抗氧化乳酸菌的筛选及其对小肠上皮细胞氧化损伤的保护作用

从36株分离自长寿老人粪便的乳酸菌中筛选高抗氧化活性菌株，利用过氧化氢（H₂O₂）建立大鼠小肠上皮细胞（IEC-6）氧化损伤模型，探究所筛选菌株对IEC-6细胞氧化应激的影响。结果表明，菌株HN-04、HN-05、HN-15有较强的体外抗氧化能力，其DPPH自由基、羟基自由基、超氧阴离子自由基清除能力分别为52.18%~57.16%、47.44%~52.38%、37.11%~43.31%，菌株对IEC-6细胞的黏附率分别为6.77%、6.92%和5.82%。在3株乳酸菌的干预作用下，氧化损伤细胞的存活率提高了5.31%~11.19%，细胞中的谷胱甘肽过氧化物酶（GSH-Px）、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）活性和总抗氧化能力（T-AOC）分别提升12.03%~32.39%、21.20%~47.42%、36.10%~87.14%和23.55%~48.69%，丙二醛含量（MDA）降低20.98%~48.80%。所筛选的3株乳酸菌具有缓解细胞氧化应激损伤的作用，可作为天然抗氧化剂应用于功能性食品开发。

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.