Purification and antitumor activity of two acidic polysaccharides from the roots of Polygala tenuifolia

► Two acidic polysaccharide was isolated from the roots of Polygala tenuifolia. ► They significantly inhibited the growth of A549 cells in vitro. ► They exhibited significant antitumor activity against lung cancer A549 in vivo. ► The antioxidant status in A549-bearing mice was improved by polysaccharides. ► They may be useful for the prevention of lung tumorigenesis.