双参中多糖类成分对糖尿病肾病的治疗作用及其机制研究

Diabetic nephropathy (DN) is one of important complications in diabetes. Plant polysaccharides have been widely appreciated for the usage in prevention and treatment of diabetes mellitus and its complications. Medicinal plant Triplostegia glandulifera has been used for a long time in prevention and treatment of diabetic nephropathy in the western of Yunnan, but it remains unclear what are the effective constituents and mechanism for the prevention and treatment of diabetic nephropathy. Our previous experiments confirmed that the crude extract of T. glandulifera could obviously decrease high blood sugar and could obviously protect the kidney on experimental diabetic mice. Further studies found that the crude polysaccharide from T. glandulifera has the remarkable protective effect on high glucose incubated human glomerular mesangial cells. This project intends to separate and purify homo-polysaccharides from the crude polysaccharides of T. glandulifera and prepare their oligosaccharides by modern phytochemical methods. At the same time, human glomerular mesangial cell model cultured in high glucose and diabetic nephropathy animal model in mice made by high-fat-glucose diet combined with STZ induced, will be used to investigate therapeutic effect and mode of action of the homo-polysaccharides and their oligosaccharides in diabetic nephropathy, and to evaluate effects of the effective fractions and bioactive constituents of the homo-polysaccharides and their oligosaccharides from T. glandulifera. The expressions of Nox4 and TRPC6 in the kidney tissue of experimental diabetic nephropathy mice will be simultaneously detected so as to discuss the preliminary probe into their mechanisms. The structure of active oligosaccharides will be determined by modern spectroscopic methods，and the preliminary structure of oligosaccharides and activity relationship will be discussed. This research would find the anti-diabetic nephropathy natural effective fractions and bioactive constituents with independent intellectual property rights. Finally, it will do provide scientific basis for the follow-up research and development.

糖尿病肾病（DN）是糖尿病的重要并发症。植物活性多糖在防治糖尿病及其并发症的优势已受到医药界普遍关注。双参在滇西地区民间长期用于防治糖尿病肾病，疗效确切，但其有效成分和作用机制尚未明了。本课题组前期证实：双参粗提物对糖尿病模型小鼠有明显的降血糖效果以及对其肾器官有明显的保护作用，进而发现双参中总多糖对高糖培养的人肾小球系膜细胞具有显著的保护作用。本项目拟从双参中分离纯化均一多糖，制备其寡糖。用高糖培养的人肾小球系膜细胞模型和高糖高脂加STZ诱导的糖尿病肾病动物模型，探讨双参均一多糖和寡糖类成分对糖尿病肾病的治疗作用，对其组分和单体的活性做出评价；检测模型小鼠肾组织中Nox4和TRPC6的表达情况，初步探讨其作用机制。用现代分析方法解析活性寡糖的结构，并初步分析其结构与活性之间的关系。研究成果有望成为具有自主知识产权的新型防治糖尿病肾病天然组分和单体化合物，为后续的产品研发提供科学依据。

糖尿病肾病（DN）是糖尿病的重要并发症。本项目从双参中得到活性组分、均一多糖和寡糖类成分。部分双参活性组分、低分子量均一多糖和寡糖对高糖培养的肾小球系膜细胞模型和STZ诱导的糖尿病肾病动物模型具有显著治疗作用，其作用机制可能是活性物质提高了模型小鼠肾脏的抗氧化能力、调整糖脂代谢紊乱以及改善肾功能，以及升高了模型细胞内T-SOD、SOD活性，降低了MDA和ROS的含量，使模型细胞中Nox-4的表达水平下调，从而减少氧化应激反应，进而保护肾脏损伤和改善糖尿病肾病。用波谱学方法解析了活性均一多糖和寡糖的结构，初步分析其结构与活性之间的关系。此外，本项目还从双参中分离鉴定了30个化合物，对量丰活性成分进行结构修饰，合成了36个新马钱苷衍生物，其中，13个化合物对肾小球系膜细胞模型具有保护作用，8个化合物显著升高了模型细胞内SOD活性，降低了MDA含量，缓解模型细胞的氧化应激作用，4个马钱苷衍生物对α-葡萄糖苷酶具有显著抑制作用。研究成果有望成为具有自主知识产权的新型防治糖尿病肾病天然组分和单体化合物，为药用植物双参的民间应用及后续的产品研发提供技术支撑和科学依据。