Screening of Lactic Acid Bacteria with Antioxidant Capacity and Its Protective Effect on Oxidative Damage in Intestinal Epithelial Cells

Antioxidant strains were screened from 36 lactic acid bacteria isolated from longevity elderly faces, and the oxidative damage model of small intestinal epithelial cells (IEC-6) was established by hydrogen peroxide (H₂O₂) to investigate the effects of the screened strains on the oxidative stress of IEC-6 cells. The results showed that that strains of HN-04, HN-05 and HN-15 had higher antioxidant capacity in vitro, and the scavenging capacity of DPPH radical, hydroxyl radical and superoxide anion radical of the three strains were 52.18%~57.16%, 47.44%~52.38% and 37.11%~43.31%. The adhesion rates of the strains to IEC-6 cells were 6.77%, 6.92% and 5.82%, respectively. With the intervention effects of the stains, the survival rate of IEC-6 cells was increased by 5.31%~11.19%, and the activities of glutathione peroxidase (GSH-PX), superoxide dismutase (SOD), catalase (CAT) and total antioxidant capacity (T-AOC) in cells were increased by 12.03%~32.39%, 21.20%~47.42%, 36.10%~87.14% and 23.55%~48.69%, respectively. In addition, the contents of malondialdehyde (MDA) in oxidative damaged IEC-6 cells were decreased by 20.98%~48.80% under the treatment with the strains. In summary, the three strains screened in this research could reduce oxidative stress injury of IEC-6 cells, and could be used as natural antioxidants in the development of functional foods.