WHAT IS ASTAXANTHIN? WHY IT IS SO POPULAR?
Astaxanthin, a naturally occurring carotenoid pigment, is a powerful
biological antioxidant. Astaxanthin exhibits strong free radical scavenging
activity and protects against lipid peroxidation and oxidative damage of
LDL-cholesterol, cell membranes, cells, and tissues. Consequently,
astaxanthin has important applications in the Nutraceuticals, Cosmetics,
Food and Feed industries.
For last 2 decades. more than 300 articles and patents have been
published regarding astaxanthin. Astaxanthin is a small Lipid soluble
molecule that can cross the blood brain and retina barriers easily. Because
of its antioxidant activities and blood brain/retina permeability, astaxanthin
was found to have benefits on various health conditions including
inflammation, diabetics, certain cardiovascular, vision and CNS conditions.
WHERE CAN WE FIND ASTAXANTHIN?
Astaxanthin is a naturally occurring molecule and the most abundant
carotenoid in the marine world. Astaxanthin can be found in many of
seafood such as salmon, trout, seabream and shrimps. Astaxanthin cannot
be synthesized by animals and must be provided in the diet. The main or
richest commercial source for natural astaxanthin is Haematococcus
pluvialis microalgae. Most manufacturers have the advanced biotechnology
process to cultivate large amount of enriched algae cells without the
disadvantages of open pond algae systems such as problems associated
with contaminations and salinity. In addition, the Haematococcus
microalgae is cultivated in ideal environmental conditions using the natural
sun light as the energy source all year round.
WHAT RESEARCHES HAVE BEEN DONE?
ASTAXANTHIN IS A POTENT ANTIOXIDANT, IN-VITRO STUDIES.
When the conjugated keto-carotenoids, astaxanthin was added to rat liver
microsomes undergoing radical-initiated lipid peroxidation under air,
astaxanthin is as effective as alpha-tocopherol in inhibiting this process.
This contrasts with the effect of beta-carotene, which is a much less potent
antioxidant when added in this system, without the addition of other
antioxidants. [2]
In another study, researchers demonstrated the inhibitory effect of
beta-carotene and astaxanthin on photosensitized oxidation of
phospholipid bilayers. They exposed large unilamellar liposomes comprising
of egg yolk phosphatidylcholine (PC) was exposed to photoirradiation in
the presence of methylene blue (water-soluble photosensitizer) or
12-(1-pyrene)dodecanoic acid (P-12, lipid-soluble photosensitizer).
Without sensitizers, astaxanthin decreased much slower than
beta-carotene and other hydrocarbon carotenoids (lycopene,
alpha-carotene). Astaxanthin lasted longer than beta-carotene even in the
presence of methylene blue or P-12. Decrease of astaxanthin was also
much slower than that of beta-carotene when egg yolk PC was replaced by
dimyristoyl PC. However, inhibitory effect of astaxanthin was lower than
beta-carotene in the case of P-12 sensitized photooxidation. [4]
Another early study showed that astaxanthin (10 nM) was able to protect
against UVA (intensity of 5.6 mW/cm2 for 4 h)-induced oxidative stress in
rat kidney fibroblasts (NRK). [7]
ASTAXANTHIN IS AN IMMUNOMODULATOR, IN ANIMAL STUDIES.
Studies have shown that astaxanthin enhances in vitro antibody
production to sheep red blood cells in normal B6 mice. [3]
When the actions of carotenoids were tested in normal strains of mice,
researchers found that astaxanthin enhanced in vitro antibody production
to T cell-dependent antigen. And, astaxanthin exerted maximum enhancing
actions when it was present at the initial period of antigen priming. [3]
ASTAXANTHIN MAY OFFER BENEFIT OF LIVER PROTECTION
Astaxanthin protects liver damage induced by CCl4 by inhibiting lipid
peroxidation and stimulating the cellular antioxidant system.
Researchers studied if astaxanthin could have protective effects in the
CCl4-treated rat liver by activating the antioxidant system. They found that
astaxanthin could subside the increased glutamate-oxalacetate
transaminase (GOT) and glutamate-pyruvate transaminase (GTP) activities
in response to carbon tetrachloride (CCl4), while causing an increase in
glutathione (GSH) levels and superoxide dismutase (SOD) activities in the
CCl4-treated rat liver. [9]
ASTAXANTHIN MAY BENEFIT RATS WITH DIABETES
Oxidative stress induced by hyperglycemia possibly causes the dysfunction
of pancreatic beta-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. Researchers have examined whether
astaxanthin can elicit beneficial effects on the progressive destruction of
pancreatic beta-cells in db/db mice--a well-known obese model of type 2
diabetes. They 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 beta-cell histology. They found that 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 decreased after
treatment with astaxanthin. [10]
ASTAXANTHIN MAY HAVE BENEFITS ON CARDIAC PROTECTION
A study of mice has shown that astaxanthin attenuated exercise-induced
damage in mouse skeletal muscle and heart, including an associated
neutrophil infiltration that induces further damage. In the study, the
researchers required the mice to perform vigorous exercise and they found
the protection of astaxanthin on the cardiac muscle. [11]
ASTAXANTHIN MAY INHBITS LDL OXIDATION AND LOWER THE RISK OF
ATHEROSLEROSIS.
A study has demonstrated that astaxanthin significantly prolonged the LDL
oxidation lag time (31.5, 45.4, 65.0 min) compared with the control (19.9
min) in a dose-proportionality manner. In the same study, the researchers
dosed 24 volunteers with astaxanthin at doses of 1.8, 3.6,14.4 and 21.6
mg per day for 14 days. They also found the a longer LDL oxidation lag
time. [12]
ASTAXANTHIN MAY BENEFIT MALE INFERTILITY
A double blind, randomized trial of 30 men suffered from infertility showed
that astaxanthin increased the sperm linear velocity and decreased
reactive oxygen species and Inhibin B. [13]
ASTAXANTHIN HAS ANTI-CANCER ACTIVITIES IN ANIMAL STUDIES.
In a study, mice were given 250 p.p.m. OH-BBN in drinking water for 20
weeks then, water containing astaxanthin. Researches found astaxanthin
administration after OH-BBN exposure significantly reduced the incidence of
bladder cancer (transitional cell carcinoma). Treatment with astaxanthin
also decreased the number/nucleus of silver-stained nucleolar organizer
region proteins, an index of cell proliferation. Astaxanthin may suppress cell
proliferation. [5]
In another study, researchers induced oral carcinogenesis in male F344
rats with 4-nitroquinoline 1-oxide (4-NQO). Then, they fed the animals with
100 ppm astaxanthin during the initiation or post-initiation phase of
4-NQO-induced oral carcinogenesis. They found the incidences of
preneoplastic lesions and neoplasms in the oral cavity of rats fed with
astaxanthin were significantly smaller than those without astaxanthin
treatment. In particular, no oral neoplasms developed in rats fed with
astaxanthin during the 4-NQO exposure. [6]
One early study demonstrated the anticancer activities of astaxanthin
against the growth of mammary tumors were studied in female
eight-wk-old BALB/c mice. Researchers fed the mice with a synthetic diet
containing 0, 0.1 or 0.4% astaxanthin. After 3 weeks, they inoculated all
mice with 1 x 10(6) WAZ-2T tumor cells into the mammary fat pad. They
killed all animals on 45 d after inoculation with the tumor cells and they
found that astaxanthin decreased mammary tumor volume in a
dose-dependent fashion. [8]
Astaxanthin also demonstrated 98% inhibition of 5alpha-reductase at 300
microg/mL in vitro. Inhibition of 5alpha-reductase has been reported to
decrease the symptoms of benign prostate hyperplasia (BPH) and possibly
inhibit or help treat prostate cancer. [14]
ASTAXANTHIN BENEFITS RAT SUFFERED FROM ULCERATION
Researchers isolated astaxanthin from Xanthophyllomyces dendrorhous.
And then, they supplemented rats suffered from naproxen-induced gastric
antral ulceration with astaxanthin. 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. They
also found that pretreatment of astaxanthin resulted in a significant
increase in the activities of radical scavenging enzymes such as superoxide
dismutase, catalase, and glutathione peroxidase. The acute gastric
mucosal lesion induced by naproxen nearly disappeared after the
pretreatment of astaxanthin. [15]
ASTAXANTHIN MAY BENEFIT ANIMALS SUFFERED FROM HIGH BLOOD
PRESSURE
A study of spontaneously hypertensive rats has shown the
antihypertensive effects of astaxanthin. Oral administration of astaxanthin
for 14 days induced a significant reduction in the arterial blood pressure.
The long-term administration of astaxanthin (50 mg/kg) for 5 weeks in
stroke prone rats induced a significant reduction in the blood pressure. [16]
THIS ARTICLE IS FOR YOUR INFORMATION ONLY. MOST OF THE STUDIES HAVE
BEEN DONE IN ANIMALS, IT IS NOT SURE IF THE DATA CAN BE APPLIED TO HUMAN
BEING. IF YOU HAVE ANY QUESTION, YOU SHOULD CONSULT WITH YOUR DOCTOR.
ALL RIGHT RESERVED 2008 zhion.
REFERENCE [1] Lorenz RT and Cysewski GR Commercial potential for Haematococcus microalgae
as a natural source of astaxanthin. Trends Biotechnol. 2000 Apr;18(4):160-7. [2] Palozza P and
Krinsky NI Astaxanthin and canthaxanthin are potent antioxidants in a membrane model. Arch
Biochem Biophys. 1992 Sep;297(2):291-5. [3] Jyonouchi H, Zhang L Tomita Y Studies of
immunomodulating actions of carotenoids. II. Astaxanthin enhances in vitro antibody production to
T-dependent antigens without facilitating polyclonal B-cell activation. Nutr Cancer.
1993;19(3):269-80. [4] Oshima S et al, Inhibitory effect of beta-carotene and astaxanthin on
photosensitized oxidation of phospholipid bilayers. J Nutr Sci Vitaminol (Tokyo). 1993
Dec;39(6):607-15. [5] Tanaka T et al, Chemoprevention of mouse urinary bladder carcinogenesis by
the naturally occurring carotenoid astaxanthin. Carcinogenesis. 1994 Jan;15(1):15-9. [6] Tanaka T et
al, Chemoprevention of rat oral carcinogenesis by naturally occurring xanthophylls, astaxanthin and
canthaxanthin. Cancer Res. 1995 Sep 15;55(18):4059-64. [7] O'Connor I and O'Brien N Modulation
of UVA light-induced oxidative stress by beta-carotene, lutein and astaxanthin in cultured fibroblasts.
J Dermatol Sci. 1998 Mar;16(3):226-30. [8] Chew BP et al, A comparison of the anticancer activities
of dietary beta-carotene, canthaxanthin and astaxanthin in mice in vivo. Anticancer Res. 1999
May-Jun;19(3A):1849-53. [9] Kang JO et al, Effect of astaxanthin on the hepatotoxicity, lipid
peroxidation and antioxidative enzymes in the liver of CCl4-treated rats. Methods Find Exp Clin
Pharmacol. 2001 Mar;23(2):79-84. [10] Uchiyama K et al, Astaxanthin protects beta-cells against
glucose toxicity in diabetic db/db mice. Redox Rep. 2002;7(5):290-3. [11] Aoi W et al, Astaxanthin
limits exercise-induced skeletal and cardiac muscle damage in mice. Antioxid Redox Signal. 2003
Feb;5(1):139-44. [12] Iwamoto T et al, Inhibition of low-density lipoprotein oxidation by astaxanthin. J
Atheroscler Thromb. 2000;7(4):216-22. [13] Comhaire FH et al, Combined conventional/antioxidant
"Astaxanthin" treatment for male infertility: a double blind, randomized trial. Asian J Androl. 2005
Sep;7(3):257-62. [14] Anderson ML A preliminary investigation of the enzymatic inhibition of
5alpha-reduction and growth of prostatic carcinoma cell line LNCap-FGC by natural astaxanthin and
Saw Palmetto lipid extract in vitro. J Herb Pharmacother. 2005;5(1):17-26. [15] Kim JH et al,
Protective effect of astaxanthin on naproxen-induced gastric antral ulceration in rats. Eur J
Pharmacol. 2005 May 2;514(1):53-9. Epub 2005 Apr 20. [16] Hussein G et al, Antihypertensive and
neuroprotective effects of astaxanthin in experimental animals. Biol Pharm Bull. 2005
Jan;28(1):47-52.

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