OBJECTIVETo investigate the expressions of nestin and vascular endothehal growth factor (VEGF) mRNAs in rat brain tissue after cerebral ischemia-reperfusion injury and their changes in response to Tongxinluo (a traditional Chinese herbal preparation) treatment.

METHODSCerebral ischemia was induced in rats by temporary middle cerebral artery occlusion (MCAO) followed by treatment with Tongxinluo at high and low doses. On days 3, 7, 14 and 21 after MCAO, nestin and VEGF mRNA expressions in the ependyma, subventricular zone (SVZ), and hippocampal subdentate gyrus zone (HDG) in the ischemic hemisphere were quantitatively analyzed using immunohistochemistry and RT-PCR.

RESULTSCompared with the sham-operated group, the rats with cerebral ischemia-reperfusion injury showed significantly increased nestin-positive neurons and VEGF mRNA expression in the SVZ and HDG 7, 14 and 21 days after MCAO (P<0.05). Treatment with Tongxinluo, especially at high doses, significantly increased the number of nestin-positive neurons and VEGF mRNA expression in the rats 7, 14 and 21 days after MCAO (P<0.05).

CONCLUSIONFocal cerebral ischemia in rats results in rapid response and proliferation of neural stem cells in the SVZ and HDG in the ischemic hemisphere possibly by increasing VEGF mRNA expression in the adjacent tissues around the ischemic focus. Tongxinluo may enhance the differentiation and proliferation capacity of the neural stem cells after MCAO by inducing the expression of VEGF mRNA.