Astragalus membranaceus, also known as Astragalus propinquus, is a flowering plant in the family Fabaceae. The dried root of A. membranaceus, one of the most popular health-promoting herbal medicines, has been used to treat the common cold, diarrhea, fatigue and anorexia for thousands of years. It is reported that the dried root contains more than 100 chemical compounds, including polysaccharides, flavonoids, astragalosides, saponins, amino acids, and trace elements. Scientific investigations have revealed that polysaccharides are one of the major active ingredients responsible for immune modulation, anti-oxidant, anti-tumor, anti-diabetes, anti-viral, hepatoprotection, anti-inflammation, anti-atherosclerosis, hematopoiesis, and neuroprotection.