Neuroprotective effects of ultra-low-molecular-weight heparin on cerebral ischemia/reperfusion injury in rats: involvement of apoptosis, inflammatory reaction and energy metabolism

Venous thromboembolic pharmacological prophylaxis in severe traumatic acute subdural hematomas: Early prophylaxis is effective and safe

BACKGROUND

The purpose of this study was to evaluate the optimal timing and type of pharmacological venous thromboembolism prophylaxis (VTEp) in patients with severe blunt head trauma with acute subdural hematomas (ASDH).

METHODS

Matched cohort study using ACS-TQIP database (2013-2016) including patients with isolated ASDH. Outcomes of matched patients receiving early prophylaxis (EP, ≤48 h) and late prophylaxis (LP, >48 h) were compared with univariable and multivariable regression analysis.

RESULTS

In 1,660 matched cases VTE complications (3.1% vs 0.5%, p < 0.001) were more common in the LP compared to the EP group. Multivariable regression analysis identified EP as an independent protective factor for VTE complications (OR 0.169, p < 0.001) but not mortality (p = 0.260). The adjusted risk for delayed craniectomy was not associated with EP compared to LP (p = 0.095). LMWH was independently associated with a lower mortality (OR 0.480, p = 0.008) compared to UH.

CONCLUSIONS

Early VTEp (≤48 h) does not increase the risk for craniectomies and is independently associated with fewer VTE complications in patients with isolated ASDH. LMWH was independently associated with a lower mortality compared to UH.

Neuroprotective Effects of Normobaric Hyperoxia and Transplantation of Encapsulated Choroid Plexus Epithelial Cells on The Focal Brain Ischemia

Objective

Choroid plexus epithelial cells (CPECs) have the epithelial characteristic, produce cerebrospinal fluid, contribute to the detoxification process in the central nervous system (CNS), and are responsible for the synthesis and release of many nerve growth factors. On the other hand, studies suggest that normobaric hyperoxia (HO) by induction of ischemic tolerance (IT) can protect against brain damage and neurological diseases. We examined the effect of combination therapy of encapsulated CPECs and HO to protect against ischemic brain injury.

Materials and Methods

In this experimental study, six groups of adult male Wistar rats were randomly organized: sham, room air (RA)+middle cerebral artery occlusion (MCAO), HO+MCAO, RA+MCAO+encapsulated CPECs, HO+MCAO+encapsulated CPECs, RA+MCAO+empty capsules. RA/HO were pretreatment. The CPECs were isolated from the brain of neonatal Wistar rats, cultured, and encapsulated. Then microencapsulated CPECs were transplanted in the neck of the animal immediately after the onset of reperfusion in adult rats that had been exposed to 60 minutes MCAO. After 23 hours of reperfusion, the neurologic deficit score (NDS) was assessed. Next, rats were killed, and brains were isolated for measuring brain infarction volume, blood-brain barrier (BBB) permeability, edema, the activity of superoxide dismutase (SOD), and catalase (CAT) and also, the level of malondialdehyde (MDA).

Results

Our results showed that NDS decreased equally in HO+MCAO, RA+MCAO+encapsulated CPECs, and HO+MCAO+encapsulated CPECs groups. Brain infarction volume decreased up 79%, BBB stability increased, edema decreased, SOD and CAT activities increased, and MDA decreased in the combination group of HO and transplantation of encapsulated CPECs in the ischemic brain as compared with when HO or transplantation of encapsulated CPECs was applied alone.

Conclusion

The combination of HO and transplantation of encapsulated CPECs for stroke in rats was more effective than the other treatments, and it can be taken into account as a promising treatment for ischemic stroke.

Preclinical animal studies in ischemic stroke: Challenges and some solutions

Despite the impressive efficacies demonstrated in preclinical research, hundreds of potentially neuroprotective drugs have failed to provide effective neuroprotection for ischemic stroke in human clinical trials. Lack of a powerful animal model for human ischemic stroke could be a major reason for the failure to develop successful neuroprotective drugs for ischemic stroke. This review recapitulates the available cerebral ischemia animal models, provides an anatomical comparison of the circle of Willis of each species, and describes the functional assessment tests used in these ischemic stroke models. The distinct differences between human ischemic stroke and experimental stroke in available animal models is explored. Innovative animal models more closely resembling human strokes, better techniques in functional outcome assessment and better experimental designs generating clearer and stronger evidence may help realise the development of truly neuroprotective drugs that will benefit human ischemic stroke patients. This may involve use of newer molecules or revisiting earlier studies with new experimental designs. Translation of any resultant successes may then be tested in human clinical trials with greater confidence and optimism.

Timing and Type of Venous Thromboembolic Prophylaxis in Isolated Severe Liver Injury Managed Non-Operatively

BACKGROUND

The optimal timing and type of pharmacological venous thromboembolic prophylaxis (VTEp) after severe liver injury selected for nonoperative management (NOM) are controversial. The aim of this study was to assess the effect of timing and type of VTEp in severe liver injuries selected for NOM.

METHODS

ACS-TQIP database study (2013-17) including patients with blunt isolated severe liver injuries (AIS ≥ 3), selected for NOM, who received VTEp with either unfractionated heparin (UH) or low-molecular-weight heparin (LMWH). Patients who underwent laparotomy or angiointervention within 24 h or prior to the initiation of VTEp were excluded. The study population was stratified according to the timing of VTEp ≤ 48 h (EP) and > 48 h (LP) groups. Univariate and multivariate analyses were used to identify differences between the groups.

RESULTS

A total of 4074 patients was included in the study. 2004 (49.2%) received EP and 2070 (50.8%) LP. Patients with more severe injuries were more likely to receive LP than an EP [ISS 24 (19-29) vs 22 (17-27), p < 0.001]. On multivariate analysis (correcting for age, gender, comorbidities, blood pressure, GCS, ISS, type of VTEp), LP was identified as an independent risk factor for thromboembolic events (OR 1.52, p = 0.032) and mortality (OR 2.49, p = 0.031). LMWH was independently associated with lower mortality (OR 0.36, p = 0.007), compared to UH. EP did not increase the risk of laparotomy or angiointervention after starting VTEp, compared to LP (p = 0.992).

CONCLUSION

Early VTEp (≤ 48 h) is safe and independently associated with fewer thromboembolic events and a lower mortality after isolated severe liver injuries managed nonoperatively. LMWH was independently associated with improved outcomes when compared with UH.

Venous thromboembolism prevention with low molecular weight heparin may reduce hemorrhagic transformation in acute ischemic stroke

BACKGROUND

Subcutaneous heparin at a prophylactic dose (SHPD) is a rather common treatment in ischemic stroke, but whether it confers an increased risk of hemorrhagic transformation of cerebral infarct (HT) and whether its reduction or discontinuation favors HT regression are presently poorly understood.

METHODS

Two samples of ischemic stroke patients with a cerebral lesion diameter ≥ 3 cm on brain CT scan, admitted over 7 years to our stroke unit, were retrospectively examined: (1) patients treated or not treated with SHPD (enoxaparin 4000 U/day), with subsequent assessment of possible HT appearance (N = 267, mean age 75.9 ± 12.8 years) and (2) patients treated with SHPD, with HT and subsequent reduction/discontinuation or maintenance of the initial dose, and subsequent assessment of HT evolution (N = 116, mean age 75.7 ± 11.1 years). HT severity was quantified according to the ECASS study (HT score).

RESULTS

In the first sample, after adjustment for age, sex, stroke severity, cerebral lesion diameter, and other possible confounders, SHPD was inversely associated with HT appearance (hazard ratio 0.62, 95% CI 0.39-0.98, P = 0.04). In the second sample, after adjustment for age, sex, stroke severity, cerebral lesion diameter, and initial HT severity, SHPD reduction/discontinuation had an inverse effect on both HT score improvement (odds ratio 0.42, 95% CI 0.18-0.99, P = 0.049) and HT improvement according to neuroradiological reports (odds ratio 0.34, 95% CI 0.14-0.82, P = 0.015).

CONCLUSIONS

This retrospective study suggests that SHPD may play a protective role in HT appearance and evolution, which requires verification by a randomized clinical trial.

The protective effect of cordyceps sinensis extract on cerebral ischemic injury via modulating the mitochondrial respiratory chain and inhibiting the mitochondrial apoptotic pathway

Cerebral ischemia is a common refractory brain disease, resulting from a reduction in the blood flow to the brain. Mitochondrial dysfunction leads to ischemic stroke and brain injury. Cordyceps sinensis (CS) is an important traditional Chinese medicine, which has been linked to neuroprotection in recent studies. In this study, we investigated the role of the mitochondrial respiratory chain and the mitochondrial apoptotic pathway on the protective effect of Cordyceps sinensis extract (CSE) against cerebral ischemia injury both in vivo and in vitro. In a murine middle cerebral artery occlusion (MCAO) model, administration of CSE relieved neuronal morphological damage and attenuated the neuronal apoptosis. CSE also reduced neurobehavioral scores and oxygen free radical (OFR), while improving the levels of ATP, cytochrome c oxidase (COX), and mitochondrial complexes I-IV. Furthermore, the mRNA expression of Bax, cytochrome c (Cyt c) and caspase-3 were down-regulated. In brain microvascular endothelial cells (BMECs) exposed to oxygen and glucose deprivation (OGD), CSE prevented OGD-induced cellular apoptosis, and recovered the reduction of mitochondrial membrane potential (MMP). Moreover, CSE treatment induced an increase of Bcl-2 protein expression and a decrease of Bax, Cyt c and caspase-3 protein expression. Meanwhile, the caspase-3, -8, and -9 activities were also inhibited. The results indicate that CSE can relieve cerebral ischemia injury and exhibit protective effects via modulating the mitochondrial respiratory chain and inhibiting the mitochondrial apoptotic pathway.

Investigation of the protective effect of heparin pre-treatment on cerebral ischaemia in gerbils

Context: The interruption of cerebral blood circulation may cause stroke characterized by high neurological deficits (NDs) as a result of neuronal dysfunction or destruction. Heparin may exert a neuroprotective effect against cerebral ischaemia/reperfusion injury. Objective: The objective of this study was to investigate the mechanism underlying the effects of heparin pre-treatment on cerebral injury in the gerbil. Materials and methods: A total of 80 healthy Mongolian gerbils were randomly divided into four groups to establish cerebral ischaemia model by bilateral carotid artery occlusion: control (no anaesthesia and surgery), sham (no occlusion), non-anticoagulation (occlusion), and anti-coagulation treatment groups (50 IU/100 g heparin pre-treated, occlusion). Gerbils were anesthetized with 40 mg/kg pentobarbital sodium through intraperitoneal injection before operation except for the control group. Then, the ND and histopathological damage (HD) scores were determined. The percentage of tumour necrosis factor (TNF)-α- and interleukin (IL)-1β-positive cells were calculated based on immunohistochemical results. The mRNA and protein levels of caspase-9, caspase-8, FasL, and calpain were evaluated with real-time polymerase chain reaction (RT-PCR) and western blotting, respectively. Results: Compared with non-anticoagulation group, heparin pre-treatment (50 IU/100 g) delayed the onset of dyspnoea (p < 0.05), and showed a significant decrease in ND (p < 0.01), mortality rate (p < 0.05), HD (p < 0.01) and percentage of positive cells for TNF-α, IL-1β (p < 0.01) in cerebral ischaemia gerbils. Besides, the expression levels of caspase-9, caspase-8, FasL, and calpain were reduced after pre-treatment with 50 IU/100 g heparin. Discussion and conclusions: The damage caused to gerbil brain was reduced upon pre-treatment with heparin, possibly through the amelioration of neuronal cell apoptosis and expression of TNF-α and IL-1β. These findings are expected to provide a new breakthrough in the study and treatment of cerebral ischaemia.

Protective effect of glycyrrhizic acid on cerebral ischemia/reperfusion injury via inhibiting HMGB1-mediated TLR4/NF-κB pathway

Cerebral ischemia is caused by various disorders, such as stroke, myocardial infarction, or peripheral vascular disease. The purpose of this paper was to investigate the effects of glycyrrhizic acid (GA) on cerebral ischemia/reperfusion (I/R) injury. Middle cerebral artery occlusion was established to evaluate the effects of GA on cerebral ischemia. In this study, our results showed that GA could dramatically decrease cerebral edema, reduce the neurological deficits, and smaller brain infarct volume was found in the GA treatment group. In serum and brain tissue, GA also increased superoxide dismutase activity. In addition, in serum and brain tissue, GA also dramatically inhibited the secretion of inflammatory cytokines, including interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α. Moreover, GA inhibited the expressions of high-mobility group protein box-1 (HMGB1)-mediated TLR4/NF-κB pathway. Our data determined that GA may provide protective effect on the I/R-induced cerebral ischemia disease.

Early low-anticoagulant desulfated heparin after traumatic brain injury: Reduced brain edema and leukocyte mobilization is associated with improved watermaze learning ability weeks after injury

BACKGROUND

Unfractionated heparin administered immediately after traumatic brain injury (TBI) reduces brain leukocyte (LEU) accumulation, and enhances early cognitive recovery, but may increase bleeding after injury. It is unknown how non-anticoagulant heparins, such as 2,3-O desulfated heparin (ODSH), impact post-TBI cerebral inflammation and long-term recovery. We hypothesized that ODSH after TBI reduces LEU-mediated brain inflammation and improves long-term neurologic recovery.

METHODS

CD1 male mice (n = 66) underwent either TBI (controlled cortical impact [CCI]) or sham craniotomy. 2,3-O desulfated heparin (25 mg/kg [25ODSH] or 50 mg/kg [50ODSH]) or saline was administered for 48 hours after TBI in 46 animals. At 48 hours, intravital microscopy visualized rolling LEUs and fluorescent albumin leakage in the pial circulation, and the Garcia Neurologic Test assessed neurologic function. Brain edema (wet/dry ratio) was evaluated post mortem. In a separate group of animals (n = 20), learning/memory ability (% time swimming in the Probe platform quadrant) was assessed by the Morris Water Maze 17 days after TBI. Analysis of variance with Bonferroni correction determined significance (p < 0.05).

RESULTS

Compared with CCI (LEU rolling: 32.3 ± 13.7 LEUs/100 μm per minute, cerebrovascular albumin leakage: 57.4 ± 5.6%), both ODSH doses reduced post-TBI pial LEU rolling (25ODSH: 18.5 ± 9.2 LEUs/100 μm per minute, p = 0.036; 50ODSH: 7.8 ± 3.9 LEUs/100 μm per minute, p < 0.001) and cerebrovascular albumin leakage (25ODSH: 37.9 ± 11.7%, p = 0.001, 50ODSH: 32.3 ± 8.7%, p < 0.001). 50ODSH also reduced injured cerebral hemisphere edema (77.7 ± 0.4%) vs. CCI (78.7 ± 0.4 %, p = 0.003). Compared with CCI, both ODSH doses improved Garcia Neurologic Test at 48 hours. Learning/memory ability (% time swimming in target quadrant) was lowest in CCI (5.9 ± 6.4%) and significantly improved in the 25ODSH group (27.5 ± 8.2%, p = 0.025).

CONCLUSION

2,3-O desulfated heparin after TBI reduces cerebral LEU recruitment, microvascular permeability and edema. 2,3-O desulfated heparin may also improve acute neurologic recovery leading to improved learning/memory ability weeks after injury.

Early heparin administration after traumatic brain injury: Prolonged cognitive recovery associated with reduced cerebral edema and neutrophil sequestration

BACKGROUND

Early administration of unfractionated heparin (UFH) after traumatic brain injury (TBI) reduces early in vivo circulating leukocytes (LEUs) in peri-injury penumbral brain tissue, enhancing cognitive recovery 2 days after injury. It remains unclear how long this effect lasts and if this is related to persistently accumulating LEUs in penumbral brain tissue. We hypothesized that UFH reduces LEU brain tissue sequestration resulting in prolonged cognitive recovery.

METHODS

CD1 male mice underwent either TBI by controlled cortical impact (CCI) or sham craniotomy. Unfractionated heparin (75 or 225 U/kg) or vehicle was repeatedly administered after TBI. Neurologic function (Garcia Neurological Test [maximum score = 18]) and body weight loss ratios were evaluated at 24 hours to 96 hours after TBI. Brain and lung wet-to-dry ratios, hemoglobin levels, and brain LEU sequestration (Ly6G immunohistochemistry) were evaluated 96 hours postmortem. Analysis of variance with Bonferroni correction determined significance (p < 0.05).

RESULTS

Compared with untreated CCI animals (24 hours, 14.7 ± 1.0; 48 hours, 15.5 ± 0.7; 72 hours, 15.0 ± 0.8; 96 hours, 16.5 ± 0.9), UFH75 (24 hours, 16.0 ± 1.0, p < 0.01; 48 hours, 16.5 ± 0.7, p < 0.05; 72 hours, 17.1 ± 0.6, p < 0.01; 96 hours, 17.4 ± 0.7, p < 0.05) increased cognitive recovery throughout the entire observation period after TBI. At 48 hours, UFH225 significantly worsened body weight loss (10.2 ± 4.7%) as compared with uninjured animals (5.5 ± 2.9%, p < 0.05). Both UFH75 (60.8 ± 40.9 PMNs per high-power field [HPF], p < 0.05) and UFH225 (36.0 ± 17.6 PMNs/HPF, p < 0.01) significantly decreased brain neutrophil sequestration found in untreated CCI animals (124.2 ± 44.1 PMNs/HPF) 96 hours after TBI. Compared with untreated CCI animals (78.8 ± 0.8%), UFH75 (77.3 ± 0.6%, p = 0.04) reduced cerebral edema to uninjured levels (77.4 ± 0.6%, p = 0.04 vs. CCI). Only UFH225 (10.6 ± 1.2 g/dL) resulted in lower hemoglobin than in uninjured animals (13.0 ± 1.2 g/dL, p < 0.05).

CONCLUSIONS

Heparin after TBI reduces tissue LEU sequestration and edema in injured brain for up to 4 days. This is associated with persistent improved cognitive recovery, but only when low-dose UFH is given. Early administration of UFH following TBI may blunt LEU-related cerebral swelling and slow progression of secondary brain injury.

Global gene expression profile of cerebral ischemia-reperfusion injury in rat MCAO model

It is well-established that reperfusion following cerebral ischemic injury gives rise to secondary injury accompanied by structural and functional damage. However, it remains unclear how global genes changes in cerebral ischemia-reperfusion injury (IRI). This study investigated global gene expression in the hippocampi of Wistar rats following transient cerebral IRI using an RNA-sequencing strategy. The results revealed ≥2-fold up-regulation of 156 genes and ≥2-fold down-regulation of 26 genes at 24 h post-reperfusion. Fifteen differentially expressed genes were selected to confirm the RNA-sequencing results. Gene expression levels were dynamic, with the peak expression level of each gene occurring at different time points post-reperfusion. Gene Ontology (GO) analysis classified the differentially expressed genes as mainly involved in inflammation, stress and immune response, glucose metabolism, proapoptosis, antiapoptosis, and biological processes. KEGG pathway analysis suggested that IRI activated different signaling pathways, including focal adhesion, regulation of actin cytoskeleton, cytokine-cytokine receptor interaction, MAPK signaling, and Jak-STAT signaling. This study describes global gene expression profiles in the hippocampi of Wistar rats using the middle cerebral artery occlusion (MCAO) model. These findings provide new insights into the molecular pathogenesis of IRI and potential drug targets for the prevention and treatment of IRI in the future.

High-Dose Nadroparin Following Endovascular Aneurysm Treatment Benefits Outcome After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Delayed cerebral ischemia (DCI) is one of the major causes of delayed morbidity and mortality in patients with aneurysmal subarachnoid hemorrhage (aSAH).

OBJECTIVE

To evaluate the effect of high-dose nadroparin treatment following endovascular aneurysm treatment on the occurrence of DCI and clinical outcome.

METHODS

Medical records of 158 adult patients with an aSAH were retrospectively analyzed. Those patients treated endovascularly for their ruptured aneurysm were included in this study. They received either high-dose (twice daily 5700 AxaIE) or low-dose (once daily 2850 AxaIE) nadroparin treatment after occlusion of the aneurysm. Medical charts were reviewed and imaging was scored by 2 independent neuroradiologists. Data with respect to in-hospital complications, peri-procedural complications, discharge location, and mortality were collected.

RESULTS

Ninety-three patients had received high-dose nadroparin, and 65 patients prophylactic low-dose nadroparin. There was no significant difference in clinical DCI occurrence between patients treated with high-dose (34%) and low-dose (31%) nadroparin. More patients were discharged to home in patients who received high-dose nadroparin (40%) compared to low-dose (17%; odds ratio [OR] 3.13, 95% confidence interval [95% CI]: 1.36-7.24). Furthermore, mortality was lower in the high-dose group (5%) compared to the low-dose group (23%; OR 0.19, 95% CI: 0.07-0.55), also after adjusting for neurological status on admission (OR 0.21, 95% CI: 0.07-0.63).

CONCLUSION

Patients who were treated with high-dose nadroparin after endovascular treatment for aneurysmal SAH were more often discharged to home and showed lower mortality. High-dose nadroparin did not, however, show a decrease in the occurrence of clinical DCI after aSAH. A randomized controlled trial seems warranted.

Heparin and Heparin-Derivatives in Post-Subarachnoid Hemorrhage Brain Injury: A Multimodal Therapy for a Multimodal Disease

Pharmacologic efforts to improve outcomes following aneurysmal subarachnoid hemorrhage (aSAH) remain disappointing, likely owing to the complex nature of post-hemorrhage brain injury. Previous work suggests that heparin, due to the multimodal nature of its actions, reduces the incidence of clinical vasospasm and delayed cerebral ischemia that accompany the disease. This narrative review examines how heparin may mitigate the non-vasospastic pathological aspects of aSAH, particularly those related to neuroinflammation. Following a brief review of early brain injury in aSAH and heparin’s general pharmacology, we discuss potential mechanistic roles of heparin therapy in treating post-aSAH inflammatory injury. These roles include reducing ischemia-reperfusion injury, preventing leukocyte extravasation, modulating phagocyte activation, countering oxidative stress, and correcting blood-brain barrier dysfunction. Following a discussion of evidence to support these mechanistic roles, we provide a brief discussion of potential complications of heparin usage in aSAH. Our review suggests that heparin’s use in aSAH is not only safe, but effectively addresses a number of pathologies initiated by aSAH.

Effect of inhibiting mitochondrial fission on energy metabolism in rat hippocampal neurons during ischemia/reperfusion injury

OBJECTIVE

Previous studies have shown that mitochondrial division inhibitor 1 (mdivi-1) protects rat brain from ischemia/reperfusion (I/R) injury, but the precise mechanisms are unclear. This study aims to elucidate the effect of mdivi-1 on energy metabolism and neuronal apoptosis induced by I/R in vitro.

METHODS

Cultured hippocampal neurons from Wistar rats were randomly divided into four treatment groups: control (C), vehicle (V), I/R (I), and I/R plus mdivi-1 (M). Ischemia/reperfusion was induced by oxygen-glucose deprivation for 6 h followed by normoxic/normoglycemic reperfusion for 20 h. Neurons in the M group were pretreated with mdivi-1 for 40 min before I/R. Expression levels of the mdiv-1 target dynamin-related protein 1 and apoptosis regulators Bcl-2 and Bax were examined by Western blotting. Mitochondrial membrane potential ( ) was measured by flow cytometry. Intracellular ATP content and the activities of mitochondrial complexes I-IV, Na⁺-K⁺-ATPase, and Ca²⁺-Mg²⁺-ATPase were measured by standard assays.

RESULTS

Compared to group I neurons, group M neurons exhibited markedly reduced Drp-1 and Bax expression, higher Bcl-2 expression, , and intracellular ATP, and elevated mitochondrial complex I-IV, Na⁺-K⁺-ATPase, and Ca²⁺-Mg²⁺-ATPase activities.

CONCLUSION

Inhibition of mitochondrial fission significantly improved mitochondrial function and suppressed apoptotic signaling induced by I/R.

Therapeutic Effect Analysis of Sinomenine on Rat Cerebral Ischemia-Reperfusion Injury

OBJECTIVE

The objective of this study is to investigate the therapeutic effect of sinomenine (SIN) on rat cerebral ischemia-reperfusion (IR) injury and the molecular mechanism.

METHODS

One hundred thirty-five rats were equally randomized into sham-operated group, middle cerebral artery occlusion (MCAO) group, and SIN group, and reversible rat MCAO model was made according to the Longa method for the MCAO and SIN groups. Then, 15 rats from each group were decapitated at 6, 12, and 24 hours after reperfusion to obtain brain tissue samples. Rats in the SIN group were injected with sinomenine by tail vein (90 mg/kg) 1 hour before ischemia; rats in the MCAO and sham-operated groups were administrated with the same volume of saline. Neurological severity score (NSS), infarction volume, ischemic brain water content, and blood-brain barrier (BBB) permeability were determined at corresponding time points. Acid-sensing ion channel (ASIC) 1a mRNA level was determined by quantitative real-time polymerase chain reaction; ischemic brain contents of lactic acid (LD), lactic dehydrogenase (LDH), ATPase, and inflammatory factors were determined by spectrophotometric method.

RESULTS

At 12 hours after reperfusion and since then, NSS in the SIN group decreased obviously; infarction volume, brain water content, and BBB permeability in the SIN group were lower than those in the MCAO group (P < .05). IR injury resulted in the upregulation of the contents of ASIC1a mRNA, LD, LDH, and inflammatory factors and the downregulation of the contents of ATPase, while SIN could reverse the upregulation/downregulation effect induced by IR injury (P < .05).

CONCLUSION

Through its anti-inflammation effect, which alleviates acidosis, improves energy metabolism, and inhibits ASIC1a level, SIN protects ischemic rat brain against cerebral IR injury.

Propofol reduces inflammatory reaction and ischemic brain damage in cerebral ischemia in rats

Our previous studies demonstrated that inflammatory reaction and neuronal apoptosis are the most important pathological mechanisms in ischemia-induced brain damage. Propofol has been shown to attenuate ischemic brain damage via inhibiting neuronal apoptosis. The present study was performed to evaluate the effect of propofol on brain damage and inflammatory reaction in rats of focal cerebral ischemia. Sprague-Dawley rats underwent permanent middle cerebral artery occlusion, then received treatment with propofol (10 or 50 mg/kg) or vehicle after 2 h of ischemia. Neurological deficit scores, cerebral infarct size and morphological characteristic were measured 24 h after cerebral ischemia. The enzymatic activity of myeloperoxidase (MPO) was assessed 24 h after cerebral ischemia. Nuclear factor-kappa B (NF-κB) p65 expression in ischemic rat brain was detected by western blot. Cyclooxygenase-2 (COX-2) expression in ischemic rat brain was determined by immunohistochemistry. ELISA was performed to detect the serum concentration of tumor necrosis factor-α (TNF-α). Neurological deficit scores, cerebral infarct size and MPO activity were significantly reduced by propofol administration. Furthermore, expression of NF-κB, COX-2 and TNF-α were attenuated by propofol administration. Our results demonstrated that propofol (10 and 50 mg/kg) reduces inflammatory reaction and brain damage in focal cerebral ischemia in rats. Propofol exerts neuroprotection against ischemic brain damage, which might be associated with the attenuation of inflammatory reaction and the inhibition of inflammatory genes.

Cerebroprotective effect of Moringa oleifera against focal ischemic stroke induced by middle cerebral artery occlusion

The protection against ischemic stroke is still required due to the limitation of therapeutic efficacy. Based on the role of oxidative stress in stroke pathophysiology, we determined whether Moringa oleifera, a plant possessing potent antioxidant activity, protected against brain damage and oxidative stress in animal model of focal stroke. M. oleifera leaves extract at doses of 100, 200 and 400 mg·kg(-1) was orally given to male Wistar rats (300-350 g) once daily at a period of 2 weeks before the occlusion of right middle cerebral artery (Rt.MCAO) and 3 weeks after Rt.MCAO. The determinations of neurological score and temperature sensation were performed every 7 days throughout the study period, while the determinations of brain infarction volume, MDA level, and the activities of SOD, CAT, and GSH-Px were performed 24 hr after Rt.MCAO. The results showed that all doses of extract decreased infarction volume in both cortex and subcortex. The protective effect of medium and low doses of extract in all areas occurred mainly via the decreased oxidative stress. The protective effect of the high dose extract in striatum and hippocampus occurred via the same mechanism, whereas other mechanisms might play a crucial role in cortex. The detailed mechanism required further exploration.