Astragalus root (astragalus membranaceus) is a popular herbal tonic commonly used in Chinese medicine. Historically, astragalus has been used in traditional Chinese medicine, usually in combination with other herbs, to support and enhance the immune system. While there are multiple species of astragalus, most astragalus supplements contain Astragalus membranaceus.
Astragalus is used to strengthen the immune system against colds or flu, high blood pressure, hyperthyroidism, diabetes, insomnia, genital herpes, hepatitis, AIDS and chemotherapy side effects.
Astragalus is classified as an adaptogen, an herb that increases the body’s endurance and resistance to a wide array of physical, chemical, and biological stressors. Adaptogens have the unique ability to normalize body functions and balance body systems. In TCM (Traditional Chinese Medicine), astragalus is often combined with other tonic herbs, such as cordyceps, ginseng or ashwagandha, to keep the immune system humming during periods of high stress. Astragalus increases the effectiveness of other herbs when used in combinations.
Astragalus stimulated NK-cell activity of human peripheral blood lymphocytes and restored steroid inhibited NK-cell activity. Oral doses of the whole root or root extracts have been shown to increase phagocytic activity, enhance production of interferon and activate natural killer cell activity. In tests at the Hiroshima School of Medicine in Japan, it was shown to directly increase B-lymphocyte and T-lymphocyte levels, interleukin and antibody production. In a study in the Journal of Ehtnopharmacolory, published in 2010, large carbohydrate molecules extracted from astragalus stimulated the function of T lymphocytes in the laboratory. Astragalus increases white blood cell production of the body’s own anti-viral compounds alpha-and gamma-interferon, which generally protect against viral invasion. In addition to boosting immunity, Astragalus has antibacterial, adaptogenic, anti-inflammatory, and anti-viral effects. Astragalus helps the body resist virus infections, particularly in the lungs, by increasing production of interferon, an immune factor that inhibits viral growth. Has been shown to inhibit the replication of coxsackie B-3 virus, shown to a causative factor in myocarditis.
Researchers at The University of Texas MD Anderson Cancer Center found that astragalus extract boosted the cell-destroying ability, or cytotoxicity, of the conventional immune system drug interleukin-2 by helping cells of the immune system. Researchers from the University of Texas, Houston, have reported that cancer patients receiving Astragalus have twice the survival rate of those only receiving placebos. Improvement in quality of life was reported following use of an injectable form of astragalus with vinorelbine and cisplatin in patients with advanced non-small cell lung cancer. According to clinical trials from the University of California, Berkeley, Astragalus was shownto increase chemotherapy efficacy and reduce toxicity when combined with platinum-based chemotherapy to improve survival and tumor response for systemic treatments for advanced non–small-cell lung cancer. Data from clinical trials are suggestive that astragalus alone and in combination with other herbs may help with the toxic effects of cancer chemotherapy. In a study done with 115 patients on chemotherapy, over 80% showed higher white blood cell counts when taking Astragalus.
Extracts of astragalus have been shown to alleviate liver injury and protect hepatic cells from pathological changes. A study in the August 2008 issue of Basic and Clinical Toxicology and Pharmacology, reports that astragalus root is also effective in protecting the liver. According to a article, elevated serum levels of glutamate pyruvate transaminase returned to normal and symptoms associated with the disease subsided within one to two months of treatment with an unspecified astragalus preparation. Experiments also show astragalus to be liver cell protective in laboratory induced hepatitis by preventing liver glycogen reduction caused by carbon tetrachloride exposure.
Astragalus has protective and strengthening effects on the heart. According to The American Journal of Chinese Medicine, astragalus demonstrated cardioprotective effects, significantly improving cardiac function and increasing the survival rate from heart failure. Another clinical research showed improvement in breathing and exercise capacity, along with less chest tightness in patients with congestive heart failure. The effect of Astragalus membranaceus on left ventricular function and oxygen free radicals was evaluated in 43 cardiac patients. The herb demonstrated a strengthening of left ventricular function and an effect of anti-oxygen free radicals for a cardiotonic action. Scientific data shows that Asrtagalus has blood-thinning properties, thus preventing the clogging of the coronary arteries.
The appropriate dose of astragalus depends on several factors such as the user’s age, health, and several other conditions. For adults, 250 to 500 mg standardized extract three to four times daily. Powdered Astragalus root; 500 mg to 1000 mg in capsules three times daily. In tincture form; 30–60 drops of astragalus can be taken four times per day. Injections should only be given under the supervision of a healthcare professional.
Astragalus Side Effects
The body can develop a tolerance to immune stimulating herbs such as Astragalus if it is taken for long periods. Astragalus may interact with medications that suppress the immune system, such as the drug cyclophosphamide taken by cancer patients and similar drugs taken by organ transplant recipients. Astragalus may interfere with the actions of diuretics, phenobarbital, beta-blockers, and anticoagulants. Pregnant women should consult their doctors before taking astragalus or giving it to children.