ABSTRACT
AIM: To investigate the protective effect of ginsenoside Rb1 on brain through Cav-1 in mice with cerebral ischemia-reperfusion injury. METHODS: One hundred and twenty C57/B6 mice were randomly divided into sham operation group, model group, model + ginsenoside Rb1 group, ginsenoside Rb1+ Cav-1 siRNA group, ginsenoside Rb1+siNC group, 24 in each group. The model of cerebral ischemia-reperfusion injury in mice was established by middle cerebral artery occlusion (MCAO). The ginsenoside Rb1 group received intraperitoneally injection of ginsenoside Rb1 (40 mg/kg); the sham operation group and model group were intraperitoneally injected with an equal amount of physiological saline immediately after modeling. For the ginsenoside Rb1+ cav-1 siRNA group and the ginsenoside Rb1+siNC group, cav-1 siRNA and siNC were injected into the lateral ventricle 24 h before molding, respectively, and the other operations were the same as the ginsenoside Rb1 group. The neurobehavioral scores of the mice in each group were measured at 24 h after reperfusion, and the water content of brain tissue, cerebral infarction volume, Cav-1 mRNA and Cav-1, Bcl-2 and Bax protein expressions in the cerebral cortex penumbra were measured in each group. RESULTS:Compared with the sham operation group, the neurobehavioral scores, cerebral infarction volume and brain tissue water content in the model group were significantly increased (P<0.05), and the expressions of Cav-1 mRNA and Cav-1 protein, and the Bcl-2 /Bax ratio were significantly decreased (P<0.05). Compared with the model group, the neurobehavioral scores, cerebral infarction volume and brain tissue water content in the ginsenoside Rb1 group were significantly decreased, and the expressions of Cav-1 mRNA and Cav-1 protein, and the Bcl-2 /Bax ratio were significantly increased (P<0.05). Compared with the ginsenoside Rb1 group, the neurobehavioral scores, cerebral infarction volume and brain tissue water content in the ginsenoside Rb1 + cav-1 siRNA group were significantly increased, and the expressions of Cav-1 mRNA and Cav-1 protein, and the Bcl-2 /Bax ratio were significantly decreased (P<0.05). CONCLUSION: Ginsenoside Rb1 can protects brain for mice with cerebral ischemia-reperfusion injury. After Cav-1 siRNA decreased the expression of Cav-1 protein in the brain tissue of mice, it significantly reverses the cerebral protective effect of ginsenoside Rb1, indicating that Cav-1 protein mediated the cerebral protective effect of ginsenoside Rb1 on cerebral ischemia reperfusion injury mice.
ABSTRACT
Objective To explore the mechanism of high mobility group protein 1 (HMGB1) involved in endoplasmic reticulum stress (ERS) induced by brain ischemia/reperfusion (I/R),based on I/R-HMGB1-ERS as the breakthrough point.Methods The brain of rats birthed 1-3 days was harvested,and the brain cells were cultured in vitro,which were used in the experiment when the cells were in the third passage.The cells were divided into two groups:cells in blank control group were cultured under the normal conditions without any treatment,and the cells in hypoxia/reoxygenation group were cultured with 99.9％ nitrogen for 60 minutes (hypoxia) followed by opening the bottle neck for reoxygenation 120 minutes to simulate I/R model.The HMGB1 gene was silenced by using small interfering RNA (siRNA,siRNA and transfection reagent Lipofectamine 2000 mixture gradient was transfected into the cultured cells) as HMGB1-siRNA transfection group,and blank control (without any treatment) and negative control group (transfected with control siRNA) served as controls.The mRNA and protein expressions of HMGB1 and ERS related molecules were determined by real-time reverse transcription-polymerase chain reaction (RT-PCR) and Western Blot.Results ① In cells of hypoxia/reoxygenation group,the mRNA and protein expressions of HMGB1 and ESR related proteins,including glucose regulating protein 78 (GRP78),C/EBP homologous protein (CHOP) and caspase-12,were significantly higher than those of blank control group with statistical difference (the value in blank control group was served as baseline 1,HMGB1 mRNA:3.19±0.48 vs.1,t =2.183,P =0.008;GRP78 mRNA:2.07±0.33 vs.1,t =3.292,P =0.016;CHOP mRNA:1.93±0.28 vs.1,t =2.573,P =0.021;caspase-12 mRNA:2.42±0.42 vs.1,t =2.261,P =0.027:HMGB1 protein:2.28±0.36 vs.1,t =2.042,P =0.009;GRP78 protein:1.33±0.24 vs.1,t =2.781,P =0.016;CHOP protein:1.67±0.34 vs.1,t =2.174,P =0.021;easpase-12 protein:1.36±0.44 vs.1,t =3.192,P =0.008).It was indicated that ERS related molecules involved in cell hypoxia/reoxygenation process.2② After HMGB1 gene was silenced by siRNA,the cells after hypoxia/reoxygenation showed a decrease in the mRNA and protein expressions of HMGB1 and ERS related moleculars as compared with those of blank control group and negative control group (served the value in blank control group as baseline 1,HMGB1 mRNA:0.27±0.12 vs.1,1.02 ± 0.04;GRP78 mRNA:0.16 ± 0.13 vs.1,0.96 ± 0.04;CHOP mRNA:0.47 ± 0.09 vs.1,0.98 ± 0.07;caspase-12 mRNA:0.31 ±0.11 vs.1,1.05±0.02;HMGBI protein:0.23±0.04 vs.1,1.08±0.01;GRP78 protein:0.14±0.09 vs.1,1.35±0.03;CHOP protein:0.32±0.10 vs.1,0.93±0.06;caspase-12 protein:0.27±0.09 vs.1,0.97±0.08;P ＜ 0.05 or P ＜ 0.01).It was indicated that HMGB1 involved in ERS related with GPR7,CHOP,caspase-12.Conclusion Hypoxia/reoxygenation brain intracellular HMGB1 and ERS related molecules expression levels were significantly up-regulated,and silencing HMGB1 gene can significantly inhibit the expression levels of these molecules,and I/R-HMGB 1-ERS pathway may participate in the mechanism of brain I/R injury.
ABSTRACT
Objective: To study the protection and mechanisms of effective fraction from Buyang Huanwu Decoction (EFBHD) on rat brain after cerebral ischemia-reperfusion injury. Methods: Rat model of cerebral ischemia-reperfusion injury was created by the middle cerebral artery occlusion (MCAO) by modified suture method. Healthy male SD rats were randomly divided into six groups: Sham-operated group, model group, high-, middle-, and low-dose (200, 100, and 50 mg/kg) of EFBHD groups, and positive control group (treated with EGB 100 mg/kg). The neurological deficit symptom scores were observed and the infarct volume was measured by triphenyltetrazolium chloride (TTC) staining in 24 h after the cerebral ischemia. The contents of TNF-α, IL-1β, and IL-6 in serum were measured by enzyme-linked immunosorbent assay (ELISA) methods. In addition, the activity of LDH and MDA content in serum were determined by abdominal arterial blood and centrifuged. Results: Compared with the model group, EFBHD could significantly improve the neruological dysfuction, decrease the cerebral infarct volume, and inhibit the activity of LDH, and reduce the contents of MDA, TNF-α, IL-1β, and IL-6 in serum (P<0.01, 0.05). Conclusion: EFBHD has significant protection on cerebral ischemia-reperfusion injury in rats, which may be related to the inhibition of inflammatory cytokine secretion and expression and inducing the inflammation in brain tissue.
ABSTRACT
AIM: To observe the neuroprotective effect of combined treatment with taurine and diazepam against focal cerebral ischemia-reperfusion in rats. METHODS: Sixty male Sprague-Dawley rats were randomly divided into five groups: sham-operation group, vehicle group, taurine group (200 mg/kg, ip), diazepam group (10 mg/kg, ip) and combined treatment group (taurine 100 mg/kg+diazepam 5 mg/kg). Focal cerebral ischemia was induced by the method of middle cerebral artery occlusion (MCAO) in rats, and reperfusion was emerged by removing the thread 2 h later. The drugs were administered respectively at the time of reperfusion, and subsequently repeated once 12 h later. The animals in vehicle group were intraperitoneally injected with isodose normal saline. The neurological deficit score, the brain water content and cerebral infarction were measured 48 h after MCAO. Other 5 group animals of focal cerebral ischemia-reperfusion (n=16 in each group) were set up as mentioned above and accepted treatments 10 h after reperfusion, likewise repeated once 12 h later. Twelve animals in each group were adopted the same management as the previous 5 groups at 48 h after MCAO. The remained 4 animals in each group were sacrificed until two weeks after MCAO to observe the histopathological changes by nissl staining. RESULTS: Compared to vehicle group, the animals in combined treatment group at 2 h or 12 h after MCAO both decreased the neurological deficit score, reduced the brain water content and infarct volume (P<0.01 or P<0.05). The combined treatment significantly alleviated the neurological necrosis as well. The neuroprotective effect of the combined treatment was superior to that of using taurine or diazepam alone. CONCLUSION: These results suggest that combination of taurine and diazepam treatment has a coordinate neuroprotective effect on both the acute and chronic brain damage of focal cerebral ischemia-reperfusion.
ABSTRACT
@#ObjectiveTo investigate the effects of Angelica sinensis on the expression of vascular endothelial growth factor (VEGF) Flt-1, Flk-1 mRNA after the brain ischemia-reperfusion injury in rats.MethodsWistar rats were randomly divided into the group A, group B and normal control group. The group A underwent middle cerebral artery occlusion (MCAO) for 2h by suture, group B underwent MCAO for 2h meanwhile received treatment with Angelica sinensis (5 g/kg). Immunohistochemistry and quantitative reverse transcription and polymerase chain reaction (RT-PCR) technique were used to examine the gene expression of VEGF.ResultsThe result of immunohistry revealed that VEGF in the group A and group B reached its peak at 24 h after reperfusion then declined gradually. The result of RT-PCR manifested that the gene expression of VEGF in the group A increased from 3 h after reperfusion and reached its peak at 6 h; in the group B reached its peak on the 3rd day. The expression of VEGF in the group B was significantly increased than group A at the same time point.ConclusionAngelica sinensis can enhance the expression of Flt-1, Flk-1 after transient interruption of cerebral blood flow in rats.
ABSTRACT
Aim To study the effects of amitriptyline(Ami)on focal cerebral ischemia-reperfusion injury in rats.Methods An animal model of focal cerebral ischemia-reperfusion injury was induced by the middle cerebral artery occlusion(MCAO) by reversibly inserting a nylon thread method.The rats were decapitated after ischemia for 1 hour and reperfusion for 2 hours.The infarct volumes were determined using a 2,3,5-tri-phenyl tetrazolium chloride(TTC) staining and assessed by image analysis system.The neurologic deficit status were evaluated on 0~5 grade scale.The levels of dopamine(DA),norepinephrine(NE),serotonin(5-HT) and its metabolic product~hydroxyindole acetic acid(5-HIAA) in cortex and striatum were measured by fluoro-spectrophotometry.Results Ami treatment exhibited a remarkable reduction in infarct volume and neurologic deficit scores.The monoamines content of cortex and striatum had a significant increase compared with ischemia-reperfusion group.Conclusion Amitriptyline has protective effect on cerebral ischemia-reperfusion injury in rats.The mechanism might be related to reducing the release of NE,DA and 5-HT during cerebral ischemia-reperfusion,attenuating or inhibiting of the neurotoxic effects of monoamine neurotransmitters.