壳聚糖及相关产物降脂活性和机制研究

发布时间：2018-05-25 04:08

本文选题：高脂血症 + 壳聚糖　；参考：《广东药学院》2014年硕士论文

【摘要】：高脂血症是一种严重危害人类健康的全身脂质代谢异常疾病，是心脑血管疾病的重要危险因素，随着现代饮食和生活方式的转变，高脂血症已经成为全球性公共卫生问题。目前以化学药物治疗为主，但存在多种严重不良反应。开发安全、有效、不良反应少的天然降血脂药物意义重大。壳聚糖（CTS）是从虾蟹壳中提取出的带正电荷的碱性多糖，具有良好的生物相容性和生物可降解性，大量体内外实验证明壳聚糖具有良好的降脂和减肥活性。但其水溶性差需大剂量服用，易产生恶心、呕吐和便秘等副作用。课题组成员前期将其制备成分散性好、利用度高的壳聚糖微球（CTMS）以及载辣椒碱的壳聚糖微球（CCMS），达到了增强活性和降低副作用的目的。壳寡糖（COSII和COSI）和氨基葡萄糖（GLC）是壳聚糖的降解产物，水溶性高、易吸收且无毒副作用。本实验研究CTS及相关产物对油酸诱导的HepG2细胞内脂质堆积的作用，，MTT法确定安全给药浓度范围，油红O染色后观察细胞形态和脂滴分布，提取油红O定量脂质含量，测定细胞内TG含量。结果表明，CTS、CTMS、CCMS、COSII、COSI和GLC均可有效抑制HepG2细胞内的脂质堆积，显著降低细胞内TG含量，呈剂量依赖性。采用高脂饮食诱导高脂血症大鼠模型，研究CTS及降解产物的降脂药效活性。结果表明，CTS、COSII和GLC可不同程度的减缓高脂血症大鼠的体重、脂体比、Lee's指数、脏器指数的增长，抑制脂肪细胞的生长，具有一定的减肥活性，呈剂量依赖性；可显著降低血清TC、TG和LDL-C含量；减少肝脏中TC和TG含量、增加总胆汁酸（TBA）含量，促进粪便中TC、TG和TBA的排泄，发挥降脂作用。COSII、GLC可不同程度的提高高脂血症大鼠SOD酶活性，具有抗氧化作用。CTS、COSII和GLC可显著降低高脂血症大鼠血清和肝脏中AST、ALT的含量，不同程度地缓解脂肪肝症状，具有保肝护肝作用。为进一步研究CTS及相关物质降脂活性的作用机理，通过Western Blot技术检测其对HepG2细胞内脂质代谢相关的肝脂酶（HL）和过氧化物酶体增殖物激活受体α（PPARα）的蛋白表达。结果显示，CTMS可促进HepG2细胞内HL蛋白和PPARα蛋白的表达，而CTS、CCMS、COSII、COSI和GLC对其表达基本无影响；抑制PPARα基因表达，可显著抑制HL蛋白表达，表明CTMS促进HL蛋白表达与PPARα基因有关；在高TC、TG条件下，CTMS干预后对HL蛋白和PPARα蛋白表达均有促进作用，抑制PPARα基因后，上述作用消失，说明CTMS促进HL蛋白表达影响可能是先通过促进PPARα表达实现。
[Abstract]:Hyperlipidemia is a serious disease of lipid metabolism and an important risk factor of cardiovascular and cerebrovascular diseases. With the change of modern diet and lifestyle, hyperlipidemia has become a global public health problem. At present, chemotherapeutic therapy is the main treatment, but there are many serious adverse reactions. It is of great significance to develop natural hypolipidemic drugs that are safe, effective and less adverse. Chitosan (CTS) is a positively charged alkaline polysaccharide extracted from shrimp and crab shell. It has good biocompatibility and biodegradability. A large number of experiments in vivo and in vitro have proved that chitosan has good lipid-lowering and weight loss activities. However, its poor water-solubility needs a large dose, easy to produce nausea, vomiting and constipation and other side effects. In the early stage, the chitosan microspheres (CTMSs) with good dispersity and high availability and capsaicin loaded chitosan microspheres (CCMSS) were prepared, which achieved the purpose of enhancing the activity and reducing the side effects. Chito-oligosaccharide (COSII and COSI) and glucosamine (GLC) are the degradation products of chitosan, which have high water solubility, easy absorption and no toxic side effects. The effect of CTS and its related products on lipid accumulation in HepG2 cells induced by oleic acid was studied in this experiment. The safe range of administration concentration was determined by MTT method. After oil red O staining, cell morphology and lipid droplet distribution were observed, and the quantitative lipid content of oil red O was extracted. The content of TG in cells was measured. The results showed that both CTS and GLC could effectively inhibit lipid accumulation in HepG2 cells and decrease the content of TG in a dose-dependent manner. Hyperlipidemic rat model was induced by high fat diet to study the antilipidemic effect of CTS and its degradation products. The results showed that CTSS-COSII and GLC could decrease the body weight, fat / body ratio, Leehs index and viscera index of hyperlipidemia rats, inhibit the growth of adipocytes, and have a certain weight loss activity in a dose-dependent manner. TC and TG contents in liver, total bile acid (TBA) content and excretion of TCTG and TBA in feces were significantly decreased, and the activity of SOD in hyperlipidemia rats was increased in different degree. The results showed that the antioxidative activity. CTSS-COSII and GLC could significantly reduce the alt content in serum and liver of rats with hyperlipidemia, relieve the symptoms of fatty liver in varying degrees, and protect the liver and liver of hyperlipidemic rats. In order to study the mechanism of lipid lowering activity of CTS and its related substances, the expression of lipopolipase HL1 and peroxisome proliferator-activated receptor 伪 -PPAR- 伪) in HepG2 cells was detected by Western Blot technique. The results showed that CTMS could promote the expression of HL protein and PPAR 伪 protein in HepG2 cells, but the expression of PPAR 伪 gene was not affected by CTS- CCMS CS-III-COSI and GLC, and the expression of HL protein was significantly inhibited by inhibiting the expression of PPAR 伪 gene, indicating that the expression of HL protein promoted by CTMS was related to PPAR 伪 gene. Under the condition of high TCT-TG, the expression of HL protein and PPAR 伪 protein were promoted by CTMS. After inhibiting PPAR 伪 gene, the above effects disappeared, which suggested that the effect of CTMS on HL protein expression might be achieved by promoting PPAR 伪 expression first.
【学位授予单位】：广东药学院
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R96

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