Structural Characterization And Immunomodulatory Activity Of The Polysaccharide DMP4a-1 From Dendrobium Moniliforme (L.) Sw.

The Chinese crude drug "Shi Hu" is prepared from the dried steins of Dendrobium species, and polysaccharide is the major active constituent from Dendrobium plant. Dendrobium moniliforme(L. ) SW , from which the Chinese traditional medicine was most originally prepared, was studied in this paper. The structure features and immunomodulate activity of polysaccharide DMP4a — 1 from Dendrobium moniliforme (L. ) SW were investigated on the basis of previous researches. The main results indicated as follows:DMP4a — 1 is a protein-bound polysaccharide, with the molecular average-weight(Mw) 3049, composed of Glucose (Glc):Mannose(Man) : Rhamnose(Rha):Arabinose(Ara):Galactose(Gal) in a molar ratios of 2.873:2.850:1.762:1.279:1 by HPGPC, TLC, GC, GC-MS and IR. Periodate oxidation analysis revealed that the DMP4a—1 has (1→4, 1→3, 1→6) linked glycosidic residues, in a ratio of 1.194:2.430:1.Experimental data show DMP4a-1 significantly stimulate the secretion of TNF a in RAW264. 7 Cells —a macrophage cell line on a concertration dependent pattern, and the advanced research elucidate that the mechanism is DMP4a-1 upgrade the TNFα mRNA level in RAW264.7 Cells by RT-PCR Method. Moreover, the polysaccharide DMP4a-1 also can promote the proliferarion of lymphocyte from spleen and the production of NO from macrophage in vitro.