| Objective:Ischemic stroke is the main cause of death and disability worldwide.At present,the treatment is limited,and there is an urgent need to develop new methods of stroke treatment.Traditional Chinese medicine(TCM)is a recognized source of drug discovery.Chinese medicine has a history of more than 2000 years in China.TCM therapy is a promising method for the treatment of stroke.Inflammation and apoptosis play an important role in the pathogenesis of cerebral ischemia and may be one of the therapeutic targets.Mole cricket is an insect kind medicinal material,has the sedative,diuretic,blood pressure,defecate,analgesic,anti-tuberculosis and so many kinds of action,with its medicine prescription all has the record in the many kinds of medicine classics,also has the widespread application in the clinical.The effects of mole cricket extract on behavior,infarct volume,microglia and expression of apoptosis-related protein bcl-2 and bax after cerebral ischemia in rats were observed by pMCAO operation.Methods:96 male SD rats(250-300g)were randomly divided into sham group(n = 32),model group(n = 32)and Mole cricket intervention group(n = 32).Fifteen rats(5 rats in each group)were killed 24 hours after operation for TTC staining.The remaining 81 rats were divided into four subgroups of 1 day,3 days and 7 days,with 9 rats in each subgroup.The left middle cerebral artery was occluded in order to make permanent model of focal cerebral ischemia(pMCAO).The sham-operation group only separatedthe cervical vessels and did not perform the middle cerebral artery occlusion,and the other procedures were the same.At 2 hours after operation,Mole cricket extract intervention group was given mole cricket extract by gavage according to the dosage of1ml/100g(crude drug concentration is 1g/ml),and was given every other day until the end of each time point.Sham operation group and control group were given an equal volume of saline by gavage at the same time.At the corresponding time points in each subgroup,behavioral manifestations and neurological function scores were observed,cerebral infarction volume was measured by TTC staining method,pathological changes of cerebral tissue were observed by HE staining method.Immunohistochemical technique was used to detect the expression of Iba-1,Bcl-2 and Bax cells in the striatum of the infarct side of rats(9 rats in each subgroup).Results:1.Neurologic function evaluation: there was no symptom of neurologic function defect in sham-operation group,and the score was 0.At each time point,the neurologic function score of Mole cricket extract intervention group was significantly lower than that of model group,which had statistical significance(p<0.05).2.Infarction volume measurement: the infarct volume was measured by TTC staining 24 hours after modeling.There was no infarction in sham-operation group,and the infarct volume in Mole cricket extract intervention group was smaller than that in model group,with statistical significance(P < 0.05).3.HE staining: HE staining was used to evaluate the pathological changes of ischemic striatum.In sham operation group,there was no obvious abnormality in striatum structure,the shape of the neurons is normal,nuclear chromatin is homogenous,the nucleolus is clear,there was no swelling and shrinkage in the cytoplasm;In the model group,the cells in the striatum of ischemic side were disordered,neuronal body swelling,nuclear pyknosis;Compared with the model group,the cells of Mole cricket extractintervention group were arranged neatly,the structure of neurons is basically normal,the swelling degree of the cell body was reduced.4.Immunohistochemical staining:(1)Expression of Iba-1 protein: Iba-1 labels microglia.In sham operation group,a small number of Iba-1 positive microglia cells were observed.The number of Iba-1 positive microglia in model group increased compared with that in sham operation group(p<0.05).Compared with model group,the number of Iba-1 positive microglia in Mole cricket extract intervention group was significantly lower than that in model group(P <0.05).(2)Bcl-2 protein expression: BCL-2 protein is an anti-apoptotic protein,which is expressed in mitochondria outer membrane,nuclear membrane and endoplasmic omentum.A small amount of expression was observed in the sham operation group;In model group,the expression of bcl-2 decreased with the prolongation of ischemic time.;Compared with model group,the number of Bcl-2 positive cells in Mole cricket extract intervention group was higher than that in model group at each time point,which had statistical significance(P < 0.05).(3)Bax protein expression: Bax is a pro-apoptotic protein expressed in cytoplasm and mitochondrial membrane.A small amount of expression was observed in the sham operation group;In the model group,the expression of Bax protein began to increase on the 1st day,there was a lot of expression on the 3rd day,and began to decrease on the 7th day;Compared with the model group,the number of positive cells in the Mole cricket extract intervention group was lower than that in the model group at all time points,with statistical significance(P < 0.05).Conclusion:Inflammatory reaction and apoptosis play an important role in cerebral ischemic injury after cerebral ischemia.Microglia are one of the most active inflammatory cells,which can induce a series of inflammatory responses.Bcl-2 family proteins,includingBcl-2 and Bax,play a key role in intracellular apoptotic signal transduction.Chinese medicine preparation mole cricket extract can not only inhibit the proliferation of microglia and attenuate the damage caused by inflammation,but also promote the anti-apoptotic effect of Bcl-2 and inhibit the pro-apoptotic effect of Bax by regulating the endogenous apoptotic pathway.It promoted the expression of anti-apoptotic protein bcl-2,inhibited the expression of crude apoptotic protein bax,and decreased apoptosis in infarcted area,promoting cell survival,and restore neurologic function in ischemic area,thus it can protect the injured brain tissue. |
PDF Full Text Request