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Accumulation of pathological tau isoforms, especially hyperphosphorylated tau at serine 396 (pS396-tau) and tau oligomers, has been demonstrated in the retinas of patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD). Previous studies have noted a decrease in retinal ganglion cells (RGCs) in AD patients, but the presence and impact of pathological tau isoforms in RGCs and RGC integrity, particularly in early AD stages, have not been explored. To investigate this, we examined retinal superior temporal cross-sections from 25 patients with MCI (due to AD) or AD dementia and 16 cognitively normal (CN) controls, matched for age and gender. We utilized the RGC marker ribonucleic acid binding protein with multiple splicing (RBPMS) and Nissl staining to assess neuronal density in the ganglion cell layer (GCL). Our study found that hypertrophic RGCs containing pS396-tau and T22-positive tau oligomers were more frequently observed in MCI and AD patients compared to CN subjects. Quantitative analyses indicated a decline in RGC integrity, with 46-55% and 55-56% reductions of RBPMS + RGCs (P<0.01) and Nissl + GCL neurons (P<0.01-0.001), respectively, in MCI and AD patients. This decrease in RGC count was accompanied by increases in necroptotic-like morphology and the cleaved caspase-3 apoptotic marker in RGCs of AD patients. Furthermore, there was a 2.1 to 3.1-fold increase (P<0.05-0.0001) in pS396-tau-laden RGCs in MCI and AD patients, with a greater abundance observed in individuals with higher Braak stages (V-VI), more severe clinical dementia ratings (CDR=3), and lower mini-mental state examination (MMSE) scores. Strong correlations were noted between the decline in RGCs and the total amount of retinal pS396-tau and pS396-tau + RGCs, with pS396-tau + RGC counts correlating significantly with brain neurofibrillary tangle scores ( r = 0.71, P= 0.0001), Braak stage ( r = 0.65, P= 0.0009), and MMSE scores ( r = -0.76, P= 0.0004). These findings suggest that retinal tauopathy, characterized by pS396-tau and oligomeric tau in hypertrophic RGCs, is associated with and may contribute to RGC degeneration in AD. Future research should validate these findings in larger cohorts and explore noninvasive retinal imaging techniques that target tau pathology in RGCs to improve AD detection and monitor disease progression., Competing Interests: Competing interest: The authors declare no conflict of interest relevant for this study.

The retina is an emerging CNS target for potential noninvasive diagnosis and tracking of Alzheimer's disease (AD). Studies have identified the pathological hallmarks of AD, including amyloid β-protein (Aβ) deposits and abnormal tau protein isoforms, in the retinas of AD patients and animal models. Moreover, structural and functional vascular abnormalities such as reduced blood flow, vascular Aβ deposition, and blood-retinal barrier damage, along with inflammation and neurodegeneration, have been described in retinas of patients with mild cognitive impairment and AD dementia. Histological, biochemical, and clinical studies have demonstrated that the nature and severity of AD pathologies in the retina and brain correspond. Proteomics analysis revealed a similar pattern of dysregulated proteins and biological pathways in the retina and brain of AD patients, with enhanced inflammatory and neurodegenerative processes, impaired oxidative-phosphorylation, and mitochondrial dysfunction. Notably, investigational imaging technologies can now detect AD-specific amyloid deposits, as well as vasculopathy and neurodegeneration in the retina of living AD patients, suggesting alterations at different disease stages and links to brain pathology. Current and exploratory ophthalmic imaging modalities, such as optical coherence tomography (OCT), OCT-angiography, confocal scanning laser ophthalmoscopy, and hyperspectral imaging, may offer promise in the clinical assessment of AD. However, further research is needed to deepen our understanding of AD's impact on the retina and its progression. To advance this field, future studies require replication in larger and diverse cohorts with confirmed AD biomarkers and standardized retinal imaging techniques. This will validate potential retinal biomarkers for AD, aiding in early screening and monitoring., Competing Interests: Declaration of competing interest HH declares no competing financial interests related to the present article. He is an employee of Eisai Inc. The present article has been initiated and prepared as part of his academic position at Sorbonne University, Paris, France, and reflects entirely and exclusively his own opinion. He serves as Senior Associate Editor for the Journal Alzheimer's & Dementia and does not receive any fees or honoraria since May 2019. He is inventor of 11 patents and has received no royalties: AV declares no competing financial interests related to the present article. AV contribution to this work relates to his previous academic position at Sorbonne University, Paris, France. AV was an employee of Eisai Inc. (Nov 2019–June 2021). AV does not receive any fees or honoraria since November 2019. Before November 2019 he had he received lecture honoraria from Roche, MagQu LLC, and Servier. YK and MKH are co-founding members and consultants of NeuroVision Imaging, Inc., 1395 Garden Highway, Suite 250, Sacramento, CA 95833, USA. KLB is chair and SV is CEO, co-founders and shareholders of NeuroVision Imaging, Inc., 1395 Garden Highway, Suite 250, Sacramento, CA 95833, USA. All other authors declare no competing interests related to this article., (Copyright © 2024. Published by Elsevier Ltd.)

Naturally occurring homoisoflavonoids isolated from some Liliaceae plants have been reported to have diverse biological activities (e.g., antioxidant, anti-inflammatory, and anti-angiogenic effects). The exact mechanism by which homoisoflavonones exert anti-neuroinflammatory effects against activated microglia-induced inflammatory cascades has not been well studied. Here, we aimed to explore the mechanism of homoisoflavonoid SH66 having a potential anti-inflammatory effect in lipopolysaccharide (LPS)-primed BV2 murine microglial cells. Microglia cells were pre-treated with SH66 followed by LPS (100 ng/mL) activation. SH66 treatment attenuated the production of inflammatory mediators, including nitric oxide and proinflammatory cytokines, by down-regulating mitogen-activated protein kinase signaling in LPS-activated microglia. The SH66-mediated inhibition of the nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome complex and the respective inflammatory biomarker-like active interleukin (IL)-1β were noted to be one of the key pathways of the anti-inflammatory effect. In addition, SH66 increased the neurite length in the N2a neuronal cell and the level of nerve growth factor in the C6 astrocyte cell. Our results demonstrated the anti-neuroinflammatory effect of SH66 against LPS-activated microglia-mediated inflammatory events by down-regulating the NLRP3 inflammasome complex, with respect to its neuroprotective effect. SH66 could be an interesting candidate for further research and development regarding prophylactics and therapeutics for inflammation-mediated neurological complications.

While recent advances in diagnostics and therapeutics offer promising new approaches for Alzheimer's disease (AD) diagnosis and treatment, there is still an unmet need for an effective remedy, suggesting new avenues of research are required. Besides many plausible etiologies for AD pathogenesis, mounting evidence supports a possible role for microbial infections. Various microbes have been identified in the postmortem brain tissues of human AD patients. Among bacterial pathogens in AD, Chlamydia pneumoniae (Cp) has been well characterized in human AD brains and is a leading candidate for an infectious involvement. However, no definitive studies have been performed proving or disproving Cp's role as a causative or accelerating agent in AD pathology and cognitive decline. In this review, we discuss recent updates for the role of Cp in human AD brains as well as experimental models of AD. Furthermore, based on the current literature, we have compiled a list of potential mechanistic pathways which may connect Cp with AD pathology., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Subedi, Gaire, Koronyo, Koronyo-Hamaoui and Crother.)

Introduction: Osteopontin (OPN; also known as SPP1), an immunomodulatory cytokine highly expressed in bone marrow-derived macrophages (BMMΦ), is known to regulate diverse cellular and molecular immune responses. We previously revealed that glatiramer acetate (GA) stimulation of BMMΦ upregulates OPN expression, promoting an anti-inflammatory, pro-healing phenotype, whereas OPN inhibition triggers a pro-inflammatory phenotype. However, the precise role of OPN in macrophage activation state is unknown., Methods: Here, we applied global proteome profiling via mass spectrometry (MS) analysis to gain a mechanistic understanding of OPN suppression versus induction in primary macrophage cultures. We analyzed protein networks and immune-related functional pathways in BMMΦ either with OPN knockout (OPN KO ) or GA-mediated OPN induction compared with wild type (WT) macrophages. The most significant differentially expressed proteins (DEPs) were validated using immunocytochemistry, western blot, and immunoprecipitation assays., Results and Discussion: We identified 631 DEPs in OPN KO or GA-stimulated macrophages as compared to WT macrophages. The two topmost downregulated DEPs in OPN KO macrophages were ubiquitin C-terminal hydrolase L1 (UCHL1), a crucial component of the ubiquitin-proteasome system (UPS), and the anti-inflammatory Heme oxygenase 1 (HMOX-1), whereas GA stimulation upregulated their expression. We found that UCHL1, previously described as a neuron-specific protein, is expressed by BMMΦ and its regulation in macrophages was OPN-dependent. Moreover, UCHL1 interacted with OPN in a protein complex. The effects of GA activation on inducing UCHL1 and anti-inflammatory macrophage profiles were mediated by OPN. Functional pathway analyses revealed two inversely regulated pathways in OPN-deficient macrophages: activated oxidative stress and lysosome-mitochondria-mediated apoptosis ( e.g ., ROS, Lamp1-2, ATP-synthase subunits, cathepsins, and cytochrome C and B subunits) and inhibited translation and proteolytic pathways ( e.g ., 60S and 40S ribosomal subunits and UPS proteins). In agreement with the proteome-bioinformatics data, western blot and immunocytochemical analyses revealed that OPN deficiency perturbs protein homeostasis in macrophages-inhibiting translation and protein turnover and inducing apoptosis-whereas OPN induction by GA restores cellular proteostasis. Taken together, OPN is essential for macrophage homeostatic balance via the regulation of protein synthesis, UCHL1-UPS axis, and mitochondria-mediated apoptotic processes, indicating its potential application in immune-based therapies., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Rentsendorj, Raedschelders, Fuchs, Sheyn, Vaibhav, Porritt, Shi, Dagvadorj, de Freitas Germano, Koronyo, Arditi, Black, Gaire, Van Eyk and Koronyo-Hamaoui.)

Acetylcholinesterase inhibitors (ChEI) are the global standard of care for the symptomatic treatment of Alzheimer's disease (AD) and show significant positive effects in neurodegenerative diseases with cognitive and behavioral symptoms. Although experimental and large-scale clinical evidence indicates the potential long-term efficacy of ChEI, primary outcomes are generally heterogeneous across outpatient clinics and regional healthcare systems. Sub-optimal dosing or slow tapering, heterogeneous guidelines about the timing for therapy initiation (prodromal versus dementia stages), healthcare providers' ambivalence to treatment, lack of disease awareness, delayed medical consultation, prescription of ChEI in non-AD cognitive disorders, contribute to the negative outcomes. We present an evidence-based overview of determinants, spanning genetic, molecular, and large-scale networks, involved in the response to ChEI in patients with AD and other neurodegenerative diseases. A comprehensive understanding of cerebral and retinal cholinergic system dysfunctions along with ChEI response predictors in AD is crucial since disease-modifying therapies will frequently be prescribed in combination with ChEI. Therapeutic algorithms tailored to genetic, biological, clinical (endo)phenotypes, and disease stages will help leverage inter-drug synergy and attain optimal combined response outcomes, in line with the precision medicine model., Competing Interests: Conflict of Interest SL declares no competing financial interests related to the present article. This work was conceptualized and initiated during his previous position at Sorbonne University (Paris, France) and it reflects only and exclusively his own opinion and academic expertise on the matter. AV declares no competing financial interests related to the present article, and his contribution to this article reflects only and exclusively his own academic expertise on the matter. This work was conceptualized and initiated during his previous academic position at Sorbonne University, Paris, France. AV was an employee of Eisai Inc. [Nov 2019 - June 2021]. AV does not receive any fees or honoraria since November 2019. Before November 2019 he had received lecture honoraria from Roche, MagQu LLC, and Servier. YK, and MKH are co-founding members and consultants of NeuroVision Imaging, Inc., Sacramento, CA, USA. HH is an employee of Eisai Inc. The present article has been initiated and prepared as part of his academic position at Sorbonne University, Paris, France, and reflects entirely and exclusively his own opinion. He serves as Senior Associate Editor for the Journal Alzheimer’s & Dementia and does not receive any fees or honoraria since May 2019. He is inventor of 11 patents and has received no royalties: In Vitro Multiparameter Determination Method for The Diagnosis and Early Diagnosis of Neurodegenerative Disorders Patent Number: 8916388; In Vitro Procedure for Diagnosis and Early Diagnosis of Neurodegenerative Diseases Patent Number: 8298784; Neurodegenerative Markers for Psychiatric Conditions Publication Number: 20120196300; In Vitro Multiparameter Determination Method for The Diagnosis and Early Diagnosis of Neurodegenerative Disorders Publication Number: 20100062463; In Vitro Method for The Diagnosis and Early Diagnosis of Neurodegenerative Disorders Publication Number: 20100035286; In Vitro Procedure for Diagnosis and Early Diagnosis of Neurodegenerative Diseases Publication Number: 20090263822; In Vitro Method for The Diagnosis of Neurodegenerative Diseases Patent Number: 7547553; CSF Diagnostic in Vitro Method for Diagnosis of Dementias and Neuroinflammatory Diseases Publication Number: 20080206797; In Vitro Method for The Diagnosis of Neurodegenerative Diseases Publication Number: 20080199966; Neurodegenerative Markers for Psychiatric Conditions Publication Number: 20080131921; Method for diagnosis of dementias and neuroinflammatory diseases based on an increased level of procalcitonin in cerebrospinal fluid: Publication number: United States Patent 10921330. SJT, PL, FSG, AG, FG, NBM, CB, BPG, and RN declare that they have no conflict of interest., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Microglial activation is considered as the critical pathogenic event in diverse central nervous system disorders including cerebral ischemia. Proinflammatory responses of activated microglia have been well reported in the ischemic brain and neuroinflammatory responses of activated microglia have been believed to be the potential therapeutic strategy. However, despite having proinflammatory roles, microglia can have significant anti-inflammatory roles and they are associated with the production of growth factors which are responsible for neuroprotection and recovery after ischemic injury. Microglia can directly promote neuroprotection by preventing ischemic infarct expansion and promoting functional outcomes. Indirectly, microglia are involved in promoting anti-inflammatory responses, neurogenesis, and angiogenesis in the ischemic brain which are crucial pathophysiological events for ischemic recovery. In fact, anti-inflammatory cytokines and growth factors produced by microglia can promote neuroprotection and attenuate neurobehavioral deficits. In addition, microglia regulate phagocytosis, axonal regeneration, blood-brain barrier protection, white matter integrity, and synaptic remodeling, which are essential for ischemic recovery. Microglia can also regulate crosstalk with neurons and other cell types to promote neuroprotection and ischemic recovery. This review mainly focuses on the roles of microglia in neuroprotection and recovery following ischemic injury. Furthermore, this review also sheds the light on the therapeutic potential of microglia in stroke patients., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Moringa oleifera , popularly known as a miracle tree or tree of life, has been extensively used as a functional food and nutritional asset worldwide. Ethnomedicinal and traditional uses of M. oleifera indicate that this plant might have a pleiotropic therapeutic efficacy against most human ailments. In fact, M. oleifera is reported to have several pharmacological activities, including antioxidant, antibacterial, antifungal, antidiabetic, antipyretic, antiulcer, antispasmodic, antihypertensive, antitumor, hepatoprotective, and cardiac stimulant properties. Recently, a few experimental studies reported the neuroprotective effects of M. oleifera against Alzheimer's disease, dementia, Parkinson's disease, stroke, and neurotoxicity-related symptoms. In addition, several neuroprotective phytochemicals have been isolated from M. oleifera , which signifies that it can have promising neuroprotective effects. Therefore, this review aimed to explore the current updates and future prospective of neuroprotective efficacies of M. oleifera .

Activation of microglia and/or astrocytes often releases proinflammatory molecules as critical pathogenic mediators that can promote neuroinflammation and secondary brain damages in diverse diseases of the central nervous system (CNS). Therefore, controlling the activation of glial cells and their neuroinflammatory responses has been considered as a potential therapeutic strategy for treating neuroinflammatory diseases. Recently, receptor-mediated lysophospholipid signaling, sphingosine 1-phosphate (S1P) receptor- and lysophosphatidic acid (LPA) receptor-mediated signaling in particular, has drawn scientific interest because of its critical roles in pathogenies of diverse neurological diseases such as neuropathic pain, systemic sclerosis, spinal cord injury, multiple sclerosis, cerebral ischemia, traumatic brain injury, hypoxia, hydrocephalus, and neuropsychiatric disorders. Activation of microglia and/or astrocytes is a common pathogenic event shared by most of these CNS disorders, indicating that lysophospholipid receptors could influence glial activation. In fact, many studies have reported that several S1P and LPA receptors can influence glial activation during the pathogenesis of cerebral ischemia and multiple sclerosis. This review aims to provide a comprehensive framework about the roles of S1P and LPA receptors in the activation of microglia and/or astrocytes and their neuroinflammatory responses in CNS diseases.

Despite being a major global health concern, cerebral ischemia/stroke has limited therapeutic options. Tissue plasminogen activator (tPA) is the only available medication to manage acute ischemic stroke, but this medication is associated with adverse effects and has a narrow therapeutic time window. Curcumin, a polyphenol that is abundantly present in the rhizome of the turmeric plant ( Curcuma longa ), has shown promising neuroprotective effects in animal models of neurodegenerative diseases, including cerebral ischemia. In the central nervous system (CNS), neuroprotective effects of curcumin have been experimentally validated in Alzheimer's disease, Parkinson's disease, multiple sclerosis, and cerebral ischemia. Curcumin can exert pleiotropic effects in the postischemic brain including antioxidant, anti-inflammatory, antiapoptotic, vasculoprotective, and direct neuroprotective efficacies. Importantly, neuroprotective effects of curcumin has been reported in both ischemic and hemorrhagic stroke models. A broad-spectrum neuroprotective efficacy of curcumin suggested that curcumin can be an appealing therapeutic strategy to treat cerebral ischemia. In this review, we aimed to address the pharmacotherapeutic potential of curcumin in cerebral ischemia including its cellular and molecular mechanisms of neuroprotection revealing curcumin as an appealing therapeutic candidate for cerebral ischemia.

Tanshinones, lipophilic diterpenes isolated from the rhizome of Salvia miltiorrhiza, have diverse pharmacological activities against human ailments including neurological diseases. In fact, tanshinones have been used to treat heart diseases, stroke, and vascular diseases in traditional Chinese medicine. During the last decade, tanshinones have been the most widely studied phytochemicals for their neuroprotective effects against experimental models of cerebral ischemia and Alzheimer's diseases. Importantly, tanshinone IIA, mostly studied tanshinone for biological activities, is recently reported to attenuate blood-brain barrier permeability among stroke patients, suggesting tanshinone IIA as an appealing therapeutic candidate for neurological diseases. Tanshinone I and IIA are also effective in experimental models of Parkinson's disease, Multiple sclerosis, and other neuroinflammatory diseases. In addition, several experimental studies suggested the pleiotropic neuroprotective effects of tanshinones such as anti-inflammatory, antioxidant, anti-apoptotic, and BBB protectant further value aiding to tanshinone as an appealing therapeutic strategy in neurological diseases. Therefore, in this review, we aimed to compile the recent updates and cellular and molecular mechanisms of neuroprotection of tanshinone IIA in diverse neurological diseases., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Nitric oxide (NO) is a neurotransmitter that mediates the activation and inhibition of inflammatory cascades. Even though physiological NO is required for defense against various pathogens, excessive NO can trigger inflammatory signaling and cell death through reactive nitrogen species-induced oxidative stress. Excessive NO production by activated microglial cells is specifically associated with neuroinflammatory and neurodegenerative conditions, such as Alzheimer's and Parkinson's disease, amyotrophic lateral sclerosis, ischemia, hypoxia, multiple sclerosis, and other afflictions of the central nervous system (CNS). Therefore, controlling excessive NO production is a desirable therapeutic strategy for managing various neuroinflammatory disorders. Recently, phytochemicals have attracted considerable attention because of their potential to counteract excessive NO production in CNS disorders. Moreover, phytochemicals and nutraceuticals are typically safe and effective. In this review, we discuss the mechanisms of NO production and its involvement in various neurological disorders, and we revisit a number of recently identified phytochemicals which may act as NO inhibitors. This review may help identify novel potent anti-inflammatory agents that can downregulate NO, specifically during neuroinflammation and neurodegeneration.

Sphingosine 1-phosphate (S1P) is an important lipid biomolecule that exerts pleiotropic cellular actions as it binds to and activates its five G-protein-coupled receptors, S1P 1-5 . Through these receptors, S1P can mediate diverse biological activities in both healthy and diseased conditions. S1P is produced by S1P-producing enzymes, sphingosine kinases (SphK1 and SphK2), and is abundantly present in different organs, including the brain. The medically important roles of receptor-mediated S1P signaling are well characterized in multiple sclerosis because FTY720 (Gilenya™, Novartis), a non-selective S1P receptor modulator, is currently used as a treatment for this disease. In cerebral ischemia, its role is also notable because of FTY720's efficacy in both rodent models and human patients with cerebral ischemia. In particular, some of the S1P receptors, including S1P 1 , S1P 2 , and S1P 3 , have been identified as pathogenic players in cerebral ischemia. Other than these receptors, S1P itself and S1P-producing enzymes have been shown to play certain roles in cerebral ischemia. This review aims to compile the current updates and overviews about the roles of S1P signaling, along with a focus on S1P receptors in cerebral ischemia, based on recent studies that used in vivo rodent models of cerebral ischemia.

The search for novel therapeutic agents for the management of cerebral ischemia/stroke has become an appealing research interest in the recent past. Neuroprotective phytochemicals as novel stroke drug candidates have recently drawn significant interests from stroke scientists due to their strong brain protective effects in animal stroke models. The underlying mechanism of action is likely owing to their anti-inflammatory properties, even though other mechanisms such as anti-oxidation and vasculoprotection have also been proposed. It is generally held that the early proinflammatory responses after stroke can lead to a secondary brain injury, mainly due to the damaging effect exerted by over-activation of brain resident microglial cells and infiltration of circulating monocytes and macrophages. This review focuses on the anti-inflammatory properties of bioactive phytochemicals, including activation and polarization of microglia/macrophages in the post-ischemic brain. The latest studies in animal stroke models demonstrate that this group of bioactive phytochemicals exerts their anti-inflammatory effects via attenuation of brain proinflammatory microglia and macrophages M1 polarization while promoting anti-inflammatory microglial and macrophages M2 polarization. As a result, stroked animals treated with brain protective phytochemicals have significantly fewer brain active M1 microglia and macrophages, smaller brain infarct volume, better functional recovery, and better survival rate. Therefore, this review provides insights into a new category of drug candidates for stroke drug development by employing neuroprotective phytochemicals., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2/COVID-19), is a worldwide pandemic, as declared by the World Health Organization (WHO). It is a respiratory virus that infects people of all ages. Although it may present with mild to no symptoms in most patients, those who are older, immunocompromised, or with multiple comorbidities may present with severe and life-threatening infections. Throughout history, nutraceuticals, such as a variety of phytochemicals from medicinal plants and dietary supplements, have been used as adjunct therapies for many disease conditions, including viral infections. Appropriate use of these adjunct therapies with antiviral proprieties may be beneficial in the treatment and/or prophylaxis of COVID-19. In this review, we provide a comprehensive summary of nutraceuticals, such as vitamins C, D, E, zinc, melatonin, and other phytochemicals and function foods. These nutraceuticals may have potential therapeutic efficacies in fighting the threat of the SARS-CoV-2/COVID-19 pandemic.

Lysophosphatidic acid receptor 1 (LPA 1 ) contributes to brain injury following transient focal cerebral ischemia. However, the mechanism remains unclear. Here, we investigated whether nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome activation might be an underlying mechanism involved in the pathogenesis of brain injury associated with LPA 1 following ischemic challenge with transient middle cerebral artery occlusion (tMCAO). Suppressing LPA 1 activity by its antagonist attenuated NLRP3 upregulation in the penumbra and ischemic core regions, particularly in ionized calcium-binding adapter molecule 1 (Iba1)-expressing cells like macrophages of mouse after tMCAO challenge. It also suppressed NLRP3 inflammasome activation, such as caspase-1 activation, interleukin 1β (IL-1β) maturation, and apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) speck formation, in a post-ischemic brain. The role of LPA 1 in NLRP3 inflammasome activation was confirmed in vitro using lipopolysaccharide-primed bone marrow-derived macrophages, followed by LPA exposure. Suppressing LPA 1 activity by either pharmacological antagonism or genetic knockdown attenuated NLRP3 upregulation, caspase-1 activation, IL-1β maturation, and IL-1β secretion in these cells. Furthermore, nuclear factor-κB (NF-κB), extracellular signal-regulated kinase 1/2 (ERK1/2), and p38 were found to be LPA 1 -dependent effector pathways in these cells. Collectively, results of the current study first demonstrate that LPA 1 could contribute to ischemic brain injury by activating NLRP3 inflammasome with underlying effector mechanisms.

Stroke is a leading cause of death. Stroke survivors often suffer from long-term functional disability. This study demonstrated neuroprotective effects of BMS-986020 (BMS), a selective lysophosphatidic acid receptor 1 (LPA 1 ) antagonist under clinical trials for lung fibrosis and psoriasis, against both acute and sub-acute injuries after ischemic stroke by employing a mouse model with transient middle cerebral artery occlusion (tMCAO). BMS administration immediately after reperfusion significantly attenuated acute brain injuries including brain infarction, neurological deficits, and cell apoptosis at day 1 after tMCAO. Neuroprotective effects of BMS were preserved even when administered at 3 h after reperfusion. Neuroprotection by BMS against acute injuries was associated with attenuation of microglial activation and lipid peroxidation in post-ischemic brains. Notably, repeated BMS administration daily for 14 days after tMCAO exerted long-term neuroprotection in tMCAO-challenged mice, as evidenced by significantly attenuated neurological deficits and improved survival rate. It also attenuated brain tissue loss and cell apoptosis in post-ischemic brains. Mechanistically, it significantly enhanced neurogenesis and angiogenesis in injured brains. A single administration of BMS provided similar long-term neuroprotection except survival rate. Collectively, BMS provided neuroprotection against both acute and sub-acute injuries of ischemic stroke, indicating that BMS might be an appealing therapeutic agent to treat ischemic stroke.

Advanced glycation end products (AGEs) are produced through the binding of glycated protein or lipid with sugar, and they are known to be involved in the pathogenesis of both age-dependent and independent neurological complications. Among dicarbonyl compounds, methylglyoxal (MGO), which is produced from glucose breakdown, is a key precursor of AGE formation and neurotoxicity. Several studies have shown the toxic effects of bovine serum albumin (BSA)-AGE (prepared with glucose, sucrose or fructose) both in in vitro and in vivo. In fact, MGO-derived AGEs (MGO-AGEs) are highly toxic to neurons and other cells of the central nervous system. Therefore, we aimed to investigate the role of MGO-AGEs in microglial activation, a key inflammatory event, or secondary brain damage in neuroinflammatory diseases. Interestingly, we found that sulforaphane (SFN) as a potential candidate to downregulate neuroinflammation induced by MGO-AGEs in BV2 microglial cells. SFN not only inhibited the formation of MGO-AGEs, but it did not show breaking activity on the MGO-mediated AGEs cross-links with protein, indicating that SFN could potentially trap MGO or inhibit toxic AGE damage. In addition, SFN significantly attenuated the production of neuroinflammatory mediators induced by MGO-AGEs in BV2 microglial cells. SFN also lowered the expression levels of AGE receptor (RAGE) in microglial cells, suggesting that SFN could downregulate MGO-AGE-mediated neurotoxicity at the receptor activation level. Altogether, our current study revealed that SFN might show neuropharmacological potential for downregulating MGO-AGEs-mediated neuronal complications thorough attenuating AGE formation and neuroinflammatory responses induced by MGO-AGEs in vitro.

The pathogenesis of psoriasis, an immune-mediated chronic skin barrier disease, is not fully understood yet. Here, we identified lysophosphatidic acid (LPA) receptor 5 (LPA 5 )-mediated signaling as a novel pathogenic factor in psoriasis using an imiquimod-induced psoriasis mouse model. Amounts of most LPA species were markedly elevated in injured skin of psoriasis mice, along with LPA 5 upregulation in injured skin. Suppressing the activity of LPA 5 with TCLPA5, a selective LPA 5 antagonist, improved psoriasis symptoms, including ear thickening, skin erythema, and skin scaling in imiquimod-challenged mice. TCLPA5 administration attenuated dermal infiltration of macrophages that were found as the major cell type for LPA 5 upregulation in psoriasis lesions. Notably, TCLPA5 administration attenuated the upregulation of macrophage NLRP3 in injured skin of mice with imiquimod-induced psoriasis. This critical role of LPA 5 in macrophage NLRP3 was further addressed using lipopolysaccharide-primed bone marrow-derived macrophages. LPA exposure activated NLRP3 inflammasome in lipopolysaccharide-primed cells, which was evidenced by NLRP3 upregulation, caspase-1 activation, and IL-1β maturation/secretion. This LPA-driven NLRP3 inflammasome activation in lipopolysaccharide-primed cells was significantly attenuated upon LPA 5 knockdown. Overall, our findings establish a pathogenic role of LPA 5 in psoriasis along with an underlying mechanism, further suggesting LPA 5 antagonism as a potential strategy to treat psoriasis.

Tumor necrosis factor-alpha (TNF-α) is a well-known pro-inflammatory cytokine responsible for the modulation of the immune system. TNF-α plays a critical role in almost every type of inflammatory disorder, including central nervous system (CNS) diseases. Although TNF-α is a well-studied component of inflammatory responses, its functioning in diverse cell types is still unclear. TNF-α functions through its two main receptors: tumor necrosis factor receptor 1 and 2 (TNFR1, TNFR2), also known as p55 and p75, respectively. Normally, the functions of soluble TNF-α-induced TNFR1 activation are reported to be pro-inflammatory and apoptotic. While TNF-α mediated TNFR2 activation has a dual role. Several synthetic drugs used as inhibitors of TNF-α for diverse inflammatory diseases possess serious adverse effects, which make patients and researchers turn their focus toward natural medicines, phytochemicals in particular. Phytochemicals targeting TNF-α can significantly improve disease conditions involving TNF-α with fewer side effects. Here, we reviewed known TNF-α inhibitors, as well as lately studied phytochemicals, with a role in inhibiting TNF-α itself, and TNF-α-mediated signaling in inflammatory diseases focusing mainly on CNS disorders., Competing Interests: The authors declare no conflict of interest.

Isorhapontigenin (ISO), a tetrahydroxylated stilbenoid, is an analog of resveratrol (Rsv). The various biological activities of Rsv and its derivatives have been previously reported in the context of both cancer and inflammation. However, the anti-cancer effect of ISO against breast cancer has not been well established, despite being an orally bioavailable dietary polyphenol. In this study, we determine the anti-cancer effects of ISO against breast cancer using MCF7, T47D, and MDA-MB-231 cell lines. We observed that ISO induces breast cancer cell death, cell cycle arrest, oxidative stress, and the inhibition of cell proliferation. Additionally, sphingosine kinase inhibition by ISO controlled tubulin polymerization and cancer cell growth by regulating MAPK/PI3K-mediated cell cycle arrest in MCF7 cells. Interestingly, SPHK1/2 gene silencing increased oxidative stress, cell death, and tubulin destabilization in MCF7 cells. This suggests that the anti-cancer effect of ISO can be regulated by SPHK/tubulin destabilization pathways. Overall, ISO successfully induced breast cancer cell death and cell growth arrest, suggesting this phytochemical is a better alternative for breast cancer treatment. Further studies in animal models could confirm the potency and usability of ISO over Rsv for targeting breast cancer, potentially posing an alternative candidate for improved therapy in the near future.

M1/M2 polarization of immune cells including microglia has been well characterized. It mediates detrimental or beneficial roles in neuroinflammatory disorders including cerebral ischemia. We have previously found that sphingosine 1-phospate receptor subtype 1 (S1P 1 ) in post-ischemic brain following transient middle cerebral artery occlusion (tMCAO) can trigger microglial activation, leading to brain damage. Although the link between S1P 1 and microglial activation as a pathogenesis in cerebral ischemia had been clearly demonstrated, whether the pathogenic role of S1P 1 is associated with its regulation of M1/M2 polarization remains unclear. Thus, this study aimed to determine whether S1P 1 was associated with regulation of M1/M2 polarization in post-ischemic brain. Suppressing S1P 1 activity with its functional antagonist, AUY954 (5 mg/kg, p.o .), attenuated mRNA upregulation of M1 polarization markers in post-ischemic brain at 1 day and 3 days after tMCAO challenge. Similarly, suppressing S1P 1 activity with AUY954 administration inhibited M1-polarizatioin-relevant NF-κB activation in post-ischemic brain. Particularly, NF-κB activation was observed in activated microglia of post-ischemic brain and markedly attenuated by AUY954, indicating that M1 polarization through S1P 1 in post-ischemic brain mainly occurred in activated microglia. Suppressing S1P 1 activity with AUY954 also increased mRNA expression levels of M2 polarization markers in post-ischemic brain, further indicating that S1P 1 could also influence M2 polarization in post-ischemic brain. Finally, suppressing S1P 1 activity decreased phosphorylation of M1-relevant ERK1/2, p38, and JNK MAPKs, but increased phosphorylation of M2-relevant Akt, all of which were downstream pathways following S1P 1 activation. Overall, these results revealed S1P 1 -regulated M1/M2 polarization toward brain damage as a pathogenesis of cerebral ischemia.

Sphingosine 1-phosphate (S1P) signaling has emerged as a drug target in cerebral ischemia. Among S1P receptors, S1P 2 was recently identified to mediate ischemic brain injury. But, pathogenic mechanisms are not fully identified, particularly in view of microglial activation, a core pathogenesis in cerebral ischemia. Here, we addressed whether microglial activation is the pathogenesis of S1P 2 -mediated brain injury in mice challenged with transient middle cerebral artery occlusion (tMCAO). To suppress S1P 2 activity, its specific antagonist, JTE013 was given orally to mice immediately after reperfusion. JTE013 administration reduced the number of activated microglia and reversed their morphology from amoeboid to ramified microglia in post-ischemic brain after tMCAO challenge, along with attenuated microglial proliferation. Moreover, JTE013 administration attenuated M1 polarization in post-ischemic brain. This S1P 2 -directed M1 polarization appeared to occur in activated microglia, which was evidenced upon JTE013 exposure in vivo as suppressed M1-relevant NF-κB activation in activated microglia of post-ischemic brain. Moreover, JTE013 exposure or S1P 2 knockdown reduced expression levels of M1 markers in vitro in lipopolysaccharide-driven M1 microglia. Additionally, suppressing S1P 2 activity attenuated activation of M1-relevant ERK1/2 and JNK in post-ischemic brain or lipopolysaccharide-driven M1 microglia. Overall, our study demonstrated that S1P 2 regulated microglial activation and M1 polarization in post-ischemic brain.

Background: Lysophosphatidic acid receptor 1 (LPA 1 ) is in the spotlight because its synthetic antagonist has been under clinical trials for lung fibrosis and psoriasis. Targeting LPA 1 might also be a therapeutic strategy for cerebral ischemia because LPA 1 triggers microglial activation, a core pathogenesis in cerebral ischemia. Here, we addressed this possibility using a mouse model of transient middle cerebral artery occlusion (tMCAO)., Methods: To address the role of LPA 1 in the ischemic brain damage, we used AM095, a selective LPA 1 antagonist, as a pharmacological tool and lentivirus bearing a specific LPA 1 shRNA as a genetic tool. Brain injury after tMCAO challenge was accessed by determining brain infarction and neurological deficit score. Role of LPA 1 in tMCAO-induced microglial activation was ascertained by immunohistochemical analysis. Proinflammatory responses in the ischemic brain were determined by qRT-PCR and immunohistochemical analyses, which were validated in vitro using mouse primary microglia. Activation of MAPKs and PI3K/Akt was determined by Western blot analysis., Results: AM095 administration immediately after reperfusion attenuated brain damage such as brain infarction and neurological deficit at 1 day after tMCAO, which was reaffirmed by LPA 1 shRNA lentivirus. AM095 administration also attenuated brain infarction and neurological deficit at 3 days after tMCAO. LPA 1 antagonism attenuated microglial activation; it reduced numbers and soma size of activated microglia, reversed their morphology into less toxic one, and reduced microglial proliferation. Additionally, LPA 1 antagonism reduced mRNA expression levels of proinflammatory cytokines and suppressed NF-κB activation, demonstrating its regulatory role of proinflammatory responses in the ischemic brain. Particularly, these LPA 1 -driven proinflammatory responses appeared to occur in activated microglia because NF-κB activation occurred mainly in activated microglia in the ischemic brain. Regulatory role of LPA 1 in proinflammatory responses of microglia was further supported by in vitro findings using lipopolysaccharide-stimulated cultured microglia, showing that suppressing LPA 1 activity reduced mRNA expression levels of proinflammatory cytokines. In the ischemic brain, LPA 1 influenced PI3K/Akt and MAPKs; suppressing LPA 1 activity decreased MAPK activation and increased Akt phosphorylation., Conclusion: This study demonstrates that LPA 1 is a new etiological factor for cerebral ischemia, strongly indicating that its modulation can be a potential strategy to reduce ischemic brain damage.

Background: The pathogenic roles of receptor-mediated sphingosine 1-phosphate (S1P) signaling in cerebral ischemia have been evidenced mainly through the efficacy of FTY720 that binds non-selectively to four of the five S1P receptors (S1P 1,3,4,5 ). Recently, S1P 1 and S1P 2 were identified as specific receptor subtypes that contribute to brain injury in cerebral ischemia; however, the possible involvement of other S1P receptors remains unknown. S1P 3 can be the candidate because of its upregulation in the ischemic brain, which was addressed in this study, along with underlying pathogenic mechanisms., Methods: We used transient middle cerebral artery occlusion/reperfusion (tMCAO), a mouse model of transient focal cerebral ischemia. To identify S1P 3 as a pathogenic factor in cerebral ischemia, we employed a specific S1P 3 antagonist, CAY10444. Brain damages were assessed by brain infarction, neurological score, and neurodegeneration. Histological assessment was carried out to determine microglial activation, morphological transformation, and proliferation. M1/M2 polarization and relevant signaling pathways were determined by biochemical and immunohistochemical analysis., Results: Inhibiting S1P 3 immediately after reperfusion with CAY10444 significantly reduced tMCAO-induced brain infarction, neurological deficit, and neurodegeneration. When S1P 3 activity was inhibited, the number of activated microglia was markedly decreased in both the periischemic and ischemic core regions in the ischemic brain 1 and 3 days following tMCAO. Moreover, inhibiting S1P 3 significantly restored the microglial shape from amoeboid to ramified microglia in the ischemic core region 3 days after tMCAO, and it attenuated microglial proliferation in the ischemic brain. In addition to these changes, S1P 3 signaling influenced the proinflammatory M1 polarization, but not M2. The S1P 3 -dependent regulation of M1 polarization was clearly shown in activated microglia, which was affirmed by determining the in vivo activation of microglial NF-κB signaling that is responsible for M1 and in vitro expression levels of proinflammatory cytokines in activated microglia. As downstream effector pathways in an ischemic brain, S1P 3 influenced phosphorylation of ERK1/2, p38 MAPK, and Akt., Conclusions: This study identified S1P 3 as a pathogenic mediator in an ischemic brain along with underlying mechanisms, involving its modulation of microglial activation and M1 polarization, further suggesting that S1P 3 can be a therapeutic target for cerebral ischemia.

Microglia regulate immune responses in the brain, and their activation is key to the pathogenesis of diverse neurological diseases. Receptor-mediated lysophosphatidic acid (LPA) signaling has been known to regulate microglial biology, but it is still unclear which receptor subtypes guide the biology, particularly, microglial activation. Here, we investigated the pathogenic aspects of LPA receptor subtype 1 (LPA 1 ) in microglial activation using a systemic lipopolysaccharide (LPS) administration-induced septic mouse model in vivo and LPS-stimulated rat primary microglia in vitro. LPA 1 knockdown in the brain with its specific shRNA lentivirus attenuated the sepsis-induced microglia activation, morphological transformation, and proliferation. LPA 1 knockdown also resulted in the downregulation of TNF-α, at both mRNA and protein levels in septic brains, but not IL-1β or IL-6. In rat primary microglia, genetic or pharmacological blockade of LPA 1 attenuated gene upregulation and secretion of TNF-α in LPS-stimulated cells. In particular, the latter was associated with the suppressed TNF-α converting enzyme (TACE) activity. We reaffirmed these biological aspects using a BV2 microglial cell line in which LPA 1 expression was negligible. LPA 1 overexpression in BV2 cells led to significant increments in TNF-α production upon stimulation with LPS, whereas inhibiting LPA 1 reversed the production. We further identified ERK1/2, but not p38 MAPK or Akt, as the underlying effector pathway after LPA 1 activation in both septic brains and stimulated microglia. The current findings of the novel role of LPA 1 in microglial activation along with its mechanistic aspects could be applied to understanding the pathogenesis of diverse neurological diseases that involve microglial activation., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Herbal medicines, mainly of plant source, are invaluable source for the discovery of new therapeutic agents for all sorts of human ailments. The complex pathogenesis of stroke and multifactorial effect of herbal medicine and their active constituents may suggest the promising future of natural medicine for stroke treatment. Anti-oxidant, anti-inflammatory, anti-apoptotic, neuroprotective and vascular protective effect of herbal medicines are believed to be efficacious in stroke treatment. Herbs typically have fewer reported side effects than allopathic medicine, and may be safer to use over longer period of time. Herbal medicines are believed to be more effective for the longstanding health complaints, such as stroke. Several medicinal plants and their active constituents show the promising results in laboratory research. However failure in transformation of laboratory animal research to the clinical trials has created huge challenge for the use of herbal medicine in stroke. Until and unless scientifically comprehensive evidence of the efficacy and safety of herbal medicine in ischemic stroke patients is available, efforts should be made to continue implementing treatment strategies of proven effectiveness. More consideration should be paid to natural compounds that can have extensive therapeutic time windows, perfect pharmacological targets with few side effects. Herbal medicine has excellent prospective for the treatment of ischemic stroke, but a lot of effort should be invested to transform the success of animal research to human use.

Medically relevant roles of receptor-mediated sphingosine 1-phosphate (S1P) signaling have become a successful or promising target for multiple sclerosis or cerebral ischemia. Animal-based proof-of-concept validation for the latter is particularly through the neuroprotective efficacy of FTY720, a non-selective S1P receptor modulator, presumably via activation of S1P 1 . In spite of a clear link between S1P signaling and cerebral ischemia, it remains unknown whether the role of S1P 1 is pathogenic or neuroprotective. Here, we investigated the involvement of S1P 1 along with its role in cerebral ischemia using a transient middle cerebral artery occlusion ("tMCAO") model. Brain damage following tMCAO, as assessed by brain infarction, neurological deficit score, and neural cell death, was reduced by oral administration of AUY954, a selective S1P 1 modulator as a functional antagonist, in a therapeutic paradigm, indicating that S1P 1 is a pathogenic mediator rather than a neuroprotective mediator. This pathogenic role of S1P 1 in cerebral ischemia was reaffirmed because tMCAO-induced brain damage was reduced by genetic knockdown with an intracerebroventricular microinjection of S1P 1 shRNA lentivirus into the brain. Genetic knockdown of S1P 1 or AUY954 exposure reduced microglial activation, as assessed by reduction in the number of activated microglia and reversed morphology from amoeboid to ramified, and microglial proliferation in ischemic brain. Its role in microglial activation was recapitulated in lipopolysaccharide-stimulated primary mouse microglia, in which the mRNA expression level of TNF-α and IL-1β, well-known markers for microglial activation, was reduced in microglia transfected with S1P 1 siRNA. These data suggest that the pathogenic role of S1P 1 is associated with microglial activation in ischemic brain. Additionally, the pathogenic role of S1P 1 in cerebral ischemia appears to be associated with the blood-brain barrier disruption and brain-derived neurotrophic factor (BDNF) downregulation. Overall, findings from the current study clearly identify S1P 1 signaling as a pathogenic factor in transient focal cerebral ischemia, further implicating S1P 1 antagonists including functional antagonists as plausible therapeutic agents for human stroke.

Matrix metalloproteinases (MMPs) play a pivotal role in neuroinflammation that is associated with neurodegenerative diseases. Our group recently reported that MMP-8 mediates inflammatory reactions by modulating the processing of TNF-α. To improve the efficacy of the currently available MMP-8 inhibitor (M8I), we have synthesized structurally modified M8I derivatives (comp 2, 3, 4, 5) and compared their efficacy with original compound (comp 1). Among M8I derivatives, comp 2, 3, and 5 inhibited the production of NO, ROS, and IL-6 more efficiently than the original compound in lipopolysaccharide (LPS)-stimulated microglia. When we compared the anti-inflammatory mechanisms of the most effective derivative, comp 3, with comp 1, comp 3 suppressed the mRNA expression of iNOS and cytokines more efficiently than comp 1. Although comp 1 inhibits only TNF-α processing, comp 3 additionally inhibits the expression of TNF-α. Both compounds inhibited LPS-induced activity of MAP kinases, NF-κB, and AP-1, while they increased heme oxygenase-1 expression by upregulating AMPK-Nrf2 signaling. Overall, the effect of comp 3 on anti-inflammatory signaling was much stronger than comp 1. We verified the anti-inflammatory effects of comp 1 and 3 in the LPS-injected mouse brain and primary cultured astrocytes. Comp 1 and 3 suppressed microglial activation, astrogliosis, and proinflammatory gene expression in the brain. Moreover, the compounds inhibited proinflammatory gene expression in the cultured astrocytes. Collectively, our data suggest that the MMP-8 inhibitor may be a promising therapeutic agent for neuroinflammatory disorders., Competing Interests: CONFLICTS OF INTEREST The authors declare no conflicts of interest.

Microglial activation and its-driven neuroinflammation are characteristic pathogenetic features of neurodiseases, including focal cerebral ischemia. The Artemisia asiatica (Asteraceae) extract and its active component, eupatilin, are well-known to reduce inflammatory responses. But the therapeutic potential of eupatilin against focal cerebral ischemia is not known, along with its anti-inflammatory activities on activated microglia. In this study, we investigated the neuroprotective effect of eupatilin on focal cerebral ischemia through its anti-inflammation, particularly on activated microglia, employing a transient middle cerebral artery occlusion/reperfusion (tMCAO), combined with lipopolysaccharide-stimulated BV2 microglia. Eupatilin exerted anti-inflammatory responses in activated BV2 microglia, in which it reduced secretion of well-known inflammatory markers, including nitrite, IL-6, TNF-α, and PGE2, in a concentration-dependent manner. These observed in vitro effects of eupatilin led to in vivo neuroprotection against focal cerebral ischemia. Oral administration of eupatilin (10 mg/kg) in a therapeutic paradigm significantly reduced brain infarction and improved neurological functions in tMCAO-challenged mice. The same benefit was also observed when eupatilin was given even within 5 hours after MCAO induction. In addition, the neuroprotective effects of a single administration of eupatilin (10 mg/kg) immediately after tMCAO challenge persisted up to 3 days after tMCAO. Eupatilin administration reduced the number of Iba1-immunopositive cells across ischemic brain and induced their morphological changes from amoeboid into ramified in the ischemic core, which was accompanied with reduced microglial proliferation in ischemic brain. Eupatilin suppressed NF-κB signaling activities in ischemic brain by reducing IKKα/β phosphorylation, IκBα phosphorylation, and IκBα degradation. Overall, these data indicate that eupatilin is a neuroprotective agent against focal cerebral ischemia through the reduction of microglial activation., Competing Interests: The authors have no conflict of interest to declare.

Background: Lindera neesiana Kurz (Lauraceae), popularly known as Siltimur in Nepal, is an aromatic and spicy plant with edible fruits. It is a traditional herbal medicine widely used for the treatment of diarrhea, tooth pain, headache, and gastric disorders and is also used as a stimulant., Purpose: The aim of the present study was to examine in vitro cytoprotective, anti-neuroinflammatory and neuroprotective potential of an aqueous extract of L. neesiana (LNE) fruit using different central nervous system (CNS) cell lines., Methods: In order to study the neuroprotective potential of LNE, we used three different types of CNS cell lines: murine microglia (BV2), rat glioma (C6), and mouse neuroblastoma (N2a). Cell viability was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reagent, and prostaglandin E2 (PGE2), tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, and nerve growth factor (NGF) release in the culture media was determined using enzyme linked immunosorbent assay (ELISA) kits. Western blot analysis was performed to determine the protein expression of inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX2), mitogen activated protein kinase (MAPK) family proteins, Bax, B cell lymphoma (BCL)-2, and cleaved caspase 3. Neurite outgrowth was determined using the IncuCyte imaging system., Results: LNE treatment not only reduced nitric oxide (NO) production in a dose-dependent manner, but also significantly reduced proinflammatory cytokines, iNOS and COX-2 production by lipopolysaccharide (LPS) stimulated BV-2 cells. LNE increased the expression of phosphorylated (p)-extracellular signal-regulated kinase (ERK), whereas p-p38 and p- janus kinase (JNK) expression was significantly decreased in activated microglia. Furthermore, LNE increased cell viability of N2a cells, which was accompanied by decreased caspase-3 expression and the ratio of Bax/Bcl2 protein expression as well as increased NGF and neurite outgrowth, suggesting its neuroprotective potential against LPS-induced effects. Additionally, LNE substantially increased nuclear factor erythroid 2-related factor 2 (Nrf2) secretion in N2a cells and inhibited lipid dehydrogenase (LDH) release in H2O2-stimulated BV2 cells demonstrating the strong anti-inflammatory and antioxidant effects of LNE in CNS cell lines., Conclusion: Here we found that water the soluble extract of LNE has promising anti-neuroinflammation and anti-apoptotic properties and identify LNE as a potential natural candidate for neuroprotection., (Copyright © 2016. Published by Elsevier GmbH.)

Paradols are non-pungent and biotransformed metabolites of shogaols and reduce inflammatory responses as well as oxidative stress as shogaols. Recently, shogaol has been noted to possess therapeutic potential against several central nervous system (CNS) disorders, including cerebral ischemia, by reducing neuroinflammation in microglia. Therefore, paradol could be used to improve neuroinflammation-associated CNS disorders. Here, we synthesized paradol derivatives (2- to 10-paradols). Through the initial screening for anti-inflammatory activities using lipopolysaccharide (LPS)-stimulated BV2 microglia, 6-paradol was chosen to be the most effective compound without cytotoxicity. Pretreatment with 6-paradol reduced neuroinflammatory responses in LPS-stimulated BV2 microglia by a concentration-dependent manner, which includes reduced NO production by inhibiting iNOS upregulation and lowered secretion of proinflammatory cytokines (IL-6 and TNF-α). To pursue whether the beneficial in vitro effects of 6-paradol leads towards in vivo therapeutic effects on transient focal cerebral ischemia characterized by neuroinflammation, we employed middle cerebral artery occlusion (MCAO)/reperfusion (M/R). Administration of 6-paradol immediately after reperfusion significantly reduced brain damage in M/R-challenged mice as assessed by brain infarction, neurological deficit, and neural cell survival and death. Furthermore, as observed in cultured microglia, 6-paradol administration markedly reduced neuroinflammation in M/R-challenged brains by attenuating microglial activation and reducing the number of cells expressing iNOS and TNF-α, both of which are known to be produced in microglia following M/R challenge. Collectively, this study provides evidences that 6-paradol effectively protects brain after cerebral ischemia, likely by attenuating neuroinflammation in microglia, suggesting it as a potential therapeutic agent to treat cerebral ischemia.

Phyllanthus emblica L. (syn. Emblica officinalis) is commonly known as Indian gooseberry. In Ayurveda, P. emblica has been extensively used, both as edible (tonic) plants and for its therapeutic potentials. P. emblica is highly nutritious and is reported as an important dietary source of vitamin C, minerals and amino acids. All parts of the plant are used for medicinal purposes, especially the fruit, which has been used in Ayurveda as a potent Rasayana (rejuvenator). P. emblica contains phytochemicals including fixed oils, phosphatides, essential oils, tannins, minerals, vitamins, amino acids, fatty acids, glycosides, etc. Various pharmaceutical potential of P. emblica has been reported previously including antimicrobial, antioxidant, anti-inflammatory, analgesic and antipyretic, adaptogenic, hepatoprotective, antitumor and antiulcerogenic activities either in combined formulation or P. emblica alone. The various other Ayurvedic potentials of P. emblica are yet to be proven scientifically in order to explore its broad spectrum of therapeutic effects. On this regards we, in this review, tried to explore the complete information of P. emblica including its pharmacognosy, phytochemistry and pharmacology.

Scutellaria baicalensis Georgi is the most widely used medicinal plant in traditional Eastern medicine, especially in Chinese medicine. The major phytochemicals isolated from S. baicalensis are flavonoids, glycosides and their glucoronides such as baicalin, baicalein, wogonin etc. More than 30 different kinds of flavonoids are isolated from this plant. S. baicalensis and its flavonoids are reported to have several pharmacological activities, which includes anti-allergic, antioxidant, anti apoptic, anti-inflammatory effects and many more. Recently, S. baicalensis and its isolated flavonoids have been studied for their neuroprotective effects, through a variety of in vitro and in vivo models of neurodegenerative diseases, plausibly suggesting that S. baicalensis has salutary effect as a nature's blessing for neuroprotection. In this review, we are focousing on the neuroprotective effects of S. baicalensis and its flavonoids in ischemia or stroke-induced neuronal cell death. We aimed at compiling all the information regarding the neuroprotective effect of S. baicalensis in various experimental models of cerebral ischemia or stroke.

Objective: To investigate the neuroprotective effects of Fructus Chebulae extract using both in vivo and in vitro models of cerebral ischemia., Methods: As an in vitro model, oxygen glucose deprivation followed by reoxygenation (OGD-R) and hydrogen peroxide (H2O2) induced cellular damage in rat pheochromocytoma (PC12) cells was used to investigate the neuroprotective effects of extract of Fructus Chebulae. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to calculate cell survival. For in vivo, occlusion of left middle cerebral artery on rats was carried out as a focal cerebral ischemic model., Results: Fructus Chebulae extract increases the PC12 cell survival against OGD-R and H2O2 by 68% and 91.4% respectively. Fructus Chebulae also decreases the cerebral infarct volume by 39% and extent of hemisphere swelling from 17% in control group to 10% in Fructus Chebulae treated group., Conclusion: Fructus Chebulae, as a traditional medicine, can rescue the neuronal cell death against ischemia related damage. The possible mechanism for the neuroprotection might be the inhibition of oxidative damages occurring after acute phase of cerebral ischemia.

Terminalia chebula, native to Southeast Asia, is a popular medicinal plant in Ayurveda. It has been previously reported to have strong antioxidant and anti-inflammatory efficacy. In this study, we aimed to investigate if fruit extract from T. chebula might protect neuronal cells against ischemia and related diseases by reduction of oxidative damage and inflammation in rat pheochromocytoma cells (PC12) using in vitro oxygen-glucose deprivation followed by reoxygenation (OGD-R) ischemia and hydrogen peroxide (H2O2) induced cell death. Cell survival was evaluated by a 2-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Free radical scavenging, lipid peroxidation and nitric oxide inhibition were measured by diphenyl-1-picrylhydrazyl (DPPH), thiobarbituric acid (TBA) and Griess reagent, respectively. We found that T. chebula extract: (1) increases the survival of cells subjected to OGD-R by 68%, and H2O2 by 91.4%; (2) scavenges the DPPH free radical by 96% and decreases malondialdehyde (MDA) levels from 237.0 ± 15.2% to 93.7 ± 2.2%; (3) reduces NO production and death rate of microglia cells stimulated by lipopolysaccharide (LPS). These results suggest that T. chebula extract has the potential as a natural herbal medicine, to protect the cells from ischemic damage and the possible mechanism might be the inhibition of oxidative and inflammatory processes.

Datura stramonium L., a wild-growing plant of the Solanaceae family, is widely distributed and easily accessible. It contains a variety of toxic tropane alkaloids such as atropine, hyoscamine, and scopolamine. In Eastern medicine, especially in Ayurvedic medicine, D. stramonium has been used for curing various human ailments, including ulcers, wounds, inflammation, rheumatism and gout, sciatica, bruises and swellings, fever, asthma and bronchitis, and toothache. A few previous studies have reported on the pharmacological effects of D. stramonium; however, complete information regarding the pharmacology, toxicity, ethnobotany and phytochemistry remains unclear. Ethnomedicinally, the frequent recreational abuse of D. stramonium has resulted in toxic syndromes. D. stramonium, in the form of paste or solution to relieve the local pain, may not have a deleterious effect; however, oral and systemic administration may lead to severe anticholinergic symptoms. For this reason, it is very important for individuals, mainly young people, to be aware of the toxic nature and potential risks associated with the use of this plant. This comprehensive review of D. stramonium includes information on botany, phytochemistry, pharmacology, toxicology and ethnomedicinal uses.

This study evaluated the anti-obesity effects of HT048, a combination of C. pinnatifida fruit and C. unshiu peel extracts, in high-fat diet (HFD)-induced obese rats. 4-Week-old male Sprague Dawley (SD) rats were divided into normal and high fat diet (HFD) groups. The HFD groups were further divided into five groups treated with distilled water, orlistat (40 mg/kg, twice daily, p.o) and HT048 (30, 100 and 300 mg/kg, twice daily, p.o.) for 12 weeks. Orlistat, an anti-obesity drug, was used as positive control in the HFD-induced obese rats. We measured the food intake, body weight, epididymal adipose tissue and liver weights, and serum total cholesterol (TC), triglyceride (TG), alanine transaminase (ALT), and aspartate aminotransferase (AST) levels. The body weight and epididymal adipose tissue and liver weights of the HT048 100 and 300 mg/kg treated groups were significantly lower than that of the HFD control group. Also, serum TC, TG, ALT, and AST levels in the HT048 100 and 300 mg/kg treated groups were significantly decreased. Moreover, the orlistat treated group showed significantly reduced body weight and improved serum lipoprotein, compared with the HFD control group. These results show that HT048 supplements improved obesity-related body weight and serum lipoprotein parameters in a HFD-induced obese rat model.