Bioactive polysaccharides from Vigna umbellata and its Characterization

Abstract It was well know that Shennong's Classic of Material Medical, the first work of Traditional Chinese medicine (TCM), recorded it as one kind of drug for eliminating carbuncle and purulent. However, there was no record about the ingredient and the mechanism of treatment. This study researched its water extract. 3 polysaccharides named polysaccharides 0, 1 and 2, purified from the seed of Vigna umbellata by anion exchange chromatography were investigated, including their structure characterization and anti-inflammatory, anti-tumor activities. The result showed that polysaccharide 0 was composed of Ribose, Arabinose, Manose, Glucose and Galactose, in a ratio of 1.77%, 6.64%, 26.63%, 60.04% and 4.92%, respectively, with the mean weight (Mw) of 6.62*103 Da. Polysaccharide 1 was composed of ribose, arabinose, manose, glucose, galactose, rhamnose and xylose, in a ratio of 0.47%, 3.01%, 9.51%, 79.6%, 1.89%, 0.61% and 4.92%,respectively, with the mean weight (Mw) of 8.24*103 Da. Polysaccharide 2 was composed of mannose and glucose, in a ratio of 38.62% and 61.38%,respectively, with the mean weight (Mw) of 3.96*103 Da. Moreover, after polysaccharides treatment, the ability of RAW 264.7 macrophage was noted, they markedly regulated tumor necrosis factor (TNF-α), a key target of autoimmune diseases. And the Real-time Quantitative polymerase chain reaction (qPCR) confirmed it. In addition, it inhibited IL-10 distinctly on simulation of tumour-associated macrophages. Furthermore, it suppressed human colon cancer cell HCT116 growth.