sun S, Gross M. Astaxanthin, a carotenoid without vitamina activity, augments antibody responses in culturesT-helper cell clones and suboptimal doses of antigen [J].Nutr, 1995, 125(10): 2483.

[31] Bennedsen M, Wang X, Willen R, et al. Treatment of H. pylori infected micewithantioxidantastaxanthihreducesgastricinflammation,bacterial load and modulates cytokine release by splenocytes [J]. ImmunologyLetters, 1999,70(3):185.

[32] Yamashita E. Anti-inflammatory agent [P].Japanese Patent: #07300421[P],1995.

[33] Kistler A, Gallegos G. Metabolism and CYP-inducer properties of astaxanthin in man and primary human hepatocytes [J]. Arch Toxicol,2002, 75:665.

[34] Koyo Mercantile Company Itd. Acute toxicity test for riken vitamin K [P]. K. Appendix 24, in FDA website, Docket Number 95s-0316, Report #45.

[35] Nishikawa Y,MinenakaY, Ichimura M. Physiological and biochemical effectsofcarotenoid(beta-caroteneandastaxanthin)onrat[J].Kushien DaigkuKiyo, 1997, 25:19.

[36] Miki W, Hosoda K, Kondo K, et al. Astaxanthin-containing drink [P].Patent application number 10155459[P]. Japanese Patent: 10155459,1998.

[37] Aquasearch Inc. Heamococcus pluvialis and astaxanthin safety for human consumption [R]. Technical Report TR, 3005.001. 1999.

[38] Savoure N, Briand G,Amory MC , et al. Vitamin A status and metabolism of cutaneous polyamines in the hairless mouse after UV irradiation:action of carotene and astaxanthin [J]. IntJ Vitam Nutr Res, 1995,65: 79.

[39] Fuchs J. Potentials and limitations of the natural antioxidants RRR-alpha-tocopherol, l-ascorbic acid and beta-carotene in cutaneous photoprotection [J]. FreeRadic Biol Med, 1998, 25: 848.