Structure, antioxidant properties, and protective effects on DNA damage of exopolysaccharides from Clostridium butyricum

Exopolysaccharides (EPSs) of probiotics are naturally nontoxic antioxidants with some interesting biological activities. This research aims to explore the structural and antioxidant properties of the EPS from Clostridium butyricum, a probiotics widely existed in human and animal intestines. EPS of C. butyricum RO-07 was purified through a combination of anion-exchange column chromatography and gel chromatography and determined to be composed of glucosamine, arabinose, galactosamine, galactose, glucose, and xylose in a molar ratio of 1:1:1:2:1:1 with a molecular weight 1.23 × 10⁴ Da. It exhibited a stronger antioxidant activity than ascorbic acid, with scavenging activities up to 75.2% and 95.0% against hydroxyl radical (•OH) and superoxide radical (O₂ ^- •), respectively. It also performed protective effects on DNA against radiation destruction by ultraviolet and reactive oxygen species generated oxidation stress. With these superior advantages in oxidants and radiation resistance, the EPS from C. butyricum RO-07 therefore has great potential to be applied in food and cosmetic industry.