Abstract:

To investigate the interventional effect of puerarin (Pur) preconditioning  on focal cerebral ischemia-reperfusion(IR) injury in rats and to explore the possible therapeutic time window. Methods Fourty male Sprague-Dawley rats were randomly divided into  IR,Pur preconditioning(PC)-6h，PC-12h，PC-24h and PC-48h groups(n=8). 100 mg•kg-1 Pur was given at 6,12,24 or 48 h before cerebral ischemia in the rats in last four groups,0.9% saline 1 ml•kg-1 was injected ip at the end of 90 min ischemia in the rats in IR group. A focal cerebral ischemia reperfusion model was induced by the middle cerebral artery intraluminal suture method. All animals were subjected to  the left middle cerebral artery occlusion for 90 min，followed by reperfusion for 24 h．The neurological deficit score was measured at 24 h after IR. The brain infarct volume percentage(BIVP) was then assessed after 2％TTC staining following the last neurological outcome evaluation. Results  Compared with IR group,the neurologic deficit scores in PC-6h,PC-12h and PC-24h groups were statistically improved (P<0.01),but not in PC-48h group (P>0.05).The BIVP  in PC-6h,PC-12h and PC-24h group were significantly decreased compared with IR group (P<0.01).No statistically significant difference in BIVP was found between IR group and PC-48h group (P>0.05).There were no statistically significant differences in neurologic deficit score and BIVP between PC-6h,PC-12h and PC-24h groups(P>0.05).Conclusion Pur precondioning can protect rat brain against IR injury.The therapeutic time window of Pur neuroprotection may be over 24 h．

Key words: puerarin, precondioning, cerebral ischemia-reperfusion, neuroprotection