The protective effects of pre-treatment with propoful and Xingnaojing on different characteristic injuries in rat cerebrocortical slices / 中国中西医结合急救杂志

ABSTRACT

Objective To investigate the protective effects and mechanisms of propofol and Xingnaojing injection on different characteristic injuries in cerebrocortical slices of newborn rats in vitro. Methods The cerebral cortex of the 7 days-old Sprague-Dawley(SD)neonatal rat was cut into slices. 2,3,5-Triphenyl Tetrazolium(TTC) was used to stain the slices to judge their activities,afterwards they were randomly divided into seven different groups (each,n=12)normal control group(group A),glutamate(Glu)injury group(group B),hydrogen dioxide(H2O2) injury group(group C),propofol preconditioning before Glu injury group(group D),Xingnaojing preconditioning before Glu injury group(group E),propofol preconditioning before H2O2 injury group(group F), Xingnaojing preconditioning before H2O2 injury group(group G). On the 3rd day,the pre-medical treatments or pre-conditionings for D,E,F and G groups were carried out for 24 hours(the concentration of propofol20 mg/L,the concentration of Xingnaojing10 μg/mL);the slices were successfully incubated for 4 days,afterwards they were immersed in 1 mmol/L Glu and 0.1 mmol/L H2O2 for 30 minutes respectively to establish the injury models which had no pre-treatment,finally all the groups were transferred into normal cultural medium to incubate till the 7th day. In the above processes,the group A had no specific medical treatment. After all the operations,the changes in brain tissue and cell morphology,the quantity of Nissl body(NISSL)stained by its stain,and the proportion of cells stained with red and green dye after the slices in various groups stained with propidium iodide-acridine orange(PI-AO)were observed,and the apoptosis rate was tested by flow cytometry. Results ①Morphological observation of brain sliceson the 3rd day,the slices appeared mild edematous,3-5 days later,the edema gradually disappeared. Until the 6th day, a large number of typical nerve cells and a few glial cells were seen;on the 7th day,the growth of cells reached the peak,and afterwards,gradually apoptosis played the leading role.②Morphological observation of brain slices stained by hematoxylin-eosin(HE)stainthe neurons of group A presented multilateral-or shuttle-shaped. The cell numbers of groups B and C were significantly lower than the number of group A. In the neuron number sequence,the positions of the numbers of groups D,E,F,G were located in the interval between the number of group A and those of groups B and C,and there were differences in number among groups.③NISSLNissl-body of group A could be clearly seen. The numbers of Nissl-body in groups B and C were significantly reduced compared with the number in group A(cell/HP8.8±2.5,10.3±2.5 vs. 28.9±5.1,both P<0.05). The numbers of Nissl-body in groups D and E were obviously increased compared with the number in group B,and the greater increase being in group D(21.5±4.7 vs. 13.4±3.1, P<0.05). The numbers of Nissl-body in groups F and G were markedly increased compared with the number in group C ,and the greater increase being in group F(23.9±1.9 vs. 19.2±4.1,P<0.05). ④ Double staining with PI-AOin group A,nearly the total number of nuclei presented fluorescent green in color. In groups B and C,a large number of neurons appeared two types of fluorescence and their edges blurred. The proportions of red staining of neuron cytoplasm in groups D and E were lower than the proportion in group B,and the greater decrease being in group D. The proportions of red staining of neuron cytoplasm in groups F and G were lower than the proportion in group C ,and the greater decrease being in group F.⑤Apoptosis ratethe apoptosis rates of groups B and C were higher than the rate of group A〔(22.00±0.64)%,(21.28±1.44)%vs.(8.57±0.67)%,P<0.05〕;the apoptosis rates of groups D and E were lower than group B,the decrease in group D being greater〔(11.94±0.57)%vs.(18.17±0.65)%,P<0.05〕;the apoptosis rates of groups F and G were much lower than the rate of group C,the decrease in group F being greater〔(10.54±1.24)% vs.(13.12±0.13)%,P<0.05〕. Conclusion The pre-treatment of propoful or Xingnaojing injection has protective effect on Glu or H2O2 injury of in vitro rat cerebrocortical slices,and upon the same injury,the brain protective effect of propoful is more powerful than that of Xingnaojing injection.