Astragalus - Medicinal Uses, Interactions, Side Effects, Dosage

Astragalus(Astragalus membranaceous)rating:astragalus increases serum IgM, IgE, and cAMP;
The astragalus species that is obtained from China isenhances left ventricular function and cardiac output
A. membranaceous, also known as Mongolian milkin patients with angina pectoris; improves hemorrhagic
vetch, or by its Chinese name, huang qi. It is quiteindices in patients with systemic lupus erythematosus;
different from other species of Astragalus, known asincreases survival in lung cancer when combined with
locoweeds, which contain large amounts of seleniumconventional therapy; improves leukopenia;
and other potential toxins, and from the Middleim­proves liver function in chronic viral hepatitis;
Eastern plant, A. gummifer, which is the source ofand so on
gum tragacanth.However, none of these reports are evaluable, and
Uses and Benefits:the testing applied as well as the observations made
In Chinese traditional medicine, the root of A.by investigators do not conform to standard
membranaceous is a popular and potent tonic usedmethods used in Western medicine. In general, these
for numerous specific indications, especially infections.studies were uncontrolled or unblinded, and no reliable
It is thought to improve depressed immunity, andclinical studies in support of these indications have
therefore it has been recommended for thebeen reported in the English-language peer-reviewed
treatment of AIDS and other viral diseases, and asliterature. Thus, there is only very equivocal evidence
an adjuvant in cancer therapy. The herb is nowto support the numerous clinical claims that are made
advocated for a wide variety of illnesses, includingfor astragalus, particularly as an immune system
the common cold, influenza, respiratory insufficiency,restorative or as an immune modulator for use in the
diabetes, hypertension, liver disease, cardiac ischemia,treatment of cancer.
heart failure, vascular insufficiency, and nephritis.Adverse Effects:
Pharmacology:Herbalists regard astragalus as very safe based on its
The important constituents include numerousreputation as a valued traditional medication. It is
triterpene saponins, known as astragalosides andunlikely that astragalus has any serious toxicity,
related compounds such as soyasaponins. A numberalthough there is a lack of reliable clinical data.
of polysaccharides, such as astragalans I-IV, haveSide Effects and Interactions:
been isolated. Important flavonoids include quercetinThere are no recognized drug interactions.
and kaempferol; among its many other constituentsCautions:
are isoflavonoids, sugars, amino acids, and linoleic acid.Astragalus can be obtained in combination mixtures, in
It is unclear which of the numerous constituents arewhich other agents may have a potential for toxicity.
of therapeutic value. However, the polysaccharidesPreparations & Doses:
and saponins have been suggested to be the majorSliced astragalus root is often used to make teas,
agents.soups, or decoctions. The usual daily dose varies
The polysaccharide fractions of the root extractfrom 2 to 30 g or more of the dried root; although
have been reported to have in vitro effects thatlarge doses appear to be safe, 8-15 g/day seems to
suggest an immune-enhancing capability. There isbe more reasonable. Some products contain
some evidence that astragalus can potentiate thestandardized extracts, packaged in unit doses.
effect of interferon against viruses and can increaseCapsules containing 150-500 mg are commonly
IgA and IgM in nasal secretions in humans. Animalmarketed, to be taken as often as 8 or 9 times a
experiments have shown that extracts of astragalusday; tinctures and fluid extracts are also available. In
can restore the immune properties of cancer patienttraditional Chinese medicine, it is usual to take
T-cells in vitro. A more recent rat study does notastragalus in combination with other herbs.
confirm earlier reports that astragalus extract canSummary Evaluation
prevent myelosuppression by cyclophosphamide.A membranaceous is a popular Chinese herb that has
Clinical Trials:long been used as a tonic. Increasing claims suggest
Almost all of the clinical studies on astragalus are inthat it is of value as an immune restorative to fight
Chinese medical books or journals and are thereforeviral diseases, as a treatment for Lancer, and as a
not readily evaluated. In an open study on 1000cure for other disorders. However, the scientific
subjects, 8 it is alleged that a 2-month prophylacticevidence of clinical effectiveness is of unclear quality,
course of the herb in a dosage of 8 g/day inand has not been validated outside the Asian
combination with interferon was correlated with aliterature. Thus, actual benefits are not substantiated.
significant reduction in colds compared to placebo orThe fact that large doses can be taken with
interferon alone. Benefits in humans for a widereported toxicity suggests that astragalus has minimal
variety of chronic and serious dis­orders alsopharmacologic potency.
have been reported. For example, it is asserted that