Curcumin attenuates blood-brain barrier disruption after subarachnoid hemorrhage in mice.

BACKGROUND: Early brain injury, one of the most important mechanisms underlying subarachnoid hemorrhage (SAH), comprises edema formation and blood-brain barrier (BBB) disruption. Curcumin, an active extract from the rhizomes of Curcuma longa, alleviates neuroinflammation by as yet unknown neuroprotective mechanisms. In this study, we examined whether curcumin treatment ameliorates SAH-induced brain edema and BBB permeability changes, as well as the mechanisms underlying this phenomenon. METHODS: We induced SAH in mice via endovascular perforation, administered curcumin 15 min after surgery and evaluated neurologic scores, brain water content, Evans blue extravasation, Western blot assay results, and immunohistochemical analysis results 24 h after surgery. RESULTS: Curcumin significantly improved neurologic scores and reduced brain water content in treated mice compared with SAH mice. Furthermore, curcumin decreased Evans blue extravasation, matrix metallopeptidase-9 expression, and the number of Iba-1-positive microglia in treated mice compared with SAH mice. At last, curcumin treatment increased the expression of the tight junction proteins zonula occludens-1 and occludin in treated mice compared with vehicle-treated and sample SAH mice. CONCLUSIONS: We demonstrated that curcumin inhibits microglial activation and matrix metallopeptidase-9 expression, thereby reducing brain edema and attenuating post-SAH BBB disruption in mice.

Hyperbaric oxygen therapy ameliorates acute brain injury after porcine intracerebral hemorrhage at high altitude.

INTRODUCTION: Intracerebral hemorrhage (ICH) at high altitude is not well understood to date. This study investigates the effects of high altitude on ICH, and examines the acute neuroprotection of hyperbaric oxygen (HBO) therapy against high-altitude ICH. METHODS: Minipigs were placed in a hypobaric chamber for 72 h before the operation. ICH was induced by an infusion of autologous arterial blood (3 ml) into the right basal ganglia. Animals in the high-altitude ICH group received HBO therapy (2.5 ATA for 60 min) 30 min after ICH. Blood gas, blood glucose and brain tissue oxygen partial pressure (PbtO2) were monitored continuously for animals from all groups, as were microdialysis products including glucose, lactate, pyruvate and glutamate in perihematomal tissue from 3 to 12 h post-ICH. RESULTS: High-altitude ICH animals showed significantly lower PbtO2, higher lactate/pyruvate ratio (LPR) and glutamate levels than low-altitude ICH animals. More severe neurological deficits, brain edema and neuronal damage were also observed in high-altitude ICH. After HBO therapy, PbtO2 was significantly increased and LPR and glutamate levels were significantly decreased. Brain edema, neurological deficits and neuronal damage were also ameliorated. CONCLUSIONS: The data suggested a more serious disturbance of tissue oxygenation and cerebral metabolism in the acute stage after ICH at high altitude. Early HBO treatment reduced acute brain injury, perhaps through a mechanism involving the amelioration of the derangement of cerebral oxygenation and metabolism following high-altitude ICH.

Antisense vimentin cDNA combined with chondroitinase ABC promotes axon regeneration and functional recovery following spinal cord injury in rats.

The formation of glial scar restricts axon regeneration after spinal cord injury (SCI) in adult mammalian. Chondroitin sulfate proteoglycans (CSPGs) are mostly secreted by reactive astrocytes, which form dense scar tissues after SCI. Chondroitinase ABC (ChABC), which can digest CSPGs, is a promising therapeutic strategy for SCI. However, to date ChABC has exhibited only limited success in the treatment of chronic SCI. The intermediate filament protein vimentin underpins the cytoskeleton of reactive astrocytes. We targeted glial scar in injured spinal cord by sustained infusion of ChABC and antisense vimentin cDNA. Using anterograde tracing, BBB scoring and hind limb placing response, we found that this combined treatment promoted axon regeneration and functional recovery after SCI in rats. Our results indicate that axon regeneration may be promoted by modified physical and biochemical characteristics of intra- and extracellular architecture in glial scar tissues. Theses findings could potentially help us to understand better the composition of glial scar in central nervous system injury.

Curcumin improves neural function after spinal cord injury by the joint inhibition of the intracellular and extracellular components of glial scar.

BACKGROUND: Spinal cord injury (SCI) is characterized by a high rate of disability and imposes a heavy burden on society and patients. SCI can activate glial cells and lead to swelling, hyperplasty, and reactive gliosis, which can severely reduce the space for nerve growth. Glial cells can secrete a large amount of extracellular inhibitory components, thus altering the microenvironment of axon growth. Both these factors seriously impede nerve regeneration. In the present study, we investigate whether curcumin (cur), a phytochemical compound with potent anti-inflammatory effect, plays a role in the repair of SCI. MATERIALS AND METHODS: We established a rat model of SCI and treated the animals with different concentrations of cur. Using behavioral assessment, immunohistochemistry, real-time polymerase chain reaction, Western blotting, and enzyme-linked immunosorbent assay, we detected the intracellular and extracellular components of glial scar and related cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, nuclear factor (NF)-κb, transforming growth factor (TGF)-ß1, TGF-ß2, and sex determining region Y-box (SOX)-9. RESULTS: We found that cur inhibited the expression of proinflammatory cytokines, such as TNF-α, IL-1ß, and NF-κb; reduced the expression of the intracellular components glial fibrillary acidic protein through anti-inflammation; and suppressed the reactive gliosis. Also, cur inhibited the generation of TGF-ß1, TGF-ß2, and SOX-9; decreased the deposition of chondroitin sulfate proteoglycan by inhibiting the transforming growth factors and transcription factor; and improved the microenvironment for nerve growth. Through the joint inhibition of the intracellular and extracellular components of glial scar, cur significantly reduced glial scar volume and improved the Basso, Beattie, and Bresnahan locomotor rating and axon growth. CONCLUSIONS: Our data support a role for curcumin in promoting neural function recovery after SCI by the joint inhibition of the intracellular and extracellular components of glial scar, providing an important strategy for treating SCI.

Curcumin attenuates acute inflammatory injury by inhibiting the TLR4/MyD88/NF-κB signaling pathway in experimental traumatic brain injury.

BACKGROUND: Traumatic brain injury (TBI) initiates a neuroinflammatory cascade that contributes to substantial neuronal damage and behavioral impairment, and Toll-like receptor 4 (TLR4) is an important mediator of thiscascade. In the current study, we tested the hypothesis that curcumin, a phytochemical compound with potent anti-inflammatory properties that is extracted from the rhizome Curcuma longa, alleviates acute inflammatory injury mediated by TLR4 following TBI. METHODS: Neurological function, brain water content and cytokine levels were tested in TLR4⁻/⁻ mice subjected to weight-drop contusion injury. Wild-type (WT) mice were injected intraperitoneally with different concentrations of curcumin or vehicle 15 minutes after TBI. At 24 hours post-injury, the activation of microglia/macrophages and TLR4 was detected by immunohistochemistry; neuronal apoptosis was measured by FJB and TUNEL staining; cytokines were assayed by ELISA; and TLR4, MyD88 and NF-κB levels were measured by Western blotting. In vitro, a co-culture system comprised of microglia and neurons was treated with curcumin following lipopolysaccharide (LPS) stimulation. TLR4 expression and morphological activation in microglia and morphological damage to neurons were detected by immunohistochemistry 24 hours post-stimulation. RESULTS: The protein expression of TLR4 in pericontusional tissue reached a maximum at 24 hours post-TBI. Compared with WT mice, TLR4⁻/⁻ mice showed attenuated functional impairment, brain edema and cytokine release post-TBI. In addition to improvement in the above aspects, 100 mg/kg curcumin treatment post-TBI significantly reduced the number of TLR4-positive microglia/macrophages as well as inflammatory mediator release and neuronal apoptosis in WT mice. Furthermore, Western blot analysis indicated that the levels of TLR4 and its known downstream effectors (MyD88, and NF-κB) were also decreased after curcumin treatment. Similar outcomes were observed in the microglia and neuron co-culture following treatment with curcumin after LPS stimulation. LPS increased TLR4 immunoreactivity and morphological activation in microglia and increased neuronal apoptosis, whereas curcumin normalized this upregulation. The increased protein levels of TLR4, MyD88 and NF-κB in microglia were attenuated by curcumin treatment. CONCLUSIONS: Our results suggest that post-injury, curcumin administration may improve patient outcome by reducing acute activation of microglia/macrophages and neuronal apoptosis through a mechanism involving the TLR4/MyD88/NF-κB signaling pathway in microglia/macrophages in TBI.

Functional recovery in rat spinal cord injury induced by hyperbaric oxygen preconditioning.

BACKGROUND: It is a common belief that neurosurgical interventions can cause inevitable damage resulting from the procedure itself in surgery especially for intramedullary spinal cord tumors. The present study was designed to examine if hyperbaric oxygen preconditioning (HBO-PC) was neuroprotective against surgical injuries using a rat model of spinal cord injury (SCI). METHODS: Sprague-Dawley rats were randomly divided into three groups: HBO-PC group, hypobaric hypoxic preconditioning (HH-PC) control group, and normobaric control group. All groups were subjected to SCI by weight drop device. Rats from each group were examined for neurological behavior and electrophysiological function. Tissue sections were analyzed by using immunohistochemistry, TdT-mediated dUTP-biotin nick end labeling, and axonal tract tracing. RESULTS: Significant neurological deficits were observed after SCI and HBO-PC and HH-PC improved neurological deficits 1 week post-injury. The latencies of motor-evoked potential and somatosensory-evoked potential were significantly delayed after SCI, which was attenuated by HBO-PC and HH-PC. Compared with normobaric control group, pretreatment with HBO and hypobaric hypoxia significantly reduced the number of TdT-mediated dUTP-biotin nick end labeling-positive cells, and increased nestin-positive cells. HBO-PC and HH-PC enhanced axonal growth after SCI. CONCLUSIONS: In conclusion, preconditioning with HBO and hypobaric hypoxia can facilitate functional recovery and suppress cell apoptosis after SCI and may prove to be a useful preventive strategy to neurosurgical SCI.

Microsurgical treatment of ruptured intracranial aneurysm: a 120-case analysis.

OBJECTIVE: to investigate the influence of pre-operative conditions and microsurgical skill on the post-operative outcomes of intracranial aneurysms by retrospective analysis of 120 cases with microsurgical treatment. METHODS: 120 patients with 134 intracranial aneurysms received microsurgical treatment via pterional approach or improved pterional approach. RESULTS: of 134 aneurysms, 122 were clipped, one was coated, three were isolated and there was parent artery deligation in one case. 111 Patients were cured, seven cases gave up therapy post-operation, and two died. According to GOS standard, the outcome in the discharge stage was good in 94 cases, mild disability in 12 cases, moderate disability in three cases and severe disability in two cases. Long-term follow-up was performed in all patients, of whom 95 recovered well, mild disability in 12 cases, moderate disability in two cases and severe disability in one case. CONCLUSION: surgical clipping was the most effective method to treat intracranial aneurysm. Optimal chance and microsurgical technique, as well as microanatomical knowledge, are keys for successful treatment.

Traditional Chinese herb Dihuang Yinzi (DY) plays neuroprotective and anti-dementia role in rats of ischemic brain injury.

AIM OF THE STUDY: Traditional Chinese herb Dihuang Yinzi (DY) is well known to treat neurological diseases by traditional Chinese medical practitioners. This study is to elucidate its neuroprotective and anti-dementia role in ischemic brain injury. MATERIALS AND METHODS: The effects of DY on the pathohistological changes, lactate dehydrogenase (LDH) release, Morris water maze task, expression of synaptophysin (SYP) and extracellular signal-regulated protein kinase (ERK) of hippocampi of rats with ischemic brain injury were investigated. RESULTS: This study showed that DY not only significantly decreased the number of TUNEL-positive cells but also reduced the LDH release of hippocampus of model rat. Morris water maze test showed that the ability of learning and memory of rats dramatically impaired after ischemic brain injury. However, DY ameliorated the impairment of learning and memory of ischemic rats. Furthermore, western blotting and immunohistochemical data showed that the expression of extracellular regulated protein and synaptophysin, which correlates with synaptic formation and function, decreased after ischemic insult. However, DY inhibited the reduction of ERK an SYP expression in a dose-dependent way. CONCLUSION: These results suggest that DY possesses neuroprotective and anti-dementia properties, at least in part, by preventing the loss of neural cells and synapses in ischemic brain injury.

Antisense vimentin cDNA combined with chondroitinase ABC reduces glial scar and cystic cavity formation following spinal cord injury in rats.

The formation of glial scar and cystic cavities restricts axon regeneration after spinal cord injury. Chondroitin sulphate proteoglycans (CSPGs) are regarded as the prominent inhibitory molecules in the glial scar, and their inhibitory effects may be abolished in part by chondroitinase ABC (ChABC), which can digest CSPGs. CSPGs are secreted mostly by reactive astrocytes, which form dense scar tissues. The intermediate filament protein vimentin underpins the cytoskeleton of reactive astrocytes. Previously we have shown that retroviruses carrying full-length antisense vimentin cDNA reduce reactive gliosis. Here we administered both antisense vimentin cDNA and ChABC to hemisected rat spinal cords. Using RT-PCR, Western blotting and immunohistochemistry, we found that the combined treatment reduced the formation of glial scar and cystic cavities through degrading CSPGs molecules and inhibiting intermediate filament proteins. The modified intra- and extra-cellular architecture may alter the physical and biochemical characteristics of the scar, and the combined therapy might be used to inhibit glial scar formation.