Structural, antioxidant, and immunomodulatory activities of an acidic exopolysaccharide from Lactiplantibacillus plantarum DMDL 9010

Yan-Yan Huang; Jia-Min Wu; Wei-Tong Wu; Jia-Wei Lin; Yan-Tong Liang; Zhen-Zhen Hong; Xiang-Ze Jia; Dong-Mei Liu

doi:10.3389/fnut.2022.1073071

Structural, antioxidant, and immunomodulatory activities of an acidic exopolysaccharide from Lactiplantibacillus plantarum DMDL 9010

Front Nutr. 2022 Dec 8:9:1073071. doi: 10.3389/fnut.2022.1073071. eCollection 2022.

Authors

Yan-Yan Huang^{1

2}, Jia-Min Wu^{1

2}, Wei-Tong Wu^{1

2}, Jia-Wei Lin^{1

2}, Yan-Tong Liang^{1

2}, Zhen-Zhen Hong^{1

2}, Xiang-Ze Jia³, Dong-Mei Liu³

Affiliations

¹ College of Food Science and Engineering, Foshan University, Foshan, Guangdong, China.
² Guangdong Provincial Key Laboratory of Intelligent Food Manufacturing, Foshan University, Foshan, Guangdong, China.
³ School of Food Science and Engineering, South China University of Technology, Guangzhou, Guangdong, China.

Abstract

This study investigated the structural, antioxidant, and immunomodulatory activities of acidic exopolysaccharide (EPS-LP2) isolated from Lactiplantibacillus plantarum DMDL 9010. EPS-LP2 is composed of fucose (Fuc), arabinose (Ara), galactose (Gal), glucose (Glc), mannose (Man), and D-fructose (Fru) with a molar ratio of 0.13: 0.69: 8.32: 27.57: 62.07: 0.58: 0.46, respectively. Structural analysis of EPS-LP2 exhibited a smooth irregular lamellar surface, rod-like structure with swollen ends and slippery surfaces, and good thermal stability. Based on the methylation and NMR analysis, sugar residues including t-Manp, t-Glcp, 2-Manp, 6-Galp, 6-Glcp, and 4-Glcp were found to exist in EPS-LP2. In the 50∼400 μg/ml range, EPS-LP2 showed negligible neurotoxicity to RAW264.7 cells. Moreover, EPS-LP2 could protect RAW264.7 cells from oxidative injury by lowering the generation of reactive oxygen species (ROS), malondialdehyde (MDA), and the secretion of lactate dehydrogenase (LDH). In contrast, an increase in superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and the concentrations of glutathione (GSH) were observed. Immunoreactivity assays showed that EPS-LP2 could suppress the expression of NO, tumor necrosis factor-α (TNF-α), and interleukin 6 (IL-6) and inhibit the activation of the mitogen-activated protein kinase (MAPK)/nuclear factor-κB-gene binding (NF-κB) cell pathway. Conclusively, EPS-LP2 could be a potential natural antioxidant and immunomodulatory agent in functional foods and medicines.

Keywords: Lactiplantibacillus plantarum DMDL 9010; antioxidant activity; exopolysaccharide; immunomodulatory effect; structural characterization; structural features.