Structural characterization of a polysaccharide derived from Saposhnikovia divaricatee (Turcz.) Schischk with anti-allergic and antioxidant activities.

Ethnopharmacological Relevance: Saposhnikoviae Radix, the dry root of Saposhnikovia divaricatee (Turcz.) Schischk, is a traditional chinese medicine used for the treatment of cold, headache, and skin pruritus.

Aim Of The Study: This study aimed to identify novel active polysaccharides from Saposhnikovia divaricatee (Turcz.) Schischk and clarify their structures and bioactivities.

Materials And Methods: The structure of polysaccharides was clarified by PMP-HPLC, methylation analysis, particle acid hydrolysis analysis and NMR analysis. The anti-allergic and antioxidant activities of polysaccharides were evaluated on allergic reaction model in RBL-2H3 cells and oxidative damage model of C. elegans.

Results: We purified a novel homogenous polysaccharide named SP-3 from Saposhnikovia divaricatee (Turcz.) Schischk and its molecular weight was determined as 3.096 × 10 Da. Monosaccharide composition analysis revealed that SP-3 was composed of mannose, rhamnose, galacturonic acid, glucose, galactose, and arabinose (1.85: 5.22: 38.06: 2.36: 23.25: 29.26). The main linkage type of SP-3 was a repeat unit of →4,6)-β-D-Galp-(1 → 4)-α-D-GalpA-(1 → . The branches of SP-3 contained T-linked-α-L-Araf and 1,3,4-linked-α-L-Rhap. It was observed that SP-3 inhibited β-HEX release and inflammatory factors in RBL-2H3 cells subject to IgE stimulant. Meanwhile, SP-3 increased the mean lifespan of Caenorhabditis elegans under oxidative stress, reduced ROS content and increased antioxidant enzyme activities of C. elegans, potentially through activating the SOD-3.

Conclusions: A novel homogenous polysaccharide was identified from Saposhnikovia divaricatee (Turcz.) Schischk, and this polysaccharide SP-3 played key roles for the anti-allergic and antioxidant activities.