Protective Effects And Mechanisms Of XiaoXuMingTang(XXMT) On Pyramidal Cells In CA1 Region Of The Hippocampus Following Forebrain Ischemia In Rats

XiaoXuMingTang (XXMT),an ancient traditional Chinese medical prescription,has been used widely to treat acute stroke for many thousands years. However,from the Tang and Song Dynasties,it has been less used clinically. In the present study,our objective is to investigate protective effect and mechanisms of XXMT on neuronal injury in CA1 region of the hippocampus following transient forebrain ischemia in rats,and thereby to evaluate Qufeng method in stroke treatment. With four-vessel occlusion model of rats,the density of survival pyramidal cells in CA1 region of the hippocampus was counted at 3d or 7d following forebrain ischemia by light microcopy to determine the pharmacological effect of XXMT. We also examined the effect of XXMT on activation of caspase-3,and expression of Bcl-2 and Bax at 24h or 48h following forebrain ischemia by immunohistochemistry method to clearfy the mechanisms underlying the protective effect. Our results showed that oral administration of low doses XXMT had no effect on cell survival. However,the density of survival pyramidal cells in CA1 region of the hippocampus was significantly higher in middle and high doses XXMT treated rats than that of control. And there is a positive correlation between the effect and the doses of XXMT for 3d and 7d (r=0.877 and r=0.836,respectively,P<0.OOl) following forebrain ischemia. Our results also demonstrated that,XXMT inhibited Caspase-3 activation and upregulated Bcl-2 expression in CA1 region following forebrain ischemia,but had no effect on Bax expression. From these results,it is concluded that XXMT can protect CA1 neurons from forebrain ischemia by inhibiting Caspase-3 activation and upregulating Bcl-2 expresion,suggesting that the QuFeng method,a therapeutic strategy for stroke in traditional Chinese medicine,may be an important way in stroke treatment.