Effects Of Breviscapine On The Expression Of Caspase-12 And INOS In Rats' Hippocampus After Cerebral Resuscitation

Objective To investigate the expression of Caspase-12 and iNOS in hippocampus after the Breviscapine(Br) in intervention therapy the Sprague-Dawley (SD) rats with global cerebral ischemia/reperfusion (I/R) injury and testify the effect mechanism of Br during cerebral resuscitation. Methods 90 healthy SD rats were randomly divided into 3 groups: sham operation (SO) group (n=30), I/R group (n=30) and Br group (n=30). Then each group were assigned into 5 observing time-points:2,6,12,24,48 hours (h) according to reperfusion time. The SD rats model of global cerebral ischemia/reperfusion (including I/R and Br group) was produced by means of simple Pulsinelli-Brierley's four arteries occlusion method. SO and I/R groups were intraperitoneally injected with 0.9% Sodium chloride (dose:1ml/kg), and Br group with Breviscapine (dose:2.5mg/kg) one time per six hours after reperfusion. Then SD rats'cerebrums were taken out of their skull at each of observing time-point. The expression activation of Caspase-12 and iNOS protein in pyramidal cells in hippocampus comu ammonis (CA) 1 region were examined by immunohistochemical method (SABC) and Caspase-12mRNA by in situ hybridization, measured their average optical density(OD), and hematoxylin and eosin (HE) staining was also performed to detect the number of surviving pyramidal cells, and terminal-deoxynucleotidy transferase medatd dUTP nick end labeling (TUNEL) was used to detect apoptotic pyramidal cells (positive cells). Results In SO group, the average optical density of Caspase-12 protein and its mRNA, iNOS protein had no significance of difference. The number of surviving neurons and apoptic cells was the same condition(p>0.05). In I/R group, the average optical density of Caspase-12 protein and mRNA began to increase at 12h after reperfusion, arrived on peak at 24h, and then gradually decreased. The expression of iNOS protein was as same as Caspase-12 protein. With the reperfusion prolonged, the number of surviving neurons became more and more lower (all P<0.01), and more and more neurons emerged the phenomenon of cell-apoptosis, its apoptotic pyramidal cells then clearly rised, too(all P<0.01). In Br group,the average optical density of Caspase-12 protein and mRNA peaked at 6h, and then began to decrease at 12h, and reached the minimum at 48h. The average optical density of iNOS protein began to increase at 6h, reached the maximum at 12h, and then decreased gradually. With the reperfusion prolonged, the number of surviving neurons became more and more lower, and reached maximum at 12h, then gradually recoverd, and reached the maximum at 48h. The change of apoptic cells was just contrary. Comparing with I/R group, the average optical density in Br group was smaller at every corresponding time-point, and had statistically significant (p<0.05). Conclusions After global cerebral ischemia/reperfusion, Breviscapine could protect the brain from global cerebal ischemia/reperfusion injury by inhibiting neuronal apoptosis through inhibiting the generation of Casp ase-12 and iNOS, and incr ease the number of surviving neurons.