Curcumin protects pre-oligodendrocytes from activated microglia in vitro and in vivo

Dual Action of Curcumin as an Anti- and Pro-Oxidant from a Biophysical Perspective

Curcumin, a natural polyphenol widely used as a spice, colorant and food additive, has been shown to have therapeutic effects against different disorders, mostly due to its anti-oxidant properties. Curcumin also reduces the efficiency of melanin synthesis and affects cell membranes. However, curcumin can act as a pro-oxidant when blue light is applied, since upon illumination it can generate singlet oxygen. Our review aims to describe this dual role of curcumin from a biophysical perspective, bearing in mind its concentration, bioavailability-enhancing modifications and membrane interactions, as well as environmental conditions such as light. In low concentrations and without irradiation, curcumin shows positive effects and can be recommended as a beneficial food supplement. On the other hand, when used in excess or irradiated, curcumin can be toxic. Therefore, numerous attempts have been undertaken to test curcumin as a potential photosensitizer in photodynamic therapy (PDT). At that point, we underline that curcumin-based PDT is limited to the treatment of superficial tumors or skin and oral infections due to the weak penetration of blue light. Additionally, we conclude that an increase in curcumin bioavailability through the using nanocarriers, and therefore its concentration, as well as its topical use if skin is exposed to light, may be dangerous.

Inhibition of Microglial Activation by Delayed Mild Hypothermia Reduced Preoligodendrocyte Injury in a Neonatal Rat Brain Slice Model

Periventricular leukomalacia (PVL), characterized by distinctive form of white matter injury, often arises after neonatal cardiac surgery. Proven therapies for PVL are absent. In this study, we designed to quest therapeutic effects of delayed mild hypothermia on PVL and its mechanism in a neonatal rat brain slice model. With the increase of delayed mild hypothermia-treating time, the reduced expression of myelin basic protein and loss of preoligodendrocytes were significantly attenuated after oxygen-glucose deprivation. In addition, the proportion of ionized calcium binding adapter molecule 1 (Iba-1)-positive cells and the expression of Iba-1 were apparently reduced with the increased duration of mild hypothermia treatment. Furthermore, the levels of tumor necrosis factor alpha and interleukin-6 reduced after the mild hypothermia treatment relative to the control. Inhibition of microglial activation with prolonged mild hypothermia may be a potential strategy for white matter protection during cardiopulmonary bypass and hypothermic circulatory arrest.

Multiple mechanisms of curcumin targeting spinal cord injury

Spinal cord injury (SCI) is an irreversible disease process with a high disability and mortality rate. After primary spinal cord injury, the secondary injury may occur in sequence, which is composed of ischemia and hypoxia, excitotoxicity, calcium overload, oxidative stress and inflammation, resulting in massive death of parenchymal cells in the injured area, followed by the formation of syringomyelia. Effectively curbing the process of secondary injury can promote nerve repair and improve functional prognosis. As the main active ingredient in turmeric, curcumin can play an important role in reducing inflammation and oxidation, protecting the neurons, and ultimately reducing spinal cord injury. This article reviews the effects of curcumin on the repair of nerve injury, with emphasis on the various mechanisms by which curcumin promotes the treatment of spinal cord injury.

Pharmacological Neuroprotection of the Preterm Brain: Current Evidence and Perspectives

Despite improvements in viability, the long-term neurodevelopmental outcomes of preterm babies remain serious concern as a significant percentage of these infants develop neurological and/or intellectual impairment, and they are also at increased risk of psychiatric illnesses later in life. The current challenge is to develop neuroprotective approaches to improve adverse outcomes in preterm survivors. The purpose of this review was to provide an overview of the current evidence on pharmacological agents targeting the neuroprotection of the preterm brain. Among them, magnesium sulfate, given antenatally to pregnant women with imminent preterm birth before 30 to 34 weeks of gestation, as well as caffeine administered to preterm infants after birth, exhibited neuroprotective effects for human preterm brain. Erythropoietin treatment of preterm infants did not result in neuroprotection at 2 years of age in two out of three published large randomized controlled trials; however, long-term follow-up of these infants is needed to come to definite conclusions. Further studies are also required to assess whether melatonin, neurosteroids, inhaled nitric oxide, allopurinol, or dietary supplements (omega-3 fatty acids, choline, curcumin, etc.) could be implemented as neuroprotectants in clinical practice. Furthermore, other pharmacological agents showing promising signs of neuroprotective efficacy in preclinical studies (growth factors, hyaluronidase inhibitors or treatment, antidiabetic drugs, cannabidiol, histamine-H3 receptor antagonists, etc.), as well as stem cell- or exosomal-based therapies and nanomedicine, may prove useful in the future as potential neuroprotective approaches for human preterm brain. KEY POINTS: · Magnesium and caffeine have neuroprotective effects for the preterm brain.. · Follow-up of infants treated with erythropoietin is needed.. · Neuroprotective efficacy of several drugs in animals needs to be shown in humans..

Inflammaging and Brain: Curcumin and Its Beneficial Potential as Regulator of Microglia Activation

Inflammaging is a term used to describe the tight relationship between low-grade chronic inflammation and aging that occurs during physiological aging in the absence of evident infection. This condition has been linked to a broad spectrum of age-related disorders in various organs including the brain. Inflammaging represents a highly significant risk factor for the development and progression of age-related conditions, including neurodegenerative diseases which are characterized by the progressive dysfunction and degeneration of neurons in the brain and peripheral nervous system. Curcumin is a widely studied polyphenol isolated from Curcuma longa with a variety of pharmacologic properties. It is well-known for its healing properties and has been extensively used in Asian medicine to treat a variety of illness conditions. The number of studies that suggest beneficial effects of curcumin on brain pathologies and age-related diseases is increasing. Curcumin is able to inhibit the formation of reactive-oxygen species and other pro-inflammatory mediators that are believed to play a pivotal role in many age-related diseases. Curcumin has been recently proposed as a potential useful remedy against neurodegenerative disorders and brain ageing. In light of this, our current review aims to discuss the potential positive effects of Curcumin on the possibility to control inflammaging emphasizing the possible modulation of inflammaging processes in neurodegenerative diseases.

Multi-Hit White Matter Injury-Induced Cerebral Palsy Model Established by Perinatal Lipopolysaccharide Injection

Cerebral palsy (CP) is a group of permanent, but not unchanging, disorders of movement and/or posture and motor function. Since the major brain injury associated with CP is white matter injury (WMI), especially, in preterm infants, we established a "multi-hit" rat model to mimic human WMI in symptomatology and at a histological level. In our WMI model, pups suffering from limb paresis, incoordination, and direction difficulties fit the performance of CP. Histologically, they present with fewer neural cells, inordinate fibers, and more inflammatory cell infiltration, compared to the control group. From the electron microscopy results, we spotted neuronal apoptosis, glial activation, and myelination delay. Besides, the abundant appearance of IBA1-labeled microglia also implied that microglia play a role during neuronal cell injury. After activation, microglia shift between the pro-inflammatory M1 type and the anti-inflammatory M2 type. The results showed that LPS/infection stimulated IBA1 + (marked activated microglia) expression, downregulated CD11c + (marked M1 phenotype), and upregulated Arg 1 + (marked M2 phenotype) protein expression. It indicated an M1 to M2 transition after multiple infections. In summary, we established a "multi-hit" WMI-induced CP rat model and demonstrated that the microglial activation correlates tightly with CP formation, which may become a potential target for future studies.

Curcumin Ameliorates White Matter Injury after Ischemic Stroke by Inhibiting Microglia/Macrophage Pyroptosis through NF-κB Suppression and NLRP3 Inflammasome Inhibition

NLRP3 inflammasome-mediated pyroptosis is a proinflammatory programmed cell death pathway, which plays a vital role in functional outcomes after stroke. We previously described the beneficial effects of curcumin against stroke-induced neuronal damage through modulating microglial polarization. However, the impact of curcumin on microglial pyroptosis remains unknown. Here, stroke was modeled in mice by middle cerebral artery occlusion (MCAO) for 60 minutes and treated with curcumin (150 mg/kg) intraperitoneally immediately after reperfusion, followed by daily administrations for 7 days. Curcumin ameliorated white matter (WM) lesions and brain tissue loss 21 days poststroke and improved sensorimotor function 3, 10, and 21 days after stroke. Furthermore, curcumin significantly reduced the number of gasdermin D⁺ (GSDMD⁺) Iba1⁺ and caspase-1⁺Iba1⁺ microglia/macrophage 21 days after stroke. In vitro, lipopolysaccharide (LPS) with ATP treatment was used to induce pyroptosis in primary microglia. Western blot revealed a decrease in pyroptosis-related proteins, e.g., GSDMD-N, cleaved caspase-1, NLRP3, IL-1β, and IL-18, following in vitro or in vivo curcumin treatment. Mechanistically, both in vivo and in vitro studies confirmed that curcumin inhibited the activation of the NF-κB pathway. NLRP3 knocked down by siRNA transfection markedly increased the inhibitory effects of curcumin on microglial pyroptosis and proinflammatory responses, both in vitro and in vivo. Furthermore, stereotaxic microinjection of AAV-based NLRP3 shRNA significantly improved sensorimotor function and reduced WM lesion following curcumin treatment in MCAO mice. Our study suggested that curcumin reduced stroke-induced WM damage, improved functional outcomes, and attenuated microglial pyroptosis, at least partially, through suppression of the NF-κB/NLRP3 signaling pathway, further supporting curcumin as a potential therapeutic drug for stroke.

Curcumin mitigates neurotoxic and neurobehavioral changes of gentamicin and sodium salicylate in rats by adjusting oxidative stress and apoptosis

Currently, antibiotics and salicylates are the most highly consumed medications worldwide. The side effects of these pharmaceuticals on the nervous system have been little investigated. Thus, this study aimed to examine the influence of the gentamicin (GM) and sodium salicylates (SS) on neurobehavioral functions, including locomotors function, memory, and sensorimotor functions together with gamma-aminobutyric acid (GABA) neurotransmitter levels. Also, oxidative stress, lipid peroxidation, and apoptotic indicators of brain tissue were assessed. Additionally, the histopathological architecture of brain tissues was investigated. This study also evaluated the curcumin (CUR) efficacy to counteract the GM or SS induced neurotoxic impacts in rats. For this purpose, seven groups were administered physiological saline (1 ml/rat; orally), olive oil (1 ml/rat; orally), CUR (50 mg/kg bwt; orally), GM (120 mg/kg bwt; intraperitoneally), SS (300 mg /kg bwt; intraperitoneally), CUR + GM, or CUR + SS for consecutive 15 days. The results revealed that GM and SS exposure evoked impaired memory, sensorimotor deficit functions, and depressive-like behavior together with the depletion of GABA. GM and SS exposure elevated malondialdehyde and Caspase-3 levels, but total antioxidant capacity and Bcl-2 levels were reduced. Besides, GM and SS exposure induced distinct pathological perturbations in cerebral cortices and hippocampus tissues. CUR significantly reversed the GM and SS harmful impacts. In conclusion, these findings verified that CUR could be a biologically efficient protective intervention against GM and SS induced neurotoxic impacts and neurobehavioral aberrations.

Curcumin inhibits proliferation, migration and neointimal formation of vascular smooth muscle via activating miR-22

Context: Curcumin has antitumor, antioxidative, anti-inflammatory, and anti-proliferative properties.Objective: To investigate the role of miR-22 during curcumin-induced changes in vascular smooth muscle cells (VSMC) and neointima formation in balloon-injured rat abdominal aorta.Materials and methods: Sprague-Dawley rats were randomised to the sham-operated (n = 10), operated control (injured, n = 10), and curcumin treatment (n = 10) groups. miR-22 expression was determined by real-time PCR. SP1 was assessed by western blot and real-time PCR. Rat aortic smooth muscle A7r5 cells were used to determine VSMC proliferation and migration, which were measured by the MTS, EdU staining, Transwell, and wound healing assays.Results: miR-22 levels declined following arterial balloon injury in vivo (48% at 3d, p < 0.05) and serum stimulation in vitro (45% at 24 h, p < 0.01). Functional studies revealed that miR-22 negatively regulated the proliferation and migration of VSMCs by directly targeting the SP1 transcription factor in VSMCs. Curcumin increased the expression of miR-22 (81%, p < 0.05) and decreased the protein expression of SP1 in VSMCs (25%, p < 0.05). miR-22 inhibition was found to attenuate the effects of curcumin on VSMC functions. Curcumin increased miR-22 (46%, p < 0.01), decreased the SP1 protein (19%, p < 0.05), and inhibited vascular neointimal area (48%, p < 0.01) in vivo.Discussion: The miR-22/SP1 pathway is involved in the protective role of curcumin during arterial balloon injury, but the mechanisms remain unclear.Conclusion: miR-22 is involved in the inhibitory effects of curcumin on VSMCs' proliferation, migration and neointima hyperplasia after arterial balloon injury in rats. Curcumin could be used to prevent neointimal hyperplasia after angioplasty.

Can Brain Health Be Supported by Vitamin D-Based Supplements? A Critical Review

This review presents recent knowledge on the neuroprotective effects of vitamin D and their usefulness as oral supplementation when combined with other molecules, such as curcumin. A critical look at the effectiveness of vitamin D in this field is also provided. Vitamin D plays a crucial role in neuroprotection and in the cognitive decline associated with aging, where vitamin D’s levels are related to the levels of several neurotrophic factors. An important role of vitamin D has also been observed in the mechanism of neuroinflammation, which is the basis of several aging conditions, including cognitive decline and neurodegeration; furthermore, the neuroprotective effect of vitamin D in the cognitive decline of aging has recently been reported. For this reason, many food supplements created for humans contain vitamin D alone or combined with other molecules with antioxidant properties. However, recent studies also explored negative consequences of the use at a high dosage of vitamin D. Vitamin D in tissues or brain cells can also modulate calbindin-D28K, parvalbumin, and calretinin, and is involved in immune function, thanks also to the combination with curcumin. Curcumin acts as a free radical scavenger and antioxidant, inhibiting lipid peroxidation and oxidative DNA damage. In particular, curcumin is a potent immune-regulatory agent and its administration has been reported to attenuate cognitive impairments. These effects could be exploited in the future to control the mechanisms that lead to the brain decay typical of neurodegenerative diseases.

Notch pathway up-regulation via curcumin mitigates bisphenol-A (BPA) induced alterations in hippocampal oligodendrogenesis

CNS myelination process involves proliferation and differentiation of oligodendrocyte progenitor cells (OPCs). Defective myelination causes onset of neurological disorders. Bisphenol-A (BPA), a component of plastic items, exerts adverse effects on human health. Our previous studies indicated that BPA impairs neurogenesis and myelination process stimulating cognitive dysfunctions. But, the underlying mechanism(s) of BPA induced de-myelination and probable neuroprotection by curcumin remains elusive. We found that curcumin protected BPA mediated adverse effects on oligosphere growth kinetics. Curcumin significantly improved proliferation and differentiation of OPCs upon BPA exposure both in-vitro and in-vivo. Curcumin enhanced the mRNA expression and protein levels of myelination markers in BPA treated rat hippocampus. Curcumin improved myelination potential via increasing β-III tubulin-/MBP⁺ cells (neuron-oligodendrocyte co-culture) and augmented fluoromyelin intensity and neurofilament/MBP⁺ neurons in vivo. In silico docking studies suggested Notch pathway genes (Notch-1, Hes-1 and Mib-1) as potential targets of BPA and curcumin. Curcumin reversed BPA mediated myelination inhibition via increasing the Notch pathway gene expression. Genetic and pharmacological Notch pathway inhibition by DAPT and Notch-1 siRNA exhibited decreased curcumin mediated neuroprotection. Curcumin improved BPA mediated myelin sheath degeneration and neurobehavioral impairments. Altogether, results suggest that curcumin protected BPA induced de-myelination and behavioural deficits through Notch pathway activation.

Anti‑inflammatory role of Prunus persica L. Batsch methanol extract on lipopolysaccharide‑stimulated glial cells

Glial cells are the resident immune cells of the central nervous system. Reactive glial cells release inflammatory mediators that induce neurotoxicity or aggravate neurodegeneration. Regulation of glial activation is crucial for the initiation and progression of neuropathological conditions. Constituents of the peach tree (Prunus persica L. Batsch), which has a global distribution, have been found to exert therapeutic effects in pathological conditions, such as rashes, eczema and allergies. However, the therapeutic potential of its aerial parts (leaves, fruits and twigs) remains to be elucidated. The present study aimed to evaluate the anti-inflammatory role of P. persica methanol extract (PPB) on lipopolysaccharide (LPS)-stimulated glial cells. High-performance liquid chromatography coupled with tandem mass spectrometry analysis showed that PPB contained chlorogenic acid and catechin, which have antioxidant properties. Western blot and reverse transcription polymerase chain reaction results indicated that PPB reduced the transcription of various proinflammatory enzymes (nitric oxide synthase and cyclooxygenase-2) and cytokines [tumor necrosis factor-α, interleukin (IL)-1β and IL-6] in LPS-stimulated BV2 cells. In addition, PPB inhibited the activation of NF-κB and various mitogen-activated protein kinases required for proinflammatory mediator transcription. Finally, nitrite measurement and immunocytochemistry results indicated that PPB also suppressed nitrite production and NF-κB translocation in LPS-stimulated primary astrocytes. Thus, PPB may be used as a potential therapeutic agent for neurodegenerative diseases and neurotoxicity via the suppression of glial cell activation.

Molecular Mechanisms of Curcumin in Neuroinflammatory Disorders: A Mini Review of Current Evidences

OBJECTIVE

Neuroinflammatory disease is a general term used to denote the progressive loss of neuronal function or structure. Many neuroinflammatory diseases, including Alzheimer's, Parkinson's, and multiple sclerosis (MS), occur due to neuroinflammation. Neuroinflammation increases nuclear factor-κB (NF-κB) levels, cyclooxygenase-2 enzymes and inducible nitric oxide synthase, resulting in the release of inflammatory cytokines, such as interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). It could also lead to cellular deterioration and symptoms of neuroinflammatory diseases. Recent studies have suggested that curcumin (the active ingredient in turmeric) could alleviate the process of neuroinflammatory disease. Thus, the present mini-review was conducted to summarize studies regarding cellular and molecular targets of curcumin relevant to neuroinflammatory disorders.

METHODS

A literature search strategy was conducted for all English-language literature. Studies that assessed the various properties of curcuminoids in respect of neuroinflammatory disorders were included in this review.

RESULTS

The studies have suggested that curcuminoids have significant anti- neuroinflammatory, antioxidant and neuroprotective properties that could attenuate the development and symptom of neuroinflammatory disorders. Curcumin can alleviate neurodegeneration and neuroinflammation through multiple mechanisms, by reducing inflammatory mediators (such as TNF-α, IL-1β, nitric oxide and NF-κB gene expression), and affect mitochondrial dynamics and even epigenetic changes.

CONCLUSION

It is a promising subject of study in the prevention and management of the neuroinflammatory disease. However, controlled, randomized clinical trials are needed to fully evaluate its clinical potential.

Modulation of Biological Activities in Glioblastoma Mediated by Curcumin

Curcumin is an alkaloid with various pharmacologic properties; numerous investigations have suggested that in the Central Nervous System, Curcumin has anti-inflammatory, antimicrobial, antioxidant, and antitumor effects. Gliomas are the most common primary intracranial tumors in adults. The prognosis of glioblastoma is still dismal. In this review, we profile that Curcumin could suppress cell proliferation and induce apoptosis of cancer cells and genomic modulation. In particular, Curcumin could exert its therapeutic effect via modulating miRNA, affecting a variety of miRNAs involved in the response to cancer therapy. The combination of Curcumin with chemotherapeutic drugs or radiotherapy could prime the sensitivity of cancer cells to chemotherapy or radiotherapy. We also discuss the use of exosomes as Curcumin delivery vehicles. In this context, exosomes containing Curcumin may change the behavior of recipient cells by targeting a sequence of cellular and molecular pathways. Hence, the application of exosomes containing Curcumin may prove to be an emerging area of research in cancer therapy.

Effects of Curcumin on Microglial Cells

Microglia are innate immune system cells which reside in the central nervous system (CNS). Resting microglia regulate the homeostasis of the CNS via phagocytic activity to clear pathogens and cell debris. Sometimes, however, to protect neurons and fight invading pathogens, resting microglia transform to an activated-form, producing inflammatory mediators, such as cytokines, chemokines, iNOS/NO and cyclooxygenase-2 (COX-2). Excessive inflammation, however, leads to damaged neurons and neurodegenerative diseases (NDs), such as Parkinson's disease (PD), Alzheimer's disease (AD), Huntington's disease (HD), multiple sclerosis (MS) and amyotrophic lateral sclerosis (ALS). Curcumin is a phytochemical isolated from Curcuma longa. It is widely used in Asia and has many therapeutic properties, including antioxidant, anti-viral, anti-bacterial, anti-mutagenic, anti-amyloidogenic and anti-inflammatory, especially with respect to neuroinflammation and neurological disorders (NDs). Curcumin is a pleiotropic molecule that inhibits microglia transformation, inflammatory mediators and subsequent NDs. In this mini-review, we discuss the effects of curcumin on microglia and explore the underlying mechanisms.

Curcumin's antiepileptic effect, and alterations in Nav1.1 and Nav1.6 expression in iron-induced epilepsy

The present study was carried out to evaluate: the antiepileptic effect of dietary curcumin, and the effect of epileptic state and curcumin on the molecular expression of voltage-activated Na⁺ channel subtypes Na_v1.1 and Na_v1.6 in the iron-induced experimental epilepsy in the rat. Rats were divided into four groups; Group I (control rats), Group II (epileptic rats), Group III (curcumin-fed epileptic rats), and Group IV (curcumin-fed rats). Curcumin was fed chronically to rats approximately at the dose of 100 mg/kg body wt. The animals were made epileptic by intracortical injection of FeCl_3. The mRNA and protein expressions of Na_v1.1 and Na_v1.6 were examined by RT-PCR analysis and immuno-histochemistry. Results showed a significant increase (upregulation) in the expression of both Na_v1.1 and Na_v1.6 with seizure activity in the cortex and hippocampus of epileptic rats. Epileptic rats fed with curcumin showed a marked decrease in epileptiform activity, and reduced mRNA and protein levels of Na_v1.1. It appears that the antiepileptic action of curcumin may be associated with the downregulation of Na_v1.1 in the cortex.

Local low dose curcumin treatment improves functional recovery and remyelination in a rat model of sciatic nerve crush through inhibition of oxidative stress

Traumatic injuries to peripheral nerves are frequent, however, specific pharmacological treatments are currently lacking. Curcumin has antioxidant, anti-inflammatory and neuroprotective properties but high oral doses are required for therapeutic use, particularly due to its low bioavailability. The aim of the present study was to investigate the effects of local and continuous treatment using low curcumin doses on functional recovery and nerve regeneration after rat sciatic nerve crush (SNC). Curcumin was administered by osmotic pumps with a catheter delivering the drug at the injury site (0.2 mg/day for 4 weeks). Functionally, early improvements in mechanical sensitivity, finger spacing of the injured paw, skilful walking and grip strength were observed in curcumin-treated animals. The curcumin treatment increased expression of compact myelin proteins (MPZ and PMP22), myelin sheath thickness and, correspondingly, increased motor and sensitive nerve conduction velocity. Microscopic analysis of gastrocnemius muscle indicated a curcumin-induced decrease in neurogenic lesions. Curcumin treatment reduced the production of reactive oxygen species (ROS) (which were notably produced by macrophages), lipid peroxidation and increased expression of transcription factor Nrf2. In silico analyses indicated that curcumin combines all the characteristics required to be an efficient lipid peroxidation inhibitor at the heart of biological membranes, hence protecting their degradation due to ROS. This antioxidant capacity is likely to contribute to the beneficial effects of curcumin after SNC injury. These results demonstrate that, when administrated locally, low doses of curcumin represent a promising therapy for peripheral nerve regeneration.

Curcumin-loaded nanoparticles ameliorate glial activation and improve myelin repair in lyolecithin-induced focal demyelination model of rat corpus callosum

Curcumin has been introduced as effective anti-inflammatory agent in treatment of several inflammatory disorders. Despite the wide range pharmacological activities, clinical application of curcumin is restricted mainly due to the low water solubility of this substance. More recently, we could remarkably improve the aqueous solubility of curcumin by its encapsulation in chitosan-alginate-sodium tripolyphosphate nanoparticles (CS-ALG-STPP NPs). In this study, the anti-inflammatory and myelin protective effects of curcumin-loaded NPs were evaluated in lysolecithin (LPC)-induced focal demyelination model. Pharmacokinetic of curcumin was assessed using high performance liquid chromatography (HPLC). Local demyelination was induced by injection of LPC into corpus callosum of rats. Animals were pre-treated with intraperitoneal (i.p.) injections of curcumin or curcumin-loaded NPs at dose of 12.5 mg/kg, 10 days prior to LPC injection and the injections were continued for 7 or 14 days post lesion. Hematoxylin and eosin (H&E) staining and immunostaining against activated glial cells including astrocytes and microglia were carried out for assessment of inflammation level in lesion site. Myelin specific staining was performed to evaluate the effect of curcumin-loaded NPs on myelination of LPC receiving animals. HPLC results showed the higher plasma concentration of curcumin after administration of NPs. Histological evaluation demonstrated that, the extent of demyelination areas was reduced in animals under treatment of curcumin-loaded NPs. Furthermore, treatment with curcumin-loaded NPs effectively attenuated glial activation and inflammation in LPC-induced demyelination model compared to curcumin receiving animals. Overall; these findings indicate that treatment with curcumin-loaded NPs preserve myelinated axons through amelioration of glial activation and inflammation in demyelination context.

Microglia: Housekeeper of the Central Nervous System

Microglia, of myeloid origin, play fundamental roles in the control of immune responses and the maintenance of central nervous system homeostasis. These cells, just like peripheral macrophages, may be activated into M1 pro-inflammatory or M2 anti-inflammatory phenotypes by appropriate stimuli. Microglia do not respond in isolation, but form part of complex networks of cells influencing each other. This review addresses the complex interaction of microglia with each cell type in the brain: neurons, astrocytes, cerebrovascular endothelial cells, and oligodendrocytes. We also highlight the participation of microglia in the maintenance of homeostasis in the brain, and their roles in the development and progression of age-related neurodegenerative disorders.

Curcumin protects dopaminergic neurons against inflammation-mediated damage and improves motor dysfunction induced by single intranigral lipopolysaccharide injection

Various studies have indicated a lower incidence and prevalence of neurological conditions in people consuming curcumin. The ability of curcumin to target multiple cascades, simultaneously, could be held responsible for its neuroprotective effects. The present study was designed to investigate the potential of curcumin in minimizing microglia-mediated damage in lipopolysaccharide (LPS) induced model of PD. Altered microglial functions and increased inflammatory profile of the CNS have severe behavioral consequences. In the current investigation, a single injection of LPS (5 ug/5 µl PBS) was injected into the substantia nigra (SN) of rats, and curcumin [40 mg/kg b.wt (i.p.)] was administered daily for a period of 21 days. LPS triggered an inflammatory response characterized by glial activation [Iba-1 and glial fibrillary acidic protein (GFAP)] and pro-inflammatory cytokine production (TNF-α and IL-1β) leading to extensive dopaminergic loss and behavioral abnormality in rats. The behavioral observations, biochemical markers, quantification of dopamine and its metabolites (DOPAC and HVA) using HPLC followed by IHC of tyrosine hydroxylase (TH) were evaluated after 21 days of LPS injection. Curcumin supplementation prevented dopaminergic degeneration in LPS-treated animals by normalizing the altered levels of biomarkers. Also, a significant improvement in TH levels as well as behavioral parameters (actophotometer, rotarod, beam walking and grid walking tests) were seen in LPS injected rats. Curcumin shielded the dopaminergic neurons against LPS-induced inflammatory response, which was associated with suppression of glial activation (microglia and astrocytes) and transcription factor NF-κB as depicted from RT-PCR and EMSA assay. Curcumin also suppressed microglial NADPH oxidase activation as observed from NADPH oxidase activity. The results suggested that one of the important mechanisms by which curcumin mediates its protective effects in the LPS-induced PD model is by inhibiting glial activation. Therefore, curcumin could be a potential therapeutic agent for inflammation-driven neurodegenerative disorders like PD, and its neuroprotective role should be explored further.

Curcuma longa L. extract improves the cortical neural connectivity during the aging process

Turmeric or Curcuma is a natural product that has anti-inflammatory, antioxidant and anti-apoptotic pharmacological properties. It can be used in the control of the aging process that involves oxidative stress, inflammation, and apoptosis. Aging is a physiological process that affects higher cortical and cognitive functions with a reduction in learning and memory, limited judgment and deficits in emotional control and social behavior. Moreover, aging is a major risk factor for the appearance of several disorders such as cerebrovascular disease, diabetes mellitus, and hypertension. At the brain level, the aging process alters the synaptic intercommunication by a reduction in the dendritic arbor as well as the number of the dendritic spine in the pyramidal neurons of the prefrontal cortex, hippocampus and basolateral amygdala, consequently reducing the size of these regions. The present review discusses the synaptic changes caused by the aging process and the neuroprotective role the Curcuma has through its anti-inflammatory, antioxidant and anti-apoptotic actions

Dietary phytochemicals and neuro-inflammaging: from mechanistic insights to translational challenges

An extensive literature describes the positive impact of dietary phytochemicals on overall health and longevity. Dietary phytochemicals include a large group of non-nutrients compounds from a wide range of plant-derived foods and chemical classes. Over the last decade, remarkable progress has been made to realize that oxidative and nitrosative stress (O&NS) and chronic, low-grade inflammation are major risk factors underlying brain aging. Accumulated data strongly suggest that phytochemicals from fruits, vegetables, herbs, and spices may exert relevant negative immunoregulatory, and/or anti-O&NS activities in the context of brain aging. Despite the translational gap between basic and clinical research, the current understanding of the molecular interactions between phytochemicals and immune-inflammatory and O&NS (IO&NS) pathways could help in designing effective nutritional strategies to delay brain aging and improve cognitive function. This review attempts to summarise recent evidence indicating that specific phytochemicals may act as positive modulators of IO&NS pathways by attenuating pro-inflammatory pathways associated with the age-related redox imbalance that occurs in brain aging. We will also discuss the need to initiate long-term nutrition intervention studies in healthy subjects. Hence, we will highlight crucial aspects that require further study to determine effective physiological concentrations and explore the real impact of dietary phytochemicals in preserving brain health before the onset of symptoms leading to cognitive decline and inflammatory neurodegeneration.

IL-1β induces hypomyelination in the periventricular white matter through inhibition of oligodendrocyte progenitor cell maturation via FYN/MEK/ERK signaling pathway in septic neonatal rats

Neuroinflammation elicited by microglia plays a key role in periventricular white matter (PWM) damage (PWMD) induced by infectious exposure. This study aimed to determine if microglia-derived interleukin-1β (IL-1β) would induce hypomyelination through suppression of maturation of oligodendrocyte progenitor cells (OPCs) in the developing PWM. Sprague-Dawley rats (1-day old) were injected with lipopolysaccharide (LPS) (1 mg/kg) intraperitoneally, following which upregulated expression of IL-1β and IL-1 receptor 1 (IL-1R1 ) was observed. This was coupled with enhanced apoptosis and suppressed proliferation of OPCs in the PWM. The number of PDGFR-α and NG2-positive OPCs was significantly decreased in the PWM at 24 h and 3 days after injection of LPS, whereas it was increased at 14 days and 28 days. The protein expression of Olig1, Olig2, and Nkx2.2 was significantly reduced, and mRNA expression of Tcf4 and Axin2 was upregulated in the developing PWM after LPS injection. The expression of myelin basic protein (MBP) and 2',3'-cyclic-nucleotide 3"-phosphodiesterase (CNPase) was downregulated in the PWM at 14 days and 28 days after LPS injection; this was linked to reduction of the proportion of myelinated axons and thinner myelin sheath as revealed by electron microscopy. Primary cultured OPCs treated with IL-1β showed the failure of maturation and proliferation. Furthermore, FYN/MEK/ERK signaling pathway was involved in suppression of maturation of primary OPCs induced by IL-1β administration. Our results suggest that following LPS injection, microglia are activated and produce IL-1β in the PWM in the neonatal rats. Excess IL-1β inhibits the maturation of OPCs via suppression of FYN/MEK/ERK phosphorylation thereby leading to axonal hypomyelination.

Neuroprotective potential of molecular hydrogen against perinatal brain injury via suppression of activated microglia

Exposure to inflammation in utero is related to perinatal brain injury, which is itself associated with high rates of long-term morbidity and mortality in children. Novel therapeutic interventions during the perinatal period are required to prevent inflammation, but its pathogenesis is incompletely understood. Activated microglia are known to play a central role in brain injury by producing a variety of pro-inflammatory cytokines and releasing oxidative products. The study is aimed to investigate the preventative potential of molecular hydrogen (H2), which is an antioxidant and anti-inflammatory agent without mutagenicity. Pregnant ICR mice were injected with lipopolysaccharide (LPS) intraperitoneally on embryonic day 17 to create a model of perinatal brain injury caused by prenatal inflammation. In this model, the effect of maternal administration of hydrogen water (HW) on pups was also evaluated. The levels of pro-inflammatory cytokines, oxidative damage and activation of microglia were determined in the fetal brains. H2 reduced the LPS-induced expression of pro-inflammatory cytokines, oxidative damage and microglial activation in the fetal brains. Next, we investigated how H2 contributes to neuroprotection, focusing on microglia, using primary cultured microglia and neurons. H2 prevented LPS- or cytokine-induced generation of reactive oxidative species by microglia and reduced LPS-induced microglial neurotoxicity. Finally, we identified several molecules influenced by H2, involved in the process of activating microglia. These results suggested that H2 holds promise for the prevention of inflammation related to perinatal brain injury.

Stromal Cell-Derived Factor-1α Plays a Crucial Role Based on Neuroprotective Role in Neonatal Brain Injury in Rats

Owing to progress in perinatal medicine, the survival of preterm newborns has markedly increased. However, the incidence of cerebral palsy has risen in association with increased preterm birth. Cerebral palsy is largely caused by cerebral hypoxic ischemia (HI), for which there are no effective medical treatments. We evaluated the effects of stromal cell-derived factor-1α (SDF-1α) on neonatal brain damage in rats. Left common carotid (LCC) arteries of seven-day-old Wistar rat pups were ligated, and animals were exposed to hypoxic gas to cause cerebral HI. Behavioral tests revealed that the memory and spatial perception abilities were disturbed in HI animals, and that SDF-1α treatment improved these cognitive functions. Motor coordination was also impaired after HI but was unimproved by SDF-1α treatment. SDF-1α reduced intracranial inflammation and induced cerebral remyelination, as indicated by the immunohistochemistry results. These data suggest that SDF-1α specifically influences spatial perception abilities in neonatal HI encephalopathy.

Curcumin improves synaptic plasticity impairment induced by HIV-1gp120 V3 loop

Curcumin has been shown to significantly improve spatial memory impairment induced by HIV-1 gp120 V3 in rats, but the electrophysiological mechanism remains unknown. Using extracellular microelectrode recording techniques, this study confirmed that the gp120 V3 loop could suppress long-term potentiation in the rat hippocampal CA1 region and synaptic plasticity, and that curcumin could antagonize these inhibitory effects. Using a Fura-2/AM calcium ion probe, we found that curcumin resisted the effects of the gp120 V3 loop on hippocampal synaptosomes and decreased Ca²⁺ concentration in synaptosomes. This effect of curcumin was identical to nimodipine, suggesting that curcumin improved the inhibitory effects of gp120 on synaptic plasticity, ameliorated damage caused to the central nervous system, and might be a potential neuroprotective drug.

Retinal microglia: just bystander or target for therapy?

Resident microglial cells can be regarded as the immunological watchdogs of the brain and the retina. They are active sensors of their neuronal microenvironment and rapidly respond to various insults with a morphological and functional transformation into reactive phagocytes. There is strong evidence from animal models and in situ analyses of human tissue that microglial reactivity is a common hallmark of various retinal degenerative and inflammatory diseases. These include rare hereditary retinopathies such as retinitis pigmentosa and X-linked juvenile retinoschisis but also comprise more common multifactorial retinal diseases such as age-related macular degeneration, diabetic retinopathy, glaucoma, and uveitis as well as neurological disorders with ocular manifestation. In this review, we describe how microglial function is kept in balance under normal conditions by cross-talk with other retinal cells and summarize how microglia respond to different forms of retinal injury. In addition, we present the concept that microglia play a key role in local regulation of complement in the retina and specify aspects of microglial aging relevant for chronic inflammatory processes in the retina. We conclude that this resident immune cell of the retina cannot be simply regarded as bystander of disease but may instead be a potential therapeutic target to be modulated in the treatment of degenerative and inflammatory diseases of the retina.

Curcumin supplementation improves mitochondrial and behavioral deficits in experimental model of chronic epilepsy

The present study was aimed to investigate the potential beneficial effect of curcumin, a polyphenol with pleiotropic properties, on mitochondrial dysfunctions, oxidative stress and cognitive deficits in a kindled model of epilepsy. Kindled epilepsy was induced in rats by administering a sub-convulsive dose of pentylenetetrazole (PTZ, 40 mg/kg body weight) every alternate day for 30 days. PTZ administered rats exhibited marked cognitive deficits assessed using active and passive avoidance tasks. This was accompanied by a significant decrease in NADH:cytochrome-c reductase (complex I) and cytochrome-c oxidase (complex IV) activities along with an increase in ROS, lipid peroxidation and protein carbonyls. The levels of glutathione also decreased in the cortex and hippocampus. Electron micrographs revealed disruption of mitochondrial membrane integrity with distorted cristae in PTZ treated animals. Histopathological examination showed pyknotic nuclei and cell loss in the hippocampus as well as in the cortex of PTZ treated animals. Curcumin administration at a dose of 100 mg/kg, p.o. throughout the treatment paradigm was able to ameliorate cognitive deficits with no significant effect on seizure score. Curcumin was able to restore the activity of mitochondrial complexes. In addition, significant reduction in ROS generation, lipid peroxidation and protein carbonyls was observed in PTZ animals supplemented with curcumin. Moreover, glutathione levels were also restored in PTZ treated rats supplemented with curcumin. Curcumin protected mitochondria from seizure induced structural alterations. Further, the curcumin supplemented PTZ rats had normal cell morphology and reduced cell loss. These results suggest that curcumin supplementation has potential to prevent mitochondrial dysfunctions and oxidative stress with improved cognitive functions in a chronic model of epilepsy.

Microglia toxicity in preterm brain injury

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Microglia responses in the preterm human brain in association with injury.

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Microglia responses in animal models of preterm brain injury.

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Mechanisms of microglia toxicity from in vitro primary microglia cell culture experiments.

Microglia are the resident phagocytic cells of the central nervous system. During brain development they are also imperative for apoptosis of excessive neurons, synaptic pruning, phagocytosis of debris and maintaining brain homeostasis. Brain damage results in a fast and dynamic microglia reaction, which can influence the extent and distribution of subsequent neuronal dysfunction. As a consequence, microglia responses can promote tissue protection and repair following brain injury, or become detrimental for the tissue integrity and functionality. In this review, we will describe microglia responses in the human developing brain in association with injury, with particular focus on the preterm infant. We also explore microglia responses and mechanisms of microglia toxicity in animal models of preterm white matter injury and in vitro primary microglia cell culture experiments.

Pathophysiology of glia in perinatal white matter injury

Injury to the preterm brain has a particular predilection for cerebral white matter. White matter injury (WMI) is the most common cause of brain injury in preterm infants and a major cause of chronic neurological morbidity including cerebral palsy. Factors that predispose to WMI include cerebral oxygenation disturbances and maternal-fetal infection. During the acute phase of WMI, pronounced oxidative damage occurs that targets late oligodendrocyte progenitors (pre-OLs). The developmental predilection for WMI to occur during prematurity appears to be related to both the timing of appearance and regional distribution of susceptible pre-OLs that are vulnerable to a variety of chemical mediators including reactive oxygen species, glutamate, cytokines, and adenosine. During the chronic phase of WMI, the white matter displays abberant regeneration and repair responses. Early OL progenitors respond to WMI with a rapid robust proliferative response that results in a several fold regeneration of pre-OLs that fail to terminally differentiate along their normal developmental time course. Pre-OL maturation arrest appears to be related in part to inhibitory factors that derive from reactive astrocytes in chronic lesions. Recent high field magnetic resonance imaging (MRI) data support that three distinct forms of chronic WMI exist, each of which displays unique MRI and histopathological features. These findings suggest the possibility that therapies directed at myelin regeneration and repair could be initiated early after WMI and monitored over time. These new mechanisms of acute and chronic WMI provide access to a variety of new strategies to prevent or promote repair of WMI in premature infants.

Effects of SuperUlam on Supporting Concentration and Mood: A Randomized, Double-Blind, Placebo-Controlled Crossover Study

Background. SuperUlam is a proprietary blend of natural ingredients aimed at supporting brain health. We aimed to evaluate the effect of SuperUlam on attention and mood in healthy adults. Methods. Twenty healthy individuals aged 35–65 were enrolled in this randomized, double-blind, placebo-controlled, crossover study. Study duration was 3 weeks and consisted of 3 visits. Measurement of cognitive function included computer-based testing of reaction time, complex attention, working memory, sustained attention, and executive functioning. Mood testing was performed via the profile of mood states (POMS) survey and the Chalder fatigue scale. Results. Cognitive function testing demonstrated a significant improvement from baseline in executive functioning, cognitive flexibility, reaction time, and working memory in the product group only (P < 0.05). When comparing the study product to placebo, the data demonstrated a significant decrease in tension, depression, and anger (P < 0.05). There was no significant difference between the product and placebo in the other measures of mood, including vigor, fatigue, confusion, and total mood disturbance. No adverse events were reported. Conclusions. Supplementation with SuperUlam is safe to consume with potential benefits to cognitive function and mood.

Progressive retinal degeneration and glial activation in the CLN6 (nclf) mouse model of neuronal ceroid lipofuscinosis: a beneficial effect of DHA and curcumin supplementation

Neuronal ceroid lipofuscinosis (NCL) is a group of neurodegenerative lysosomal storage disorders characterized by vision loss, mental and motor deficits, and spontaneous seizures. Neuropathological analyses of autopsy material from NCL patients and animal models revealed brain atrophy closely associated with glial activity. Earlier reports also noticed loss of retinal cells and reactive gliosis in some forms of NCL. To study this phenomenon in detail, we analyzed the ocular phenotype of CLN6^nclf mice, an established mouse model for variant-late infantile NCL. Retinal morphometry, immunohistochemistry, optokinetic tracking, electroretinography, and mRNA expression were used to characterize retinal morphology and function as well as the responses of Müller cells and microglia. Our histological data showed a severe and progressive degeneration in the CLN6^nclf retina co-inciding with reactive Müller glia. Furthermore, a prominent phenotypic transformation of ramified microglia to phagocytic, bloated, and mislocalized microglial cells was identified in CLN6^nclf retinas. These events overlapped with a rapid loss of visual perception and retinal function. Based on the strong microglia reactivity we hypothesized that dietary supplementation with immuno-regulatory compounds, curcumin and docosahexaenoic acid (DHA), could ameliorate microgliosis and reduce retinal degeneration. Our analyses showed that treatment of three-week-old CLN6^nclf mice with either 5% DHA or 0.6% curcumin for 30 weeks resulted in a reduced number of amoeboid reactive microglia and partially improved retinal function. DHA-treatment also improved the morphology of CLN6^nclf retinas with a preserved thickness of the photoreceptor layer in most regions of the retina. Our results suggest that microglial reactivity closely accompanies disease progression in the CLN6^nclf retina and both processes can be attenuated with dietary supplemented immuno-modulating compounds.

Small molecule activators of the Nrf2-HO-1 antioxidant axis modulate heme metabolism and inflammation in BV2 microglia cells

The nuclear factor erythroid derived 2-related factor 2 (Nrf2) and the antioxidant protein heme oxygenase-1 (HO-1) are crucial components of the cellular stress response. These two systems work together to combat oxidative stress and inflammation and are attractive drug targets for counteracting different pathologies, including neuroinflammation. We aimed to identify the most effective Nrf2/HO-1 activators that modulate the inflammatory response in microglia cells. In the present study, we searched the literature and selected 56 compounds reported to activate Nrf2 or HO-1 and analyzed them for HO-1 induction at 6 and 24h and cytotoxicity in BV2 microglial cells in vitro. Approximately 20 compounds up-regulated HO-1 at the concentrations tested (5-20 μM) with carnosol, supercurcumin, cobalt protoporphyrin-IX and dimethyl fumarate exhibiting the best induction/low cytotoxicity profile. Up-regulation of HO-1 by some compounds resulted in increased cellular bilirubin levels but did not augment the expression of proteins involved in heme synthesis (ALAS 1) or biliverdin reductase. Bilirubin production by HO-1 inducers correlated with their potency in inhibiting nitrite production after challenge with interferon-γ (INF-γ) or lipopolysaccharide (LPS). The compounds down-regulated the inflammatory response (TNF-α, PGE2 and nitrite) more strongly in cells challenged with INF-γ than LPS, and silencing HO-1 or Nrf2 with shRNA differentially affected the levels of inflammatory markers. These findings indicate that some small activators of Nrf2/HO-1 are effective modulators of microglia inflammation and highlight the chemical scaffolds that can serve for the synthesis of potent new derivatives to counteract neuroinflammation and neurodegeneration.

Curcumin and its derivatives: their application in neuropharmacology and neuroscience in the 21st century

Curcumin (diferuloylmethane), a polyphenol extracted from the plant Curcuma longa, is widely used in Southeast Asia, China and India in food preparation and for medicinal purposes. Since the second half of the last century, this traditional medicine has attracted the attention of scientists from multiple disciplines to elucidate its pharmacological properties. Of significant interest is curcumin's role to treat neurodegenerative diseases including Alzheimer's disease (AD), and Parkinson's disease (PD) and malignancy. These diseases all share an inflammatory basis, involving increased cellular reactive oxygen species (ROS) accumulation and oxidative damage to lipids, nucleic acids and proteins. The therapeutic benefits of curcumin for these neurodegenerative diseases appear multifactorial via regulation of transcription factors, cytokines and enzymes associated with (Nuclear factor kappa beta) NFκB activity. This review describes the historical use of curcumin in medicine, its chemistry, stability and biological activities, including curcumin's anti-cancer, anti-microbial, anti-oxidant, and anti-inflammatory properties. The review further discusses the pharmacology of curcumin and provides new perspectives on its therapeutic potential and limitations. Especially, the review focuses in detail on the effectiveness of curcumin and its mechanism of actions in treating neurodegenerative diseases such as Alzheimer's and Parkinson's diseases and brain malignancies.

Curcumin inhibits LPS-induced inflammation in rat vascular smooth muscle cells in vitro via ROS-relative TLR4-MAPK/NF-κB pathways

AIM

To investigate whether curcumin (Cur) suppressed lipopolysaccharide (LPS)-induced inflammation in vascular smooth muscle cells (VSMCs) of rats, and to determine its molecular mechanisms.

METHODS

Primary rat VSMCs were treated with LPS (1 μg/L) and Cur (5, 10, or 30 μmol/L) for 24 h. The levels of MCP-1, TNF-α, and iNOS were measured using ELISA and real-time RT-PCR. NO level was analyzed with the Griess reaction. Western-blotting was used to detect the activation of TLR4, MAPKs, IκBα, NF-κB p65, and the p47(phox) subunit of NADPH oxidase in the cells.

RESULTS

Treatment of VSMCs with LPS dramatically increased expression of inflammatory cytokines MCP-1 and TNF-α, expression of TLR4 and iNOS, and NO production. LPS also significantly increased phosphorylation of IκBα, nuclear translocation of NF-κB (p65) and phosphorylation of MAPKs in VSMCs. Furthermore, LPS significantly increased production of intracellular ROS, and decreased expression of p47(phox) subunit of NADPH oxidase. Pretreatment with Cur concentration-dependently attenuated all the aberrant changes in LPS-treated VSMCs. The LPS-induced overexpression of MCP-1 and TNF-α, and NO production were attenuated by pretreatment with the ERK inhibitor PD98059, the p38 MAPK inhibitor SB203580, the NF-κB inhibitor PDTC or anti-TLR4 antibody, but not with the JNK inhibitor SP600125.

CONCLUSION

Cur suppresses LPS-induced overexpression of inflammatory mediators in VSMCs in vitro via inhibiting the TLR4-MAPK/NF-κB pathways, partly due to block of NADPH-mediated intracellular ROS production.

Incidence of brain injuries in premature infants with gestational age ≤ 34 weeks in ten urban hospitals in China

BACKGROUND

There is a large number (1.5 million per year) of premature births in China. It is necessary to obtain the authentic incidences of intraventricular hemorrhage (IVH) and periventricular leukomalacia (PVL), the common brain injuries, in Chinese premature infants. The present multicenter study aimed to investigate the incidence of brain injuries in premature infants in ten urban hospitals in China.

METHODS

The research proposal was designed by the Subspecialty Group of Neonatology of Pediatric Society of the Chinese Medical Association. Ten large-scale urban hospitals voluntarily joined the multicenter investigation. All premature infants with a gestational age ≤ 34 weeks in the ten hospitals were subjected to routine cranial ultrasound within three days after birth, and then to repeated ultrasound every 3-7 days till their discharge from the hospital from January 2005 to August 2006. A uniform data collection sheet was designed to record cases of brain injuries.

RESULTS

The incidences of overall IVH and severe IVH were 19.7% (305/1551) and 4.6% (72/1551), respectively with 18.4% (56/305) for grade 1, 58.0% (177/305) for grade 2, 17.7% (54/305) for grade 3 and 5.9% (18/305) for grade 4 in nine hospitals. The incidences of overall PVL and cystic PVL were 5.0% (89/1792) and 0.8% (14/1792) respectively, with 84.3% (75/89) for grade 1, 13.5% (12/89) for grade 2, and 2.2% (2/89) for grade 3 in the ten hospitals. The statistically significant risk factors that might aggravate the severity of IVH were vaginal delivery (OR=1.883, 95% CI: 1.099-3.228, P=0.020) and mechanical ventilation (OR=4.150, 95% CI: 2.384-7.223, P=0.000). The risk factors that might result in the development of cystic PVL was vaginal delivery (OR=21.094, 95% CI: 2.650-167.895, P=0.000).

CONCLUSIONS

The investigative report can basically reflect the incidence of brain injuries in premature infants in major big cities of China. Since more than 60% of the Chinese population live in the rural areas of China, it is expected to undertake a further multicenter investigation covering the rural areas in the future.

White matter injury following fetal inflammatory response syndrome induced by chorioamnionitis and fetal sepsis: lessons from experimental ovine models

Chorioamnionitis and fetal sepsis can induce a fetal inflammatory response syndrome (FIRS) which is closely related to the development of white matter injury in the fetal brain. Large epidemiological studies support the link between FIRS and fetal brain injury with a clear association between the presence of in utero inflammation and neurodevelopmental complications such as cerebral palsy, autism and cognitive impairments later in life. Translational animal models of chorioamnionitis and fetal sepsis are essential in understanding the underlying pathophysiological mechanisms of fetal brain injury after exposure to intra-uterine inflammation. Concerning this aspect, ovine models have high translational value since neurodevelopment in sheep closely resembles the human situation. In this article, we will review clinical and experimental evidence for the link between FIRS and white matter injury in the fetal brain. With respect to experimental findings, we will particularly focus on the lessons learned from ovine models of chorioamnionitis and fetal sepsis. We also highlight two key players implied in the pathophysiology of white matter injury after in utero exposure to inflammation.

Diphenyleneiodonium protects preoligodendrocytes against endotoxin-activated microglial NADPH oxidase-generated peroxynitrite in a neonatal rat model of periventricular leukomalacia

The contribution of microglial activation to preoligodendroglial (preOL) damage in the central nervous system (CNS) is considered to be one of the principal causes of periventricular leukomalacia (PVL) pathogenesis. The present study explores the effect of diphenyleneiodonium (DPI), a NADPH oxidase (NOX) inhibitor, on protection of preOLs from bacterial lipopolysaccharide (LPS)-induced microglial toxicity in vivo and in vitro. In vitro, preOLs co-cultured with microglia exhibited increased preOL apoptosis, accompanied by overproduction of superoxide anion (O(2)(-)) and the formation of peroxynitrite (ONOO(-)) after LPS exposure. LPS also significantly up-regulated accumulation of activated microglial NOX subunits p67-phox and gp91-phox in the plasma membrane. Diphenyleneiodonium (DPI) (10μm) was found to significantly attenuate up-regulation of this NOX activity. In vivo, DPI was administered (1mg/kg/day) by subcutaneous injection for 3 days to two-day-old neonatal Sprague-Dawley rats subjected to intracerebral injection of LPS. Treatment with DPI within 24h of LPS injection significantly ameliorated white matter injury, decreasing preOL loss, O(2)(-) generation, and ONOO(-) formation, and inhibiting p67-phox, gp91-phox synthesis and p67phox membrane translocation in microglia. These results indicated that LPS-induced preOL apoptosis may have been mediated by microglia-derived ONOO(-). DPI prevented this LPS-induced brain injury, most likely by inhibiting ONOO(-) formation via NOX, thereby preventing preOL loss and immature white matter injury.

Curcumin--from molecule to biological function

Turmeric is traditionally used as a spice and coloring in foods. It is an important ingredient in curry and gives curry powder its characteristic yellow color. As a consequence of its intense yellow color, turmeric, or curcumin (food additive E100), is used as a food coloring (e.g. mustard). Turmeric contains the curcuminoids curcumin, demethoxycurcumin, and bisdemethoxycurcumin. Recently, the health properties (neuroprotection, chemo-, and cancer prevention) of curcuminoids have gained increasing attention. Curcuminoids induce endogenous antioxidant defense mechanisms in the organism and have anti-inflammatory activity. Curcuminoids influence gene expression as well as epigenetic mechanisms. Synthetic curcumin analogues also exhibit biological activity. This Review describes the development of curcumin from a "traditional" spice and food coloring to a "modern" biological regulator.

The role of cytokines and inflammatory cells in perinatal brain injury

Perinatal brain injury frequently complicates preterm birth and leads to significant long-term morbidity. Cytokines and inflammatory cells are mediators in the common pathways associated with perinatal brain injury induced by a variety of insults, such as hypoxic-ischemic injury, reperfusion injury, toxin-mediated injury, and infection. This paper examines our current knowledge regarding cytokine-related perinatal brain injury and specifically discusses strategies for attenuating cytokine-mediated brain damage.