Structure and anti-tumor activity of a polysaccharide from Bletilla ochracea Schltr

• Published in: International journal of biological macromolecules 2020-07, Vol.154, p.1548-1555
• Main Authors: Niu, Junfeng, Wang, Shangping, Wang, Bulei, Chen, Lijun, Zhao, Guangming, Liu, Shuai, Wang, Shiqiang, Wang, Zhezhi
• Format: Article
• Language: English
• Subjects: Animals; Anti-tumor; Antineoplastic Agents - chemistry; Antineoplastic Agents - pharmacology; Bletilla ochracea; Carbohydrate Sequence; Cell Line, Tumor; Cell Survival - drug effects; Humans; Immuno-modulation; Methylation; Mice; Molecular Weight; Monosaccharides; Orchidaceae - chemistry; Polysaccharide; Polysaccharides - chemistry; Polysaccharides - pharmacology; Structure; Xenograft Model Antitumor Assays
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2019.11.039

The polysaccharide fraction of Bletilla ochracea (BOP) was isolated from its tubers, and purified by DEAE-52 Cellulose and Sephadex G-200 column chromatography. The structural features of BOP were analyzed by GC–MS, HPLP, FT-IR, methylation and NMR. The average molecular weight of BOP was approximately 4.9 × 105 Da, and the monosaccharide composition was 7.88:2.12 mix of mannose and glucose. The FT-IR and NMR analyses revealed the following linkage: [→(4-β-D-Man-1)4 → (4-β-D-Glc-1)2 → 4-2-O-acetyl-β-D-Man-1 → 4-β-D-Man-1 → 4-3-O-acetyl-β-D-Man-1 → 4-2-O-acetyl-β-D-Man-1→]. Although BOP had no effect on the proliferation rate of CT26 colon carcinoma cells, it significantly inhibited tumor xenograft growth in vivo by stimulating CD4+ T cell expansion in the spleen of the tumor-bearing mice. Taken together, BOP is a potent immunomodulatory agent that can be considered for anti-tumor therapy.