Sulfation can enhance antitumor activities of Artemisia sphaerocephala polysaccharide in vitro and vivo

•Sulfated Artemisia sphaerocephala polysaccharide (ASPS) could inhibit the proliferation of HepG2 and Hela cells in vitro.•ASPS exhibited greater antitumor activities in H22 tumor-bearing mice.•ASPS showed stronger property in decreasing the expression of mutant p53 protein in vivo.•The introduction of sulfate group could enhance antitumor activities of polysaccharide in vitro and vivo. In this study, a sulfated Artemisia sphaerocephala polysaccharide (ASPs) was prepared and its antitumor activity was evaluated in tumor cells and Hepatoma 22 (H22) tumor-bearing mice. In vitro experiments, ASPs significantly inhibited the growth of HepG2 and Hela cells with the IC50 values of 172.03 and 161.42μg/mL, respectively. Moreover, no direct cytotoxicity against mouse fibroblast L929 normal cells was observed in vitro. After oral administration for 12days, the tumor growth was significantly suppressed by ASPs at the doses of 200mg/kg (inhibition rate of 60.85%). Results of tumor histological morphology and cell cycle analysis showed that ASPs could arrest H22 cells at S phase and promote cell apoptosis. Additionally, immunohistochemical analysis demonstrated that ASPs caused the down-regulation of mutant p53 protein expression in a dose-dependent manner. Therefore, these findings proposed new insight into antitumor properties of sulfated polysaccharide as a promising agent in cancer treatment.