Antioxidant activity of an exopolysaccharide purified from Lactococcus lactis subsp. lactis 12

A novel exopolysaccharide (EPS) was obtained by ultra-filtration, ion exchange and sizing chromatography from a culture of Lactococcus lactis subsp. lactis 12. The EPS was mainly composed of fructose and rhamnose with a mean molecular weight of 6.9 × 105 Da. The EPS and its antioxidant properties were evaluated in vitro and in vivo. The EPS displayed strong antioxidant effects, exhibited the ability to scavenge hydroxyl and superoxide anion radicals, and significantly decreased the level of malondialdehyde (MDA), even while increasing the activity of catalase (CAT) and superoxide dismutase (SOD) in mice in a dose-dependent manner. The results suggest that the EPS has direct and potent antioxidant properties.