Structures and immunomodulatory activity of one galactose- and arabinose-rich polysaccharide from Sambucus adnata

One galactose-and arabinose-rich polysaccharide isolated from Sambucus adnata was named SPS-1, which had an average molecular weight 138.52 kDa, and was composed of L-rhamnose, D-glucuronic acid, D-galacturonic acid, D-galactose, and L-arabinose in a molar ratio of 0.6:0.4:0.1:4.9:4.0. The primary structure of SPS-1 was further analyzed through methylation and NMR spectroscopy. The results showed that SPS-1 had the structural char-acteristics of AG-II pectin. The immunoactivity test showed that SPS-1 activated the phosphorylation of MAPKs-related proteins and further elevated the expression levels of related nuclear transcription factors (I kappa B alpha and NF-kappa B p65) in the cells through the TLR2 and MyD88/TRAF6-dependent pathway, thereby significantly enhancing the phagocytosis of macrophages and stimulating the secretion of NO, IL-1 beta, IL-6, and TNF-alpha, which activated the RAW264.7 cells. Therefore, SPS-1, acting as an immunomodulator, is a potential drug for immunological diseases.

Automated summary

SPS-1, a galactose- and arabinose-rich polysaccharide from Sambucus adnata, functions as an immunomodulator by activating MAPKs-related proteins, increasing the expression levels of nuclear transcription factors, and enhancing macrophage phagocytosis, ultimately stimulating immune response. This suggests that SPS-1 has the potential to be a drug for immunological diseases.