Structural features and anti-gastric cancer activity of polysaccharides from stem, root, leaf and flower of cultivated Dendrobium huoshanense.

The structure features and anti-gastric cancer activities in vitro of stem, root, leaf and flower polysaccharides from cultivated Dendrobium huoshanense were investigated systematically. Stem polysaccharide (cDHPS) was composed of →4)-β-D-Glcp-(1→, →4)-β-D-Manp-(1→, →4)-3-O-acetyl-β-D-Manp-(1→ with the molecular weight of 2.59 × 105 Da; root polysaccharide (cDHPR) was composed of →3,5)-α-L-Araf-(1→, →4)-β-D-Glcp-(1→, →4)-β-D-Manp-(1→, →4,6)-β-D-Manp-(1→, →6)-α-D-Galp-(1→ and terminal β-L-Araf with the molecular weight of 1.41 × 104 Da; leaf polysaccharide (cDHPL) was composed of →4)-β-D-Glcp-(1→, →4)-β-D-Manp-(1→, →4)-3-O-acetyl-β-D-Manp-(1→, →3,6)-β-D-Manp-(1→ and terminal α-D-Galp with the molecular weight of 2.09 × 105 Da; and flower polysaccharide (cDHPF) was composed of →4)-β-D-Glcp-(1→, →4)-β-D-Manp-(1→, →3,6)-β-D-Manp-(1→ and terminal α-D-Galp with the molecular weight of 4.78 × 105 Da. Among these four polysaccharides, cDHPS showed the best anti-gastric cancer activity evidenced by the inhibited growth and c-myc expression as well as the enhanced apoptosis and p53 expression of murine forestomach carcinoma (MFC) cells, suggesting their difference in anti-gastric cancer activity should be contributed to their difference in structure features.