Impact of puerarin preconditioning on apoptosis and expression of p53 in focal cerebral ischemia reperfusion injury rats

Objective To observe the expression of P53 protein and apoptosis cells in hippocampus of rats with cerebral ischemia after the pretreatment with puerarin and the effect of pretreatment with puerarin and explain the cerebral ischemia tollerating mechanism that was induced by pretreatment of puerarin.Methods The models of focal cerebral ischemia reperfusion injury by middle cerebral artery occlusion(MCAO)was established in SD rats.SD rats(n=72)were randomly divided into three groups each consisted of 24 rats.S group was only exposed anatomically without cerebral ischemia and reperfusion.IR group was cerebral ischemia-reperfusion through abdomenal injection of normal saline.P group was cerebral ischemia and reperfusion given puerarin through abdomenal injection.The rats in every group were again divided into three subgroups each group consisted of 8 rats.The expression of p53 protein in hippocampus was detected by immunhistochemical method.Apoptosis cell in hippocampus was determined by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling(TUNEL).Results In P2h group the expression level of p53 protein was increased 2 hours after reperfusion,the level of p53 was significantly increased in P24h group and decreased in P72h group after reperfusion,but still significantly lower than that of IR group(P0.01).The number of apoptosis cells in P2h,P24h and P72h groups was significantly lower than that of IR2h,IR24h and IR72h group,respectively(P0.01).Conclusion The down-regulation of expression of p53 protein may be one of mechanisms of cerebral protective effect due to use of puerarin.Puerarin is assooicated with the ocurrence of delayed neuron death.