Action mechanisms of polysaccharides in Chinese herbal decoctions

Water decoction is the main form of traditional Chinese medicine (TCM) administered in clinics. Polysaccharides are major components of decoction. Recent studies reported that polysaccharides possess multiple pharmacological activities. However, the mechanism by which oral Chinese herbal polysaccharides play vital roles in the body remains uncertain. This review discussed the polysaccharides in Chinese herbal decoctions and their effects, direct and indirect. The direct impact from polysaccharides includes being absorbed into the body immunity regulation through Peyer's patches; electrostatic adsorption, hydrophobic interaction, and glycoprotein receptors-induced antibacterial effects; prebiotic functions; gut microbiota structural regulation; and increasing the relative abundance of beneficial bacteria. The indirect effects of the polysaccharides in Chinese herbal decoctions include phytochemical toxicity reduction and activity enhancement. Finally, their clinical and research significance is summarized and future research directions are discussed. Graphical abstract: http://links.lww.com/AHM/A155.