Neuroprotective effect of puerarin after hypoxic-ischemic in neonatal and its mechanism

AIM:To investigate the effects of puerarin on the expression of BDNF,Bax,Caspase-3 in hippocampal cell and impact on learning and memory ability after hypoxia-ischemia brain injury in neonatal rats.METHODS:All SD rats(P7) were randomly divided into 3 groups:treatment with Puerarin group,control group,and sham group.Rats in Puerarin group and control received hypoxia-ischemia brain injury.Rats in Puerarin group were treated with Puerarin in doses of 50 mg/kg ip at 5 min after reoxygenation,once a day for 7 d in total.Rats in control group were given the same volume of saline.The rat pups of sham group were separated the right common carotid,but not ligated and they were not exposed to hypoxia.At 1 week after hypoxia,expression of BDNF,Bax,Caspase-3 were detected in the hippocampal region by immunohistochemistry.At 4 weeks after surgery,behavioral changes in the remaining rats were tested by Morris water maze.RESULTS:①One week later,the expression of BDNF in the Puerarin group was significantly higher than that of the control group after hypoxic-ischemic(P0.05);and the expression of Bax and Caspase-3 in the Puerarin group was lower than that of the control group(P0.05,P0.01).②The average time of escape latency in Puerarin is much shorter than control group(P0.05,P0.01),In addition,the frequency platform passing in the Puerarin group and the percentage of swimming time traveled in the previous target quadrant was significantly greater than the control group(P0.05,P0.01).CONCLUSION:Puerarin may reduce brain injury and improve learning and memory in hypoxic-ischemic brain injury rats.This protection may be associated with increased BDNF levels and decreased pro-apoptoic protein(Bax)and Caspase-3.