Structural features and anti-neuroinflammatory activity of a glucan, FSBP-2, from Ferula sinkiangensis

Ferula sinkiangensis is a genuine medicinal material of Xinjiang, China. It has a particular odor, and is used clinically for treatment of peptic gastric ulcers. In this study, a glucan named as FSBP-2, with a molecular weight of 5.1 kDa was isolated from the root of F. sinkiangensis. The structure of FSBP-2 was elucidated through monosaccharide composition, methylation, partial acid hydrolysis, ultra high performance liquid chromatography electrospray ionisation tandem mass spectrometry, and nuclear magnetic resonance analysis. FSBP-2 is a glucan characterized by a backbone of α-D-Glcp-(1→, →4)-α-D-Glcp-(1→, →6)-α-D-Glcp-(1→, →4,6)-α-D-Glcp-(1→, and →4)-α/β-D-Glcp. Bioactivity assays indicated that FSBP-2 markedly inhibited the secretion of nitrous oxide, tumor necrosis factor-α, and interleukin-1β as well as the inflammatory protein expression of cyclooxygenase-2 and nitric oxide synthase in lipopolysaccharide-induced BV2 microglia. Moreover, FSBP-2 could decreased the ratios of p-p65/p65. These results indicate that FSBP-2 exerted anti-neuroinflammatory effect. The present work preliminarily investigated the anti-neuroinflammatory activity of a natural polysaccharide from F. sinkiangensis and provided a theoretical basis for subsequent drug development.