Structural analysis and immunomodulatory effect of polysaccharide from Atractylodis macrocephalae Koidz. on bovine lymphocytes

RAMP60, RAMP70, RAMP80 and RAMPtp extracted from the rhizome of Atractylodis macrocephalae Koidz. were chemically analyzed and tested for their lymphocyte stimulation. Among them, only RAMPtp was found to induce proliferation of lymphocytes from bovine supramammary lymph node (SMLN). It was found that RAMPtp was homogeneous polysaccharide with Mn of 1.867 × 103 by GPC analysis, composed of glucose, mannose, rhamnose, arabinose and galactose, with mass percentages of 60.67%, 14.99%, 10.61%, 8.83% and 4.90%, respectively by HPLC analysis, connected by 1, 3-linked β-D Galp and 1, 6-linked β-D Galp residues by NMR analysis and was amorphous in structure by SEM analysis. When SMLN lymphocytes were cultured with RAMPtp in vitro, increased [Ca2+]i, more cells in S and G2/M phases and upregulated IFN-γ and IL-17A while downregulated IL-4 mRNA expressions as well as the binding between SMLN lymphocytes and RAMPtp were observed. These findings might explain the lymphocyte-stimulating property of RAMPtp.