Antioxidative effect of Lactobacillus plantarum Y44 on 2,2′-azobis(2-methylpropionamidine) dihydrochloride (ABAP)-damaged Caco-2 cells

Some Lactobacillus strains have been reported to have antioxidative activity. In our previous work, we screened Lactobacillus plantarum Y44 for its antioxidative activity. In this study, we further studied the antioxidative activities of L. plantarum Y44 using chemical antioxidant methods, including the 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) free radical scavenging assays, the ferric reducing antioxidant power test, and oxygen radical absorbance capacity test, and we assessed damage caused by 2,2'-azobis(2-methylpropionamidine) dihydrochloride (ABAP) in a Caco-2 cell model. The results of the chemical antioxidant assays confirmed the antioxidative activity of L. plantarum Y44, which was consistent with the protection of Caco-2 cells against ABAP injury by L. plantarum Y44. We also found that L. plantarum Y44 significantly promoted expression of Nrf2 pathway-associated proteins, downregulated expression of inflammatory-related cytokines IL-8 and tumor necrosis factor-a in ABAP-damaged Caco-2 cells, and enhanced expression of the tight junction proteins beta-catenin and E-cadherin. We determined that L. plantarum Y44 exerted antioxidative effects by quenching oxygen free radicals and activating the Nrf2 signaling pathway in Caco-2 cells.