Evaluation the Antitumor Effects of Exopolysaccharide Produced by Newly Isolated Bacillus amyloliquefaciens Strain C-1

Exopolysaccharide (EPS) was extracted and purified from a newly isolated Bacillus amyloliquefaciens strain, C-1. The anti-tumor activities of this EPS were tested in vitro. C-1 EPS exhibited good and direct, dose-dependent in vitro anti-proliferative effects on 6 human cancer cell lines. The inhibition rates of 7 mg/ml EPS on tumor cells SGC-7901, HeLa, A549, 7721, 7402, and MCF-7 were 73.2%, 78.6%, 65.0%, 64.0%, 41.1%, and 57.7%, respectively. The anti-proliferative effect of EPS was associated with the direct induction of apoptotic cell death, rather than the cell cycle. It was also verified that the expression of anti-apoptotic Bcl-2 family proteins was decreased. These results collectively show that this EPS has considerable potential for use in medical compounds.