Astragalus

Common name: Huang qi

Botanical name: Astragalus membranaceus

 

Astragalus is native to northern China and the elevated regions of the Chinese provinces, Yunnan and Sichuan. The portion of the plant used medicinally is the four- to seven-year-old dried root, collected in the spring. While over 2,000 types of astragalus exist worldwide, the Chinese version has been extensively tested, both chemically and pharmacologically.

Historical or traditional use

Shen Nung, the founder of Chinese herbal medicine, classified astragalus as a superior herb in his classical treatise Shen Nung Pen Tsao Ching (circa A.D. 100). The Chinese name huang qi translates as “yellow leader,” referring to the yellow color of the root and its status as one of the most important tonic herbs. Traditional Chinese Medicine used this herb for night sweats, deficiency of chi (e.g., fatigue, weakness, and loss of appetite), and diarrhea.

 Active constituents

Astragalus contains numerous components, including flavonoids, polysaccharides, triterpene glycosides (e.g., astragalosides I–VII), amino acids, and trace minerals. Several preliminary clinical trials in China have suggested that astragalus can benefit immune function and improve survival in some people with cancer. Given the poor quality of these trials, it is difficult to know how useful astragalus really was. One Chinese trial also found that astragalus could decrease overactive immune function in people with systemic lupus erythematosus (SLE), an autoimmune disease. Further trials are needed, however, to know if astragalus is safe for people with SLE, or any other autoimmune disease.

A double-blind trial found that, in people undergoing dialysis for kidney failure, intravenous astragalus improved one facet of immune function compared to the immune function of untreated people.Further study is needed to determine if astragalus can help prevent infections in people undergoing dialysis. Early clinical trials in China suggest astragalus root might also benefit people with chronic viral hepatitis, though it may take one to two months to see results.

In preliminary trials in China, astragalus has been used after people suffer heart attacks. More research is needed to determine whether astragalus is truly beneficial in this situation.

How much is usually taken?

Textbooks on Chinese herbs recommend taking 9–15 grams of the crude herb per day in decoction form. A decoction is made by boiling the root in water for a few minutes and then brewing the tea. Alternatively, 3–5 ml of tincture three times per day, are sometimes recommended.