Functional properties and research progress of astaxanthin

haematococcus pluvialis extract Astaxanthin (Astaxanthin), also known as astaxanthin, now astaxanthin 10 mg, is a carotenoid oxygen-containing derivative contained in shrimp and crab shells, oysters, salmon and some algae, which can effectively suppress reactive oxygen species and has high nutritional and health care value.

As early as the 1930s, researchers isolated astaxanthin from the shells of shrimp and crabs, but its physiological functions did not attract widespread attention until the 1980s. Animal and clinical experiments have shown that pure astaxanthin supplement has strong antioxidant, anti-cancer and anti-cancer, enhance immunity, prevent cardiovascular diseases and other health functions, and has broad application prospects.

Physicochemical properties of purity astaxanthin

Crystal ivarssons astaxanthin is pink, melting point is 215 ℃~216 ℃, insoluble in water, fat soluble, soluble in chloroform, acetone, benzene and other astaxin 120 organic solvents. The conjugated double bond chains in the molecular structure of astaxanthin and the unsaturated ketone group and hydroxyl group at the end of purity products astaxanthin have relatively active electronic effects, which can attract unpaired electrons of free radicals or provide electrons to free radicals, thereby eliminating free radicals, and have strong antioxidant effects.

The structure also makes it easy to interact with light, heat and oxides, and degrades into astaxanthin after structural change.

It was found that visible light had little effect on sports research astaxanthin , while ultraviolet light had great destructive effect on astaxanthin. Below 70 ℃, temperature has little effect on astaxanthin, and above 70 ℃, astaxanthin begins to be damaged by heat. In the range of pH4~11, the effect of pH on astaxanthin was small, and the degradation of astaxanthin began when pH < 3 or pH > 13. Ca2+, Mg2+, K+, Na+, Zn2+ and other metal ions have no effect on astaxanthin, Fe2+, Fe3+, Cu2+ have obvious destructive effects on astaxanthin, among which Fe3+ has the greatest effect.

Astaxanthin exists mainly in free and esterified forms.

The free astaxanthin is very unstable and easy to be oxidized. Astaxanthin is usually synthesized chemically in the free form. Esterified astaxanthin is stable because there is a hydroxyl group in the end ring structure of astaxanthin, which is easy to form esters with fatty acids. Astaxanthin in the skin and shell of aquatic animals, Rhodococcus vulcanis and red yeast are mainly esterified. Esterified astaxanthin can be divided into astaxanthin monoester and astaxanthin diester according to the different fatty acids it binds. After esterification, the hydrophobicity of astaxanthin was enhanced, and the lipophilicity of double ester was stronger than that of single ester. At the same time, esterified astaxanthin will form complexes with proteins to produce different colors.

Functional properties of astaxanthin

In recent years, as the important physiological functions and huge economic value of astaxanthin have been gradually recognized by people, more and more researches on the functional properties of astaxanthin have been carried out at home and abroad, especially in the aspects of anti-oxidation, anti-cancer and anti-cancer, immune enhancement, anti-hypertension, prevention of cardiovascular diseases, and anti-ultraviolet radiation.

Antioxidant

Astaxanthin is a chain-broken antioxidant with a strong antioxidant effect. The body can produce a small amount of oxygen free radicals during normal life activities such as electron transfer in the respiratory chain and oxidation of other substances in the body, and will produce a large amount of oxygen free radicals when stimulated by chemical reagents and ultraviolet radiation.

These free radicals can cause lipid peroxidation, amino acid oxidation, protein degradation and DNA damage on the biofilm, and can also cause chain reactions of unsaturated fatty acids on the cell membrane, thus affecting the composition of cells. Astaxanthin can not only quench singlet oxygen, directly remove oxygen free radicals, but also block the chain reaction of fatty acids.

It was found that the ability of multiple carotenoids to quench molecular oxygen was ranked as astaxanthin > alpha-carotene > β-carotene > erythroxanthin > zeaxanthin > lutein > bilirubin > biliverdin.

By comparing the effects of lutein, zeaxanthin, lycopene, isozeaxanthin, astaxanthin 5 carotenoids and their derivatives on quenching reactive oxygen species in soybean oil photooxidation, Lee et al. found that the ability to quench reactive oxygen species increased with the increase of conjugated double bonds, and astaxanthin had the strongest quenching performance.

Some researchers also used thiobarbituric acid method to detect the half effective dose ED50 of carotenoids and their derivatives and α-tocopherol (VE) scavenging free radicals by using heme protein containing ferrous ions as the free radical producer and linoleic acid as the receiver (see Table 1). Astaxanthin was also found to have the strongest free radical scavenging ability.

In recent years, continuous studies have proved that the antioxidant effect of astaxanthin is more than one hundred times stronger than α-tocopherol, known as “super VE”. Meanwhile, astaxanthin can effectively prevent the peroxidation of phospholipids and other lipids. In addition, astaxanthin can also increase the activity of antioxidant enzymes and protein expression, and different doses of astaxanthin can significantly increase the protein expression of peroxyhydrogenase and superoxide dismutase in animal cells, and their biological activities are also significantly improved.

Anti-cancer

Through the study on the relationship between dietary carotenoid intake and cancer incidence or mortality, it was found that cancer incidence or mortality was significantly negatively correlated with carotenoid intake [14]. Nishino[15] compared the anticancer activity of various carotenoids and concluded that astaxanthin had the strongest anticancer effect.

Savoure et al. proved that the inhibitory effect of astaxanthin on tumorigenesis lies in the inhibition of tumor proliferation. At present, studies have shown that Cell Gap Junction Communication plays an important regulatory role in the normal proliferation and differentiation of cells and the stability of tissues themselves, and the inhibition or destruction of its function is an important mechanism for promoting carcinogenesis.

The anticancer effect of astaxanthin is closely related to its ability to induce cell gap connection communication. It can strengthen the connection ability between normal cells, isolate cancer cells, reduce the connection between cancer cells, control their growth, and prevent tumor transformation.

A large number of studies at home and abroad have further shown that astaxanthin has a significant inhibitory or preventive effect on a variety of cancers. For example, Tanaka et al have observed that astaxanthin has a preventive effect on oral cancer and bladder cancer through animal experiments. The research results of Gradelet et al. show that astaxanthin has a significant effect on inhibiting liver cancer. Astaxanthin has also been shown to prevent UV radiation-induced DNA damage in human fibroblasts (1BR-3), melanocytes (HEMAc), and intestinal CaCo-2 cells, thereby reducing the incidence of skin cancer.

Immune Enhancement

Jyonouchi et al. ‘s study on the immunomodulatory effects of astaxanthin and carotenoids on mouse lymphocyte tissue culture system in vitro found that astaxanthin has a strong immunomodulatory effect. The results showed that astaxanthin can significantly promote the production of antibody in the response of spleen cells to thymus dependent antigen (TD-Ag), and improve the conclusion of humoral immune response dependent on T-specific antigen.

At the same time, in vitro studies of human blood cells have also found that astaxanthin and carotenoids significantly promote the production of antibodies when stimulated by TD-Ag, and the number of cells secreting IgG and IgM increases, while supplementation of astaxanthin can partially restore the production of antibodies in elderly mice in response to TD-Ag, and help restore the humoral immunity of elderly animals.

Chew et al. ‘s study on the effects of β-carotenoid, astaxanthin and cantharidin on the function of spleen cells in mice showed that β-carotenoid and astaxanthin significantly enhanced the function of spleen lymphocytes in mice, so as to enhance the body’s immunity.

In addition, astaxanthin increased the production of human immunoglobulins and enhanced the ability of mice to release interleukin-1 and tumor necrosis factor more strongly than beta-carotene and keraxanthin. Therefore, astaxanthin has strong activity in inducing cell division and plays an important role in immune regulation.

Anti-hypertension

Hussein et al. [27] studied the antihypertensive effect of astaxanthin on spontaneously hypertensive rats (SHR), and the results showed that continuous feeding of astaxanthin for 14 days could significantly reduce SHR arterial blood pressure. Continuous feeding of astaxanthin (50 mg·kg-1) to stroke-prone SHR for 5 weeks significantly reduced blood pressure and delayed the occurrence of SHR stroke.

Regarding the mechanism of action of the antihypertensive effect of astaxanthin, studies have shown that astaxanthin can regulate hemorrheology, including the sympathetic adrenergic receptor pathway, ensure the normalization of α-adrenergic receptor sensitivity, and weaken the vasoconstriction ability caused by AngⅡ and reactive oxygen species, in order to repair vascular tension and achieve antihypertensive effect.

Harry et al. used Zucker fatty acid rat (ZFR) as a model to carry out experiments, proving that astaxanthin has the ability to reduce the activity of renin-angiotensin system (RAS) and anti-hypertension.

Prevention of cardiovascular diseases

Clinical medical studies have shown that the oxidation of low-density lipoprotein (LDL) is an important cause of arteriosclerosis. The higher the LDL concentration in the human body, and the thinner the blood vessels and the blockage of blood flow caused by platelet deposition, the greater the risk of arteriosclerosis [30].

LDL usually exists in a non-oxidized state, and oxidized low-density lipoprotein (ox-LDL) can transform cells into foam cells and produce fat lines, while the presence of inflammatory vascular wall foam cells will lead to increased oxidation capacity, proliferation of surrounding smooth muscle cells, and narrowing of the artery.

Epidemiological and clinical data suggest that dietary antioxidants protect against cardiovascular disease. This is also an important reason why astaxanthin can effectively prevent atherosclerosis. In addition, astaxanthin can also reduce the infiltration of macrophages in arterial plaque, prevent the formation of atherosclerosis, and play a role in stabilizing plaque.

Murillo et al. found that astaxanthin has the effect of significantly increasing HDL and decreasing LDL in the body. Therefore, astaxanthin has the effect of preventing cardiovascular diseases such as arteriosclerosis, coronary heart disease and ischemic brain injury.

Protection against ultraviolet radiation

Studies have shown that skin and other tissues exposed to strong light, especially ultraviolet light, can cause cell membrane and tissue to produce monatomic oxygen and free radicals, causing oxidative damage to the body.

When the body takes sufficient antioxidants such as carotenoids represented by beta-carotene from food, it can effectively reduce these damages. Carotenoids in nature play an important role in protecting tissues against UV oxidation.

Astaxanthin is more effective than beta-carotene and lutein in preventing UV radiation damage. Astaxanthin, on the other hand, has a special effect on Transglutaminase, which can consume putrescine when the skin is exposed to light to prevent the accumulation of putrescine.

In Japan, the corresponding skin protection test for astaxanthin has been carried out, and the results show that astaxanthin has a significant improvement effect on skin tension, moisture, tone, elasticity, smoothness and other aspects. Therefore, astaxanthin can be used as a potential UV radiation protector, which plays an important role in protecting cell membrane and mitochondrial membrane from oxidative damage, preventing skin photoaging, and maintaining skin health.

Applications in functional foods

A large number of studies at home and abroad have shown that astaxanthin can effectively remove free radicals produced by exercise in muscle cells, strengthen aerobic metabolism, and have significant anti-fatigue and anti-aging effects. Can significantly improve human immunity; It is the only carotenoid that can pass the blood-brain barrier, has the advantage of antioxidant protection for the eyes, and has a variety of important and unique health function properties. It can also be used as a new functional food additive, as a food coloring agent, antioxidant, etc., to improve food quality and enhance the perception of food.

Application in anti-aging functional food

The aging of the organism is mainly caused by a large number of free radicals produced in the chain oxidation reaction in the mitochondria, if not removed in time, it will lead to oxidative damage of the mitochondria and accelerate the aging of the organism cells. Astaxanthin has strong antioxidant activity and can efficiently remove oxygen free radicals, and its efficiency is more than 100 times that of VE.

Astaxanthin not only maintains strong antioxidant capacity, but also slows age-related functional decline and helps fight aging. Therefore, adding astaxanthin to functional foods will help prevent a series of diseases caused by organ aging and improve people’s health.

At present, foreign countries have carried out astaxanthin anti-aging functional food research and development, such as the United States Cyanotech company launched Derma Astin (Dema) natural astaxanthin capsules.

In addition, astaxanthin is also combined with beauty factors to produce anti-aging beauty food, which is used with cosmetics to enhance its anti-aging effect. According to the survey, 90% of international first-line cosmetics brands have launched astaxanthin containing beauty food, such as Shiseido’s “Living face G+C”.

Application in foods that enhance immune function

Astaxanthin can significantly promote the ability of spleen cells to produce antibodies in the presence of antigens, and enhance T cells to stimulate the production of immunoglobulin in human blood cells.

Astaxanthin can also enhance specific humoral immune response at the initial stage of antigen invasion. Astaxanthin has the best activity to induce cell division, can improve the production of human immunoglobulin, and has an important role in immune regulation. Goswami et al. found that astaxanthin can play a huge role as an immunomodulator.

Therefore, the application of astaxanthin to enhance the body’s immune health food is an important direction to develop astaxanthin. Japan has launched a variety of astaxanthin products, such as Fancl brand “astaxanthin 30 days” and other nutritional products to enhance immune function.

Japan’s Suntory company uses astaxanthin and other functional extracts to produce a variety of new products with higher functional effects. For example, astaxanthin is combined with other carotenoids to strengthen its immunity.

Application in eye care functional food

The main diseases that cause visual damage and even blindness are age-related macular degeneration (AMD) and senile cataracts, both of which are related to the photooxidation process inside the eye. The human retina contains more polyunsaturated fatty acids and high concentrations of oxygen than any other tissue. Singlet oxygen and oxygen free radicals produced by photooxidation will cause peroxidation damage to the retina.

For humans and other animals, dietary carotenoids are necessary to protect eye health by quenching these damaging reactive oxygen species and helping the retina resist oxidative damage. Studies have shown that astaxanthin can effectively prevent retinal oxidation and photoreceptor cell damage through the blood-brain barrier, indicating that astaxanthin has a good effect in preventing and treating “age-related macular degeneration” and improving retinal function.

Therefore, the application of astaxanthin in functional food to protect eyesight and maintain eye health is a hot topic at home and abroad. For example, Japan combines astaxanthin with blueberry extract to strengthen the protective effect on vision; Natural astaxanthin capsules and other products have been developed in the United States to protect vision and improve age-related macular degeneration.

Application in functional food additives

In the food industry, astaxanthin can not only be used as an immune enhancer, anti-aging agent and other functional ingredients added to food, but also can effectively play the role of preservation, color, taste and quality preservation, as a food coloring agent, antioxidant and so on. It is used to keep the original nutritional content of food from being damaged or to improve sensory properties and enhance the appeal of food to consumers.

Astaxanthin is a fat soluble pigment, which is gorgeous red, natural and realistic, with strong pigmentation ability, strong coloring power, safe and non-toxic, less dosage, no odor and good taste. It can be used for coloring of many health care products and coloring of tablet icing and capsule. It can also be directly used in food, such as edible oil, margarine, ice cream, candy, pastries, noodles, seasonings, especially the food containing more fat, which has good coloring effect and significant quality preservation effect. It can also be used for beverage coloring, especially for juices containing VC.

In Japan, the use of astaxanthin as a functional food additive has been relatively common, and the red oil containing astaxanthin is widely used in the pickling of vegetables, seaweed and fruits, and has also been reported in drinks, noodles, seasoning coloring.

A large number of studies at home and abroad have proved that astaxanthin has potential special health care effects in human body, which makes astaxanthin more and more favored by people. At present, the main sources of astaxanthin include chemical synthesis and natural extraction.

Chemical synthesis of astaxanthin and natural astaxanthin have certain differences in structure, properties, application and safety, and its stability, antioxidant, coloration and other important properties are significantly lower than natural astaxanthin. The efficient extraction and preparation of natural astaxanthin will be the focus of the development of astaxanthin in the future, especially the industrial fermentation of astaxanthin by yeast, algae and other microorganisms with a short production cycle. The prospects are promising.

Therefore, the further development and application of astaxanthin will be greatly facilitated by screening high-yield strains, improving fermentation technology and introducing gene improvement technology in time to increase yield and reduce cost.

The application of astaxanthin in the field of functional food, foreign countries mainly position its effect in strengthening immunity, anti-cancer, anti-aging, protecting retina, anti-inflammation, preventing oxidative damage of low density lipoprotein cholesterol (LDL-C) in the blood, etc., research and development and production of many health nutrition foods and dietary supplements containing astaxanthin.

But our country is still in the initial stage. With the deepening of the research on the functional properties of astaxanthin, the improvement of production technology, and the combination of China’s traditional “medicine and food” concept, using astaxanthin to develop functional nutritional food will have excellent application prospects and far-reaching development significance.

References: Tao Shuying, Ming Jian, Research progress on the functional properties of astaxanthin and its application in Functional Foods.

Andy