Astragalus root (Radix astragali) has a history of use for a variety of health conditions. [LINK TO 10 BENEFITS OF ASTRAGALUS ARTICLE] One of the most popular and traditional ways it’s been used is as an immune booster. Though a top and trusted herb in Chinese Herbal Medicine, many people like to use astragalus root in tonics, teas and soups both for its sweet, tannic flavor and to give their health a boost.
Research indicates neither practitioners of herbal medicine nor people who like to use it as a dietary staple have been disappointed. Astragalus contains a variety compounds known for enhancing the immune system and providing additional health benefits.
Active Compounds in Astragalus
Scientists have identified polysaccharides, flavonoids and triterpene saponins as the active compounds in astragalus. Experiments show many of these chemicals possess anti-viral, anti-inflammatory, and immune regulatory properties. Astragalus also contains several amino acids, trace minerals and coumarins.[i]
While many of the individual compounds have been identified and some of the most potent tested, most studies typically use astragalus extract.
How Astragalus Boosts the Immune System
The compounds in astragalus each act in unique ways to support the immune system. For example, polysaccharides have been attributed with anti-viral, anti-microbial and anti-inflammatory effects.[ii] Saponins are known for their cytotoxic properties.[iii] Flavonoids provide antioxidant, anti-inflammatory and have demonstrated anti-tumor effects.
Although researchers continue to explore how these compounds combine to support the immune system, they have determined they do. Here are a few ways they boost immunity.
Improves Overall Immune Response
It can be difficult to tell if an herb like astragalus works when tested in healthy individuals. Researchers in China solved that problem. They ran a double-blind randomized trial with children suffering from acute lymphoblastic leukemia.
During chemotherapy, some children received an astragalus injection while others were the control group. The researchers observed that the children who received astragalus experienced reduced bone marrow suppression. The children’s white blood cell counts also increased.[iv]
Another study looked at the effect of astragalus on patients suffering from congestive heart failure. Those who received astragalus showed an improved function based on tests of common immune system factors including an increased CD4/CD8 ratio.[v]
Helps to Regulate Immune Factors
Research shows astragalus provides an immune-modulatory effect.
In one study, 60 patients with chronic aplastic anemia were divided into two groups. In addition to their medication, one group (30 people) received astragalus via injection. That group showed improved lymphocyte activity.[viii]
Another study, this time using animal models, found astragalus helped to restore balance between Th1 and Th2 cytokines.[ix]
Astragalus also helped restore normal immune function in one hundred sixty patients with herpes simplex keratitis. Once again, the Th1 and Th2 balance was restored in those who received the astragalus. Researchers also noted raised levels of IL-4 and IL-10 after treatment.[x]
Relieves Allergy Symptoms
Patients suffering from seasonal allergies may find relief with astragalus. Researchers conducted a small trial with 48 patients over six weeks. The placebo-controlled trial saw those patients who received the astragalus report much-reduced symptoms and an overall better quality of life.[xi]
Provides Support for the Liver
The liver has a vital role in immune response. It regulates the conversion of a specific growth factor, growth factor-beta which is involved in inflammation and specific immune responses. This makes a healthy liver key to immune response. Fatty liver, viral infections that attack the liver like herpes and high blood sugar can have a dramatic impact on the liver. Astragalus has been shown to help support the liver by –
- Improving insulin response, activity attributed to the polysaccharides in astragalus.[xii],[xiii]
- Protecting against damage from all types of fatty liver disease.[xiv],[xv]
- Increasing fatty acid metabolism[xvi]
By protecting the liver, astragalus helps to keep inflammation under control and regulates immune response.
A lot more research is needed to understand the mechanisms of how astragalus and its compounds work. Even so, the ancient experience that recognized astragalus supports the immune system making it a useful way for individuals to boost their immunity and stay healthy!
[i] Hong F, Xiao W, Ragupathi G, et al. The Known Immunologically Active Components of Astragalus Account for Only a Small Proportion of the Immunological Adjuvant Activity When Combined with Conjugate Vaccines. Planta medica. 2011;77(8):817-824. doi:10.1055/s-0030-1250574.
[ii] Mišurcová L1, et al. Health benefits of algal polysaccharides in human nutrition. Adv Food Nutr Res. 2012;66:75-145. doi: 10.1016/B978-0-12-394597-6.00003-3.
[iv] Zhang XJ1, et al. [Effects of Huangqi injection on infection factors in children with acute lymphoblastic leukemia]. [Article in Chinese] Zhongguo Dang Dai Er Ke Za Zhi. 2014 Feb;16(2):147-51.
[v] Liu ZG1, et al. [Effect of astragalus injection on immune function in patients with congestive heart failure]. [Article in Chinese] Zhongguo Zhong Xi Yi Jie He Za Zhi. 2003 May;23(5):351-3.
[vi] Zwickey H1, et al. The effect of Echinacea purpurea, Astragalus membranaceus and Glycyrrhiza glabra on CD25 expression in humans: a pilot study. Phytother Res. 2007 Nov;21(11):1109-12.
[vii] Brush J, et al. The effect of Echinacea purpurea, Astragalus membranaceus and Glycyrrhiza glabra on CD69 expression and immune cell activation in humans. Phytother Res. 2006 Aug;20(8):687-95.
[viii] Wang MS, et al. Clinical study on effect of Astragalus Injection and its immuno-regulation action in treating chronic aplastic anemia. Chin J Integr Med. 2007 Jun;13(2):98-102.
[ix] Chen SM1, et al. Astragalus membranaceus modulates Th1/2 immune balance and activates PPAR? in a murine asthma model. Biochem Cell Biol. 2014 Oct;92(5):397-405. doi: 10.1139/bcb-2014-0008. Epub 2014 Sep 2
[x] Mao SP1, et al. [Modulatory effect of Astragalus membranaceus on Th1/Th2 cytokine in patients with herpes simplex keratitis]. [Article in Chinese] Zhongguo Zhong Xi Yi Jie He Za Zhi. 2004 Feb;24(2):121-3.
[xi] Matkovic Z1et al. Efficacy and safety of Astragalus membranaceus in the treatment of patients with seasonal allergic rhinitis. Phytother Res. 2010 Feb;24(2):175-81. doi: 10.1002/ptr.2877.
[xii] Agyemang K, Han L, Liu E, Zhang Y, Wang T, Gao X. Recent Advances in Astragalus membranaceus Anti-Diabetic Research: Pharmacological Effects of Its Phytochemical Constituents.Evidence-based Complementary and Alternative Medicine?: eCAM. 2013;2013:654643. doi:10.1155/2013/654643.
[xiii] Wei Z1, et al. Mechanism of Astragalus polysaccharides in attenuating insulin resistance in Rats with type 2 diabetes mellitus via the regulation of liver microRNA?203a?3p. Mol Med Rep. 2018 Jan;17(1):1617-1624. doi: 10.3892/mmr.2017.8084. Epub 2017 Nov 15.
[xiv] Kwon H-J, Kim Y-Y, Choung S-Y. Amelioration effects of traditional Chinese medicine on alcohol-induced fatty liver. World Journal of Gastroenterology?: WJG. 2005;11(35):5512-5516. doi:10.3748/wjg.v11.i35.5512.
[xv] Yi-Chen Juan, Yao-Haur Kuo, Chia-Chuan Chang, et al., “Administration of a Decoction of Sucrose- and Polysaccharide-Rich Radix Astragali (Huang Qi) Ameliorated Insulin Resistance and Fatty Liver but Affected Beta-Cell Function in Type 2 Diabetic Rats,” Evidence-Based Complementary and Alternative Medicine, vol. 2011, Article ID 349807, 11 pages, 2011. doi:10.1155/2011/349807
[xvi] Duan X1, et al. Calycosin attenuates triglyceride accumulation and hepatic fibrosis in murine model of non-alcoholic steatohepatitis via activating farnesoid X receptor. Phytomedicine. 2017 Feb 15;25:83-92. doi: 10.1016/j.phymed.2016.12.006. Epub 2016 Dec 13.