Objective: To compare the protective effect of nerve growth factor (NGF) and edaravone (a free radical scavenger) pretreatment against cerebral ischemia/reperfusion (I/R) injury to nerve cells.
Methods: Cortical neurons of Sprague-Dawley (SD) mouse aged shorter than 24 hours were cultured for 7 days, then they were randomly divided into control group, I/R group, NGF of 10, 50, 100 microg/L pretreatment groups and 100 mumol/L edaravone pretreatment group. In pretreatment groups the cells were pretreated with drugs correspondingly. After culturing for 24 hours, glutamate of 200 mumol/L was given into the culture of all groups, except control group, for half an hour. Then culture medium in all groups were renewed with ordinary culture medium, and cultures were continued for 24 hours. The survival rate (by methyl thiazolyl tetrazolium assay), the content of lactate dehydrogenase (LDH, by spectrometry) and the rate of apoptosis (by flow cytometric) were determined. The cellular shape and ultrastructure were observed by hematoxylin-eosin (HE) staining and electronic microscopy correspondingly.
Results: The survival rate of nerve cells in NGF groups and edaravone group was significantly higher than that in I/R group [(0.21 + or - 0.04)%, (0.23 + or - 0.04)%, (0.21 + or - 0.04)%, (0.24 + or - 0.04)% vs. (0.19 + or - 0.04)%]. The content of LDH in culture medium and the rate of apoptosis in NGF groups and edaravone group were lower than those in I/R group (P<0.05 or P<0.01). The release rate of LDH in each group was (0.50 + or - 0.06)%, (0.46 + or - 0.07)%, (0.50 + or - 0.02)%, (0.43 + or - 0.06)% vs. (0.56 + or - 0.03)%, respectively. The rate of apoptosis in each group was (10.77 + or - 1.07)%, (10.38 + or - 0.70)%, (13.34 + or - 0.57)%, (9.99 + or - 0.77)% vs. (14.52 + or - 0.77)%, respectively. The cellular shape and ultrastructure of nerve cells in NGF groups and edaravone group were affected much less than that of I/R group. NGF of 50 microg/L pretreatment group gave the best effect among three groups. There was no significant difference between NGF 50 microg/L pretreatment group and edaravone pretreatment group.
Conclusion: NGF and edaravone pretreatment 24 hours before cerebral I/R give protective effects against cerebral I/R injury. The protective effects are best in NGF of 50 microg/L pretreatment group and edaravone pretreatment group, and there is no significant difference between them.