姜黄素抑制Caco_2细胞胆固醇吸收的作用及机制研究_冯丹

姜黄素抑制Caco-2细胞胆固醇吸收的

作用及机制研究

冯 丹，凌文华

（广东省营养膳食与健康重点实验室，中山大学公共卫生学院，广州 510080） 【摘 要】目的探讨姜黄素对Caco-2细胞胆固醇吸收的影响以及可能机制。方法建立Caco-2 细胞单层模型，分别用25、50、100 µmol/L 姜黄素或胆固醇吸收转运蛋白尼曼-匹克C1型类似蛋白1（NPC1L1）的抑制剂依折麦布孵育细胞24h或2h后，再用[14C]-胆固醇微胶溶液孵育细胞2h。用液闪计数仪检测细胞胆固醇吸收量，荧光定量 PCR 和Western blot检测NPC1L1的基因和蛋白表达量。结果Caco-2细胞[14C]-胆固醇吸收可被依折麦布呈浓度依赖性地抑制，表明本研究建立的单层Caco-2细胞模型的胆固醇吸收是由NPC1L1所介导的。姜黄素能有效的下调NPC1L1的基因及蛋白表达水平，降低Caco-2细胞胆固醇吸收，100 µmol/L 姜黄素可引起40% 胆固醇吸收下降。结论姜黄素能够降低Caco-2细胞胆固醇吸收，这可能与其抑制NPC1L1表达有关。[营养学报，2011，33（5）：488－491]

关键词：姜黄素；NPC1L1；胆固醇；Caco-2细胞

中图分类号： R151.41 文献标识码：A 文章编号：0512-7955（2011）05-0488-04

THE INHIBITORY EFFECT OF CURCUMIN ON Caco-2 CELLS

CHOLESTEROL ABSORPTION AND THE MECHANISM

FENG Dan，LING Wen-hua

(Guangdong Provincial Key Laboratory of Food, Nutrition and Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China)

【Abstract】 Objective To investigate the effects of curcumin on intestinal cholesterol absorption and the possible mechanisms. Method The delipidized fetal bovine serum and the micelles composed of bile salt, monoolein, and 14C-cholesterol were prepared. Caco-2 cells were pretreated with 25, 50, 100 µmol/L curcumin or Niemann-Pick C1-Like 1 (NPC1L1) inhibitor ezetimibe for 24h or 2h respectively, and then incubated with cholesterol micelle solution for anther 2h. The absorption of cholesterol in Caco-2 cells was determined by liquid scintillation counting. The mRNA and protein expression of NPC1L1 was analyzed by qPCR and Western blot respectively. Results The absorption of radioactive cholesterol in Caco-2 cells was inhibited by ezetimibe in dose-dependent manner. The absorption of cholesterol was mediated by NPC1L1. The cells were pretreated with 25-100 µmol/L curcumin for 24 h and cholesterol absorption was 40% inhibited dose-dependently by 100 µmol/L curcumin. In addition, the curcumin induced inhibition of cholesterol absorption was associated with significant decrease in the levels of NPC1L1 mRNA and NPC1L1 protein. Conclusion Curcumin inhibits cholesterol absorption by suppression of NPC1L1 expression. [ACTA NUTRIMENTA SINICA, 2011,33(5)：488－491]

Key words：curcumin; NPC1L1; cholesterol; Caco-2 cells

高胆固醇血症是动脉粥样硬化(atherosc- lerosis，AS)性疾病的主要危险因素。大量证据表明，降低血浆低密度脂蛋白胆固醇(LDL-C)水平能显著降低冠心病的发生率和死亡率[1]。体内血浆胆固醇水平受胆固醇生物合成、饮食胆固醇的吸收、胆汁的清除和排泄等几个方面影响，小肠在调节体内胆固醇动态平衡中起着重要作用[2]，完全抑制小肠胆固醇吸收可引起36%血浆胆固醇水平的下降[3]。因而，调节肠道胆固醇吸收成为降脂治疗和防治AS新的重要作用靶点。

胆固醇吸收是一个多步骤调控的复杂过程，主要包括胆固醇在肠道胆盐的乳化作用下形成微

收稿日期 2010-12-22

基金项目 国家“十一五”科技支撑计划项目(No. 2008BAI58B06)；广东省医学科研基金（No.B2011063） 作者简介冯丹（1978 －），女，博士，讲师， E-mail：fengdan3@；通讯作者：凌文华