Antitumor activities of different fractions of polysaccharide purified from Ornithogalum caudatum Ait

Four water-soluble polysaccharide fractions (OCAP-2-1, OCAP-2-2, OCAP-3-1 and OCAP-3-3) extracted from the Ornithogalum caudatum Ait, were obtained by DEAE fast flow Sepharose anion-exchange, and Sephadex G-75 gel-permeation chromatography. The monosaccharide components of four polysaccharides were characterized by gas chromatography (GC), and the majority of the monosaccharide components were glucose (30-42.5%) and galactose (23-29%), with low levels of arabinose (6-14%), mannose (2-9%), xylose (4-6%), glucuronic acid (1.0-7.5%), galactose acid (1-6%). The high-performance gel-permeation chromatography (HPGPC) analysis showed that the average molecular weight (M-w) of four polysaccharides were approximately 102.1, 62.3, 46.4 and 22.8 KDa, respectively. The protein contents of four fractions were 2.13%, 2.82%, 3.45% and 3.97%, respectively. All polysaccharide fractions exhibited significantly higher antitumor activity against solid tumor Sarcoma 180 in vivo than did a blank control. Fractions OCAP-2-2, OCAP-3-1 and OCAP-3-2 significantly inhibited the growth of K562 cells in vitro. Results of these studies demonstrated that the polysaccharide had a potential application as natural antitumor drugs. Crown Copyright (C) 2010 Published by Elsevier Ltd. All rights reserved.