一株植物乳杆菌体内降胆固醇的作用机制

目的:通过构建高胆固醇血症模型小鼠评价该菌株对小鼠体内胆固醇代谢及相关基因表达的影响。方法:以健康C57BL/6雄性小鼠为对象,设置空白组、模型组、低剂量组、高剂量组、普伐他汀对照组,分别以生理盐水、KLDS1.0386悬浊液和普伐他汀连续灌胃4周,检测小鼠血清胆固醇、甘油三酯、低密度脂蛋白和高密度脂蛋白水平;采用Western blotting法检测小鼠肝脏胆固醇几个关键基因(HMGCR,LDLR,SREBP2,CYP7A1,FXR)表达水平的变化。结果:灌胃KLDS1.0386后,高剂量组小鼠血清甘油三酯、总胆固醇和低密度脂蛋白水平明显降低(P<0.05);HMGCR和FXR的表达明显受到抑制(P<0.05),CYP7A1的表达量增加(P<0.05)。结论:获得一株在体内具有高效降胆固醇能力的植物乳杆菌KLDS1.0386,该菌可用作降胆固醇的益生菌。

Molecular Mechanisms for in Vivo Cholesterol-lowering Effect by Lactobacillus plantarum

Objective:It was evaluated that the effect and genes related to hepatic cholesterol metabolism of Lactobacillus plantarum KLDS strain on the cholesterol metabolism in hyperlipidemia mice.Method:Health C57BL/6 male mice,as objects,were divided into control group,model group,low-dose group,high-dose group and pravastatin group,which were respectively given normal saline,Lactobacillus plantarum KLDS1.0386 bacteria suspension and pravastatin solution by gavage for 4 consecutive weeks.The serum levels of total cholesterol(TC),triglyceride(TG),low density lipoprotein-cholesterol(LDL-C)and high density lipoprotein-cholesterol(HDL-C)were determined on the 28th day of the experiment.The genes related to hepatic cholesterol metabolism(HMGCR,LDLR,SREBP2,CYP7A1,FXR)were investigated in mice.Results:After 4 weeks administration,compared with mice fed a high-cholesterol diet without lactic acid bacteria supplementation,there was a significant(P<0.05)decrease in TG,the total cholesterol and LDL-C levels in the serum,and the mice fed the KLDS1.0386 diet had significantly(P<0.05)the down-regulation of HMGCR and FXR(P<0.05)and the up-regulation of CYP7A1(P<0.05).Concluton:Lactobacillus plantarum KLDS1.0386 has probiotic potential as indicated by its hypocholesterolemic effect both in vivo,it could be as the probiotics with cholesterol-lowering activity.