Exopolysaccharide from Lactobacillus planterum LP6: antioxidation and the effect on oxidative stress.

An exopolysaccharide (EPS-3) was isolated from the culture of Lactobacillus planterum LP6 and purified by ion exchange and gel chromatography. The concentrations required to scavenge 50% of the initial radical for DPPH·, OH· and O2(·-) radicals were 1.38, 3.43 and 0.11 mg/mL, respectively. The reducing power (A700 nm) was 0.632 at 5mg/mL. The cell viability of PC12 was improved by 21.67% at 200 μg/mL of EPS-3. Compared with the H2O2 group, the total-antioxidant capacity, activities of superoxide dismutase and catalase were enhanced by 65.81%, 41.34% and 59.05%, respectively. Meanwhile, the level of malondialdehyde and lactate dehydrogenase were decreased by 52.80% and 30.24%. The result indicated that EPS-3 had a notable protective effect against oxidative damage on PC12 cells. The study might lay a theoretical foundation for the comprehensive utilization of lactic acid bacteria source which could result in its application in food systems.