植物乳杆菌Lp2对脂多糖诱导的小鼠急性肝损伤的保护作用

Protective Effect of Lactobacillus plantarum Lp2 on Acute Liver Injury Induced by LPS in Mice

目的:研究植物乳杆菌Lp2对急性肝损伤小鼠的保护作用。方法:从中国传统发酵食品中分离到植物乳杆菌Lp2,研究其改善脂多糖(LPS)诱导的小鼠肝脏炎症的作用机制。将30只昆明种小鼠随机分为3组:对照组、模型组(LPS组)和干预组(LPS+Lp2组)。每日对干预组小鼠补充植物乳杆菌Lp2,4周后,对模型组和干预组小鼠腹腔注射LPS,构建急性炎症模型。通过对生化指标和肝组织病理学的评价,观察小鼠肝损伤情况。采用RT-PCR和免疫印迹分析肠道mRNA水平、蛋白表达水平。结果:植物乳杆菌Lp2可降低LPS诱导的急性炎症小鼠血清、肝脏和回肠组织中谷草转氨酶(AST)、谷丙转氨酶(ALT)、肿瘤坏死因子-α(TNF-α)、白介素-1β(IL-1β)、白介素-6(IL-6)、一氧化氮(NO)、环氧合酶-2(COX-2)、丙二醛(MDA)、髓过氧化物酶(MPO)和LPS水平,升高超氧化物歧化酶(SOD)、谷胱甘肽过氧化酶(GSH-Px)和过氧化氢酶(CAT)的水平,明显改善LPS诱导的急性肝损伤。RT-PCR和免疫印迹分析表明,LPS引起小鼠肠道上皮紧密连接蛋白表达显著下降,植物乳杆菌Lp2明显上调紧密连接蛋白ZO-1、Occludin和Claudin-1的表达,改善LPS炎症小鼠的肠道通透性,肝脏LPS显著降低。结论:植物乳杆菌Lp2通过抑制氧化应激、炎症反应和调节肠道通透性对LPS诱导的急性肝损伤具有保护作用。

Objective:To study the protective effects of Lactobacillus plantarum Lp2 on acute liver injury in mice.Methods:The effect and mechanism of L.plantarum Lp2 isolated from traditional Chinese fermented foods on improving lipopolysaccharide(LPS)induced liver inflammation in mice were studied.Male KM mice were randomly assigned into three groups:Control group,model group(LPS group),and intervention group(LPS+Lp2 group).The mice in the LPS+Lp2 group were supplemented with L.plantarum Lp2 every day.After 4 weeks,the mice in the LPS group and the LPS+Lp2 group were injected intraperitoneally with LPS to construct acute inflammation model.The liver injury of LPS-induced mice was observed through the evaluation of biochemical indexes,liver histopathology,mRNA and protein expression level.Result:L.plantarum Lp2 treatment reduced significantly the levels of aspartate transaminase(AST),alanine aminotransferase(ALT),tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β),interleukin-6(IL-6),nitric oxide(NO),cyclooxygenase-2(COX-2),malondialdehyde(MDA),myeloperoxidase(MPO)and LPS in serum,liver and ileum tissue of mice with acute inflammation induced by LPS,and increased the levels of superoxide dismutase(SOD),glutathione peroxidase(GSH-Px)and catalase(CAT).RT-PCR and western-blotting analysis showed that L.plantarum Lp2 pretreatment reduced ileum protein expression of ZO-1,Occludin and Claudin-1.Conclusion:L.plantarum Lp2 ameliorates LPS-induced acute liver disease by improving intestinal barrier integrity,inhibiting oxidative stress and attenuating inflammation.