Sulfated modification, characterization, immunomodulatory activities and mechanism of the polysaccharides from Cyclocarya paliurus on dendritic cells

In this study, a crude and purified polysaccharide from Cyclocarya paliurus (CPP, CPP0.05) were performed with chlorosulfonic acid–pyridine (CSA–Pyr) method to obtain sulfated derivatives (S-CPP, S-CPP0.05). After comparatively investigating, characterization results showed that the modifications were successful. Polysaccharides were used to culture mouse bone marrow-derived dendritic cells (BM-DCs) to evaluate their immunomodulatory activity and explore mechanism. The functional activity of CPP was significantly stronger than that of the purified polysaccharide CPP0.05. Meanwhile, S-CPP showed stronger immunomodulatory activity than CPP through determination of cytokine expression levels. We found that p-JNK, p-p38MAPK and NF-κB p65 proteins were significantly increased by stimulus of CPP and S-CPP, blocking TLR2/4 could significantly decreased proteins above which proved that immune regulation effect of CPP and S-CPP on DCs was performed via MAPK and NF-κB signaling pathways by triggering TLR2/4. S-CPP could serve as potential immunomodulatory agents used as complementary medicine or functional foods.