中文摘要：

目的观察淫羊藿苷（Ica）对侧脑室注射链脲佐菌素（STZ）所致大鼠痴呆模型的保护作用。方法雄性SD大鼠分为假手术组、STZ模型组、Ica给药组。除假手术组外,所有大鼠双侧侧脑室注射STZ（3 mg·kg-1）模拟散发性老年性痴呆,假手术组只注射等体积的溶剂,制模前后分别给予Ica（40 mg·kg-1·d-1）灌胃3周。给药结束后采用Morris水迷宫观察大鼠行为学改变,血糖仪检测空腹血糖,收集海马组织观察乙酰胆碱酯酶（Ach E）和转化生长因子β1（TGF-β1）蛋白表达情况。结果侧脑室注射STZ后Morris水迷宫结果显示大鼠找到水下平台的逃避潜伏期显著延长（P〈0.05）,记忆功能受损,海马组织Ach E和TGF-β1蛋白水平增高（P〈0.05）,而双侧侧脑室注射STZ并不影响大鼠空腹血糖值（P〉0.05）;给予Ica后大鼠逃避潜伏期缩短（P〈0.05）,海马组织Ach E和TGF-β1蛋白高表达状态缓解（P〈0.05）。结论 Ica对侧脑室注射STZ引起认知功能损伤具有保护作用,其机制可能与改善海马组织Ach E和TGF-β1蛋白的高表达相关。

英文摘要：

AIM To investigate the neuroprotective effects of icariin（ Ica） on a rat model of sporadic Alzheimer disease（ SAD） induced by an intracerebroventricular（ ICV） injection of streptozotocin（ STZ）.METHODS Male Sprague- Dawley（SD） rats were randomly divided into 3 groups： Sham, STZ model and Ica groups. After 3 weeks of treatment with Ica（40 mg·kg-1·d-1）, STZ- induced animals were injected with STZ（3 mg·kg-1） bilaterally through ICV on days 1 and 3, while the sham rats received the same volume of vehicle instead of STZ. Ica was administered for another 3 weeks post- surgery. Morris water maze was used to test the behavioural alternation of rats, the serum glucose level was measured, and the protein levels of Ach E and TGF-β1 in the hippocampus of rats were tested by Western blot. RESULTS ICV- STZ resulted in poor retention of memory in Morris water maze（ P〈0.05）. It also increased the protein levels of Ach E and TGF- β1 in the hippocampus（ P〈0.05）, however, ICV- STZ did not affect the serum glucose level compared to the sham animals（P〈0.05）. Ica significantly improved memory function（P〈0.05）, and attenuated the upregulation of protein parameters（P〈0.05）. CONCLUSION The results of the present study indicate the effectiveness of Ica in preventing cognitive impairment induced by ICV- STZ by down- regulating the high level of Ach E and TGF- β1proteins in hippocampus.