jueves, septiembre 25, 2008


Astragalus ( Astragalus membranaceus) has been used in Traditional Chinese Medicine for thousands of years, often in combination with other herbs, to strengthen the body against disease. It contains antioxidants, which protect cells against damage caused by free radicals, byproducts of cellular energy. Astragalus is used to protect and support the immune system, for preventing colds and upper respiratory infections, to lower blood pressure, to treat diabetes, and to protect the liver.
Astragalus has antibacterial, anti-inflammatory, and diuretic (helps eliminate fluid from the body) properties. It is sometimes used topically for wounds. In addition, studies have shown that astragalus has antiviral properties and stimulates the immune system, suggesting that it is indeed effective at preventing colds.
In the United States, researchers have investigated astragalus as a possible treatment for people whose immune systems have been compromised by chemotherapy or radiation. In these studies, astragalus supplements have been shown to speed recovery and extend life expectancy. Research on using astragalus for people with AIDS has produced inconclusive results.
Recent research in China indicates that astragalus may offer antioxidant benefits to people with severe forms of heart disease, relieving symptoms and improving heart function. At low to moderate doses, astragalus has few side effects, although it does interact with a number of other herbs and prescription medications.
Plant Description

Astragalus is a perennial plant, about 16 - 36 inches tall, that is native to the northern and eastern parts of China as well as Mongolia and Korea. It has hairy stems with leaves made up of 12 - 18 pairs of leaflets. The root is the medicinal part, and is usually harvested from 4-year-old plants.
Parts Used

The dried root is used medicinally.
Medicinal Uses and Indications

Traditional uses include the treatment of the following:
Colds and influenza
Persistent infection
Multiple allergies
Chronic fatigue
Fatigue or lack of appetite associated with chemotherapy
Heart disease
Kidney disease
Stomach ulcers
It is also used to treat general digestive disturbances, including diarrhea, gas, and bloating.
Available Forms

Astragalus root may be available in a variety of forms:
Tincture (liquid alcohol extract)
Injectable forms for use in hospital or clinical settings
Ointments for the skin
How to Take It

Astragalus may be given to children to support the immune system but should not be used if the child has a fever because, according to Traditional Chinese Medicine, it may make the fever last longer or grow stronger. The dose should be determined by adjusting the recommended adult dose to account for the child's weight. Most herbal dosages for adults are calculated on the basis of a 150 lb (70 kg) adult. Therefore, if the child weighs 50 lb (20 - 25 kg), the appropriate dose of astragalus would be 1/3 of the adult dosage. However, because strengths and concentrations will vary with different preparations, dosages should be determined on an individual basis. Any long-term dosage should be determined by your doctor.
Doses from 1 - 25 g per day are sometimes used. Higher doses may suppress the immune system. Recommended doses are as follows:
Decoction (strong boiled tea): 3 - 6 g of dried root per 12 oz water, three times per day
Fluid extract (1:1) in 25% ethanol: 2 - 4 mL three times a day
Powdered root: 500 - 1,000 mg three or four times per day
Powdered extract (solid): 100 to 150 mg of a product standardized to 0.5% 4-hydroxy-3-methoxy isoflavone. Note : this chemical is used only as a manufacturing marker, not as a guarantee of potency or effectiveness.
Ointment: 10% astragalus applied to surface of wound. Do not apply to open wound without your doctor's supervision.
Tincture (1:5) in 30% ethanol: 3 - 5 mL three times a day

At recommended doses, astragalus has no serious side effects and can generally be used safely. It does interact with other herbs and medications (see " Possible Interactions ")
If you are pregnant or breastfeeding, you should talk to your doctor before taking any medication, including herbs.
Possible Interactions

If you are being treated with any of the following medications, you should not use astragalus without first talking to your health care provider:
Antiviral medications -- Astragalus may increase the effects of some antiviral medications such as acyclovir and interferon.
Drugs that suppress the immune system -- Astragalus may counteract the immune-suppressing effects of cyclophosphamide, a medication used to reduce the chances of rejection in transplant recipients, as well as corticosteroids.
Diabetes medications -- Astragalus may lower blood sugar, making the effects of diabetes drugs stronger.
High blood pressure medication -- Astragalus may lower blood pressure, making the effects of these drugs stronger.
Diuretics (water pills) -- Astragalus is a diuretic and may make the effects of other diuretics stronger.
Anti-coagulants(blood thinners) -- Astragalus may make the effects of these drugs stronger, increasing the risk of bleeding and stroke.
Supporting Research

Brush J, Mendenhall E, Guggenheim A, Chan T, Connelly E, Soumyanath A, Buresh R, Barrett R, Zwickey H. The effect of Echinacea purpurea, Astragalus membranaceus and Glycyrrhiza glabra on CD69 expression and immune cell activation in humans. Phytother Res . 2006 Aug;20(8):687-95.
Chen LX, Liao JZ, Guo WQ. Effects of Astragalus membranaceus on left ventricular function and oxygen free radical in acute myocardial infarction patients and mechanism of its cardiotonic action [in Chinese]. Chung Kuo Chung Hsi I Chieh Ho Tsa Chih. 1995;15(3):141-143.
Chevallier A. The Encyclopedia of Medicinal Plants. New York, NY: DK Publishing; 1996.
Chu DT, Wong WL, Mavligit GM. Immunotherapy with Chinese medicinal herbs. I. Immune restoration of local xenogeneic graft-versus-host reaction in cancer patients by fractionated Astragalus membranaceus in vitro. J Clin Lab Immunol . 1988a;25(3):119-123.
Chu DT, Wong WL, Mavligit GM. Immunotherapy with Chinese medicinal herbs. II. Reversal of cyclophosphamide-induced immune suppression by administration of fractionated Astragalus membranaceus in vivo. J Clin Lab Immunol . 1988b;25(3):125-129.
Huang KC. The Pharmacology of Chinese Herbs . 2nd ed. New York, NY: CRC Press; 1999.
Khoo KS, Ang PT. Extract of Astragalus membranaceus and Ligustrum lucidum does not prevent cyclophosphamide-induced myelosuppression. Singapore Med J . 1995;36:387-390.
Kurashige A, Akuzawa Y, Endo F. Effects of astragali radix extract on carcinogenesis, cytokine production, and cytotoxicity in mice treated with a carcinogen, N-butyl-N¢-butanolnitrosoamine. Cancer Invest . 1999;17(1):30-35.
Li SQ, Yuan RX, Gao H. Clinical observation on the treatment of ischemic heart disease with Astragalus membranaceus [in Chinese]. Chung Kuo Chung Hsi I Chieh Ho Tsa Chih . 1995;15(2):77-80.
Li XY. Immunomodulating Chinese herbal medicines. Mem Inst Oswaldo Cruz . 1991;86(suppl 2):159-164.
Ma J, Peng A, Lin S. Mechanisms of the therapeutic effect of Astragalus membranaceus on sodium and water retention in experimental heart failure. Chin Med J (Engl). 1998;111(1):17-23.
McGuffin M, Hobbs C, Upton R, eds. American Herbal Products Association's Botanical Safety Handbook . Boca Raton, Fla: CRC Press; 1997.
Miller L, Murray W, eds. Herbal Medicinals: A Clinician's Guide. New York, NY: Pharmaceutical Products Press; 1998.
Peng T, Yang Y, Riesemann H, Kandolf R. The inhibitory effect of Astragalus membranaceus on coxsackie B-3 virus RNA replication. Chin Med Sci J. 1995;10(3):146-150.
Tan BK, Vanitha J. Immunomodulatory and antimicrobial effects of some traditional chinese medicinal herbs: a review. Curr Med Chem . 2004 Jun;11(11):1423-30.
Upton R. American Herbal Pharmacopoeia and Therapeutic Compendium -- Astragalus Root . Santa Cruz, Calif: American Herbal Pharmacopoeia; 1999.
Wagner H, Bauer R, Xiao P, Chen J, Offerman F. Chinese drug monographs and analysis -- Radix Astragali (Huang Qi). Verlag Fur Ganzheitliche Medizin . 1996;1(8).
Wang LX, Han ZW. The effect of Astragalus polysaccharide on endotoxin-induced toxicity in mice [in Chinese]. Yao Hsueh Hsueh Pao . 1992;27(1):5-9.
White L, Mavor S. Kids, Herbs, Health . Loveland, Colo: Interweave Press; 1998: 22, 25.
Wu Y, Ou-Yang JP, Wu K, Wang Y, Zhou YF, Wen CY. Hypoglycemic effect of Astragalus polysaccharide and its effect on PTP1B. Acta Pharmacol Sin. 2005 Mar;26(3):345-52.
Yu DH, Bao YM, Wei CL, An LJ. Studies of chemical constituents and their antioxidant activities from Astragalus mongholicus Bunge. Biomed Environ Sci. 2005 Oct;18(5):297-301.
Zhang WD, Zhang C, Wang XH, Gao PJ, Zhu DL, Chen H, Liu RH, Li HL. Astragaloside IV dilates aortic vessels from normal and spontaneously hypertensive rats through endothelium-dependent and endothelium-independent ways. Planta Med . 2006 Jun;72(7):621-6.
Review Date: 1/7/2007
Reviewed By: Steven D. Ehrlich, N.M.D., private practice specializing in complementary and alternative medicine, Phoenix, AZ. Review provided by VeriMed Healthcare Network.

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