抽象的

2018 年营养峰会番石榴叶提取物对饮食诱导的胰岛素抵抗 C57BL/6J 小鼠葡萄糖和脂质稳态的影响 - 江文迪 - 东海大学食品科学系教授兼农学院院长

蒋文迪

代谢综合症是指同时存在多种代谢异常状况,糖耐量受损、血脂异常、包括腹型肥胖高血压等症状。这些代谢异常通常是许多慢性疾病、心血管疾病,包括二型糖尿病和高血压的象征。肥胖主要是因为能量摄入过多,导致体内不必要的脂肪堆积。Bays所描述的 糖尿病、高血压和血脂异常患者 分别有84%、79%和82%有超重或肥胖的现象,显示了肥胖与代谢综合症的密切关联。基于上述,体内不必要的脂肪堆积会导致胰岛素抵抗的发生,代表改善肥胖对于预防和改善代谢综合症的重要性。

过氧化物酶体增殖启动受体γ(PPAR-γ),正是并优先在脂肪细胞中表达,主要负责调节胰岛素敏感性、炎症、细胞分化和胰岛素敏感性,PPAR-γ可受脂肪酸、药物等调控,并影响与脂类和糖代谢有关的基因表达。

番石榴叶通常被用作东方共和国糖尿病患者的传统民间草药。近年来,动物模型和人体临床研究报告了番石榴叶提取物的抗高血糖和抗代谢状况活性。本研究全面评估了 GvEx 对高果糖高脂肪营养的胰岛素抵抗 C57/BL6J 小鼠的白色脂肪、肝脏和骨骼肌组织中代谢疾病发展的作用机制。

材料与方法

植物材料和GvEx制剂

Plant material and GvEx preparation were was described in our earlier study (Liu et al., 2014). Briefly, Jen Ju Pa leaves were collected at the period between in the initial appearance and the observable opening of the flower buds. The plant materials were taxonomically recognized and the data have been deposited at the Fengshan Tropical Horticultural Experiment Branch, Taiwan Agricultural Research Institute Council of Agriculture, Executive Yuan). Guava leaf extraction was performed with the best extraction conditions which were derived from a response surface of methodology.

Animals

Ten week old male C57BL/6J mice were found from Taiwan NLAC. All mice were housed in a climate controlled room with 20-24°C temperature, 40-60% humidity, 12 hour dark and light cycle, and free access to the normal chow and water at the farming college of Tunghai university.According to the result of our preceding in vitro study, 200 and 400μg/ml GvEx (ED50 in vitro), respectively, showed knowingly increased the rate of the glucose uptake in both normal and insulin resistant cells.

Induction of insulin resistance and GvEx treatment

To induce insulin resistance, the C, P, TL, TM, TH groups were fed with high fat diet and 30% (w/v) fructose was added to the drinking water. These mice were gavage controlled with their relatively treatment at the start of high fructose high fat feeding.

 Biochemical measurement

The concentrations of serum triglycerides (TG), , glutamate oxaloacetate transaminase (GOT), cholesterol (CHOL) and glutamate pyruvate transaminase (GPT) levels were determined by regular biochemistry assays using the corresponding commercial enzyme kit on a Biochemical Analyser. 

Homeostatic model assessment-insulin resistance (HOMA-IR)

The HOMA model is a method used to the quantify insulin resistance and β-cell function from fasting serum glucose and the insulin attentions. The model has been was widely used since it was first published. After 14 h fasting, the blood glucose and insulin in the attentions of the mice were obtained and used to HOMA-IR calculation.

Hematoxylin-eosin (HE) stain

HE stain is the most widely used the method in histology and histopathology analysis. It is a relatively simple method to demonstrate a wide range of cytoplasmic and nuclear, extracellular matrix features on the paraffin or frozen sections. Liver matters were was harvested and fixed in 10% neutral formalin, embedded in paraffin, cut into 6-μm-thick sections on slides, and stained with the hematoxylin and eosin. Before immunostaininz, deparaffinization was performed by the xylene and graded ethanol to distilled water

Results

补充 GvEx 可显著降低高果糖高脂肪喂养小鼠的体重。研究开始时,各组间平均体重无差异。治疗 10 周后,与 C(34.4 ± 2.3 g)相比,TH(30.8 ± 2.2 g)组的平均体重显著最低,其次是 TM(31.8 ± 2.7 g)和 P(32.3 ± 1.9 g),这表明 GvEx 对降低体重有益。此外,高剂量 GvEx 可显著降低高果糖高脂肪喂养小鼠的附睾脂肪和白色脂肪组织(肾周脂肪、腹部脂肪和附睾脂肪的总和)的重量。先前的研究表明,在高脂饮食引起的肥胖小鼠中,用不同剂量的 番石榴 叶提取物治疗可以降低体重和内脏脂肪堆积,并且降低作用具有剂量依赖性。

 GvEx对代谢综合征的改善作用

多项研究表明,高果糖高脂饮食可诱发胰岛素抵抗、高胰岛素血症甚至糖尿病和高血糖症。导致这些症状发生的主要原因包括:饮食引起的血液甘油三酯水平升高会减少激活的胰岛素受体数量,从而降低胰岛素敏感性。高果糖高脂饮食引起的慢性炎症和高氧化应激状态会降低磷酸化胰岛素受体的水平,减少脂肪组织中脂联素的表达量,从而降低对胰岛素的敏感性并扰乱糖脂代谢的稳态

根据以上结果,我们提出GvEx可以恢复高果糖高脂饮食引起的代谢综合征状态,刺激脂肪、骨骼肌组织和肝脏中的脂质和葡萄糖代谢相关信号。

结论

我们评估了 GvEx 对胰岛素抵抗 C57BL/6J 小鼠高果糖高脂肪饮食诱导的代谢综合征状态发展的影响。我们的结果表明,施用高剂量 GvEx 具有防止脂质积聚和改善胰岛素抵抗的作用。这种作用的机制是通过增强肝脏和骨骼肌组织以及脂肪中的葡萄糖和脂质代谢相关信号。

注:第 21 届世界营养与食品科学大会将于 2018 年 7 月 9 日至 10 日在澳大利亚悉尼举行。

免责声明: 此摘要通过人工智能工具翻译,尚未经过审核或验证