Effects of puerarin on learning and memory and NMDAR in rats following hypoxic-ischemic brain damage

Objective:To investigate the effects of puerarin on learning and memory ability after hypoxia-ischemia brain damage and to understand the underlying mechanisms.Methods:A total of 102 S-D rats(P7)were randomly assigned to three groups(n=34):sham group,Con group,and puerarin group.At 8 weeks after birth,learning and memory ability were tested by Morris water maze.At 3,4,8 weeks after birth,expressions of NR2A and NR2B were detected in the CA1 region of the hippocampus by immunohistochemistry.Results:①The average time of escape latency was significantly longer and the number of platform location crossing was less in Con group than these in sham group(P0.05,P0.01).Compared with Con group,the average time of escape latency was significantly shorter(P0.05)and the number of platform location crossing was more(P0.05)in puerarin group.②The expression levels of NR2A and NR2B in hippocampal CA1 areas in the Con group were less than those in the sham-operated rats at any time points(P0.01).These levels of NR2A were significantly increased in the puerarin group when the rats were 3 w and 8 w of age,compared with the Con group(P0.05).These levels of NR2B were significantly increased in the puerarin group when the rats were 3 w and 4 w of age,compared with the Con group(P0.05).Conclusion:Puerarin can improve learning and memory in hypoxia-ischemia brain damage rats.This protection may be associated with the increased NR2A and NR2B in the CA1 region of hippocampus.