【作者】 刘智华；

【导师】 李青旺；

【作者基本信息】 西北农林科技大学 ， 动物学， 2007， 硕士

【摘要】 糖尿病是一种慢性的内分泌代谢性疾病,目前已成为危害人类健康的致死性疾病之一,寻找治愈糖尿病及其并发症的有效药物已成为当今医药界的热点。在抗糖尿病药物中,合成药物具有明显的副作用,因此筛选安全、有效的天然降血糖药物具有重要实际意义。本试验以女贞子的提取物齐墩果酸为研究对象,对其降血糖的功能进行了研究。(1)本试验研究了女贞子齐墩果酸的提取工艺。对女贞子果实进行皮仁分离、95%乙醇超声提取、酸沉淀、碱处理、盐析、酸处理、活性碳脱色、正己烷脱脂、冷冻干燥和重结晶,得到了齐墩果酸的白色针状结晶。经检测,齐墩果酸在95%乙醇溶液中的溶解性稳定,比旋光度为+73.3°,含量达到96.98%。(2)建立了四氧嘧啶糖尿病小鼠模型。结果表明,18～22 g小鼠糖尿病模型的最佳四氧嘧啶剂量为雌性260 mg/kg,雄性270 mg/kg。(3)将四氧嘧啶诱导的糖尿病小鼠随机分为四组:糖尿病组、齐墩果酸组、优降糖组和正常组。结果表明,齐墩果酸明显降低糖尿病小鼠的血糖以及血清中TC、TG和LDL-c的含量(P<0.05),并有效增加HDL-c的含量(P<0.05)。与正常组相比较,糖尿病组血清中的AST、ALT、HbAl-c和ALP明显升高(P<0.05),而给予齐墩果酸治疗后明显下降(P<0.05)。此外,齐墩果酸明显抑制糖尿病小鼠肝、肾组织中MDA含量的增加(P<0.05),而增强SOD、T-AOC和GSH-Px的活性(P<0.05)。免疫器官指数表明齐墩果酸明显增加糖尿病小鼠的脾脏指数和胸腺指数(P<0.05)。病理切片显示齐墩果酸对受损的胰岛细胞有保护作用。上述研究揭示齐墩果酸可能通过提高非特异性免疫力、清除自由基、增强抗氧化、保护肝脏、肾脏和胰腺细胞等作用,从而改善四氧嘧啶诱导的糖尿病小鼠的症状,降低了血糖。更多还原

【Abstract】 Diabetes Mellitus (DM),a severe,chronic form of endocrinopathic metabolic disease, Now diabetes has been one of the leading cause of death.Thus the screening of new compounds including plant extracts for antidiabetic effects is mandatory.In the research of antidiabetic medicament,there are many evident side-effects of the synthetic medication during treatment.So screening effective and lowering side-effect medication becomes very important in Chinese herb investigation.The extraction of Oleanolic acid which from Ligustrum lucidum Ait was used,antidiabetic function and it’s mechanism was researched.(1)The separating procedures of Oleanolic acid from Ligustrum lucidum Ait was researched.The main separating procedures were described as follows,Dried fruits of Ligustrum lucidum Ait,Dissociation on shelled rapeseed,Ultrasonic Extraction with ethanol of 95 percent,Acid precipitation,Alkali treatment,Salting-out,Acid treatment,decolour with activated carbon,Degreasing with n-hexane and then freezedried to get powde.then recrystallized into white needle crystal-oleanolic acid.By determination,The effective component had a good solubility in 95%ethanol,[a]D21=+73.3°.The results showed that the oleanolic acid in white needle crystal was about 96.98%.(2)Optimal experimental conditions for establishing a diabetic model with alloxan in ICR mice,Result shows the optimal dosage of alloxan about female mice with body weight 18～22 g was 260 mg/kg.The male mice was 270 mg/kg.(3)The alloxan-induced hyperglycemic mice were randomized to three groups,diabetes vehicle group,oleanolic acid group,glibenclamide group and normal mice were set up as vehicle group.result shows administration of OLA significantly decreased fasting blood glucose levels,serum contents of TC,TG,LDL-c,and effectively increased HDL-c in diabetic mice (P<0.05).The levels of AST,ALT,HbA1-c,and ALP were significantly increased in the plasma of untreated alloxan-diabetic mice compared to normal vehicle group(P<0.05),and decreased in OLA-treated diabetic mice(P<0.05).Furthermore,OLA treatment significantly blocked the increase of MDA in liver and kidney tissues(P<0.05),but increased SOD,T-AOC and GSH-Px levels in diabetic mice (P<0.01).Immune organ’s index means OLA can increase the spleen index and thymus index(P<0.05).Histopathological results showed that OLA could restore the damage of pancreas tissues in diabetic mice.These result shows OLA can remove the free radical,increase antioxidation, improve immunity,protect liver,kidney and pancreatic cells from alloxan induced injuries.By through these ways we know OLA improved the symptoms of alloxan-induced diabetes in our mouse model,decrease serum glucose in alloxan-induced hyperglycemic mice.更多还原