Four non-starch polysaccharides isolated from Chinese yams exhibit varied immunomodulatory and antioxidant effects in zebrafish and mice

The growth conditions and varieties of Chinese yam significantly affect the monosaccharide composition in non-starch polysaccharides (NSPs). Studying the extraction efficiency and biological functions of NSPs in different yam varieties is important. This study isolated four NSPs from Chinese yams planted in Hebei Province (Bai, Bang, Shuangbang, and Purple yams), and Bang yam polysaccharide demonstrated the highest extraction efficiency and glucose content. Biological study in zebrafish and cells indicated that NSPs isolated from Bang, Shuangbang, and purple yams possessed strong immunomodulatory and antioxidant activities. Immunodeficient mice administrated with NSPs in Bang and Shuangbang yams showed recovered body weight and reduced spleen enlargement. The calculated spleen index and thymus index dramatically improved, and the shortened colon recovered their original length. Furthermore, splenic lymphocytes collected from mice showed high proliferation rate after treatment with the NSPs, and the mRNA levels ( IL-6 , TNF-α , IFN-γ , and COX-2 ) related to immunomodulatory significantly improved. In conclusion, Bang yam non-starch polysaccharide (NSP) demonstrates high extraction efficiency and potent bioactivity, showing promise for functional food development. • Four non-starch polysaccharides from Chinese yams planted in Hebei Province . • The biological function of polysaccharides was studied in zebrafish. • Mice were used to investigate the immunomodulatory activity.