Effect of Dihuang Yinzi on synaptophysin,extracellular regulated protein in hippocampus of aged rats

Objective To explore the function and mechanism of Dihuang Yinzi (DHYZ) in promoting learning and memory and delaying brain aging. Methods The Wistar rats aged 20 months were randomly assigned to receive oral administration of 6, 12, 18 g·kg~ -1 ·d~ -1 DHYZ, or 2 ml/d normal saline (control) for 30 d (n=12 in each group), then space memory was detected with Morris Water Maze, and expression of synaptophysin (SYP) and extracellular regulated protein (ERK) were measured by immunohistochemistry and Western blotting. Results Rats administrated with DHYZ showed shorter mean escape latency (P0.01), and higher percentage of distance and time spent in the platform quadrant (P0.05 for low dose DHYZ group, P0.01 for high dose DHYZ group) than control. The expressions of SYP and ERK in hippocampus of rats pretreated with DHYZ were increased significantly. Conclusion DHYZ promotes learning and memory of the aged rats and delays brain aging, which may be associated with high expressions of SYP and ERK in hippocampus .