galus polysaccharide (APS) is the most important bioactive component isolated from a Chinese traditional herbal medicine of Astragalus membranaceus, which is composed of glucose, mannose, d-glucose, and D-galactose (Fig. 3) [[44], [45], [46]]. Radix Isatidis (RI) is also a kind of traditional Chinese herbal medicine with significant antiviral effect, and polysaccharide is its main active component [47,48]. The polysaccharide from R