Neuroprotection of Neuro2a cells and the cytokine suppressive and anti-inflammatory mode of action of resveratrol in activated RAW264.7 macrophages and C8-B4 microglia

Anti-inflammatory potential of aspergillus unguis SP51-EGY: TLR4-dependent effects & chemical diversity via Q-TOF LC-HRMS

Inflammation serves as an intricate defense mechanism for tissue repair. However, overactivation of TLR4-mediated inflammation by lipopolysaccharide (LPS) can lead to detrimental outcomes such as sepsis, acute lung injury, and chronic inflammation, often associated with cancer and autoimmune diseases. This study delves into the anti-inflammatory properties of "Aspergillus unguis isolate SP51-EGY" on LPS-stimulated RAW 264.7 macrophages. Through real-time qPCR, we assessed the expression levels of pivotal inflammatory genes, including iNOS, COX-2, TNF-α, and IL-6. Remarkably, our fungal extracts significantly diminished NO production and showed noteworthy reductions in the mRNA expression levels of the aforementioned genes. Furthermore, while Nrf2 is typically associated with modulating inflammatory responses, our findings indicate that the anti-inflammatory effects of our extracts are not Nrf2-dependent. Moreover, the chemical diversity of the potent extract (B Sh F) was elucidated using Q-TOF LC-HRMS, identifying 54 compounds, some of which played vital roles in suppressing inflammation. Most notably, compounds like granisetron, fenofibrate, and umbelliprenin were found to downregulate TNF-α, IL-1β, and IL-6 through the NF-κB signaling pathway. In conclusion, "Aspergillus unguis isolate SP51-EGY", isolated from the Red Sea, Egypt, has been unveiled as a promising TLR4 inhibitor with significant anti-inflammatory potentials, presenting novel insights for their potential therapeutic use in inflammation.

Progress in the Treatment of Central Nervous System Diseases Based on Nanosized Traditional Chinese Medicine

Traditional Chinese Medicine (TCM) is widely used in clinical practice to treat diseases related to central nervous system (CNS) damage. However, the blood-brain barrier (BBB) constitutes a significant impediment to the effective delivery of TCM, thus substantially diminishing its efficacy. Advances in nanotechnology and its applications in TCM (also known as nano-TCM) can deliver active ingredients or components of TCM across the BBB to the targeted brain region. This review provides an overview of the physiological and pathological mechanisms of the BBB and systematically classifies the common TCM used to treat CNS diseases and types of nanocarriers that effectively deliver TCM to the brain. Additionally, drug delivery strategies for nano-TCMs that utilize in vivo physiological properties or in vitro devices to bypass or cross the BBB are discussed. This review further focuses on the application of nano-TCMs in the treatment of various CNS diseases. Finally, this article anticipates a design strategy for nano-TCMs with higher delivery efficiency and probes their application potential in treating a wider range of CNS diseases.

Alzheimer, Parkinson, dementia, and phytochemicals: insight review

Alzheimer's, Parkinson's, and dementia are the leading neurodegenerative diseases that threaten the world with the aging population. Although the pathophysiology of each disease is unique, the steps to be taken to prevent diseases are similar. One of the changes that a person can make alone is to gain the habit of an antioxidant-rich diet. Phytochemicals known for their antioxidant properties have been reported to prevent neurodegenerative diseases in various studies. Phytochemicals with similar chemical structures are grouped. Accordingly, there are two main groups of phytochemicals, flavonoid and non-flavonoid. Various in vitro and in vivo studies on phytochemicals have proven neuroprotective effects by increasing cognitive function with their anti-inflammatory and antioxidant mechanisms. The purpose of this review is to summarize the in vitro and in vivo studies on phytochemicals with neuroprotective effects and to provide insight.

Natural bioactive compounds in Alzheimer's disease: From the perspective of type 3 diabetes mellitus

There is a close relationship between Alzheimer's disease (AD) and diabetes mellitus (DM), and the link between the two is often referred to as type 3 diabetes mellitus (T3DM). Many natural bioactive compounds have shown the potential to treat AD and diabetes. We mainly review the polyphenols represented by resveratrol (RES) and proanthocyanidins (PCs) and alkaloids represented by berberine (BBR) and Dendrobium nobile Lindl. alkaloids (DNLA) from the perspective of T3DM to review the neuroprotective effects and molecular mechanisms of natural compounds in AD.

Neuronutraceuticals Combating Neuroinflammaging: Molecular Insights and Translational Challenges—A Systematic Review

Neuropathologies, such as neuroinflammaging, have arisen as a serious concern for preserving the quality of life due to the global increase in neurodegenerative illnesses. Nowadays, neuronutraceuticals have gained remarkable attention. It is necessary to investigate the bioavailability, off-target effects, and mechanism of action of neuronutraceuticals. To comprehend the comprehensive impact on brain health, well-designed randomized controlled trials testing combinations of neuronutraceuticals are also necessary. Although there is a translational gap between basic and clinical research, the present knowledge of the molecular perspectives of neuroinflammaging and neuronutraceuticals may be able to slow down brain aging and to enhance cognitive performance. The present review also highlights the key emergent issues, such as regulatory and scientific concerns of neuronutraceuticals, including bioavailability, formulation, blood–brain permeability, safety, and efficacy.

Ethanolic Fruit Extract of Emblica officinalis Suppresses Neuroinflammation in Microglia and Promotes Neurite Outgrowth in Neuro2a Cells

Inhibiting neuroinflammation and modulating neurite outgrowth could be a promising strategy to prevent neurological disorders. Emblica officinalis (EO) may be a potent agent against them. Although EO extract reportedly has anti-inflammatory properties in macrophages, there is limited knowledge about its neuroprotective activity by suppressing microglia-mediated proinflammatory cytokine production and inducing neurite outgrowth. The present study aimed to elucidate the effect of EO fruit extract on the lipopolysaccharide- (LPS-) induced neuroinflammation using microglial (BV2) and neuroblastoma (Neuro2a) cells. The results demonstrated that, in LPS-treated BV2 cells, EO fruit extract reduced nitric oxide, interleukin-6, and tumor necrotic factor-α production. It also enhanced the neurite length of Neuro2a cells, which was linked to the upregulation of TuJ1 and MAP2 expressions. In conclusion, these findings indicate that the ethanolic extract of EO fruits has promising neuroprotective potential to exhibit antineuroinflammation activity and accelerative effect on neurite outgrowth in vitro. Therefore, EO fruit extract can be considered a novel herbal medicine candidate for managing neuroinflammatory diseases.

Microglial TREM2 Mitigates Inflammatory Responses and Neuronal Apoptosis in Angiotensin II-Induced Hypertension in Middle-Aged Mice

Growing evidence suggests that hypertension and aging are prominent risk factors for the development of late-onset Alzheimer's disease (LOAD) by inducement of neuroinflammation. Recent study showed that neuroinflammation via activated microglia induces reactive astrocytes, termed A1 astrocytes, that highly upregulate numerous classical complement cascade genes that are destructive to neurons in neurodegeneration diseases. Moreover, triggering receptor expressed on myeloid cells 2 (TREM2) is considered as one of the strongest single-allele genetic risk factors and plays important roles in neuroinflammation for LOAD. However, the mechanisms of microglia in the regulation of A1 astrocytic activation are still not clear. We introduced angiotensin II-induced hypertension in middle-aged mice and found that hypertension-upregulated TREM2 expression and A1 astrocytic activation were involved in neuroinflammation in the animal models used in this study. The in vitro results revealed that overexpression of microglial TREM2 not only mitigated microglial inflammatory response but also had salutary effects on reverse A1 astrocytic activation and neuronal toxicity.

The neuroprotective effects of polyphenols, their role in innate immunity and the interplay with the microbiota

Neurodegenerative disorders, particularly in the elderly population, represent one of the most pressing social and health-care problems in the world. Besides the well-established role of both oxidative stress and inflammation, alterations of the immune response have been found to be closely linked to the development of neurodegenerative diseases. Interestingly, various scientific evidence reported that an altered gut microbiota composition may contribute to the development of neuroinflammatory disorders. This leads to the proposal of the concept of the gut-brain-immune axis. In this scenario, polyphenols play a pivotal role due to their ability to exert neuroprotective, immunomodulatory and microbiota-remodeling activities. In the present review, we summarized the available literature to provide a scientific evidence regarding this neuroprotective and immunomodulatory effects and the interaction with gut microbiota of polyphenols and, the main signaling pathways involved that can explain their potential therapeutic application in neurodegenerative diseases.

Therapeutic Opportunities for Food Supplements in Neurodegenerative Disease and Depression

Emerging evidence is showing nutrition as a crucial factor in the high prevalence and incidence of neurodegenerative mental disorders. Preventive interventions on neuroinflammation seem to be able to interfere with neurodegeneration. Supplementation of essential nutrients, such as long-chain-polyunsaturated fatty acids, vitamin E and mineral elements, may minimize inflammation, enhancing antioxidative defense, and lowering the risk and incidence of age-related diseases, such as cardiovascular diseases and neurodegenerative diseases. This manuscript reviews the current evidence on the role of neuroinflammation in the pathophysiology of neurodegenerative and mental disorders, and preventive strategies for food supplementation in these neuropsychiatric diseases. Dietary supplementation-based strategies have been demonstrated to be effective in subjects with mild cognitive impairment, while weaker results have been obtained in patients with advance neurodegenerative disease. Adjunctive supplementation has also been demonstrated to improve depression, this being of marked benefit considering the comorbidity between cognitive impairment/dementia and depression. Further research is needed to improve the prescriptive precision of supplementation in patients, and to better understand potential interactions with clinical and pharmacokinetic factors.

The role of nutrition in space exploration: Implications for sensorimotor, cognition, behavior and the cerebral changes due to the exposure to radiation, altered gravity, and isolation/confinement hazards of spaceflight

Multi-year crewed space exploration missions are now on the horizon; therefore, it is important that we understand and mitigate the physiological effects of spaceflight. The spaceflight hazards-radiation, isolation, confinement, and altered gravity-have the potential to contribute to neuroinflammation and produce long-term cognitive and behavioral effects-while the fifth hazard, distance from earth, limits capabilities to mitigate these risks. Accumulated evidence suggests that nutrition has an important role in optimizing cognition and reducing the risk of neurodegenerative diseases caused by neuroinflammation. Here we review the nutritional perspective of how these spaceflight hazards affect the astronaut's brain, behavior, performance, and sensorimotor function. We also assess potential nutrient/nutritional countermeasures that could prevent or mitigate spaceflight risks and ensure that crewmembers remain healthy and perform well during their missions. Just as history has taught us the importance of nutrition in terrestrial exploration, we must understand the role of nutrition in the development and mitigation of spaceflight risks before humans can successfully explore beyond low-Earth orbit.

New Deoxyisoaustamide Derivatives from the Coral-Derived Fungus Penicillium dimorphosporum KMM 4689

Seven new deoxyisoaustamide derivatives (1-7) together with known compounds (8-10) were isolated from the coral-derived fungus Penicillium dimorphosporum KMM 4689. Their structures were established using spectroscopic methods, X-ray diffraction analysis and by comparison with related known compounds. The absolute configurations of some alkaloids were determined based on CD and NOESY data as well as biogenetic considerations. The cytotoxic and neuroprotective activities of some of the isolated compounds were examined and structure-activity relationships were pointed out. New deoxyisoaustamides 4-6 at concentration of 1 µM revealed a statistical increase of PQ(paraquat)-treated Neuro-2a cell viability by 30-39%.

Signaling mechanisms underlying inhibition of neuroinflammation by resveratrol in neurodegenerative diseases

Neurodegenerative diseases (NDs), including Alzheimer's disease (AD), and Parkinson's disease (PD), are characterized by the progressive loss of the structure and function of neurons and most commonly occur in the elderly population. Microglia are resident macrophages of the central nervous system (CNS). The neuroinflammation caused by excessive microglial activation is closely related to the onset and progression of many NDs. Therefore, inhibiting excessive microglial activation is a potential drug target for controlling neuroinflammation. In recent years, natural products as modulators of microglial polarization have attracted considerable attention in the field of NDs therapy. Furthermore, resveratrol (RES) has been found to have a protective effect in NDs through the inhibition of microglial activation and the regulation of neuroinflammation. In this review, we mainly summarize the therapeutic potential of RES and its various molecular mechanisms in the treatment of NDs through the modulation of microglial activation.

Combined Treatment with Fasudil and Menthol Improves Functional Recovery in Rat Spinal Cord Injury Model

Neuroprotective measures by preventing secondary spinal cord injury (SCI) are one of the main strategies for repairing an injured spinal cord. Fasudil and menthol may be potent neuroprotective agents, which act by inhibiting a rho-associated protein kinase (ROCK) and suppressing the inflammatory response, respectively. We hypothesized that combined treatment of fasudil and menthol could improve functional recovery by decreasing inflammation, apoptosis, and glial scar formation. We tested our hypothesis by administering fasudil and menthol intraperitoneally (i.p.) to female Sprague Dawley rats after moderate static compression (35 g of impounder for 5 min) of T10 spinal cord. The rats were randomly divided into five experimental groups: (i) sham animals received laminectomy alone, (ii) injured (SCI) and untreated (saline 0.2 mL/day, i.p.) rats, (iii) injured (SCI) rats treated with fasudil (10 mg/kg/day, i.p.) for two weeks, (iv) injured (SCI) rats treated with menthol (10 mg/kg/day, i.p.) for twoweeks, (v) injured (SCI) rats treated with fasudil (5 mg/kg/day, i.p.) and menthol (10 mg/kg/day, i.p.) for two weeks. Compared to single treatment groups, combined treatment of fasudil and menthol demonstrated significant functional recovery and pain amelioration, which, thereby, significantly reduced inflammation, apoptosis, and glial/fibrotic scar formation. Therefore, combined treatment of fasudil and menthol may provide effective amelioration of spinal cord dysfunction by a synergistic effect of fasudil and menthol.

Biologically Active Echinulin-Related Indolediketopiperazines from the Marine Sediment-Derived Fungus Aspergillus niveoglaucus

Seven known echinulin-related indolediketopiperazine alkaloids (1–7) were isolated from the Vietnamese sediment-derived fungus Aspergillus niveoglaucus. Using chiral HPLC, the enantiomers of cryptoechinuline B (1) were isolated as individual compounds for the first time. (+)-Cryptoechinuline B (1a) exhibited neuroprotective activity in 6-OHDA-, paraquat-, and rotenone-induced in vitro models of Parkinson’s disease. (−)-Cryptoechinuline B (1b) and neoechinulin C (5) protected the neuronal cells against paraquat-induced damage in a Parkinson’s disease model. Neoechinulin B (4) exhibited cytoprotective activity in a rotenone-induced model, and neoechinulin (7) showed activity in the 6-OHDA-induced model.

DC and AC magnetic fields increase neurite outgrowth of SH-SY5Y neuroblastoma cells with and without retinoic acid

It has been suggested that electromagnetic fields could be used to differentiate neurons in culture but how to do this is not clear. We investigated the effect of external magnetic fields (DC and AC MF) on neuronal viability, differentiation, and neurite outgrowth of human SH-SY5Y neuroblastoma cells in vitro. A strong low frequency DC MF or a weak AC MF improved retinoic acid-mediated neuronal differentiation and increased neurite length, without any adverse effects on neuronal viability. Even in the absence of the conventional differentiation factor, retinoic acid, DC and AC MF promoted neurite outgrowth. No significant negative effect on cell viability was observed after MF exposure and the DC MF had greater effects on neurite length and branch number than AC MF. Thus, we have identified a novel, simple and cost-effective method that is easy to set up in any cell culture laboratory that can be used to efficiently differentiate neuronal-like cells, using a DC MF without the need for expensive reagents. This research provides a fresh approach to promote neurite outgrowth in a commonly used neuronal-like cell line model and may be applicable to neural stem cells or primary neurons.

Targeting Inflammatory Pathways in Alzheimer's Disease: A Focus on Natural Products and Phytomedicines

Studies of the brains of Alzheimer's disease (AD) patients have revealed key neuropathological features, such as the deposition of aggregates of insoluble amyloid-β (Aβ) peptides and neurofibrillary tangles (NFTs). These pathological protein deposits, including Aβ peptides (which form senile plaques) and hyperphosphorylated tau (which aggregates into NFTs), have been assumed to be 'the cause of AD'. Aβ has been extensively targeted to develop an effective disease-modifying therapy, but with limited clinical success. Emerging therapies are also now targeting further pathological processes in AD, including neuroinflammation. This review focuses on the inflammatory and oxidative stress-related changes that occur in AD, and discusses some emerging anti-inflammatory natural products and phytomedicines. Many of the promising compounds are cytokine-suppressive anti-inflammatory drugs (CSAIDs), which target the proinflammatory AP1 and nuclear factor-κB signalling pathways and inhibit the expression of many proinflammatory cytokines, such as interleukin (IL)-1, IL-6, tumour necrosis factor-α, or nitric oxide produced by inducible nitric oxide synthase. However, many of these phytomedicines have not been tested in rigorous clinical trials in AD patients. It is not yet clear if the active compounds reach an effective concentration in the brain (due to limited bioavailability) or if they can slow down AD progression in long-term trials. The authors suggest that it is crucial for both the pharmacological and complementary medicine industries to conduct and fund those studies to significantly advance the field.

Effects of Carbazole Derivatives on Neurite Outgrowth and Hydrogen Peroxide-Induced Cytotoxicity in Neuro2a Cells

Many studies have demonstrated that oxidative stress plays an important role in several ailments including neurodegenerative diseases and cerebral ischemic injury. Previously we synthesized some carbazole compounds that have anti-oxidant ability in vitro. In this present study, we found that one of these 22 carbazole compounds, compound 13 (3-ethoxy-1-hydroxy-8- methoxy-2-methylcarbazole-5-carbaldehyde), had the ability to protect neuro2a cells from hydrogen peroxide-induced cell death. It is well known that neurite loss is one of the cardinal features of neuronal injury. Our present study revealed that compound 13 had the ability to induce neurite outgrowth through the PI3K/Akt signaling pathway in neuro2a cells. These findings suggest that compound 13 might exert a neurotrophic effect and thus be a useful therapy for the treatment of brain injury.

Adenosine receptors as a new target for resveratrol-mediated glioprotection

Resveratrol, a natural polyphenolic compound, has been studied as a neuroprotective molecule. Our group has demonstrated that such effect is closely associated with modulation of glial functionality, but the underlying mechanisms are not fully understood. Because astrocytes actively participate in the brain inflammatory response, and activation of adenosine receptors can attenuate inflammatory processes, the aim of this study was to investigate the role of adenosine receptors as a mechanism for resveratrol glioprotection, particularly regarding to neuroinflammation. Therefore, primary astrocyte cultures were co-incubated with resveratrol and selective antagonists of A₁, A_2A, and A₃ adenosine receptors, as well as with caffeine (a non-selective adenosine receptor antagonist), and then challenged with bacterial inflammogen lipopolysaccharide (LPS). Caffeine and selective adenosine receptor antagonists abolished the anti-inflammatory effect of resveratrol. In accordance with these effects, resveratrol prevented LPS-induced decrease in mRNA levels of adenosine receptors. Resveratrol could also prevent the activation of pro-inflammatory signaling pathways, such as nuclear factor κB (NFκB) and p38 mitogen-activated protein kinase (p38 MAPK) in a mechanism dependent on adenosine receptors. Conversely, trophic factors and protective signaling pathways, including sirtuin 1 (SIRT1), nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and phosphoinositide 3-kinase (PI3K)/Akt were positively modulated by resveratrol in both LPS-stimulated and unstimulated astrocytes, but adenosine receptor antagonism did not abrogate all effects of resveratrol. To our knowledge, our data provide the first evidence that adenosine receptors are involved in the anti-inflammatory activity of resveratrol in astrocytes, thus exerting an important role for resveratrol-mediated glioprotection.

Phenolic Compounds Characteristic of the Mediterranean Diet in Mitigating Microglia-Mediated Neuroinflammation

Neuroinflammation is a pathological feature of quite a number of Central Nervous System diseases such as Alzheimer and Parkinson's disease among others. The hallmark of brain neuroinflammation is the activation of microglia, which are the immune resident cells in the brain and represents the first line of defense when injury or disease occur. Microglial activated cells can adopt different phenotypes to carry out its diverse functions. Thus, the shift into pro-inflammatory/neurotoxic or anti-inflammatory/neuroprotective phenotypes, depending of the brain environment, has totally changed the understanding of microglia in neurodegenerative disease. For this reason, novel therapeutic strategies which aim to modify the microglia polarization are being developed. Additionally, the understanding of how nutrition may influence the prevention and/or treatment of neurodegenerative diseases has grown greatly in recent years. The protective role of Mediterranean diet (MD) in preventing neurodegenerative diseases has been reported in a number of studies. The Mediterranean dietary pattern includes as distinctive features the moderate intake of red wine and extra virgin olive oil, both of them rich in polyphenolic compounds, such as resveratrol, oleuropein and hydroxytyrosol and their derivatives, which have demonstrated anti-inflammatory effects on microglia on in vitro studies. This review summarizes our understanding of the role of dietary phenolic compounds characteristic of the MD in mitigating microglia-mediated neuroinflammation, including explanation regarding their bioavailability, metabolism and blood-brain barrier.

Metabolic Enhancer Piracetam Attenuates the Translocation of Mitochondrion-Specific Proteins of Caspase-Independent Pathway, Poly [ADP-Ribose] Polymerase 1 Up-regulation and Oxidative DNA Fragmentation

Piracetam, a nootropic drug, has been clinically used for decades; however, its mechanism of action still remains enigmatic. The present study was undertaken to evaluate the role of mitochondrion-specific factors of caspase-independent pathway like apoptotic-inducing factor (AIF) and endonuclease-G (endo-G) in piracetam-induced neuroprotection. N2A cells treated with lipopolysaccharide (LPS) exhibited significant cytotoxicity, impaired mitochondrial activity, and reactive oxygen species generation which was significantly attenuated with piracetam co-treatment. Cells co-treated with LPS and piracetam exhibited significant uptake of piracetam in comparison to only piracetam-treated cells as estimated by liquid chromatography-mass spectrometry (LC-MSMS). LPS treatment caused significant translocation of AIF and endonuclease-G in neuronal N2A cells which were significantly attenuated with piracetam co-treatment. Significant over-expression of proinflammatory cytokines was also observed after treatment of LPS to cells which was inhibited with piracetam co-treatment demonstrating its anti-inflammatory property. LPS-treated cells exhibited significant oxidative DNA fragmentation and poly [ADP-ribose] polymerase-1 (PARP-1) up-regulation in nucleus, both of which were attenuated with piracetam treatment. Antioxidant melatonin but not z-VAD offered the inhibited LPS-induced DNA fragmentation indicating the involvement of oxidative DNA fragmentation. Further, we did not observe the altered caspase-3 level after LPS treatment initially while at a later time point, significantly augmented level of caspase-3 was observed which was not inhibited with piracetam treatment. In total, our findings indicate the interference of piracetam in mitochondrion-mediated caspase-independent pathway, as well as its anti-inflammatory and antioxidative properties. Graphical Abstract Graphical abstract indicating the novel interference of metabolic enhancer piracetam (P) in neuronal death mechanisms.

Resveratrol-decreased hyperalgesia mediated by the P2X7 receptor in gp120-treated rats

Background

Chronic pain is a common symptom in human immunodeficiency virus (HIV)-1 infection/acquired immunodeficiency syndrome patients. The literature shows that the HIV envelope glycoprotein 120 (gp120) can directly cause hyperalgesia by stimulating primary sensory afferent nerves. The P2X₇ receptor in the dorsal root ganglia (DRG) is closely related to neuropathic and inflammatory pain. In this study, we aimed to explore the effect of resveratrol (RES) on gp120-induced neuropathic pain that is mediated by the P2X₇ receptor in the rat DRG.

Results

Mechanical hyperalgesia in rats treated with gp120 was increased compared with that in the sham group. The P2X₇ expression levels in rats treated with gp120 were higher than those in the sham group. Co-localization of the P2X₇ receptor and glial fibrillary acidic protein (GFAP, a marker of satellite glial cells [SGCs]) in the DRG SGCs of the gp120 group exhibited more intense staining than that of the sham group. RES decreased the mechanical hyperalgesia and P2X₇ expression levels in gp120 treatment rats. Co-localization of the P2X₇ receptor and GFAP in the gp120+ RES group was significantly decreased compared to the gp120 group. RES decreased the IL-1β and TNF-α receptor (R) expression levels and ERK1/2 phosphorylation levels as well as increased IL-10 expression in the DRG of gp120-treated rats. Whole cell clamping demonstrated that RES significantly inhibited adenosine triphosphate-activated currents in HEK293 cells that were transfected with the P2X₇ plasmid.

Conclusions

RES relieved mechanical hyperalgesia in gp120-treated rats by inhibiting the P2X₇ receptor.

Antineuroinflammation of Minocycline in Stroke

Accumulating research substantiates the statement that inflammation plays an important role in the development of stroke. Both proinflammatory and anti-inflammatory mediators are involved in the pathogenesis of stroke, an imbalance of which leads to inflammation. Anti-inflammation is a kind of hopeful strategy for the prevention and treatment of stroke. Substantial studies have demonstrated that minocycline, a second-generation semisynthetic antibiotic belonging to the tetracycline family, can inhibit neuroinflammation, inflammatory mediators and microglia activation, and improve neurological outcome. Experimental and clinical data have found the preclinical and clinical potential of minocycline in the treatment of stroke due to its anti-inflammation properties and anti-inflammation-induced pathogeneses, including antioxidative stress, antiapoptosis, inhibiting leukocyte migration and microglial activation, and decreasing matrix metalloproteinases activity. Hence, it suggests a great future for minocycline in the therapeutics of stroke that diminish the inflammatory progress of stroke.

Separation of caffeoylquinic acids and flavonoids from Asteris souliei by high-performance counter-current chromatography and their anti-inflammatory activity in vitro

Eleven compounds were successfully separated from Asteris souliei by using a two-step high-performance counter-current chromatography method. The first step involved a reversed phase isocratic counter-current chromatography separation using hexane/ethyl acetate/methanol/water (1:0.8:1:1 v/v/v/v), which produced three fractions, the first two of which were mixtures. The second step used step-gradient reversed-phase counter-current chromatography with hexane/butanol/ethyl acetate/methanol/water (1:0.5:3.5:1:4 v/v/v/v/v) initially followed by hexane/ethyl acetate/methanol/water (1:2:1:2 v/v/v/v) to separate Fraction 1 into seven compounds; and hexane/ethyl acetate/methanol/water (1:1:1:1.2 v/v/v/v) to separate Fraction 2 into three further compounds. The chemical structures of the separated compounds were identified by ESI-MS and NMR spectroscopy (¹ H and ¹³ C). Baicalin (5), eriodictyol (7), apigenin-7-glycoside (8), quercetin (9), luteolin (10), and apigenin (11) showed obvious inhibitory effects on lipopolysaccharide-induced nitric oxide production in RAW264.7 cells at a concentration of 10 μg/mL.

Resveratrol inhibits LPS-induced mice mastitis through attenuating the MAPK and NF-κB signaling pathway

Resveratrol is a natural polyphenol extracted from mangy plants. It has been reported that resveratrol show multitudinous positive role in biology such as anti-oxidant, anti-nociception and anti-inflammatory effects. Therefore, the present study devotes to test the effect of resveratrol on LPS-induced mastitis in mice. Resveratrol was administered intraperitoneally 1 h before LPS treatment. And the anti-inflammatory effect of resveratrol was measured by histopathological examination, MPO assay, real-time PCR and western blotting analysis. The results showed that resveratrol significantly reduced the LPS-induced mammary histopathological changes. Meanwhile, it sharply attenuated the activity of MPO. The result also indicated that the resveratrol can decrease the expression of pro-inflammatory cytokines TNF-α and IL-1β. From the results of western blotting, resveratrol suppressed the expression of phosphorylation of p65 and IκB from NF-κB signal pathway and phosphorylation of p38 and ERK from MAPK signal pathway. These findings suggested that resveratrol may inhibit the inflammatory response in the mastitis.

Medicinal Plants of the Australian Aboriginal Dharawal People Exhibiting Anti-Inflammatory Activity

Chronic inflammation contributes to multiple ageing-related musculoskeletal and neurodegenerative diseases, cardiovascular diseases, asthma, rheumatoid arthritis, and inflammatory bowel disease. More recently, chronic neuroinflammation has been attributed to Parkinson's and Alzheimer's disease and autism-spectrum and obsessive-compulsive disorders. To date, pharmacotherapy of inflammatory conditions is based mainly on nonsteroidal anti-inflammatory drugs which in contrast to cytokine-suppressive anti-inflammatory drugs do not influence the production of cytokines such as tumour necrosis factor-α or nitric oxide. However, their prolonged use can cause gastrointestinal toxicity and promote adverse events such as high blood pressure, congestive heart failure, and thrombosis. Hence, there is a critical need to develop novel and safer nonsteroidal anti-inflammatory drugs possessing alternate mechanism of action. In this study, plants used by the Dharawal Aboriginal people in Australia for the treatment of inflammatory conditions, for example, asthma, arthritis, rheumatism, fever, oedema, eye inflammation, and inflammation of bladder and related inflammatory diseases, were evaluated for their anti-inflammatory activity in vitro. Ethanolic extracts from 17 Eucalyptus spp. (Myrtaceae) were assessed for their capacity to inhibit nitric oxide and tumor necrosis factor-α production in RAW 264.7 macrophages. Eucalyptus benthamii showed the most potent nitric oxide inhibitory effect (IC₅₀  5.57 ± 1.4 µg/mL), whilst E. bosistoana, E. botryoides, E. saligna, E. smithii, E. umbra, and E. viminalis exhibited nitric oxide inhibition values between 7.58 and 19.77 µg/mL.

The protective effect of resveratrol in the transmission of neuropathic pain mediated by the P2X7 receptor in the dorsal root ganglia

The P2X₇ receptor mediates afferent nerve activation and is related to chronic neuropathic pain. Resveratrol (RES) has also been reported to exhibit anti-inflammatory effects. In this study, we investigated the neuroprotective effect of RES on the transmission of neuropathic pain mediated by the P2X₇ receptor. The P2X₇ mRNA and protein expression levels in L4-L5 dorsal root ganglia (DRG)s of the chronic constriction injury (CCI) group were significantly higher than those observed in the Ctrl + NS, Sham + RES and Sham groups. RES increased the threshold of thermal and mechanical hypersensitivity in rats with chronic neuropathic pain. The P2X₇ mRNA and protein expression levels in the CCI + RES group were decreased compared with those in the CCI group. Our results showed that RES inhibited the upregulated co-expression of P2X₇ and glial fibrillary acidic protein (GFAP, a marker of satellite glial cells) in satellite glial cells of DRG in the CCI group. The results demonstrated that the expression of GFAP was increased in the CCI group and that RES inhibited the upregulated expression of GFAP in the rats in the CCI group. In addition, the phosphorylation levels of p38 and extracellular regulated protein kinases (ERK)1/2 in the CCI group were markedly higher than those observed in the Ctrl + NS, Sham + RES and Sham groups, whereas the phosphorylation levels of p38 and ERK1/2 in CCI + RES group were markedly lower than those observed in the CCI group. RES inhibited BzATP-activated currents in DRG non-neurons in the CCI rats. Our data provide evidence that RES may suppress the transmission of neuropathic pain mediated by the P2X₇ receptor in the satellite glial cells of dorsal root ganglia.

Programmed death (PD)-1 attenuates macrophage activation and brain inflammation via regulation of fibrinogen-like protein 2 (Fgl-2) after intracerebral hemorrhage in mice

Neuroinflammation plays an important role in the recovery of brain injury in ICH. Macrophage is the major executor in the neuroinflammation and initiates neurological defects. Programmed death 1 (PD-1) delivers inhibitory signals that regulate the balance between T cell activation, tolerance, and immunopathology. PD-1 expression by macrophages plays a pathologic role in the innate inflammatory response. However, the exact role of PD-1 on inflammatory responses following ICH has not been well identified. In this experiment, PD-1 KO (PD-1 -/-) ICH mice and Wild-type (WT) ICH mice were caused by intracranial injection of type IV collagenase. The level of macrophage activation, inflammatory cytokines and fibrinogen-like protein 2 (Fgl-2) were detected using immunofluorescence staining and ELISA assays. In addition, brain edema and neurological scores of ICH mice were also measured. Our data demonstrated that ICH promoted PD-1 expression of macrophage and enhanced inflammatory cytokines and Fgl-2 concentrations. PD-1 -/- mice exhibited significantly higher expression of the inflammatory cytokines which initiate Fgl-2, than did their wild-type (WT) littermates. As a result, macrophage activation, cerebral edema and neurological deficit scores of PD-1 -/- mice were higher. In conclusion, our data demonstrate that PD-1 plays a vital role in brain inflammation via regulation of Fgl-2 after ICH, and that manipulation of PD-1 might be a promising therapeutical target in ICH.

Curcumin and Resveratrol in the Management of Cognitive Disorders: What is the Clinical Evidence?

A growing body of in vitro and in vivo evidences shows a possible role of polyphenols in counteracting neurodegeneration: curcumin and resveratrol are attractive substances in this regard. In fact, epidemiological studies highlight a neuroprotective effect of turmeric (rhizome of Curcuma longa L.), the main source of curcumin. Moreover, the consumption of red wine, the main source of resveratrol, has been related to a lower risk of developing dementia. In this review, we analyzed the published clinical trials investigating curcumin and resveratrol in the prevention or treatment of cognitive disorders. The ongoing studies were also described, in order to give an overview of the current search on this topic. The results of published trials (five for curcumin, six for resveratrol) are disappointing and do not allow to draw conclusions about the therapeutic or neuroprotective potential of curcumin and resveratrol. These compounds, being capable of interfering with several processes implicated in the early stages of dementia, could be useful in preventing or in slowing down the pathology. To this aim, an early diagnosis using peripheral biomarkers becomes necessary. Furthermore, the potential preventive activity of curcumin and resveratrol should be evaluated in long-term exposure clinical trials, using preparations with high bioavailability and that are well standardized.

Neuroprotective effects of apigenin against inflammation, neuronal excitability and apoptosis in an induced pluripotent stem cell model of Alzheimer's disease

Alzheimer's disease (AD) is one of the most prevalent neurodegenerative diseases, yet current therapeutic treatments are inadequate due to a complex disease pathogenesis. The plant polyphenol apigenin has been shown to have anti-inflammatory and neuroprotective properties in a number of cell and animal models; however a comprehensive assessment has not been performed in a human model of AD. Here we have used a human induced pluripotent stem cell (iPSC) model of familial and sporadic AD, in addition to healthy controls, to assess the neuroprotective activity of apigenin. The iPSC-derived AD neurons demonstrated a hyper-excitable calcium signalling phenotype, elevated levels of nitrite, increased cytotoxicity and apoptosis, reduced neurite length and increased susceptibility to inflammatory stress challenge from activated murine microglia, in comparison to control neurons. We identified that apigenin has potent anti-inflammatory properties with the ability to protect neurites and cell viability by promoting a global down-regulation of cytokine and nitric oxide (NO) release in inflammatory cells. In addition, we show that apigenin is able to protect iPSC-derived AD neurons via multiple means by reducing the frequency of spontaneous Ca(2+) signals and significantly reducing caspase-3/7 mediated apoptosis. These data demonstrate the broad neuroprotective action of apigenin against AD pathogenesis in a human disease model.

Pathophysiological Role of Neuroinflammation in Neurodegenerative Diseases and Psychiatric Disorders

Brain diseases and disorders such as Alzheimer disease, Parkinson disease, depression, schizophrenia, autism, and addiction lead to reduced quality of daily life through abnormal thoughts, perceptions, emotional states, and behavior. While the underlying mechanisms remain poorly understood, human and animal studies have supported a role of neuroinflammation in the etiology of these diseases. In the central nervous system, an increased inflammatory response is capable of activating microglial cells, leading to the release of pro-inflammatory cytokines including interleukin (IL)-1β, IL-6, and tumor necrosis factor-α. In turn, the pro-inflammatory cytokines aggravate and propagate neuroinflammation, degenerating healthy neurons and impairing brain functions. Therefore, activated microglia may play a key role in neuroinflammatory processes contributing to the pathogenesis of psychiatric disorders and neurodegeneration.

Xuefu Zhuyu decoction, a traditional Chinese medicine, provides neuroprotection in a rat model of traumatic brain injury via an anti-inflammatory pathway

Neuroinflammation is central to the pathology of traumatic brain injury (TBI). Xuefu Zhuyu decoction (XFZY) is an effective traditional Chinese medicine to treat TBI. To elucidate its potential molecular mechanism, this study aimed to demonstrate that XFZY functions as an anti-inflammatory agent by inhibiting the PI3K-AKT-mTOR pathway. Sprague-Dawley rats were exposed to controlled cortical impact to produce a neuroinflammatory response. The treatment groups received XFZY (9 g/kg and 18 g/kg), Vehicle group and Sham group were gavaged with equal volumes of saline. The modified neurologic severity score (mNSS) and the Morris water maze test were used to assess neurological deficits. Arachidonic acid (AA) levels in brain tissue were measured using tandem gas chromatography-mass spectrometry. TNF-α and IL-1β levels in injured ipsilateral brain tissue were detected by ELISA. AKT and mTOR expression were measured by western blot analysis. The results indicated that XFZY significantly enhanced spatial memory acquisition. XFZY (especially at a dose of 9 g/kg) markedly reduced the mNSS and levels of AA, TNF-α and IL-1β. Significant downregulation of AKT/mTOR/p70S6K proteins in brain tissues was observed after the administration of XFZY (especially at a dose of 9 g/kg). XFZY may be a promising therapeutic strategy for reducing inflammation in TBI.