[HNMP]HSO4 catalyzed synthesis of selenized polysaccharide and its immunomodulatory effect on RAW264.7 cells via MAPKs pathway

In this paper, selenized Artemisia sphaerocephala polysaccharides (SePAS) were obtained through employing N-methyl-2-pyrrolidone hydrosulfate as catalyst, which showed a maximum Se content enhanced to 8744 mu g/g, FT-IR, 1D/2D NMR, X-ray photoelectron spectroscopy (XPS) and size-exclusion chromatograph analysis exhibited that Se had been successfully introduced into PAS and existed in the form of selenate group (Se4+) with the substitution position at C-6. Furthermore, immunostimulating assays indicated that SePAS with high Se content exhibited stronger immunomodulatory activities by upregulated the phosphorylation level of ERK, JNK and p38, thus enhancing RAW264.7 cells proliferation, phagocytosis, levels of interleukin-6, nitric oxide, tumor necrosis factor and interleukin-1 beta. The current outcome suggested that Se content might be a critical factor affecting the immunomodulatory effects of selenized PAS on macrophage RAW264.7. (C) 2020 Elsevier B.V. All rights reserved.