Comparisons of Isolation Methods, Structural Features, and Bioactivities of the Polysaccharides from Three Common Panax Species: A Review of Recent Progress

Panax spp. (Araliaceae family) are widely used medicinal plants and they mainly include Panax ginseng C.A. Meyer, Panax quinquefolium L. (American ginseng), and Panax notoginseng (notoginseng). Polysaccharides are the main active ingredients in these plants and have demonstrated diverse pharmacological functions, but comparisons of isolation methods, structural features, and bioactivities of these polysaccharides have not yet been reported. This review summarizes recent advances associated with 112 polysaccharides from ginseng, 25 polysaccharides from American ginseng, and 36 polysaccharides from notoginseng and it compares the differences in extraction, purification, structural features, and bioactivities. Most studies focus on ginseng polysaccharides and comparisons are typically made with the polysaccharides from American ginseng and notoginseng. For the extraction, purification, and structural analysis, the processes are similar for the polysaccharides from the three Panax species. Previous studies determined that 55 polysaccharides from ginseng, 18 polysaccharides from American ginseng, and 9 polysaccharides from notoginseng exhibited anti-tumor activity, immunoregulatory effects, anti-oxidant activity, and other pharmacological functions, which are mediated by multiple signaling pathways, including mitogen-activated protein kinase, nuclear factor kappa B, or redox balance pathways. This review can provide new insights into the similarities and differences among the polysaccharides from the three Panax species, which can facilitate and guide further studies to explore the medicinal properties of the Araliaceae family used in traditional Chinese medicine.