Abstract: To study the effect of Cistanche deserticola phenylethanoside on the expression of β-amyloid protein in hippocampus of mice with Alzheimer disease,60 6-month-old APP/PS1 double-transgenic AD mice were randomly divided into modle groups,donepezil group (0.65 mg/kg),the high,middle,low dosages of total glycosides of Cistanche deserticola (250,125,62.5 mg/kg) and acteoside(125 mg/kg) were given drugs and distilled water for 3 months.At the age of 9 months,the Morris water maze and passive avoidance tests were used to determine the learning and memory impairments,the hippocampal lesions of mice were observed by HE staining,and the expressions of Aβ_1-42 and Aβ_1-40 proteins in hippocampus of mice were detected by immunohistochemical method and Western-blot method.Cistanche deserticola phenylethanoside can significantly improve the learning and memory ability and the damage of hippocampal neurons in APP/PS1 double transgenic mice.Compared with the model group,the number of Aβ_1-42,Aβ_1-40 positive cells in the hippocampus CA1 of the Cistanche deserticola group and the control group was significantly decreased,and the results of Western-blot showed that the expression of Aβ_1-42,Aβ_1-40 protein in hippocampus of Cistanche deserticola in each dose group and the intervention group was significantly lower than that in model group.Cistanche deserticola glycoside can protect neurons and antagonize AD by down-regulating the expression of Aβ_1-42,Aβ_1-40 protein in hippocampus brain of mice.In this study,phenylethanoside was identified as the main effective substance for Cistanche deserticola to exert its anti-AD activity,which provides theoretical support for its further development as a new drug against AD.

Key words: Cistanche deserticola, phenylethanoside, Alzheimer disease, APP/PS1 double transgenic mice, &beta, -amyloid protein