ABSTRACT
Objective To study the therapeutic effects and related mechanism of Tongmai Yizhi granules on vascular dementia in rats. Methods Bilateral carotid artery ligation was used to establish rat model of vascular dementia (VD). The rats were randomly divided into 6 groups: sham operated,the model control,piracetam (0. 375 g·kg-1 ·d-1 ) as positive con-trol,low dose (2. 5 g·kg-1 ·d-1 ),middle dose(5. 0 g·kg-1 ·d-1 ),and high dose (10. 0 g·kg-1 ·d-1 ) of Tongmai Yizhi granules. Each group was intragastrically administered with 10 mL·kg-1 of corresponding medications for 31 days after the VD model was established. The sham group was given with 0. 9% NaCl solution. Y-electric maze was used to test the learning and memory function of rats at the second and fourth weeks. On the day 32,hippocampal tissues were collected for pathological analy-sis by microscope. The activities of SOD and content of MDA in serum and tissue homogenate were tested. Results Compared with model control group,each dose of Tongmai Yizhi granules obviously shortened the incubation period of VD rats in electric maze test,and accuracy of learning and memory was improved (P<0. 05 or P<0. 01). The activity of SOD was decreased,and the content of MDA was increased after treatment with Tongmai Yizhi granules (P < 0. 01). Hippocampal neuronal cells were disar-ranged,and the number of cone cells was decreased significantly in the model control group. In contrast,the necrosis and degener-ation of hippocampal neurons were alleviated in all Tongmai Yizhi treatment groups. Conclusion Tongmai Yizhi granule can apparently improve learning and memory function of VD rats. It can also improve the activity of SOD and reduce the content of MDA in serum and hippocampus,effectively remove free radicals,and alleviate the injury of hippocampal pyramidal cells.