Molecular mechanism of Wulongdan for improving the learning and memory abilities of rats with chronic cerebral ischemia / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the effect of Wulongdan on the learning and memory abilities of rats with chronic cerebral ischemia and explore the mechanisms.</p><p><b>METHODS</b>Male SD Rat models of chronic cerebral ischemia were established by permanent ligation of the bilateral carotid arteries. Three weeks after the operation, the rats were randomly divided into sham-operated group, chronic cerebral ischemia group (model group), high-dose drug group, low-dose drug group and Yinxingye group and received the corresponding treatments on a daily basis for 5 consecutive weeks. Morris water maze was used to assess the learning and memory abilities of the rats, and Western blotting was carried out for detecting the expressions of NR1 and NR2B in the hippocampus and cerebral cortex.</p><p><b>RESULTS</b>Compared with the model group, the rats in high-dose drug, low-dose drug and Yinxingye groups showed significantly shorter time of finding platform in Morris water maze test (P<0.05 or 0.01). The rats in the model group showed significantly lowered expressions of NR1 and NR2B of the cortex and hippocampus than those in the sham-operated group (P<0.01). In comparison with the model group, the high-dose Wulongdan group and Yinxingye group both showed significantly increase expressions of NR1 and NR2B (P<0.01), but their expression levels still remained significantly lower than those in the sham-operated group (P<0.01).</p><p><b>CONCLUSION</b>Wulongdan can enhance the learning and memory abilities of rats with chronic cerebral ischemia, the mechanisms of which may involve increased expressions of NR1 and NR2B in the hippocampus and cortex.</p>

Effects of Wulongdan on learning and memory abilities of rats with chronic cerebral ischemia / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the effect of Wulongdan, a tradition Chinese medicinal preparation, on the learning and memory abilities of rats with chronic cerebral ischemia and explore the mechanisms.</p><p><b>METHODS</b>Male rats with chronic cerebral ischemia induced by permanent ligation of the bilateral carotid arteries were randomized into sham-operated group, chronic cerebral ischemia (model) group, and high-, middle-, and low-dose Wulongdan groups and Yinxingye group. The corresponding treatments were administered in the rats 24 h after the operation once daily for 8 consecutive weeks. Morris water maze and step-through tests were performed after 7 weeks of drug administration. The brain tissues were then taken to observe the morphological changes in the hippocampal neurons with Nissl staining by transmission electron microscopy.</p><p><b>RESULTS</b>Compared with the model group, the latency of finding the platform in Morris water maze test was significantly shortened (P<0.05 or 0.01), and that in step-through test significantly prolonged (P<0.05 or 0.01) in high-, middle-, and low-dose Wulongdan groups and Yinxingye group. In the model group, Nissl staining of the hippocampal CA1 region visualized obvious pathological changes in the neurons, showing a significant difference from the sham-operated and high-dose Wulongdan groups.</p><p><b>CONCLUSION</b>Wulongdan can enhance the learning and memory abilities of rats with chronic cerebral ischemia possibly through a mechanism in relation to neuronal protection in the hippocampus CA1 region.</p>