Extraction, preliminary characterization, antioxidant and anticancer activities in vitro of polysaccharides from Cyclina sinensis

In the present study, we investigated the extraction, purification, preliminary characterization, antioxidant and anticancer activities in vitro of polysaccharides from Cyclina sinensis (CSPS). Firstly, the optimal parameters for extraction of CSPS were obtained by using a central composite design as follows: extraction temperature, 90 °C; extraction time, 250 min; ratio of water to raw material, 29; and extraction times, two times. Then, the crude CSPS was sequentially purified by chromatography of DEAE-52 and Sephadex G-100, resulting in three purified fractions of CSPS-1, CSPS-2 and CSPS-3. We found that the composition and property of CSPS-3, having relatively higher contents of protein, uronic acid, sulfate and more complicated monosaccharide composition, were quite different from those of CSPS-1 and CSPS-2. Furthermore, we demonstrated that CSPS-3 had strong scavenging activities in vitro on superoxide radical and hydroxyl radical and strong inhibitory effect in vitro on the growth of human gastric cancer BGC-823 cells.