title: Protective effect of surface layer proteins isolated from four Lactobacillus strains on hydrogen-peroxide-induced HT-29 cells oxidative stress.
abstract: The objective of this study was to explore the antioxidant effect of the surface layer proteins (SLPs) and their mechanism. We investigated four SLPs which were extracted from L. casei zhang, L. rhamnosus, L. gasseri and L. acidophilus NCFM respectively using LiCl. The protective effect of SLPs on H2O2-induced HT-29 cells oxidative injury was investigated. As results, SLPs (100μg/mL) could significantly mitigate HT-29 cells cytotoxicity, improve the activities of total antioxidant capacity (T-AOC), catalase (CAT) and superoxide dismutase (SOD), decrease the contents of malondialdehyde (MDA) and lactate dehydrogenase (LDH), compared with H2O2-induced group (P<0.05). Furthermore, SLPs were also shown to attenuate the apoptosis rate (10.94-24.03%, P<0.01), suppress the elevation of intracellular reactive oxygen species (ROS) and calcium levels, restore mitochondrial membrane potential (MMP) and block the activation of apoptosis-related proteins of caspase-3 and caspase-9 (P<0.05). Considering all the parameters analyzed, we concluded that Lactobacillus SLPs play an essential role in the antioxidant capacity of HT-29 cells induced by H2O2, and the mechanism could be attributed to SLPs' ability to enhance the activity of the intracellular antioxidant enzyme system, reduce ROS accumulation and to inhibit apoptosis by regulating mitochondrial pathway.
authors.affiliation: School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, China.
authors.forename: Bin-Bin
authors.initials: BB
authors.lastname: Zhao
authors.affiliation: School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, China; School of Food Science and Technology, Henan University of Technology, Zhengzhou, Henan Province 450001, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Meng
authors.affiliation: School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, China.
authors.forename: Qiu-Xiang
authors.initials: QX
authors.lastname: Zhang
authors.affiliation: School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, China.
authors.forename: Ting-Ting
authors.initials: TT
authors.lastname: Kang
authors.affiliation: School of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, China. Electronic address: lurr@jiangnan.edu.cn.
authors.forename: Rong-Rong
authors.initials: RR
authors.lastname: Lu
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects; D001426:Bacterial Proteins / Q000302:isolation & purification* / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D019073:HT29 Cells; D006801:Humans; D006861:Hydrogen Peroxide / Q000633:toxicity*; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism; D007778:Lactobacillus / Q000737:chemistry*; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D000975:Antioxidants; D001426:Bacterial Proteins; D017382:Reactive Oxygen Species; D006861:Hydrogen Peroxide; D002118:Calcium
keywords: Apoptosis; Human colon cancer HT-29 cells; Lactobacillus; Oxidative stress; Surface layer proteins