Exopolysaccharides (EPS) have attracted attention recently for possible use in suppressing early stage breast cancer. In this study, a mannan EPS produced by Lactococcus lactis subsp. lactis was found to affect the production of inflammatory cytokines. EPS (300 μg/ml) can significantly enhance tumour necrosis factor alpha and inducible NO synthase release in MCF-7 cells compared to control cells in a concentration-dependent manner. Also the intracellular calcium level was found to increase with the concentration of EPS. After EPS-treatment, a significant reduction in mitochondrial potential was observed, as was nuclear condensation and cell shrinkage. These results may be helpful in further understanding the anti-tumour properties of lactic acid bacteria.
Keywords: MCF-7 cells; anti-tumour effects; apoptosis; caspases; exopolysaccharides.