Glycoprotein from selenium-enriched yam activates immune cells and enhances intestinal immunity via the NF-κB signaling pathway

Selenium-enriched yam glycoprotein (SeGLP) has potential bioactive effects. However, the mechanisms by which it regulates the immune system are still unclear. Therefore, the immunomodulatory mechanism of SeGLP1 was evaluated in Raw264.7 cells and cyclophosphamide (CTX)-induced mice in this study. First, SeGLP1 was successfully extracted and purified. And then, the results in vivo showed that SeGLP1 exerted a superior activation capacity than GLP1 on Raw264.7 cells. Hematoxylin-eosin (H&E) staining results showed that SeGLP1 had a protective effect on CTX-induced immunosuppressed mice. It's indicated that SeGLP1 facilitated the proliferation of T cells and accelerated the cell cycle from the G₀/G₁ phase to the S phase. Additionally, SeGLP1 enhanced immune function by up-regulating the secretion of TNF-α, IL-4, IL-6 and IL-17 in immunosuppressed mice. Immunofluorescence assay indicated that SeGLP1 increased the expression levels of ZO-1 and Claudin-1 thereby improving the intestinal immunity in CTX-induced mice. SeGLP1 also normalized the feces of mice, implying a possible change in the intestinal microenvironment. In conclusion, SeGLP1 exerted a superior immune-enhancing effect than GLP1, which is thought to be related with NF-κB signaling pathway.