Effect of Rehmannia glutinosa oligosaccharides on learning and memory abilities in rats with focal cerebral ischemia and reperfusion injury

AIM To investigate the effect of Rehmannia glutinosa oligosaccharides(ROS) on learning and memory abilities in rats with focal cerebral ischemia-reperfusion injury and its possible mechanism.METHODS Rat model of ischemia-reperfusion injury was established by 10 min ischemia-10 min reperfusion-10 min ischemia(I-R-I) of bilateral common carotid arteries and pretreated(ip) with sodium nitroprusside 2.5 mg·kg-1.The rats were given(ip) ROS(6.4,32.0 or 160.0 mg·kg-1) once daily for 10 d(from 3 d prior to 7 d after I-R-I).On d 7-9 after I-R-I,learning and memory abilities of rats were tested by Morris water maze.On d 10 after I-R-I,hippocampal glutamate(Glu) content and hippocampal phospho-extracellular signal regulated kinase 2(p-ERK2) expression were detected by HPLC and Western blot,respectively,after finishing Morris water maze test.RESULTS Compared with the sham group,learning and memory abilities of model group were decreased,hippocampal Glu content was increased,and hippocampal p-ERK2 expression was decreased significantly.ROS treatment significantly improved the learning and memory abilities of rat with I-R-I injury,decreased hippocampal Glu content,and increased hippocampal p-ERK2 expression.CONCLUSIONROS can improve learning and memory abilities of rats with I-R-I injury,which may be related with inhibiting the elevation of hippocampal Glu content and sustain the ERK2 signaling pathways.