Abstract:Objective: To explore the effect of scutellaria baicalensis stem-leaf total flavonoid（SSTF）on learning and memory damage induced by Aβ_25-35and on the activity of anti-oxidative enzyme.Methods：Rats were administered SSTF（100,50，25 mg• kg^-1，ig）. The AD model was made by bilateral injection of Aβ_25-35in rat hippocampus. Morris water maze was used to evaluate the learning and memory ability of the rats. HE stain was used to observe morphology of the neuron of hippocampus CA1 region. The activity of superoxide dismutase（SOD），glutathione peroxidase（GSH-Px）and the content of malondialdehyde（MDA）in rat hippocampus were measured.Results: Compared with that of the control group, the latency to find the platform in model group was significantly increased, and the ratio of path in platform quadrant to the whole path was significantly decreased. Compared with that of the model rats, the latency to find the platformin animals with SSTF 100，50 mg• kg^-1and vitamin E （Vit E）groups were significantly decreased, the ratio of path in platform quadrant to the whole path was significantly increased. The CA1 region neuron of the model rats showed severe damage. Compared with of the model rats, the neuron of SSTF and Vit E groups showed a decreased damage. Activities of SOD, GSH-Px in SSTF and Vit E group were significantly increased compared with that in the model rats. Content of MDA in SSTF and Vit E groups were significantly decreased compared with that in the model rats.Conclusion: SSTF can attenuate neuron damage and learning impairment induced by Aβ, and the mechanism may be related to the increased activity of anti-oxidative enzyme.

Key words:scutellaria baicalensis stem-leaf total flavonoid,Alzheimer&,rsquo,s disease,learning and memory,superoxide dismutase(SOD),glutathione peroxidase(GSH-Px)