Exopolysaccharides produced by <i>Lactobacillus rhamnosus</i> GG alleviate hydrogen peroxide-induced intestinal oxidative damage and apoptosis through the Keap1/Nrf2 and Bax/Bcl-2 pathways <i>in vitro</i>

Abstract

The purpose of the study was to explore the effect of exopolysaccharides (EPSs) of <i>Lactobacillus rhamnosus</i> GG (LGG) on the antioxidative and antiapoptotic activities of intestinal porcine epithelial cells (IPEC-J2). EPSs exhibited promising antioxidative activities, such as 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, hydroxyl radical (˙OH) and superoxide anion radical (O₂˙^-) scavenging, as well as ferrous ion chelating ability. Moreover, EPSs of LGG could effectively alleviate the IPEC-J2 oxidative damage induced by H₂O₂ through the Bcl-2-associated (Bax)/B cell lymphoma-2 (Bcl-2) and Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor-erythroid 2-related factor-2 (Nrf2) signaling pathways and up-regulated the intracellular tight junction (TJ)-related proteins. In addition, EPSs significantly improved the survival rates of H₂O₂-damaged IPEC-J2 cells and had no cytotoxic activity, suggesting that EPSs produced by LGG may be an effective drug for relieving oxidative stress. Our study provided a theoretical basis for exploration of the application of probiotic secondary metabolites in practice.