Written by Klara Rombauts and the CAM-Cancer Consortium.
Updated April 29, 2016

Milk vetch (Astragalus mongholicus)

Abstract and key points

  • Milk vetch (Astragalus mongholicus) is a medicinal herb that originates from traditional Chinese medicine.
  • Data from clinical trials are of low quality and need to be confirmed.
  • Milk vetch appears to be safe.

Milk vetch (Astragalus mongholicus) is a commonly used herb in traditional Chinese medicine, which is believed to have immunostimulating properties. It is mostly used in combination with other herbs, depending on the diagnosis.

Milk vetch induces apoptosis, inhibits cell proliferation, induces a pro-inflammatory response, and augments phagocytic functions.

The use of milk vetch-based products as a cancer therapy has been evaluated in about 65 trials clinical trials conducted in Asia. Only four trials, however, have looked at Milk vetch monopreparations because in traditional Chinese medicine mostly combinations of herbs are used. Most trials reported positive results including improvement of quality of life, increase in immunological parameters or direct anticancer effects. Poor design and low quality of these trials, however, prohibit any definite conclusions.

There are no severe safety concerns associated with the use of Milk vetch.

Read about the regulation, supervision and reimbursement of herbal medicine at NAFKAMs website CAM Regulation.

What is it?

Description

This review is limited to different preparations of Astragalus mongholicus root, the most commonly used Astragalus species in Chinese medicine. Other Astragalus species which are being investigated for their anti-cancer properties are the Turkish species, and include Astragalus brachypterus, Astragalus cephalotes, Astragalus microcephalus and Astragalus trojanus.

Scientific name/Common name/Brand name

Radix Astragali is the whole dried root of Astragalus mongholicus Bunge var. Dahuricus (DC.) Podlech and var. Mongholicus, common name: milk vetch, family Leguminosae. In the literature it is often named Astragalus membranaceus. The German common name is Tragant. The dried root of Astragalus mongholicus is called ‘Huangqi.1-3

Other preparations of Astragalus used in cancer therapy are tragacanth, the gummy sap of milk vetch root, and swainsonine, a water-soluble indole alkaloid produced by several plants known as locoweeds, including milk vetch.4

Ingredients

Polysaccharides, saponins, isoflavonoids, and flavonoids are the main constituents of milk vetch.5 The polysaccharides originating from Astragalus are called astragalans. The saponins (or triterpene glycosides, here called astragalosides), isoflavonoids, and flavonoids consist of aglycons or glycosides.

The amounts of astragalosides, trigonosides, and flavonoid constituents of dried root depend on the age, size and growing conditions of the root.

Although several parts of the plant seem to contain active constituents, it is especially the root that is (often) used in herbal formulas. Saponins are the most active components.

Application and dosage

Milk vetch is generally administered in combination with other Chinese herbs. The combination depends on the diagnosis.1 A common herbal formula containing milk vetch root is called “Juzentaihoto”, which means Ten Significant Tonic Decoctions.

The recommended oral dose for decoction is 3-6g of Huangqi (dried root) per 350ml water.1

Milk vetch can be bought as dried slices, shavings, powder, shredded root, whole root, capsules and liquid extracts. TCM practitioners often administer it as a tea infusion or shredded in soup.

History/providers

Milk vetch has been used for many centuries in TCM to correct ‘spleen deficiency’, which has been associated with cellular immune dysfunction.3 It originates from Shanxi Province, China, but now grows in several provinces in northern China.4 Some Astragalus-species also grow in the East Mediterranean area. In the 1980s, milk vetch was popularized as an immunostimulant in the United States by the media.6

Claims of efficacy

Internet sources claim that milk vetch can be used for the prevention and treatment of viral infections, ranging from colds to swine flu, and human immunodeficiency virus (HIV). Milk vetch is particularly promoted for its immunostimulating properties. It is also claimed to be a natural remedy in the treatment of cancer.

Mechanism of action

The anticancer and immunostimulating properties of milk vetch are reduced by multiple action modalities.

Milk vetch saponins, extracted from the root, have been shown to induce apoptosis in human hepatocellular carcinoma cells, colon cancer cells, and human erythroleukaemia cells.7

NAG-1 (nonsteroidal anti-inflammatory drug (NSAID)-activated gene) is proposed as a molecular target of milk vetch saponins in its antitumorigenic and proapoptotic actions.8 The induction of apoptosis by milk vetch saponins was confirmed in studies on colon cancer cells and human erythroleukaemia cells.9,10

Milk vetch saponins have been shown to inhibit cell proliferation through the accumulation in S phase and G2/M arrest in HT-29 human colon cancer cells and mice xenografts. Milk vetch saponins also caused suppression of p21 expression and inhibition of cyclin-dependant kinase activity. The results were comparable with those produced by 5-fluorouracil, but without its side effects.11

It has also been demonstrated that the anti-tumour activity of milk vetch is caused by abolition of tumor-induced macrophage suppression.12 Macrophages can infiltrate the tumour site to participate in inflammatory reactions leading to destruction of neoplasms.13 ,14

Astragali polysaccharides (APS) stimulate all types of immunocytes, including T cells, B cells, and NK cells.15

Alleged indications

In traditional Chinese medicine (TCM), Astragalus is believed to have a “Qi tonifying” effect (Qi is thought to be a vital energy, a concept closely linked to immunity). In TCM, milk vetch is used to treat symptoms allegedly caused by affections of the spleen, which are claimed to be diarrhoea, fatigue, spontaneous sweating, and lack of appetite. According to TCM beliefs, it could also be used to treat colds and shortness of breath because it tonifies the lungs. Besides cancer, other possible indications are wasting disorders, night sweats, chronic ulcerations and sores, numbness and paralyses of the limbs, and oedema.1

Legal issues

Jinfukang, a liquid formulation extracted from 12 botanicals is approved by the State Drug Administration (SDA), the Chinese equivalent of the FDA in the US, for its use in the treatment of non-small-cell lung cancer.

Outside Asia, milk vetch is sold as a dietary supplement. This does not require any approval by the FDA or EMA (European Medicines Agency), but no medicinal claims associated with milk vetch can be made.

Costs and expenditures

On the Internet, prices for milk vetch capsules or extracts vary from US$2.79 for 60 capsules to $23 for 30ml of the extract. According to internet reviews, a monthly supply (3 capsules twice a day 470mg) costs about US$.4,7-9

Does it work?

Most available publications investigate milk vetch (Astragalus) based combination products (n>65), which do not allow conclusions about the efficacy of milk vetch itself. The four systematic reviews available all include studies with combination products16-19 and only two of the included trials evaluate milk vetch on its own.20,21 They are discussed below together with two subsequently published studies. Most trials suffer from methodological weaknesses so their conclusions need to be considered with caution.

Controlled clinical trials

In a randomized controlled trial (n=120) milk vetch was injected (40g per day) in addition to chemotherapy in patients with solid tumours for four cycles of 21 days. They found a significant increase in CD4/CD8 ratio, IgG and IgM and Karnofsky Performance status in the treatment group compared to the control group that only received chemotherapy.20

In a randomized controlled study 136 patients with advanced non-small cell lung cancer were enrolled to receive either astragalus polysaccharide (APS) injection integrated with vinorelbine and cisplatin (treatment) or vinorelbine and cisplatin (control). Tumour response and survival were not significantly improved by adding APS injection, but improvement of quality of life was seen in physical capacity and several indices like treatment-related symptoms such as fatigue, nausea and vomiting, pain, and loss of appetite.22

A prospective quasi-experimental study included 60 patients with advanced non-small-cell lung cancer. The dosis of 120 g of milk vetch was administered intravenously daily, starting 3 days prior to chemotherapy until completion of chemotherapy treatment. There was a significant increase in remission time, median survival time, and 1-year survival time. There was a significant difference in 2- and 3-year survival time between the treatment group and control group that received conventional gelform embolisation.21

PG2, a partially purified extract of milk vetch, was evaluated in 84 advanced cancer patients for the alleviation of cancer-related fatigue in a phase II double-blind, randomized placebo-controlled study. Significant improvements for PG2 in relieving fatigue in advanced cancer patients were observed.23

Pre-clinical trials

A trial on 30 cervical cancer patients published in a Chinese journal (information retrieved from abstract only) reported Astragalus injections to regulate the imbalanced Th1/Th2 cell function of cervical cancer patients; data were compared to those of 10 healthy volunteers.24

An extract from milk vetch induced a restored immune reaction in 9 out of 10 patients with a significant increase in local graft versus host (GVH) reaction (P<0.01). This suggested that milk vetch contains potent immune stimulants. This was evaluated in 19 cancer patients and 15 normal healthy controls. Circulating mononuclear cells were isolated from heparinized peripheral venous blood, half of which were treated with milk vetch extract; the treated and untreated cells were then injected in partially immunosuppressed rats. Local GVH reaction was used as an outcome of a boosted immune reaction.4

Is it safe?

Toxicity of milk vetch is very low. The LD50 of milk vetch in rats is 40g/kg, via intraperitoneal injection of the extract.6

Some Astragalus species produce the toxin swainsonine.25-27 Other species accumulate selenium what may cause selenium poisoning.28 Therefore, it is very important to be cautious when buying Astragalus supplements.

Adverse events

No adverse effects were reported in rats given milk vetch via gastric lavage for doses up to 100g/kg.1

Animal and human studies have shown some extent of blood pressure and glucose lowering effects.6 As milk vetch is most often used in combination with other herbs, it is difficult to extrapolate the significance of reported adverse events seen under clinical settings.

Contraindications

Milk vetch showed potential hypotensive activity in rabbits, so patients who have low blood pressure (or are subject to hypotension), or are taking antihypertensive drugs, should avoid large doses of milk vetch. However, this has not been confirmed by clinical findings.4

Interactions with other herbs/drugs/therapies

Tragacanth, the gummy sap of milk vetch, may reduce absorption of pharmacological agents taken orally. Thus, tragacanth should be taken separately from other drugs. Due to its immunostimulating properties, milk vetch may lower the effects of immunosuppressant agents.4

Citation

Klara Rombauts, CAM-Cancer Consortium. Milk vetch (Astragalus mongholicus) [online document]. http://cam-cancer.org/The-Summaries/Herbal-products/Milk-vetch-Astragalus-mongholicus. April 29, 2016.

Document history

Assessed as up to date in April 2016 by Barbara Wider.
Assessed as up to date in September 2013 by Barbara Wider.
Most recent update and revision in September 2012 by Klara Rombauts.
Summary first published in April 2011, authored by Klara Rombauts.

References

  1. Sinclair S. Chinese herbs: A clinical review of Astragalus, Ligusticum, and Schizandrae. Altern Med Rev. 1998;3:338-344.
  2. Cho W, Leung K. In vitro and in vivo anti-tumor effects of Astragalus membranaceus. Cancer Letters. 2007;252(1):43-54.
  3. Block K, Mead M. Immune system effects of Echinacea, Ginseng and Astragalus: A review. Integr Cancer Ther. 2003:2(3):247-267.
  4. Sun Y, Hersh E, Talpaz M, Lee SL, Wong W, Loo T et al. Immune restoration and/or augmentation of local graft versus host reaction by traditional Chinese medicinal herbs. Cancer. 1983;52(1):70-3.
  5. Ragupathi G, Hood C, Yeung S, Vickers A, Cassileth B, Livingston P. Evaluation of widely consumed botanicals as immunological adjuvants. Vaccine. 2009;26:4860-4865.
  6. Naturalstandard. Astragalus. [Online database.] Available from www.naturalstandard.com, accessed 13 September 2012.
  7. Auyeung K, Law, P, Ko J. Astragalus saponins induce apoptosis via an ERK-independent NF-κB signaling pathway in the human hepatocellular HepG2 cell line. Int J Mol Med. 2009;23(2):189-196.
  8. Auyeung K, Ko J. Novel herbal flavonoids promote apoptosis but differentially induce cell cycle arrest in human colon cancer cell. Invest New Drugs. 2010;28(1):1-13.
  9. Auyeung K, Cho C, Ko J. A novel anticancer effect of Astragalus saponins: Transcriptional activation of NSAID-activated gene. Int J Cancer. 2009;125(5):1082-91.
  10. Cheng XD, Hou CH, Zhang XJ, Xie HY, Zhou WY, Yang L et al. Effects of Huangqi (Hex) on inducing cell differentiation and cell death in K562 and HEL cells. Acta Biochim Biophys Sin. 2004;36(3):211-7.
  11. Tin M, Cho CH, Chan K, James A, Ko J. Astragalus saponins induce growth inhibition and apoptosis in human colon cancer cells and tumor xenograft. Carcinogenesis. 2007;28(6):1347-55.
  12. Cho W, Leung K. In vitro and in vivo immunomodulating and immunorestorative effects of Astragalus membranaceus. J Ethnopharmacol. 2007;113(1):132-41.
  13. Clement-Kruzel S, Hwang SA, Kruzel M, Dasgupta A, Actor J. Immune modulation of macrophage pro-inflammatory response by Goldenseal and Astragalus species. J Med Food. 2008;11(3):493-8.
  14. Rittenhouse J, Lui P, Lau B. Chinese medicinal herbs reverse macrophage suppression induced by urological tumors. J Urol. 1991;146(2):486-90.
  15. Wagner H. Immunomodulatory agents from plants. Basel (Switzerland): Birkhäuser Verlag; 1999. p. 332-333.
  16. Wu P, Dugoua JJ, Eyawo O, Mills E. Traditional Chinese medicine in the treatment of hepatocellular cancers: a systematic review and meta-analysis. J Exp Clin Cancer Res. 2009;28:112.
  17. McCulloch M, See C, Shu XJ, Broffman M, Kramer A, Fan W et al. Astragalus-based Chinese herbs and Platinum-based chemotherapy for advanced non-small-cell lung cancer: Meta-analysis of randomized trials. J Clin Oncol 2006;24(3):419-30.
  18. Dugoua et al. Astragalus-containing Chinese herbal combinations for advanced non-small-cell lung cancer: a meta-analysis of 65 clinical trials enrolling 4751 patients. Lung cancer: Targets and Therapy 2010;1:85-100.
  19. Molassiotis A, Potrata B, Cheng KKF. A systematic review of the effectiveness of Chinese herbal medicine in symptom management and improvement of quality of life in adult cancer patients. Complement Ther Med. 2009;17(2):92-120.
  20. Duan P, Wang Z. Clinical study on effect of Astragalus in efficacy enhancing and toxicity reducing of chemotherapy in patients of malignant tumor. Zhongguo Zhong Xi Yi Jie He Za Zhi 2002;22(7):515—7.
  21. Zou YH, Liu XM. Effect of Astragalus injection combined with chemotherapy on quality of life in patients with advanced nonsmall cell lung cancer. Zhongguo Zhong Xi Yi Jie He Za Zhi 2003;23:733—5.
  22. Guo L, Bai SP, Zhao L, Wang XH. Astragalus polysaccharide injection integrated with vinorelbine and cisplatin for patients with advanced non-small cell lung cancer: effects on quality of life and survival. Med Oncol 2012 Sep;29(3):1656-62
  23. Chen HW, Lin IH, Chen YJ, Chang KH, et al. A novel infusible botanically-derived drug, PG2, for cancer-related fatigue: A phase II double-blind, randomized placebo-controlled study. Clin Invest Med 2012;35(1):E1-E11.
  24. Hu YJ, Li L, Gong SX: [Regulatory effect of astragalus injection on Th1/Th2 cell function in patients with cervical cancer]. Zhongguo Zhong Xi Yi Jie He Za Zhi 2010; 30(11):1157-1159.
  25. Stegelmeier B, James L, Panter K, Ralphs M, Gardner D et al. The pathogenesis and toxicokinetics of locoweed (Astragalus and Oxytropis spp.) poisoning in livestock. J Nat Toxins 1999;8(1):35-45.
  26. Sun JY, Yang H, Miao S, Li JP, Wang SW, Zhu MZ et al. Suppressive effects of swainsonine on C6 glioma cell in vitro and in vivo. Phytomedicine. 2009;16(11):1070-4.
  27. Livestrong – Astragalus monograph [website]. Available at http://www.livestrong.com/article/363480-is-astragalus-safe/, accessed 13 September 2012.
  28. Sors T, Ellis D, Lahner B, Lee S, Leustek T et al. Analysis of sulfur and selenium assimilation in Astragalus plants with varying capacities to accumulate selenium. Plant J 2005;42(6):785-797.