Astragalus (Astragalus membranaceus) is popular in traditional Chinese medicine, as it has been shown to possess liver-protective, diuretic, expectorant, antioxidant, antiviral, anti-inflammatory, antihyperglycemic, and immunomodulating properties. More than 100 chemical constituents have been identified with health-promoting effects, including flavonoids, saponins, polysaccharides, glycosides, amino acids, trace elements, and other bioactive substances. 

In the scientific research, astragalus root has been shown to help stimulate the immune system. It is important for natural cell-mediated immune mechanisms to become stimulated in the presence of infectious agents and neoplastic diseases to help disrupt their development and progression. 

In a recent study published in the Chinese Journal of Integrative Medicine, researchers reviewed the effects of astragalus polysaccharides on the immune system in hepatic fibrosis. Hepatic fibrosis is a reversible condition characterized by the accumulation of scar tissue and excessive deposition of extracellular matrix (ECM) and fibroblasts on the liver as an immune response to tissue damage or cell injury. Common etiologies include chronic injuries, viral infections, autoimmune diseases, drug and alcohol misuse, and metabolic conditions. 

Hepatic stellate cells (HSCs) activate and proliferate in response to liver injury, which is then transformed into myofibroblasts that produce ECM. There are pro-fibrotic and anti-fibrotic immune cells that have a bidirectional regulatory effect on HSCs that can promote or inhibit the pathogenesis of liver fibrosis.

According to the literature from this review, astragalus polysaccharides and their other bioactives inhibited lymphocyte secretion of inflammatory factors (e.g., tumor necrosis factor-alpha, nuclear factor-kappa B, interleukin-1B, interleukin-6, interferon-gamma, cyclooxygenase-2) that resulted in the inhibition of liver fibrosis progression. These results suggest that astragalus root may have beneficial effects on the immune response by inhibiting immune cell and pro-inflammatory cytokine infiltration during liver fibrosis. 

Astragalus has an ability to stimulate macrophage and other immune cell function and reduce the expression of pro-inflammatory molecules. Astragalus may be able to support conditions that are inflammatory or oxidative in nature.  

By Caitlin Higgins, MSCN, CNS