Abstract: Aim To observe the effect of Zhinao capsule on learning and memory, and f ree radical metabolism in experimental model rats with alzheimer disease (AD).Methods According to an method improved by us, the injections of β-amy loid protein (β-AP) into lateral ventricle and the transforming growth factor β1 (TGF β1) into the brain tissue in rats were applied to successfully make an experimental rat model of AD.Then the step-through test and the w ater-maze test were employed to investig ate the function of learning and memory in AD models.In addition, the xanthine o xidase method and the thiobarbituric acid clorimetry were respect ively used to assay the activi ty of superoxide dismutase (SOD) and content of malondialdeny de (MDA) in brain tissue of AD models.Results There were changes of behavior (impairment of learning and memory) as w ell as typical pathological features (β-AP deposition plaques etc.) in brain tissue in AD animal models induced by β-AP and TGF β1.The activity of SOD was lower and content of MDA was higher in AD models than that of normal rats.Zhinao capsule could relief the impairment of learning and memory, raise the activity of SOD, and reduce the content of MDA in the brain tissue of AD models.Conclusion Zhinao capsule can markedly enhance the function of learning and memory in rats with experimental AD model induced by β-AP and TGF β1, and its mechanism is closely related to the scavenging free radical.

Key words: Zhinao capsule, alzheimer disease, learning and memory, free radical