Effect of total saponins of Panax notoginseng on learning and memory of global cerebral ischemia rats and its mechanism / 中草药

ABSTRACT

Objective: To explore the effect of the total saponins of Panax notoginseng (TSPN) on learning and memory of global cerebral ischemia rats and its mechanism. Methods: Using four-vessel occlusion method to establish the global cerebral ischemia model. Rats were divided into sham group, vehicle group, and TSPN group. The rats in the TSPN group were administered TSPN intraperitoneally 30 min post-brain ischemia. The dose of TSPN (75 mg/kg) was suspended in 0.9% saline 10 g/L, once per day for 14 d after reperfusion. Rats in the vehicle group were treated with equal volume of 0.9% saline, one injection per day for 14 d. The Morris Water Maze was performed to test the learning and memory of rats and doublecortin (DCX) and NeuN expression in the hippocampus was assessed by immunohistochemistry. Furthermore, immunoblotting was adopted to test the protein level of DCX in the CA1 subfield of hippocampus. Results: The escape latency in the vehicle group was longer than that in the TSPN group (P < 0.05). The times across the platform were less in the vehicle group than that in the TSPN group (P < 0.05). In comparison with the vehicle group, the number of the NeuN+ cells in the CA1 subfield and DCX+ cells in the SGZ of the TSPN group were significantly increased (P < 0.01); Moreover, the result of immunoblotting demonstrated that the protein level of DCX in the CA1 subfield of hippocampus of the TSPN group was significantly higher than that in the vehicle group (P < 0.01). Conclusion: TSPN could improve the learning and memory of global cerebral ischemia rats and its mechanism may be related to the promotion of hippocampus neurogenesis.