柴胡配方颗粒对高三酰甘油血症模型大鼠的降脂作用及机制研究

Effect and mechanism of formulae Bupleuri Radix Granule on hypertriglyceridemia in fructose-fed rats

关键词:  柴胡配方颗粒  高三酰甘油  降血脂  脂肪组织  AMPK/SIRT1/PGC-1α

Key words:  formulae Bupleuri Radix Granule  high triglycerides  hypolipidemic  adipose tissue  AMPK/SIRT1/PGC1α

摘要:

[目的] 观察柴胡配方颗粒对高三酰甘油血症模型大鼠的降脂作用，并探讨其可能的作用机制。[方法] 将40只Sprague Dawley（SD）大鼠随机分为正常对照组、果糖诱导组和柴胡组，采用10%（W/V）果糖水构建高三酰甘油血症模型大鼠，柴胡组同时灌胃给予柴胡配方颗粒高、中、低剂量。实验4周后，进行口服葡萄糖耐量实验（OGTT）、测定血浆三酰甘油和葡萄糖含量。实验5周末，处死大鼠，取肝脏、附睾周围脂肪组织，利用苏木精-伊红染色法（HE染色）观察附睾周围脂肪组织的形态学变化，利用实时定量聚合酶链反应（qRT-PCR）及蛋白免疫印迹（Western-blot）等技术检测肝脏和附睾白色脂肪组织（eWAT）相关基因和蛋白的表达情况。[结果] 柴胡配方颗粒明显缓解高果糖所致大鼠血浆三酰甘油的升高（P<0.05）及OGTT受损。各组肝脏组织匀浆三酰甘油含量无明显影响。柴胡配方颗粒对高果糖饮食诱导的大鼠肝脏脂质合成转录基因[碳水化合物反应元件结合蛋白（ChREBP）]、脂肪酸合成基因[脂肪酸合成酶（FASN）、硬脂酰辅酶A去饱和酶-1（SCD-1）]与脂肪酸代谢基因[重组人成纤维细胞生长因子-21（FGF21）]的增加，以及脂肪酸氧化基因[过氧化物酶体增殖物激活受体-ɑ（PPAR-ɑ）、肉碱棕榈酰转移酶-1ɑ（CPT1ɑ）、过氧化物酶体增殖物活化受体γ协同刺激因子-1ɑ（PGC-1ɑ）]等的降低均无显著影响。此外，柴胡配方颗粒可显著减小高果糖饮食大鼠eWAT细胞的体积，促进eWAT中AMP依赖蛋白激酶（AMPK）的磷酸化，同时明显增加PGC-1α与沉默调节蛋白1（SIRT1）蛋白水平的表达。[结论] 柴胡配方颗粒可通过增强eWAT的AMPK/SIRT1/PGC-1α信号转导，进而改善高果糖诱导高三酰甘油血症模型大鼠血脂异常。

Abstract:

[Objective] To observe the lipid-lowering effect of formulae Bupleuri Radix granules on fructose-induced hypertriglyceridemia rats and explore its potential pharmacological mechanisms. [Methods] Forty Sprague Dawley(SD) rats were randomly divided into normal control group, fructose-induced group and formulae Bupleuri Radix group. Fructose-induced group rats were treated with 10% fructose water(W/V, prepared daily), while formulated Bupleuri Radix groups were intragastricly administrated with different doses of formulae Bupleuri Radix Granules (including high, middle and low dose). Oral glucose tolerance test (OGTT) was performed at the end of week 4. Blood was collected for detecting the plasma biochemical indexincluding triglyceride(TG) and glucose. Moreover, epididymal white adipose tissue(e-WAT) and the liver were collected. The morphological changes of e-WAT were observed by haematoxylin and eosin (HE) staining, meanwhile, the expression of related genes and proteins of e-WAT orliver were detected by real-time quantitative polymerase chain reaction(qRT-PCR) and Western-blot analysis. [Results] Formulae Bupleuri Radix Granules significantly alleviated fructose-induced increase of plasma TG(P<0.05) and improved glucose tolerance, while there is no significant change in hepatic TG among these groups. Moreover, there were no obvious effect of formulae Bupleuri Radix Granules on the increase of lipid synthesis transcription including gene carbohydrate response element binding protein(CHREBP), fatty acid synthesis gene[fatty acid synthase (FASN), stearoyl-CoA desaturase-1 (SCD1) and fatty acid metabolism gene recombinant human fibroblast growth factor-21 (FGF21)]. Meanwhile, formulae Bupleuri Radix granules caused no significant changes of the reduction of fatty acid oxidation gene such as peroxisome proliferator activated receptor-α (PPAR-α), carnitine palmitoyl transferase-1α (CPT1α) and peroxisome proliferator-activated receptor-γ coactivator 1α(PGC-1α)in the liver of high fructose-fed rats. Additionally, formulae Bupleuri Radix Granules could obviously reduce the cell volume of eWAT, and it also promote the phosphorylation of AMP-dependent protein kinase (AMPK), increase the expression of PGC-1α and SIRT1 in eWAT of fructose-fed rats. [Conclusion] Formulae Bupleuri Radix Granules ameliorated hypertriglyceridemia through strengthening AMPK/SIRT1/PGC-1α signal transduction in eWAT of fructose-fed rats.