RESUMO
OBJECTIVE： To study the improvement effect of Shenrong bunao capsule on learning and memory ability of Alzheimer’s disease （AD） model mice， and to investigate its mechanism. METHODS： Totally 72 mice were randomly divided into blank control group （normal saline）， model group （normal saline）， Piracetam tablets group （positive control，0.80 g/kg），Shenrong bunao capsule high-dose，middle-dose and low-dose groups （1.92， 0.96， 0.48 g/kg）， with 12 mice in each group. Except that blank control group was given constant volume of normal saline subcutaneously. Other groups were given D-galactose （150 mg/kg） subcutaneously and sodium nitrite （50 mg/kg） intraperitoneally every day to induce AD model. At the same time，they were given relevant medicine intragastrically，once a day， for consecutive 60 d. 1 h after last administration， Morris water maze test was used to measure escape latency and times of crossing the platform within 90 s. HE staining was used to observe pathological changes of cerebral cortex in mice. Immunohistochemistry was used to detect the expressions of TNF-α， NF-κB p65， PI3K and Akt in cerebral cortex of mice. RESULTS： Compared with blank control group， escape latency was prolonged significantly （P＜0.01）， and the times of crossing the platform within 90 s was decreased significantly in model group （P＜0.01）. The neurons in cerebral cortex was damaged obviously， and the number of intact neurons was decreased significantly （P＜0.01）. The protein expressions of TNF-α， NF-κB p65， PI3K and Akt in cerebral cortex were increased significantly （P＜0.01）. Compared with model group， except that there was no statistical significance in escape latency， protein expressions of TNF-α， NF-кB p65， PI3K and Akt in Shenrong bunao capsule low-dose group （P＞0.05）， above indexes of other administration groups were improved significantly （P＜0.05 or P＜0.01）. CONCLUSIONS： Shenrong bunao capsule can improve the learning and memory ability of AD model mice， and its mechanism may be related to the inhibiting the protein expressions of TNF-α，NF-κB p65， PI3K and Akt in cerebral cortex region and relieving inflammation injury so as to protect cranial nerve.