摘要： Objective：Beta-amyloid （Aβ） deposition is considered as vital factor leading to cognitive impairment in Alzheimer’s disease（ AD）.In addition，there are pathophysiological connections between Type 2 Diabetes Mellitus （T2DM） and AD. Diabetic patients have higher incidences of cognitive impairment and hence they are more at the risk of developing AD. As one of the active compounds of Dendrobium nobile Lindl. Dendrobium nobile Lindl. Alkaloids （DNLA） has the effect of protecting the nervous system and decreased the level of fasting blood glucose （FBG） in T2DM model mice. In this study，we attempted to investigate effects of DNLA on the proteins expression of APP，BACE1 and Aβ42 of hippocampus in db/db mice. Methods：10 male C57BL/KsJ mice were
control group. And 4-week-old mice male db/db mice were randomly divided into four groups：model，DNLA-L（ 20 mg·kg-1），DNLA-M（ 40 mg·kg-1），and DNLA-H （80 mg·kg-1），there are 9 mice in each group. After mice were treated with different concentration DNLA by gavaged for 17 weeks. The protein expression of β-amyloid 42 （Aβ42），β-site amyloid precursor protein-cleaving enzyme 1 （BACE1） and amyloid precursor protein （APP） were examined by Western Blotting. Results：Compared with control group，not only the protein expression of Aβ42，but also BACE1 and APP was signifi cantly increased in hippocampus of model group. Moreover，DNLA signifi cantly decreased the protein expressions of Aβ42，BACE1 and APP in hippocampus of db/db mice compared with model group，and decreased in a dosedependent manner. Conclusion：DNLA can decrease the protein expressions of Aβ42 in hippocampus of db/ db mice. And the mechanism may be involved the decrease of BACE1 and APP.

关键词: Alzheimer&rsquo, s disease, Dendrobium nobile Lindl. Alkaloids, db/db mice, APP, BACE1, A&beta, 42