Inhibition of human gastric carcinoma cell growth in vitro by a polysaccharide from Aster tataricus

► A water-soluble polysaccharide (WATP) is isolated from Aster tataricus. ► WATP shows a reliable tumor growth inhibitory activity on SGC-7901 cells. ► WATP could significantly induce apoptosis of SGC-7901 cells. ► WATP decreases mitochondrial transmembrane potential of SGC-7901 cells. ► WATP increases intracellular calcium concentration of SGC-7901 cells.