Purification, structural elucidation and anti-inflammatory activity in vitro of polysaccharides from Smilax china L.

Smilax china L. is a traditional Chinese medicine mainly used for the treatment of pelvic inflammation. Polysaccharide might be one of the anti-inflammatory components of Smilax china L. Based on this hypothesis, this work aimed at extraction, purification and structural elucidation of Smilax china L. polysaccharides and their preliminary anti-inflammatory effects were also studied. Two polysaccharides named SCLP1 (Smilax china L. polysaccharide 1, 42.1 kDa) and SCLP3-2 (Smilax china L. polysaccharide 3-2, 16.8 kDa) were for the first time purified from Smilax china L. The structures of SCLP1 and SCLP3-2 were elucidated by chemical and spectral analysis. The results revealed that SCLP1 was a neutral polysaccharide composed of glucose and mannose (54.5:1.0). Its backbone was 1,4‑linked α‑Glcp interspersed with 1,2‑linked α‑Glcp and Manp; the branches were 1,6‑linked α-Glcp and terminated with α‑Glcp. SCLP3-2 was composed of galacturonic acid, arabinose, galactose and rhamnose (23.3:2.1:1.7:1.0) and was a pectin-type polysaccharide with an α‑1,4‑linked homogalacturonan backbone which was partially methyl-esterified and slightly acetylated. The side chains consisted of α‑Rhap, β‑Galp and α‑Araf. SCLP1 and SCLP3-2 could inhibit the production of NO, IL-6 and TNF-α in LPS-stimulated RAW264.7 cells via NF-κB and MAPKs (ERK1/2, JNK) pathways, indicating that they possessed a potential anti-inflammatory activity.