Extraction, separation, structure identification and anti-inflammatory activity of polysaccharides from Lamiophlomis...

Lamiophlomis rotata (L. rotata) is a Tibetan medicine in the high altitude area of southwest China, which has high medicinal value. In recent years, it has attracted more and more attention. However, the understanding of L. rotata polysaccharide is still limited. In this study, three polysaccharides (LHP0-1, LHP2-1, LHP2-2) were extracted, purified and structure identification from the aerial part of L. rotata. The average molecular weights (Mw) of the three polysaccharides were 1.480 × 10⁴ Da, 1.194 × 10⁵ Da and 7.122 × 10⁴ Da, respectively, by molecular weight determination, monosaccharide composition analysis, and methylation analysis. Structurally, LHP0-1 is mainly composed of nine sugar residue fragments: T-L-Araf, →4)-L-Arap(1→, →3)-L-Araf(1→, →3,5)-α-L-Araf(1→, →4)-D-Manp(1→, →4)-D-Galp(1→, →3)-D-Galp(1→, →3,6)-D-Glcp(1→, →3,6)-D-Manp(1→. LHP2-1 is mainly composed of seven sugar residue fragments: →2)-L-Rhap(1→, →5)-L-Araf(1→, T-D-GalpA, →3,5)-L-Araf(1→, →4)-D-Galp(1→, →4)-D-GalpA(1 → and →3,6)-D-Galp(1→. LHP2-2 is mainly composed of three sugar residue fragments: T-D-GalpA, →4)-D-GalpA(1→, →3,6)-D-Galp(1→. In vitro experiments showed that the three polysaccharides had anti-inflammatory effects on LPS-induced RAW264.7 cell inflammation, including inhibiting the release of nitric oxide and reducing the protein expression of iNOS, IL-6 and TNF-α. In addition, Se-LHP2-2 was obtained by selenization with glacial acetic acid‑sodium selenite method. Finally, The results of in vitro experiments showed that selenized polysaccharides could enhance anti-inflammatory activity.