Abstract

Aoxue Luo and Yijun Fan*

Four water-soluble polysaccharides (DNP1-1, DNP2-1, DNP3-1 and DNP4-2) were obtained from the aqueous extracts of the stems of Dendrobium nobile Lindl. by hot water extraction, ethanol precipitation, and fractionated by DEAE-cellulose ion exchange chromatography and Sephadex G-200 gel filtration chromatography. The evaluation of tumor inhibition and immunomodulatory activity suggested that DNP4-2 could significantly increase the immune index, and strongly promote the secretion of IL-2, TNF-α and IFN-γ, and also decrease the concentrations of MDA in blood serum. DNP4-2 should be explored as a potential anti-tumor drug.