Antitumor effects of polysaccharide from Sargassum fusiforme against human hepatocellular carcinoma HepG2 cells.

Sargassum fusiforme (Harv.) Setchel, a kind of brown algae, has been applied as a therapeutic for thousands of years. This study was designed to investigate the antitumor effects of the polysaccharide (SFPS) from S. fusiform in liver cancer. The mice inoculated with HepG2 cells were orally administrated with SFPS at the doses of 100, 200 and 400 mg/kg body weight for 28 days. The products from peritoneal macrophages and serum in HepG2-bearing mice were measured. The effect of SFPS-induced cell apoptosis was measured by flow cytometry. Meanwhile, the expression levels of Bax and Bcl-2 were detected. Furthermore, the cytotoxicity of SFPS was evaluated by CCK-8 assay. Results showed that SFPS significantly inhibited growth of human HepG2 cell-transplanted tumor in nude mice, and remarkably increased serum TNF-α, IL-1, NO and IgM levels in HepG2-bearing mice. SFPS also promoted the cytokines (IL-1 and TNF-α) secreted by peritoneal macrophages in HepG2-bearing mice. SFPS exerted a stimulatory effect on apoptosis of HepG2 cells, increased the expression of Bax, and decreased the expression of Bcl-2. The results indicated that SFPS has anti-tumor and immunomodulatory activities at the high concentration, and it could be used as a potential chemopreventative and/or adjuvant chemotherapeutic agent in liver cancer.