Preparation, preliminary characterization, antioxidant, hepatoprotective and antitumor activities of polysaccharides from the flower of tea plant (Camellia sinensis)

► Crude TFPS was fractionated into TFPS-1, TFPS-2 and TFPS-3 by DEAE-52 chromatography. ► TFPS-1 had relative higher sulfate content and complicated monosaccharide composition. ► TFPS-1 and TFPS-3 showed relative stronger antioxidant and antitumor activity. ► Crude TFPS significantly prevented carbon tetrachloride-induced acute liver damage. In the present study, the crude polysaccharides from the flowers of tea plant (Camellia sinensis) (TFPS) were prepared with hot water and further fractionated on a DEAE-52 cellulose chromatography to afford three purified fractions of TFPS-1, TFPS-2 and TFPS-3. Then, their preliminary structures, antioxidant and antitumor activities in vitro and hepatoprotective activity in vivo were investigated. Compared with TFPS-2 and TFPS-3, TFPS-1 had relative higher content of sulfate and relative complicated monosaccharide composition. In addition, TFPS-1 and TFPS-3 showed relative stronger antioxidant activity and inhibitory activity on the growth of human gastric cancer BGC-823 cells. For hepatoprotective activity in vivo, we demonstrated that crude TFPS significantly prevented the increase of serum alanine aminotransferase and aspartate aminotransferase levels, reduced the formation of malondialdehyde and enhanced the activities of superoxide dismutase and glutathione peroxidase in carbon tetrachloride-induced liver injury mice. The results suggested that TFPS should be a potent natural polymer with antioxidant, hepatoprotective and antitumor activities.