Astragalus

Common name: Astragalus
Other names: Huangqi
Latin name: Astragalus membranaceus
Affinities: Immune system, digestive system, circulatory system, nervous system
Actions: Immunomodulator, hepatoprotective, cardiac tonic, mild adaptogen, superior tonic herb, immune tonic
Specific indications: Weak immune system, prone to infections, chronic fatigue syndrome, poor appetite
Diseases: Chronic fatigue syndrome(2), allergies(1), type II diabetes(3), high blood pressure(3), cancer(2), neuralgia(2)
Parts used: Roots
Energetics: Warming, moistening

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Characteristics: Astralagus grows beside forests in large parts of China, Korea, and Japan (Kuhn and Winston, 2000). It is cultivated in China and it is a member of the pea family. The Chinese name, ‘huang qi’, means, ‘yellow vital force’.

History: The roots of Astragalus membranaceus have been used medicinally for over 2000 years and their medicinal use was described in Shen Nong’s Materia Medica which was written in the Han dynasty (Shao et al., 2004). Traditionally, astragalus was used in the treatment of weakness, wounds, anemia, fever, allergies, chronic fatigue, loss of appetite, uterine bleeding, uterine prolapse, and various renal diseases (Fu et al., 2014). It is one of the superior tonics in traditional Chinese medicine (TCM) and it is thought to add years of health to older people, while increasing vitality. It’s specific use in TCM is to tonify the Chinese ‘spleen’, for organ prolapse, as a diuretic, to protect against colds and other infectious diseases, and to strengthen the lungs (Kuhn and Winston, 2000). TCM practitioners also believe the herb strengthens the vital force and all systems of the body (Castleman, 2001). It is particularly indicated for treating disorders associated with fatigue. They also consider it useful for diabetes, heart disease, and high blood pressure.

Current applications: Astragalus is widely used as a tonic by herbalists to support the natural functioning of the immune system (Cho et al., 2007). It may be of application in preventing infections occurring (Winston, 2007). David Winston mentions it is applied for fatigue, lack of appetite, in cancer protocols, and regular use of the root has been shown to prevent kidney and liver damage caused by medications or viruses. To protect the kidney, it is often combined with similar herbs like cordyceps, nettle seed, and S. miltiorrhiza. To protect the liver, it is combined with milk thistle, schisandra, and turmeric. Astragalus may be applied with reishi to treat chronic fatigue by gently increasing energy. Astragalus combines well with echinacea and or reishi to support the immune system.

Science: Astragalus is known to have immune enhancing properties that are associated with its polysaccharides (Shao et al., 2004). These immune potentiating properties were also detected in vivo as it increased the rejection of a foreign graft in an animal model, the authors concluded that astragalus may have applications in immune depleted patients (Chu et al., 1988). It also displays apparent anti-tumour activity using in vivo and ex vivo experimental models (Cho et al., 2007). Astragalus is observed to have a restorative effect on the nervous system in animals and may be useful in cases of nerve damage (Huang et al., 2012).

There is good scientific support in humans for astragalus’s role in reducing fatigue, as there was one positive well controlled trial conducted on cancer patients (Chen et al., 2012). An additional well controlled trial demonstrated a significant improvement in the symptoms of seasonal allergic rhinitis (Matkovic et al., 2010).

Safety: Astragalus is a very safe herb for most situations. It is suitable for young, old, pregnancy, or breastfeeding. However, astragalus is a potent immunomodulator, it activates the immune system and so likely will reduce the effectiveness of any immuno-suppressant drugs being taken. Traditionally, astragalus is not used in acute infections because it is thought to improve the health of the invading organism.

Dosage: 5-60 drops 3-4 times daily of tincture may be taken, depending on need, although more can be taken. TCM practitioners usually use high doses of this herb.

Scientific Summary

Research on models

Anti-tumour: A study found that extracts of astragalus exhibited anti-cancer activity using in vivo and ex vivo experimental models (Cho et al., 2007).

Immunomodulating properties: One study demonstrated polysaccharides from astragalus stimulated macrophages ex vivo (Lee et al., 2005).

Immunomodulating properties(II): A study found that a partially purified extract from astragalus increased the ability of the immune system to reject a foreign graft in vivo (Chu et al., 1988).

Neuroprotective effects: One study observed in mice that an astragalus root extract induced a neuroprotective effects in a model of cerebral ischemia-reperfusion injury (Huang et al., 2012).

Research on humans

Seasonal allergic rhinitis: A study (n=48, double blind placebo controlled) found that over 6 weeks significant improvement in the symptoms of allergic rhinitis were observed with a patented extract containing astragalus as its primary medicinal component (Matkovic et al., 2010).

Cancer related fatigue: One study (n=65, double blind placebo controlled) found that an astragalus extract significantly improved fatigue in patients with advanced cancer and moderate to severe fatigue (Chen et al., 2012). The extract was a specially prepared form of astragalus.

References:

Castleman, Michael. “The new healing herbs.” Bantam Book, New York (2001): 465-471.

Chen, Hong-Wen, et al. “A novel infusible botanically-derived drug, PG2, for cancer-related fatigue: a phase II double-blind, randomized placebo-controlled study.” Clinical & Investigative Medicine 35.1 (2012): 1-11.

Cho, William CS, and Kwok N. Leung. “In vitro and in vivo anti-tumor effects of Astragalus membranaceus.” Cancer Letters 252.1 (2007): 43-54.

Chu, Da-Tong, W. L. Wong, and G. M. Mavligit. “Immunotherapy with Chinese medicinal herbs. II. Reversal of cyclophosphamide-induced immune suppression by administration of fractionated Astragalus membranaceus in vivo.” Journal of clinical & laboratory immunology 25.3 (1988): 125-129.

Fu, Juan, et al. “Review of the botanical characteristics, phytochemistry, and pharmacology of Astragalus membranaceus (Huangqi).” Phytotherapy Research 28.9 (2014): 1275-1283.

Huang, Xiao-Ping, et al. “Astragalus extract alleviates nerve injury after cerebral ischemia by improving energy metabolism and inhibiting apoptosis.” Biological and Pharmaceutical Bulletin 35.4 (2012): 449-454.

Kuhn, Merrily A., and David Winston. Herbal therapy and supplements: a scientific and traditional approach. Lippincott Williams & Wilkins, 2000.

Lee, Kun Yeong, and Young Jin Jeon. “Macrophage activation by polysaccharide isolated from Astragalus membranaceus.” International immunopharmacology 5.7 (2005): 1225-1233.

Matkovic, Zinka, et al. “Efficacy and safety of Astragalus membranaceus in the treatment of patients with seasonal allergic rhinitis.” Phytotherapy research 24.2 (2010): 175-181.

Shao, Bao-Mei, et al. “A study on the immune receptors for polysaccharides from the roots of Astragalus membranaceus, a Chinese medicinal herb.” Biochemical and biophysical research communications 320.4 (2004): 1103-1111.

Winston, David, and Steven Maimes. Adaptogens: herbs for strength, stamina, and stress relief. Inner Traditions/Bear & Co, 2007.