Astragalus

(astragalus membranaceus)

Immune Stimulation

Both in vitro and in vivo investigations have confirmed that Astragalus membranaceus enhances the immune system. Investigators found that mononuclear cells, derived from cancer patients, that were preincubated with a polysaccharide fraction from A. membranaceus had significant immunopotentiating activity, and they fully corrected in vitro T-cell function deficiency found in cancer patients. Intravenous injection of a polysaccharide fraction from A. membranaceus also reversed cyclophosphamide-induced immunosuppression in rats (1).

Human adults treated with an oral dose of Astragalus root (15.6 g per person per day for 20 days) significantly increased serum IgM, IgE, and cyclic AMP concentrations (2). Extracts of A. membranaceus have been further reported to stimulate the production of interferon, a protein with antiviral activity, in both animals and humans in response to viral infections (3). A hot water extract of the herb administered intramuscularly for 3–4 months to patients with coxsackievirus B myocarditis enhanced natural killer cells, a response which was mediated through interferon induction (4)

In a pilot study on astragalus (8 g p.o./day 60) in 28 adults with 14 serving as the placebo control group, Hou et al., 1981 found the interferon inducing ability of blood leucocytes significantly higher in the astragalus group and baseline measurements taken before the treatment period. The effect persisted for 2 months after the treatment period ended compared to the placebo controls. Similar results were found against the common cold in field studies in China from 1974-1978 in 1,137 volunteers. (5)

Approved By Health Canada

Astragalus has been approved by Health Canada for lack of appetite, fatigue, and frequent colds. (6) Currently, much of the pharmacological research is focused on its immune stimulating polysaccharides and other active ingredients from the plant, useful in treating immune deficiency conditions. Astragalan, a polysaccharide fraction from A. membranaceus, has been researched in China for its ability to enhance the in vitro secretion of cytokines.

References- Astragalus