Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, 127 Youyi West Road, Xi'an, Shanxi Province 710072, China.
College of Enology, Northwest A&F University, Yangling, Shaanxi, China.
Int J Biol Macromol. 2023 Apr 30;235:123845. doi: 10.1016/j.ijbiomac.2023.123845. Epub 2023 Mar 1.
Crude exopolysaccharides produced by Lacticaseibacillus rhamnosus SHA113 were previously found to exhibit anti-alcoholic gastric ulcer activity in mice, but their major active fraction, structural characteristics, and underlying mechanisms remain unknown. Here, LRSE1 was identified as the active exopolysaccharide fraction produced by L. rhamnosus SHA113 responsible for the above effects. Purified LRSE1 had a molecular weight of 4.9 × 10 Da and was comprised of L-fucose, D-mannose, D-glucuronic acid, d-glucose, D-galactose, and L-arabinose in the molar ratio of 2.4:6.5:1.2:1.00:0.3:0.6, respectively. The oral administration of LRSE1 resulted in a significant protective and therapeutic effect on alcoholic gastric ulcers in mice. These effects were identified to involve a reduction in reactive oxygen species, apoptosis, and the inflammatory response, increases in antioxidant enzyme activities, and increases in the phylum Firmicutes and decreases in the genera Enterococcus, Enterobacter, and Bacteroides in the gastric mucosa of mice. In vitro experiments showed that the administration of LRSE1 both inhibited apoptosis in GEC-1 cells via the TRPV1-P65-Bcl-2 pathway and inhibited the inflammatory response in RAW264.7 cells via the TRPV1-PI3K pathway. For the first time, we have identified the active exopolysaccharide fraction produced by Lacticaseibacillus that protects against alcoholic gastric ulcers and determined that its effect involves TRPV1-mediated pathways.
先前发现鼠李糖乳杆菌 SHA113 产生的粗胞外多糖具有抗酒精性胃溃疡活性，但它们的主要活性部分、结构特征和潜在机制仍不清楚。在这里，LRSE1 被鉴定为负责上述作用的鼠李糖乳杆菌 SHA113 产生的活性胞外多糖部分。纯化的 LRSE1 的分子量为 4.9×10 Da，由 L-岩藻糖、D-甘露糖、D-葡萄糖醛酸、d-葡萄糖、D-半乳糖和 L-阿拉伯糖组成，摩尔比分别为 2.4:6.5:1.2:1.00:0.3:0.6。LRSE1 的口服给药对小鼠酒精性胃溃疡具有显著的保护和治疗作用。这些作用被确定涉及活性氧、凋亡和炎症反应的减少，抗氧化酶活性的增加，以及小鼠胃黏膜中厚壁菌门的增加和肠球菌属、肠杆菌属和拟杆菌属的减少。体外实验表明，LRSE1 的给药通过 TRPV1-P65-Bcl-2 途径抑制 GEC-1 细胞中的凋亡，通过 TRPV1-PI3K 途径抑制 RAW264.7 细胞中的炎症反应。我们首次鉴定出具有抗酒精性胃溃疡作用的乳杆菌属胞外多糖活性部分，并确定其作用涉及 TRPV1 介导的途径。
