Objective:To investigate the protective effect of prunetin on the neurons in the rats with cerebral ischemia reperfusion injury(CIRI),and to clarify its possible mechanisms.Methods:Thirty-six SD rats were randomly divided into sham operation group,model group,low dose of prunetin group(3.5 mg·kg-1),medium dose of prunetin group(7.0 mg·kg-1),high dose of prunetin group(14.0 mg·kg-1),and positive drug edaravone(Eda)group(n=6).Zealonga method was used to evaluate the neurological function damage of the rats in various groups;open field experiment was used to evaluate the autonomous motor function;Triphenyltetrazolium chlorde(TTC)staining was used to evaluate the areas of cerebral infarction of the rats in various groups;HE staining and Nissl staining were used to observe the pathomorphology of brain tissue of the rats in various groups.Additionally,twenty-one SD rats were randomly divided into sham operation group,model group,prunetin group,c-Jun N-terminal kinase(JNK)inhibitor group,p38 inhibitor group,JNK inhibitor+prunetin group,and p38 inhibitor+prunetin group(n=3).TUNEL staining was used to detect the positive rates of apoptosis of neurons of the rats in various groups;Western blotting method was used to detect the expression levels of apoptosis-related proteins and JNK/p38 signaling pathway-related proteins in brain tissue of cerebral infarction side of the rats in various groups.Results:Compared with sham operation group,the neurological deficit score of rats in model group was significantly increased(P＜0.001),the total motor distance was shortened(P＜0.001),and the ratio of cerebral infarction area was increased(P＜0.001).In sham group,the neuronal structure in the rat brain tissue was clear and well-organized,with an abundance of Nissl bodies and no apparent pathological changes observed.Compared with model group,the neurological deficit scores of the rats in medium and high doses of prunetin groups were decreased(P＜0.05),total motor distances of rats were increased(P＜0.05),and the cerebral infarction areas of rats were decreased(P＜0.05);the neurons showed disarrayed arrangement,cytoplasmic condensation,nuclear consolidation,and lysing and deletion of Nissl bodies were decreased.Compared with sham operation group,the positive rate of apoptosis of neurons in model group was significantly increased(P＜0.001),the expression level of B-cell lymphoma-2(Bcl-2),Bcl-2-associated X protein(Bax)and cleaved Caspase-3 proteins in brain tissue of the rats were significantly increased(P＜0.05 or P＜0.01).Compared with model group,the positive rats of apoptosis of neurons of the rats in prunetin group were decreased(P＜0.05),the expression level of Bcl-2 protein in brain tissue of the rats was increased(P＜0.001),and the expression levels of Bax and cleaved Caspase-3 proteins were significantly decreased(P＜0.05).Compared with inhibitor groups,the positive rates of apoptosis of neurons in inhibitor+prunetin groups were decreased(P＜0.01),and the expression levels of p-JNK and p-p38 proteins in brain tissue of the rats as well as the ratios of p-JNK/JNK and p-p38/p38 were decreased(P＜0.05).Conclusion:Prunetin has the effect of reducing the neurological function damage,decreasing the area of cerebral infarction,reducing the pathological damage,and inhibiting neuronal apoptosis in the rats,and its mechanism may be related to inhibiting neuronal apoptosis through regulating the JNK/p38 signaling pathway.

Objective:To discuss the protective effect of TUG-891 on ischemic stoke(IS)induced by ischemia-hypoxia,and to clarify its potential mechanism.Methods:A total of 60 healthy male C57BL/6 mice were randomly divided into sham operation group(n=20),model group[distal middle cerebral artery occlusion(dMCAO)group,n=20],and model+TUG-891 group(dMCAO+TUG-891 group,n=20).After modeling,the mice were intraperitoneally injected with TUG-891 solution(35 mg·kg?1·d?1)for 3 consecutive days.Modified neurological severity score(mNSS)and rotarod test were used to evaluate the neurological function of the mice in various groups;2,3,5-triphenyltetrazolium chloride(TTC)staining was used to observe the cerebral infarction volumes of the mice in various groups;biochemical method was used to detect the malondialdehyde(MDA)level and superoxide dismutase(SOD)activity in the supernatant of brain tissue of the mice in various groups;Hematoxylin-Eosin(HE)and NISSL staining were used to observe the pathomerphology of brain tissue of the mice in various groups;terminal deoxynucleotidyl transferase dUTP nick-end labeling(TUNEL)staining was used to detect the apoptotic indexes of neuronal cells in brain tissue of the mice in various groups;Western blotting method was used to detect the expression levels of glucose-regulated protein 78(GRP78),protein kinase R-like endoplasmic reticulum kinase(PERK),phosphorylated PERK(p-PERK),and C/EBP homologous protein(CHOP)proteins in brain tissue of the mice in various groups.Results:The mNSS and rotarod test results shoued that compared with sham operation group,the mNSS of the mice in dMCAO group was significantly increased(P<0.01),and the time on the rod was significantly decreased(P<0.01);compared with dMCAO group,the mNSS of the mice in dMCAO+TUG-891 group was decreased(P<0.05),and the time on the rod was increased(P<0.05).The TTC staining results shoued that compared with sham operation group,the volume of white infarct foci in the cerebral cortex of the mice in dMCAO group was increased(P<0.01);compared with dMCAO group,the cerebral infarction volume of the mice in dMCAO+TUG-891 group was significantly decreased(P<0.01).The HE staining results showed that compared with sham operation group,the cortex of the mice in dMCAO group was severely damaged,manifested by disordered arrangement of neuronal cells and obvious nuclear pyknosis in the infarct area,and the morphology of cortical infarct area of the mice in dMCAO+TUG-891 group was improved;the NISSL staining results showed that the Nissl bodies in the cortical infarct area of the mice in dMCAO group became thinner,elongated,and lost more.The pathological damage of brain tissue of the mice in dMCAO+TUG-891 group was significantly improved.Compared with sham operation group,the MDA level in brain tissue of the mice in model group was significantly increased(P<0.01),and the SOD activity was decreased(P<0.01);compared with model group,the MDA level in brain tissue of the mice in TUG-891 group was significantly decreased(P<0.01),and the SOD activity was significantly increased(P<0.01).The TUNEL staining results showed that compared with sham operation group,the apoptotic index of neuronal cells in brain tissue of the mice in dMCAO group was increased(P<0.01);compared with dMCAO group,the apoptotic index of neuronal cells in brain tissue of the mice in dMCAO+TUG-891 group was decreased(P<0.01).Compared with sham operation group,the expression levels of GRP78,p-PERK,and CHOP proteins in brain tissue of the mice in dMCAO group were increased(P<0.05);compared with dMCAO group,the expression levels of GRP78,p-PERK,and CHOP proteins in brain tissue of the mice in dMCAO+TUG-891 group were decreased(P<0.05).Conclusion:TUG-891 can alleviate neurological injury caused by ischemic stroke,and its mechanism may be related to the inhibition of endoplasmic reticulum stress and apoptosis.