Immunoregulatory activities of the selenylated polysaccharides of Lilium davidii var. unicolor Salisb in vitro and in vivo

Studies have demonstrated that the modification of selenylation can improve the activity of polysaccharides. Lilium davidii var. unicolor Salisb (known as "lily bulb") is the dried succulent bulb of the genus Lilium in the family Liliaceae. We wished to investigate the immunoregulatory activities of the selenized polysaccharides of lily bulb (sLP). We undertook experiments in vitro and in vivo taking the unmodified polysaccharides of lily bulb (LP) as controls. The results of in vitro studies showed that sLP could promote the phagocytosis of RAW 264.7 cells significantly, increase the content of interleukin (IL)-1β and IL-2, enhance the activity of acid phosphatase, and increase the surface molecular expression of CD86 and CD80. The results of in vivo studies showed that sLP could improve the index of immune organs, increase the contents of interferon-γ, IL-6, immunoglobulin (Ig)G and IgM in serum, and promote lymphocyte proliferation. The immunoregulatory activities of sLP were significantly more robust than those of LP in vitro and in vivo. These results indicated that selenylation could enhance the immune-enhancement activity of LP significantly.