This study aims to investigate the mechanism of acacetin in protecting rats from cerebral ischemia-reperfusion injury via the Toll-like receptor 4(TLR4)/NOD-like receptor protein 3(NLRP3) signaling pathway. Wistar rats were randomized into sham, model, low-and high-dose acacetin, and nimodipine groups, with 10 rats in each group. The rat model of middle cerebral artery occlusion(MCAO) was established with the improved suture method in other groups except the sham group. The neurological deficit score and cerebral infarction volume of each group were evaluated 24 h after modeling. Enzyme-linked immunosorbent assay(ELISA) was employed to measure the levels of interleukin-1β(IL-1β), IL-6, tumor necrosis factor-α(TNF-α), malondialdehyde(MDA), supe-roxide dismutase(SOD), and glutathione(GSH). Western blot was employed to determine the expression levels of B-cell lymphonoma-2(Bcl-2), Bcl-2-associated X protein(Bax), and TLR4/NLRP3 signaling pathway-related proteins(TLR4, p-NF-κB/NF-κB, NLRP3, pro-caspase-1, cleaved caspase-1, pro-IL-1β, and cleaved IL-1β) in the rat brain tissue. Hematoxylin-eosin(HE) staining was employed to reveal the histopathological changes in the ischemic area. Compared with the sham group, the modeling of MCAO increased the neurological deficit score and cerebral infarction volume, elevated the IL-1β, IL-6, TNF-α, and MDA levels and lowered the SOD and GSH levels in the brain tissue(P<0.05). Compared with the MCAO model group, low-and high-dose acacetin and nimodipine decreased the neurological deficit score and cerebral infarction volume, lowered the IL-1β, IL-6, TNF-α, and MDA levels and elevated the SOD and GSH levels in the brain tissue(P<0.05). Compared with the sham group, the model group showed up-regulated protein levels of Bax, TLR4, p-NF-κB/NF-κB, NLRP3, pro-caspase-1, cleaved caspase-1, pro-IL-1β, and cleaved IL-1β and down-regulated protein level of Bcl-2 in the brain tissue(P<0.05). Compared with the MCAO model group, the acacetin and nimodipine groups showed down-regulated protein levels of Bax, TLR4, p-NF-κB/NF-κB, NLRP3, pro-caspase-1, cleaved caspase-1, pro-IL-1β, and cleaved IL-1β and up-regulated protein level of Bcl-2 in the brain tissue(P<0.05). In conclusion, acacetin regulates the TLR4/NLRP3 signaling pathway to inhibit neuroinflammatory response and oxidative stress, thus exerting the protective effect on cerebral ischemia-reperfusion injury in rats.
Rats ; Animals ; NF-kappa B/metabolism* ; bcl-2-Associated X Protein ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Rats, Sprague-Dawley ; Caspase 1/metabolism* ; Toll-Like Receptor 4/metabolism* ; Nimodipine/pharmacology* ; Interleukin-6 ; Rats, Wistar ; Signal Transduction ; Infarction, Middle Cerebral Artery ; Reperfusion Injury/prevention & control* ; Superoxide Dismutase/metabolism*

To study the protective effect of Ershiwuwei Zhenzhu Pills on ischemic stroke rats. Ninety 4-weeks-old SPF male SD rats were randomly divided into 6 groups(n=15):sham operation group, model group, nimodipine group(12 mg·kg~(-1)), Ershiwuwei Zhenzhu Pills high-dose group(400 mg·kg~(-1)), Ershiwuwei Zhenzhu Pills medium-dose group(200 mg·kg~(-1)), Ershiwuwei Zhenzhu Pills low-dose group(100 mg·kg~(-1)).The permanent middle cerebral artery occlusion model(PMCAO) was established in the model group, nimodipine group, and Ershiwuwei Zhenzhu Pills groups by the improved thread plug method, while the sham operation group did not insert the thread plug.Nimodipine group and Ershiwuwei Zhenzhu Pills groups were given intragastric administration once a day for 24 days before the modeling operation, and once 1 hour before the modeling operation, while sham operation group and model group were given equal volumes of distilled water.The neuroethology of the surviving rats was measured; The volume of cerebral infarction in rats was measured by TTC method; The histopathology of rat brain was observed by HE method; The expression levels of tumor necrosis factor α(TNF-α),interleukin-1β(IL-1β),interleukin-6(IL-6),malondialdehyde(MDA),superoxide dismutase(SOD) and catalase(CAT) in serum were detected by ELISA;The mRNA expressions of Notch 1,Jagged 1,Hes 1 and Bcl-2 in rat brain were detected by RT-PCR;Western blot was used to detect the expression levels of caspase-3 protein in rat brain; the expression levels of vascular endothelial growth factor(VEGF) and CD34 positive cells in rat brain were detected by immunofluorescence.The low, medium and high dose groups of Ershiwuwei Zhenzhu Pills and nimodipine group could significantly reduce the neurobehavioral score and cerebral infarction volume of rats with permanent middle cerebral artery occlusion, reduce the morphological changes of nerve cells, decrease the expression of TNF-α,IL-1β and IL-6 in rat serum, increase the activity of SOD and CAT,and reduce the level of MDA.Furthermore, the expression levels of Notch l, Jagged l, Hes l and Bcl-2 mRNA were significantly increased, and the expression level of caspase-3 protein was decreased.Meanwhile, the number of VEGF and CD34 positive cells increased in the treatment group.The differences were statistically significant. Ershiwuwei Zhenzhu Pills has a protective effect on ischemic stroke rats, and its mechanism may be related to anti-inflammation, anti-oxidation, promotion of nerve cell proliferation, inhibition nerve cell apoptosis and promotion of angiogenesis.
Animals ; Caspase 3/metabolism* ; Drugs, Chinese Herbal/pharmacology* ; Infarction, Middle Cerebral Artery/drug therapy* ; Interleukin-6/metabolism* ; Ischemic Stroke/drug therapy* ; Male ; Nimodipine/pharmacology* ; Proto-Oncogene Proteins c-bcl-2/metabolism* ; RNA, Messenger ; Rats ; Rats, Sprague-Dawley ; Superoxide Dismutase/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Vascular Endothelial Growth Factor A/metabolism*

OBJECTIVETo observe the effects of Tongxinluo (TXL) on angiogenesis and the volume of blood perfusion in ischemic stroke rats.

METHODSThe model of middle cerebral artery occlusion (MCAO) was established using craniotomy ligation of the middle cerebral artery on one side. After screening, the male SD rats were randomly divided into the sham-operation group, the model group, the large dose TXL group, the middle dose TXL group, the low dose TXL group, and the Nimodipine group. The expression of microvascular density (MVD, CD31) of the MCAO rats was detected using immunohistochemical assay after 14 days of medication. The microvascular morphology and the volume of blood perfusion in the brain tissue were observed under laser scanning confocal microscope (LSCM).

RESULTSThe positive CD31 expression was intense with significant coloring in the large dose TXL group, the middle dose TXL group, and the Nimodipine group, better than that of the model group. The blood perfusion volume in the ischemic brain cortex could be promoted in the large dose TXL group, the middle dose TXL group, and the Nimodipine group (P<0.01, P<0.05). The optimal effects were shown in the large dose TXL group (P<0.01).

CONCLUSIONTXL significantly increased the MVD of the ischemic brain tissue, promoted the post-ischemic angiogenesis, and increased the volume of blood perfusion of ischemic brain tissue, playing certain blood flow compensatory roles.

Animals ; Brain Ischemia ; Disease Models, Animal ; Drugs, Chinese Herbal ; pharmacology ; Hemoperfusion ; Male ; Neovascularization, Physiologic ; drug effects ; Nimodipine ; pharmacology ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo study the effects of calcium and calmodulin dependent kinase against hypoxic neuronal injury and its possible mechanisms.

METHODSEmbryonic cortical neurons of 17-day pregnant embryo Sprague-Dawley rats were cultured in vitro and the cultured neurons were randomly allocated into different groups that exposed to hypoxia or hypoxia +calcium channel antagonist. Nimodipine and MK-801 were used to block the L-voltage sensitive calcium channel and NMDA receptor respectively before hypoxia. The methyl thiazolyl tetrazolium (MTT) method was used to determine the cell viability. Fluo-4AM, an intracellular calcium indictor, was used to detect the changes of intracellular calcium after hypoxia. The expressions of CaMKII and CaMKIV were detected by Western blot.

RESULTSThe cell viability of the nimodipine or MK-801-treated groups was significantly higher than that of the untreated hypoxia group. The intracellular calcium level of the nimodipine-treated group decreased rapidly after hypoxia. Compared to nimodipine treatment, MK-801 treatment could inhibit hypoxia-induced calcium influx for a longer time. Nimodipine treatment decreased the CaMKII expression while MK-801 treatment decreased the CaMKIV expression.

CONCLUSIONSNimodipine and MK-801 protect neurons from hypoxic injury possibly by the inhibition of CaMKII and CaMKIV expressions respectively.

Animals ; Calcium ; analysis ; Calcium-Calmodulin-Dependent Protein Kinase Type 2 ; Calcium-Calmodulin-Dependent Protein Kinase Type 4 ; Calcium-Calmodulin-Dependent Protein Kinases ; antagonists & inhibitors ; physiology ; Cell Hypoxia ; Dizocilpine Maleate ; pharmacology ; Female ; Neurons ; pathology ; Neuroprotective Agents ; pharmacology ; Nimodipine ; pharmacology ; Rats ; Rats, Sprague-Dawley

The aim was to study the mechanisms of HL-60 cell apoptosis induced by nimodipine (NMDP) and cytarabine (Ara-C). The DNA fragment was detected by agarose gel electrophoresis. The expressions of bcl-2 and bax gene proteins related with apoptosis were investigated by immunohistochemistry. The results showed that HL-60 cell apoptosis rate had been increasing in the experimental groups compared with the control group since culturing 8 hours. The expression of Bcl-2 protein was lower and the expression of Bax protein was higher in the experimental groups than that in the control group, while ratio of bcl-2/bax was lower in the experimental groups than that in the control group. It is concluded that NMDP and Ara-C induce apoptosis of HL-60 cells, and the mechanism of apoptosis induced by them may down-regulate the expression of bcl-2 gene and up-regulate the expression of bax gene. The mechanism of HL-60 cell apoptosis induced by Ara-C and NMDP is probably associated with the down-regulation of Bcl-2 protein expression.
Antimetabolites, Antineoplastic ; pharmacology ; Apoptosis ; drug effects ; Cytarabine ; pharmacology ; Drug Resistance, Neoplasm ; drug effects ; Drug Synergism ; Gene Expression Regulation, Neoplastic ; HL-60 Cells ; Humans ; Nimodipine ; pharmacology ; Proto-Oncogene Proteins c-bcl-2 ; biosynthesis ; genetics ; bcl-X Protein ; biosynthesis ; genetics

AIMTo build a simple and repeatable animal model of subarachnoid hemorrhage (SAH).

METHODSSAH was produced by passing a nylon thread up through the right internal carotid artery and piercing a hole in the right anterior cerebral artery. At 12 h and 24 h after SAH operation, the rats were evaluated with rotarod test and the behavior scale (5-point scale).

RESULTSThe rats were trained through rotarod test and then randomly divided into three groups, including vehicle group treated with vehicle after SAH, nimodipine treated group (i.p. 0.25 mg x kg(-1), 5 min, 6 h, 12 h after SAH) and sham group. At the point of the perforation there was usually a capping clot. There was always blood in the basal cisterns with some spread over the hemisphere. After 12 h and 24 h of SAH operation, the time of rotarod test of rats decreased significantly and the rats had serious neurological deficit. Nimodipine could alleviate the neurological deficit after 24 h of SAH.

CONCLUSIONTo present a simple and reliable model of SAH in the rats, which allows evaluating novel compounds and new drugs for treatment of SAH.

Animals ; Behavior, Animal ; drug effects ; Brain ; pathology ; Calcium Channel Blockers ; pharmacology ; Cerebrovascular Circulation ; drug effects ; Disease Models, Animal ; Male ; Nimodipine ; pharmacology ; Rats ; Rats, Wistar ; Reproducibility of Results ; Rotarod Performance Test ; Subarachnoid Hemorrhage ; etiology ; pathology ; physiopathology

AIMTo investigate the effect of nimodipine (NM) on cerebral blood flow (CBF) in dogs following intranasal administration.

METHODSNM solution was administered intranasally, intravenously (i.v.), and orally to dogs and the change of CBF was determined by using electromagnetic blood flowmeter. MFLab experimental program was applied to monitor the experimental process and analyze data.

RESULTSCBF markedly increased after iv and intranasal application, while large variance was observed after oral dosing. CBF in dogs after three administrations increased by 26.4%, 28.0% and 8.5%, respectively, compared with that of baseline. Following intranasal administration, the onset of action was slightly slower than that after iv injection [(5 +/- 4) min vs (2.2 +/- 1.2) min], however the duration of improvement was the longest [ (25 +/- 17) min].

CONCLUSIONIntranasal delivery for NM can be a promising alternative to parenteral or oral administration.

Administration, Intranasal ; Administration, Oral ; Animals ; Blood Flow Velocity ; drug effects ; Cerebrovascular Circulation ; drug effects ; Dogs ; Female ; Injections, Intravenous ; Male ; Nimodipine ; administration & dosage ; pharmacology ; Vasodilator Agents ; administration & dosage ; pharmacology

In order to explore whether the member of Bcl-2 gene family, for example, Bcl-2 and Bax, are induced after cerebral ischemia, and whether expression of genes can be modulated by calcium-antagonist, the rat cerebral ischemic models were made by occluding left middle cerebral artery. The expression of Bcl-2 and Bax mRNA was measured by RT-PCR method. After middle cerebral artery occlusion (MCAO), the expression of both Bcl-2 and Bax mRNA were induced. Level of Bcl-2 mRNA increased steadily and level of Bax mRNA increased gradually at first, reached a peak after 24 h, then decreased slowly. After administration of nimodipine, Bcl-2 mRNA was up-regulated in the hippocampus 6 and 24 h after ischemia, while Bax mRNA was down-regulated 6 and 24 h after ischemia. Focal cerebral ischemia can induce proto-oncogenes to express, which was associated with apoptosis. Calcium-antagonist can up-regulate Bcl-2 mRNA and down-regulate Bax mRNA. The increased ratio of Bcl-2 and Bax mRNA may contribute to the anti-apoptic effect of nimodipine. The study indicates that pharmacological modulation of Bcl-2 family member expression could become a new strategy to manage neuronal damage.
Animals ; Apoptosis ; drug effects ; Brain Ischemia ; metabolism ; Calcium Channel Blockers ; pharmacology ; Nimodipine ; pharmacology ; Proto-Oncogene Proteins c-bcl-2 ; biosynthesis ; genetics ; RNA, Messenger ; biosynthesis ; genetics ; Rats ; Rats, Wistar ; bcl-2-Associated X Protein ; biosynthesis ; genetics

OBJECTIVETo explore the mechanism and type of acute infectious brain edema induced by injection of pertussis bacilli (PB) in rat neocortex, to study the neuroprotective effect of non-competitive antagonist of N-methl-D-aspartate (NMDA) receptor (MK-801) and antagonist of Ca(2+) channels (nimodipine) on brain edema, and to investigate the relationship between percentage of water content and cytosolic free calcium concentration ([Ca(2+) ](i)) in synaptosomes or content of Evans Blue (EB).

METHODS95 SD rats were randomly divided into five groups, ie, normal control group, sham-operated control group, PB group, nimodipine treatment group and MK-801 pretreatment group. The acute infectious brain edema was induced by injection of PB into the rats. Quantitative measurements of water content and the concentration of EB were performed. [Ca(2+) ](i) was determined in calcium fluorescent indication Fura-2/AM loaded neuronal synaptosome with a spectrofluorophotometer. To observe the effect of MK-801 and nimodipine, we administered MK-801 48 hours and 24 hours before the injection of PB in MK-801 pretreatment group, and nimodipine after the injection of PB in nimodipine treatment group. The specific binding of NMDA receptor was measured with [(3)H]-MK-801 in the neuronal membrane of cerebral cortex.

RESULTSThe levels of water content and EB content of brain tissues, and [Ca(2+) ](i) in the neuronal synaptosomes increased more significantly in the PB-injected cerebral hemisphere in the PB group than those of normal control group and sham-operated control group (P<0.05). The water content and [Ca(2+) ](i) increased with the duration of infectious brain edema. Nimodipine administered after the injection of PB could significantly decrease the water content, EB and [Ca(2+) ](i) (P<0.05). MK-801 could significantly decrease the water content, EB and [Ca(2+) ](i) in 4 h and 24 h groups (P<0.05). The Kd values were 30.5 nmol/L+/-3.0 nmol/L and 42.1 nmol/L+/-4.2 nmol/L in PB group and NS group respectively (P<0.05), and Bmax were 0.606 pmol/mg.pro+/-0.087 pmol/mg.pro and 0.623 pmol/mg.pro+/-0.082 pmol/mg.pro respectively, without statistical significance (P>0.05).

CONCLUSIONSThe changes in the permeability of blood-brain barrier (BBB) and Ca(2+)-overload may participate in the pathogenesis of infectious brain edema. Treatment with nimodipine can dramatically reduce the damage of brain edema and demonstrate neuroprotective effect on brain edema by inhibiting the excess of Ca(2+) influx and reducing the permeability of BBB. MK-801 pretreatment may inhibit the delayed Ca(2+) influx into the neurons. The infectious brain edema is not only cytotoxic brain edema (intracellular edema) but also vasogenic brain edema (extracellular edema) followed by earlier BBB breakdown, so infectious brain edema is complicated with brain edema.

Acute Disease ; Analysis of Variance ; Animals ; Blood-Brain Barrier ; drug effects ; Bordetella pertussis ; Brain Edema ; drug therapy ; metabolism ; microbiology ; Calcium ; metabolism ; Calcium Channel Blockers ; pharmacology ; Dizocilpine Maleate ; pharmacology ; Nimodipine ; pharmacology ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo study the therapeutic effect of nimodipine on experimental brain injury.

METHODSExperimental and control rabbits were subjected to a closed head injury. In one group nimodipine was given intravenously and the effect evaluated by electron microscopy, brain water content, calcium levels, transcranial Doppler, and intracranial pressure monitoring.

RESULTSIn rabbits treated with nimodipine the level of neuronal cytosolic free calcium was markedly decreased. There were less cellular damage and less spasm of the middle cerebral artery seen on electron microscopy. No difference regarding intracranial pressure changes between the two groups was noted.

CONCLUSIONSNimodipine has a protective action on brain injury by blocking a series of pathological reactions induced by neuronal calcium overload, and by reducing the spasm of brain vessels and improving cerebral blood flow.

Animals ; Biopsy, Needle ; Brain Edema ; prevention & control ; Brain Injuries ; drug therapy ; pathology ; Calcium Channel Blockers ; pharmacology ; Disease Models, Animal ; Female ; Immunohistochemistry ; Infusions, Intravenous ; Male ; Nimodipine ; pharmacology ; Probability ; Rabbits ; Reference Values ; Sensitivity and Specificity ; Statistics, Nonparametric