%A Hai-feng Yuan, Xi LI, Qian-kun Quan, Ning-ning Wang, Yuan Li, Ming Li %T Effects of Naoerkang on expressions of β-amyloid peptide 1-42 and neprilysin in hippocampus in a rat model of Alzheimer’s disease %0 Journal Article %D 2010 %J Journal of Integrative Medicine %R 10.3736/jcim20100210 %P 152-157 %V 8 %N 2 %U {http://www.jcimjournal.com/CN/abstract/article_1680.shtml} %8 2010-02-20 %X

Objective

To investigate the effects of Naoerkang (NEK), a compound traditional Chinese herbal medicine, on the expressions of β-amyloid peptide 1-42 (Aβ1-42) and neprilysin (NEP) in hippocampal tissues in a rat model of Alzheimer’s disease (AD).
Methods

Forty-eight male SD rats were randomly divided into normal control group, untreated group, piracetam group, low-dose NEK group, medium-dose NEK group, and high-dose NEK group, with 8 rats in each group. Five microliters of Aβ1-42 (2 μg/μL) were injected into CA1 area of hippocampus in rat to establish AD model whereas the normal control rats were injected with same volume of normal saline for comparison. The rats in the NEK groups were treated respectively with high-, medium- and low-dose [60, 30, 15 g/(kg·d)] NEK for 28 days consecutively; piracetam [0.375 g/(kg·d)] was intragastrically administered to rats in the piracetam group; and normal saline was applied in the control and untreated groups. Y-maze test was used for behavioral study to test the learning and memory abilities of rats in different groups. The expressions of Aβ1-42 and NEP in hippocampus were determined by immunohistochemical method, and the results were analyzed by image acquisition and analysis system.
Results

Injection of Aβ1-42 could induce learning and memory dysfunction and up-regulate Aβ1-42 expression in hippocampal tissue in rats of the untreated group. Compared with the normal control group, the abilities of learning and memory of rats in the untreated group were significantly decreased (P<0.01) and the expression of Aβ1-42 was significantly increased (P<0.01) after model establishment. After 28-day administration of NEK and piracetam, the abilities of learning and memory of AD rats in piracetam and low-dose, medium-dose and high-dose NEK groups were significantly improved as compared with the untreated group (P<0.01 or P<0.05); the expression of Aβ1-42 in hippocampal tissues was decreased (P<0.01 or P<0.05) and the expression of NEP was increased (P<0.01 or P<0.05), especially in the high-dose NEK group.
Conclusion

NEK can play the role of anti-dementia by increasing the expression of NEP in hippocampal tissues of AD rats so as to reduce the quantity of Aβ1-42 and by improving the ability of learning and memory of rats with AD.