食品科学 ›› 2018, Vol. 39 ›› Issue (6): 88-94.doi: 10.7506/spkx1002-6630-201806015

• 生物工程 • 上一篇    下一篇

降胆固醇乳酸菌的体外筛选及其降胆固醇机理探讨

黄燕燕1,郭均1,黎恒希1,杨爱君2,冯立科2,彭小霞2,刘冬梅1,*   

  1. (1.华南理工大学食品科学与工程学院,广东?广州 510640;2.广东燕塘乳业股份有限公司,广东?广州 510640)
  • 出版日期:2018-03-25 发布日期:2018-03-14
  • 基金资助:
    国家自然科学基金面上项目(31771908);广东省自然科学基金项目(S2011010005679); 广东省省级科技计划项目(2013B020312002;2014A020208019);广东燕塘乳业股份有限公司委托项目(D8133540)

In Vitro Screening of Lactic Acid Bacteria for Cholesterol-Lowering Activity and the Underlying Mechanism

HUANG Yanyan1, GUO Jun1, LI Hengxi1, YANG Aijun2, FENG Like2, PENG Xiaoxia2, LIU Dongmei1,*   

  1. (1. School of Food Science and Engineering, South China University of Technology, Guangzhou 510640, China;2. Guangdong Yantang Dairy Co. Ltd., Guangzhou 510640, China)
  • Online:2018-03-25 Published:2018-03-14

摘要: 目的:从开菲尔粒和陈年泡菜水中分离出具有降胆固醇能力的乳酸杆菌,探讨其降解小鼠血清胆固醇的机理。方法:以耐酸性、胆盐耐受性、疏水性、胆盐水解酶活性以及降胆固醇特性筛选出1株性状优良的植物乳杆菌(Lactobacillus?plantarum?DMDL?9010)。将50?只8?周龄的Sprague?Dawley大鼠随机分为正常组、模型组、阳性组、9010高组、9010低组,分别饲喂28?d和70?d采血,测定总胆固醇(total cholesterol,TC)、甘油三酯(triglyceride,TG)、高密度脂蛋白胆固醇(high density lipoprotein-cholesterol,HDL-C)、低密度脂蛋白胆固醇(low density lipoprotein-cholesterol,LDL-C)的含量,70 d取肝组织细胞实时荧光逆转录聚合酶链式反应检测胆固醇合成限速酶3-羟基-3-甲基戊二酸单酰辅酶A还原酶(3-hydroxy-3-methylglutaryl-CoA reducase,HMGCR)的相对表达量。结果:筛选得到1株具有降胆固醇能力的L.?plantarum DMDL 9010,胆固醇去除率为37.58%,胆盐耐受性为35.48%,疏水性高达40%,具有较好的耐酸性。饲喂第28天,成功建出高脂模型大鼠,饲喂第70天,9010高组能显著降低高脂大鼠血清TC(23.03%)和LDL-C(28.00%),9010低组和阳性组无明显差异。阳性组和9010高组分别下调肝脏中HMG-CoA基因mRNA的表达(79.92%和62.86%)(P<0.05)。结论:实验获得了1?株在体内外均具有高效降胆固醇能力的L.?plantarum?DMDL?9010,可进一步开发为功能性微生态制剂。

关键词: 降胆固醇, 乳酸菌, 分离, 鉴定, 3-羟基-3-甲基戊二酰辅酶A还原酶

Abstract: Objective: To screen 29 Lactobacillus strains isolated from kefir grains and fermented pickles for cholesterol-lowering activity and to explore the mechanism of action of the selected isolates in degrading serum cholesterol in rats. Methods: One of these isolates, identified as Lactobacillus plantarum DMDL 9010, was selected for its acid resistance, bile salt tolerance, hydrophobicity, bile salt hydrolase activity and cholesterol-lowering property. A feeding experiment was conducted on fifty eight-week-old Sprague Dawley rats, which were randomly divided into normal diet control, hyperlipidaemic diet control, positive (atorvastatin calcium) control, high-dose and low-dose DMDL 9010 groups. The rats were fed for 10 weeks. The serum levels of total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol (LDL-C) were determined on the 28th and 70th day of the experiment. The real-time fluorescence reverse transcription PCR was used to detect the expression level of 3-hydroxy-3-methylglutaryl-CoA reducase (HMGCR) as the rate-limiting enzyme for cholesterol synthesis. Results: L. plantarum DMDL 9010 was capable of 37.58% degradation of cholesterol and showed 35.48% tolerance to bile salt and a hydrophobicity of up to 40%. It had good acid resistance. A hypercholesterolemic rat model was successfully constructed after feeding a high-cholesterol diet for 28 days. Administration of high-dose DMDL 9010 for 70 days significantly reduced serum TC (23.03%) and LDL-C (28.00%), but there was no significant difference between the low-dose and positive control groups. The positive control and high-dose groups significantly down-regulated the expression level of HMG-CoA mRNA in the liver (79.92% and 62.86%, respectively) (P < 0.05). Conclusion: It is possible to develop L. plantarum DMDL 9010 into a functional microecological agent.

Key words: cholesterol-lowering, Lactobacillus, isolate, identification, HMGCR

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