The Antioxidant, Anti-Inflammatory, and Neuroprotective Properties of the Synthetic Chalcone Derivative AN07.

Chalcones belong to a class of biologically active polyphenolic natural products. As a result of their simple chemical nature, they are easily synthesized and show a variety of promising biological activities. 2-Hydroxy-4'-methoxychalcone (AN07) is a synthetic chalcone derivate with potential anti-atherosclerosis effects. In this study, we demonstrated the novel antioxidant, anti-inflammatory, and neuroprotective effects of AN07. In RAW 264.7 macrophages, AN07 attenuated lipopolysaccharide (LPS)-induced elevations in reactive oxygen species (ROS) level and oxidative stress via down-regulating gp91phox expression and stimulating the antioxidant system of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) pathways, which were accompanied by increased glutathione (GSH) levels. Additionally, AN07 attenuated LPS-induced inflammatory factors, including NO, inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), and phosphorylated inhibitor of nuclear factor kappa B-alpha (p-IκBα) in RAW 264.7 macrophages. However, the effects of AN07 on promoting nuclear Nrf2 levels and decreasing COX-2 expressions were significantly abrogated by the peroxisome proliferator-activated receptor-γ (PPARγ) antagonist GW9662. In human dopaminergic SH-SY5Y cells treated with or without methylglyoxal (MG), a toxic endogenous by-product of glycolysis, AN07 up-regulated neurotrophic signals including insulin-like growth factor 1 receptor (IGF-1R), p-Akt, p-GSK3ß, glucagon-like peptide 1 receptor (GLP-1R), and brain-derived neurotrophic factor (BDNF). AN07 attenuated MG-induced apoptosis by up-regulating the B-cell lymphoma 2 (Bcl-2) protein and down-regulating the cytosolic expression of cytochrome c. AN07 also attenuated MG-induced neurite damage via down-regulating the Rho-associated protein kinase 2 (ROCK2)/phosphorylated LIM kinase 1 (p-LIMK1) pathway. Moreover, AN07 ameliorated the MG-induced down-regulation of neuroprotective Parkinsonism-associated proteins parkin, pink1, and DJ-1. These findings suggest that AN07 possesses the potentials to be an anti-inflammatory, antioxidant, and neuroprotective agent.

Neuroprotective Glycosylated Cyclic Lipodepsipeptides, Colletotrichamides A-E, from a Halophyte-Associated Fungus, Colletotrichum gloeosporioides JS419.

Glutamate neurotoxicity has been implicated in neuronal death in both acute CNS injury and in chronic neurodegenerative diseases. Five unique cyclic depsipeptides with neuroprotective activity, colletotrichamides A-E (1-5), were isolated from cultures of a halophyte Suaeda japonica-associated fungus, Colletotrichum gloeosporioides JS419. Spectroscopic analysis revealed that they were glycosylated cyclic lipodepsipeptides. Their relative configurations were determined by ROESY and J-based configuration analysis, and absolute configurations were established by chemical reactions including modified Mosher's method, advanced Marfey's method, and sugar derivatization. This is the first report of a glycosylated dimethyl-trioxygenated dodecanoyl moiety, and the relative as well as absolute stereochemistry was elucidated herein for the first time. Colletotrichamide C exhibited strong neuroprotective activity against glutamate in hippocampal HT22 cells.

Long noncoding RNA Malat1 is a potent autophagy inducer protecting brain microvascular endothelial cells against oxygen-glucose deprivation/reoxygenation-induced injury by sponging miR-26b and upregulating ULK2 expression.

Brain microvascular endothelial cell (BMEC) injury induced by ischemia-reperfusion (I/R) is the initial stage of blood-brain barrier (BBB) disruption, which results in a poor prognosis in ischemic stroke patients. Autophagy has been shown to have protective effects on BMECs against cerebral ischemic insults. However, molecular mechanism of BMEC autophagy during I/R is unclear. Long noncoding RNAs (lncRNAs) are emerging as new factors involved in cell autophagy. LncRNA Malat1 is one of the most highly upregulated I/R or OGD/R-responsive endothelial lncRNA and plays a protective role in BMECs against cerebral ischemic insults. Oxygen-glucose deprivation/reoxygenation (OGD/R) is used to mimic I/R injury in vitro. Based on these findings, we hypothesized that Malat1 might play a protective role by enhancing BMEC autophagy. We performed GFP-LC3 puncta formation, LC3 conversion, p62 expression, and cell death assays, and the results were consistent with our hypothesis that Malat1 promoted BMEC autophagy and survival under OGD/R condition. We further explored the molecular mechanisms by which Malat1 exerted regulatory effects, and found that Malat1 served as an endogenous sponge to downregulate miR-26b expression by binding directly to miR-26b. Furthermore, Malat1 overturned the inhibitory effect of miR-26b on BMEC autophagy and survival, which involved in promoting the expression of miR-26b target ULK2. Collectively, our study illuminated a new Malat1-miR-26b-ULK2 regulatory axis in which Malat1 served as a competing endogenous RNA by sponging miR-26b and upregulating ULK2 expression, thereby promoting BMEC autophagy and survival under OGD/R condition.

DHA-derived oxylipins, neuroprostanes and protectins, differentially and dose-dependently modulate the inflammatory response in human macrophages: Putative mechanisms through PPAR activation.

Whereas the anti-inflammatory properties and mechanisms of action of long chain ω3 PUFAs have been abundantly investigated, research gaps remain regarding the respective contribution and mechanisms of action of their oxygenated metabolites collectively known as oxylipins. We conducted a dose-dependent and comparative study in human primary macrophages aiming to compare the anti-inflammatory activity of two types of DHA-derived oxylipins including the well-described protectins (NPD1 and PDX), formed through lipoxygenase pathway and the neuroprostanes (14-A4t- and 4-F4t-NeuroP) formed through free-radical mediated oxygenation and expected to be new anti-inflammatory mediators. Considering the potential ability of these DHA-derived oxylipins to bind PPARs and knowing the central role of these transcription factors in the regulation of macrophage inflammatory response, we performed transactivation assays to compare the ability of protectins and neuroprostanes to activate PPARs. All molecules significantly reduced mRNA levels of cytokines such as IL-6 and TNF-α, however not at the same doses. NPD1 showed the most effect at 0.1µM (-14.9%, p<0.05 for IL-6 and -26.7%, p<0.05 for TNF-α) while the three other molecules had greater effects at 10µM, with the strongest result due to the cyclopentenone neuroprostane, 14-A4t-NeuroP (-49.8%, p<0.001 and -40.8%, p<0.001, respectively). Part of the anti-inflammatory properties of the DHA-derived oxylipins investigated could be linked to their activation of PPARs. Indeed, all tested oxylipins significantly activated PPARγ, with 14-A4t-NeuroP leading to the strongest activation, and NPD1 and PDX also activated PPARα. In conclusion, our results show that neuroprostanes and more especially cyclopentenone neuroprostanes have potent anti-inflammatory activities similar or even more pronounced than protectins supporting that neuroprostanes should be considered as important contributors to the anti-inflammatory effects of DHA.

[Influence of the concentrate of red wine polyphenols on glutamate neurotoxicity].

The purpose of the work was to assess the influence of the concentrate of red table wine Saperavi on the cultivated nerve cells exposed to glutamate. The selection of Saperavi as the source of phenolic compounds was not accidental: this type of grapes in the Krasnodar region has the highest content of them - up to 4-5 g/dm3 and more. Polyphenol concentrate was prepared by pre-distillation of ethanol using vacuum, evaporation of red table wine with a rotary vaporizer, with the subsequent lyophilic drying. By the methods of voltammetry and chemiluminescence an antioxidant activity, and a quantity of antioxidants in the concentrate have been determined. By HPLC it was established that a large group of phenolic compounds with high antioxidant activity was present in the concentrate of polyphenols: procyanidins (total concentration up to 425 mg/dm3), quercetin (21.8-32.6 mg/dm3), gallic acid (124.2-164.7 mg/dm3), resveratrol (6.26-13.22 mg/dm3), catechins (1026 - 1480 mg/dm3). Effect of red wine Saperavi concentrate on glutamate cytotoxicity was studied in the neuron culture of the cerebellum of 7-9-day-old rats. It was shown that the presence of. antioxidants reduced the intensity of chemiluminescence in model systems that generate free radicals. It was established that quenching of chemiluminescence in the system <> composed 68.43%, and in the system of the yolk lipoproteins - 86.36%. The application of concentrate Saperavi significantly increased the survivability of neurons: at the doses 5, 10 and 30 mcg/ml the number of intact neurons was respectively 38.6; 41.5 and 37.1%. The dose 20 mcg/ml was the most effective - the proportion of live neurons comprised 47.4%. The obtained results can be explained by the high antioxidant activity of concentrate flavonoids, including high content of biologically active compounds - catechins, quercetin, rutin, resveratrol. Thus, the consumption of red wine in quantities that exclude harmful effects, can have a positive impact on human health and the brain in particular.

Neuroprotective and anti-inflammatory effects of morin in a murine model of Parkinson's disease.

Parkinson's disease (PD) is one of the most common neurodegenerative disorders and is characterized by loss of dopaminergic neurons in the substantia nigra (SN). Although the causes of PD are not understood, evidence suggests that oxidative stress, mitochondrial dysfunction, and inflammation are associated with its pathogenesis. Morin (3,5,7,2',4'-pentahydroxyflavone) is a flavonol found in wine and many herbs and fruits. Previous studies have suggested that morin prevents oxidative damage and inflammation and ameliorates mitochondrial dysfunction. The present study describes the neuroprotective effects of morin in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of PD, and we report the results of our investigation into its neuroprotective mechanism in primary neurons and astrocytes. In the mouse model, morin pretreatment ameliorated motor dysfunction, protected against dopaminergic neuronal losses in SN and striatum, and alleviated MPTP-induced astrocyte activation. In vitro studies revealed that morin protected primary cultured neurons against 1-methyl-4-phenylpyridine (MPP(+) )-mediated reactive oxygen species production and mitochondrial membrane potential (MMP) disruption. In addition, morin effectively reduced MPP(+) -induced astroglial activation and nuclear translocation of nuclear factor-κB in primary cultured astrocytes. These results indicate that morin acts via multiple neuroprotective mechanisms in our mouse model and suggest that morin be viewed as a potential treatment and preventative for PD. © 2016 Wiley Periodicals, Inc.

The neuroprotective actions of oestradiol and oestrogen receptors.

Hormones regulate homeostasis by communicating through the bloodstream to the body's organs, including the brain. As homeostatic regulators of brain function, some hormones exert neuroprotective actions. This is the case for the ovarian hormone 17ß-oestradiol, which signals through oestrogen receptors (ERs) that are widely distributed in the male and female brain. Recent discoveries have shown that oestradiol is not only a reproductive hormone but also a brain-derived neuroprotective factor in males and females and that ERs coordinate multiple signalling mechanisms that protect the brain from neurodegenerative diseases, affective disorders and cognitive decline.

Flavonoids isolated from Rumex aquaticus exhibit neuroprotective and neurorestorative properties by enhancing neurite outgrowth and synaptophysin.

There is heightened interest in the field of stroke recovery as there is need for agents that would prevent the debilitating effects of the disorder, thereby tremendously reducing the societal and economic costs associated with it. In this study, the isolation of two flavonoids--quercetin-3-O-galactoside (1) and quercetin-3-O-arabinoside (2)--from Rumex aquaticus (western dock) and their neuroprotective effects were reported in the oxygen-glucose deprivation (OGD) model of in vitro ischemia using rat pheochromocytoma (PC12) cell line. Bioassay-guided fractionation of the ethyl-acetate extract of Rumex aquaticus L. afforded the isolation of compounds 1 and 2. The structures of compounds were established on the basis of spectroscopic analyses (UV, mass spectrometry (MS) and nuclear magnetic resonance spectroscopy (NMR). Both compounds were isolated for the first time from this species. In the course of the pharmacological experiments it was detected that these flavonoids at 10 µM concentration significantly improved cell survival in the oxygen-glucose deprivation model of ischemia. Moreover, they also increased neurite outgrowth in differentiated PC12 cells subjected to ischemic insult. Investigations on the cellular mechanism for the observed effect revealed that compound 1 (10 µM) enhances the expression of synaptophysin - a marker of synapses, and an indicator of synaptic plasticity. Rapid restoration of neurological function following injury is paramount to the prevention of debilitating consequences of ischemic stroke. This combination of neuroprotection and neuritogenic potential could be particularly useful in the recovery phase of stroke.

N-stearoyltyrosine protects against glutamate-induced oxidative toxicity by an apoptosis-inducing factor (AIF)-mediated caspase-independent cell death pathway.

N-stearoyltyrosine (NsTyr), a synthesized anandamide (AEA) analogue, could exert potent neuroprotective effects on cerebral ischemia models both in vivo and in vitro via intervening in multiple injuries. Glutamate, a major excitatory neurotransmitter, plays a critical role during stroke/cerebral ischemia. In this study, we explored the protective effects of NsTyr on glutamate neurotoxicity in PC12 cells and investigated its underlying mechanisms. NsTyr treatment attenuated glutamate-induced oxidative toxicity in a dose-dependent manner and the best performance was observed at 10 µΜ. NsTyr treatment suppressed glutamate-induced upregulation of lipoxygenase 12/15 (LOX 12/15) activity and reactive oxygen species (ROS) elevation, attenuated the increase of BH3-interacting domain death agonist (Bid) in the mitochondria, prevented the loss of mitochondria membrane potential and consequently inhibited apoptosis-inducing factor (AIF) translocation into the nucleus. The results demonstrated that NsTyr could protect cells against AIF-mediated caspase-independent cell death induced by glutamate, which may be due to the blockage of Bid-mediated mitochondrial damage via reducing LOX 12/15 activity and ROS accumulation.

MiR-7-1 potentiated estrogen receptor agonists for functional neuroprotection in VSC4.1 motoneurons.

Protection of motoneurons is an important goal in the treatment of spinal cord injury (SCI). We tested whether neuroprotective microRNAs (miRs) like miR-206, miR-17, miR-21, miR-7-1, and miR-106a could enhance efficacy of estrogen receptor (ER) agonists such as 1,3,5-tris (4-hydroxyphenyl)-4-propyl-1H-pyrazole (PPT, ERα agonist), Way200070 (WAY, ERß agonist), and estrogen (EST, ERα and ERß agonist) in preventing apoptosis in the calcium ionophore (CI)-insulted ventral spinal cord 4.1 (VSC4.1) motoneurons. We determined that 200 nM CI induced 70% cell death. Treatment with 50 nM PPT, 100 nM WAY, and 150 nM EST induced overexpression of ERα, ERß, and both receptors, respectively, at mRNA and protein levels. Treatment with ER agonists significantly upregulated miR-206, miR-17, and miR-7-1 in the CI-insulted VSC4.1 motoneurons. Transfection with miR-206, miR-17, or miR-7-1 mimic potentiated WAY or EST to inhibit apoptosis in the CI-insulted VSC4.1 motoneurons. Overexpression of miR-7-1 maximally increased efficacy of WAY and EST for down regulation of pro-apoptotic Bax and upregulation of anti-apoptotic Bcl-2. A search using microRNA database (miRDB) indicated that miR-7-1 could inhibit the expression of L-type Ca(2+) channel protein alpha 1C (CPα1C). miR-7-1 overexpression and WAY or EST treatment down regulated CPα1C but upregulated p-Akt to trigger cell survival signaling. The same therapeutic strategy increased expression of the Ca(2+)/calmodulin-dependent protein kinase II beta (CaMKIIß) and the phosphorylated cAMP response element binding protein (p-CREB) so as to promote Bcl-2 transcription. Whole cell membrane potential and mitochondrial membrane potential studies indicated that miR-7-1 highly potentiated EST to preserve functionality in the CI-insulted VSC4.1 motoneurons. In conclusion, our data indicated that miR-7-1 most significantly potentiated efficacy of EST for functional neuroprotection and this therapeutic strategy could be used in the future to attenuate apoptosis of motoneurons in SCI.

Calcium influx and calpain activation mediate preclinical retinal neurodegeneration in autoimmune optic neuritis.

Optic neuritis is a common manifestation of multiple sclerosis, an inflammatory demyelinating disease of the CNS. Recently, the neurodegenerative component of multiple sclerosis has come under focus particularly because permanent disability in patients correlates well with neurodegeneration; and observations in both humans and multiple sclerosis animal models highlight neurodegeneration of retinal ganglion cells as an early event. After myelin oligodendrocyte glycoprotein immunization of Brown Norway rats, significant retinal ganglion cell loss precedes the onset of pathologically defined autoimmune optic neuritis. To study the role calcium and calpain activation may play in mediating early degeneration, manganese-enhanced magnetic resonance imaging was used to monitor preclinical calcium elevations in the retina and optic nerve of myelin oligodendrocyte glycoprotein-immunized Brown Norway rats. Calcium elevation correlated with an increase in calpain activation during the induction phase of optic neuritis, as revealed by increased calpain-specific cleavage of spectrin. The relevance of early calpain activation to neurodegeneration during disease induction was addressed by performing treatment studies with the calpain inhibitor calpeptin. Treatment not only reduced calpain activity but also protected retinal ganglion cells from preclinical degeneration. These data indicate that elevation of retinal calcium levels and calpain activation are early events in autoimmune optic neuritis, providing a potential therapeutic target for neuroprotection.

The protective effect of astrocyte-derived 14,15-epoxyeicosatrienoic acid on hydrogen peroxide-induced cell injury in astrocyte-dopaminergic neuronal cell line co-culture.

Astrocytes perform several functions that are essential for normal neuronal activity. They play a critical role in neuronal survival during ischemia and other degenerative injuries and also modulate neuronal recovery by influencing neurite outgrowth. In this study, we investigated the neuroprotective effects of astrocyte-derived 14,15-epoxyeicosatrienoic acid (14,15-EET), metabolite of arachidonic acid by cytochrome P450 epoxygenases (CYP), against oxidative stress induced by hydrogen peroxide (H(2)O(2)). We found that dopaminergic neuronal cells (N27 cell line) stimulated with two different doses of H(2)O(2) (0.1 and 1mM) for 1h showed decreased cell viability compared to the control group, while astrocytes showed less cell death after stimulation with the same doses of H(2)O(2) for 1h. Dopaminergic neuronal cells (N27 cell line) pretreated with different doses of 14,15-EET (0.1-30 µM, 30 min) before H(2)O(2) stimulation also showed increased cell viability. Furthermore, pre-treatment of the co-cultured cells with 12-(3-adamantan-1-yl-ureido)-dodecanoic acid, an inhibitor of the EET metabolizing enzyme, soluble epoxide hydrolase (sEH), before H(2)O(2) stimulation (1mM, for 1h) increased cell viability. It also increased the endogenous level of 14,15-EET in the media compared to control group. However, pretreatment with the CYP epoxygenase inhibitor miconazole (1-20 µM, 1h) before H(2)O(2) (1mM, 1h) stimulation showed decreased cell viability. Our data suggest that 14,15-EET which is released from astrocytes, enhances cell viability against oxidant-induced injury. Further understanding of the mechanism of 14,15-EET-mediated protection in dopaminergic neurons is imperative, as it could lead to novel therapeutic approaches for treating CNS neuropathologies, such as Parkinson's disease.

Regulated hypoxia/reperfusion-dependent modulation of ERK1/2, cPLA2, and Bcl-2/Bax: a potential mechanism of neuroprotective effect of penehyclidine hydrochloride.

The activation of event-related kinase 1/2 (ERK1/2) and cytosolic phospholipaseA2 (cPLA2), which can aggravate hypoxia/reoxygenation (H/R) damage related to their downstream Bcl-2/Bax and Caspase-3 pathway, plays a key role in H/R. The M1 receptors could be responsible for activation of ERK1/2. Thus, it seems that the regulation of M1 receptors mediated the ERK1/2; cPLA2-mediated Bcl-2/Bax pathway may be a significant responsive signal in H/R. Penehyclidine hydrochloride (PHC) is an anticholinergic agent with high degree of selectivity for M1 and M3 receptor subtypes, it is reported that PHC has a protective effect against H/R damage. Here we hypothesize and demonstrate that PHC could downregulate the expression of pERK1/2, cPLA2, and Caspase-3, increased the ratio of Bcl-2/Bax. This study may widen the application of PHC and therapeutic agents of stroke.

Oxidative insults to neurons and synapse are prevented by aged garlic extract and S-allyl-L-cysteine treatment in the neuronal culture and APP-Tg mouse model.

Alzheimer's disease (AD) is one of the most common forms of dementia in the elderly. In AD patients, ß-amyloid peptide (Aß) plaques and neurofibrillary tangles are common features observed in the CNS. Aß deposition results in the production of reactive oxygen species (ROS) leading to the hyperphosphorylation of tau that are associated with neuronal damage. Cholinesterase inhibitors and a partial NMDA receptor antagonist (memantine) have been identified as potential treatment options for AD. However, clinical studies have found that these drugs fail to prevent the disease progression. From ancient times, garlic (Allium sativum) has been used to treat several diseases. By 'aging' of garlic, some adverse reactions of garlic can be eliminated. Recent findings suggest that 'aged garlic extract' (AGE) may be a therapeutic agent for AD because of its antioxidant and Aß lowering properties. To date, the molecular properties of AGE have been sparsely studied in vitro or in vivo. The present study tested specific biochemical and molecular effects of AGE in neuronal and AD rodent models. Furthermore, we identified S-allyl-L-cysteine (SAC) as one of the most active chemicals responsible for the AGE-mediated effect(s). We observed significant neuroprotective and neurorescue properties of AGE and one of its ingredients, SAC, from ROS (H(2)O(2))-mediated insults to neuronal cells. Treatment of AGE and SAC were found to protect neuronal cells when they were independently co-treated with ROS. Furthermore, a novel neuropreservation effect of AGE was detected in that pre-treatment with AGE alone protected ∼ 80% neuronal cells from ROS-mediated damage. AGE was also found to preserve pre-synaptic protein synaptosomal associated protein of 25 kDa (SNAP25) from ROS-mediated insult. For example, treatment with 2% AGE containing diet and SAC (20 mg/kg of diet) independently increased (∼70%) levels of SNAP25 and synaptophysin in Alzheimer's amyloid precursor protein-transgenic mice, of which the latter was significantly decreased in AD. Taken together, the neuroprotective, including preservation of pre-synaptic proteins by AGE and SAC can be utilized in future drug development in AD.