Structural characterization of a soluble polysaccharide SSPS1 from soy whey and its immunoregulatory activity in macrophages

A soluble soybean polysaccharide SSPS1 with a molecular weight of 2737 kDa was extracted and purified from soy whey. SSPS1 was composed of glucose (97.3 %) and a small amount of mannose (2.7 %). Structural analysis results suggested that SSPS1 had a -> 6)-alpha-D-Glcp-(1 -> glucan structure, with a trace amount of alpha-D-Glcp-(1 -> connected to the main chain via O-3. In vitro immunological experiments suggested that SSPS1 enhanced the growth rate and phagocytic activity of RAW 264.7 macrophages. In addition, SSPS1 stimulated the secretion of cytokines (TNF-alpha, INF-beta, IL-6 and IL-1 beta) as well as nitric oxide (NO) production through upregulating the expression of the related genes and proteins in RAW 264.7 cells. This study provided a new method for efficient utilization of soy whey, and the results indicate that SSPS1 extracted from soy whey could be used as a novel immunomodulator.

Automated summary

This study extracted and purified a soluble soybean polysaccharide SSPS1 with a molecular weight of 2737 kDa, which was found to enhance the growth rate and phagocytic activity of macrophages, as well as stimulate the secretion of cytokines and nitric oxide. These results suggest the potential of SSPS1 extracted from soy whey as a novel immunomodulator.