benzofurans and Alzheimer-Disease

Aurones are naturally occurring structural isomerides of flavones that have diverse bioactivities including antiviral, antibacterial, antifungal, anti-inflammatory, antitumor, antimalarial, antioxidant, neuropharmacological activities and so on. They constitute an important class of pharmacologically active scaffolds that exhibit multiple biological activities via diverse mechanisms. This review article provides an update on the recent advances (2013-2020.4) in the synthesis and biological activities of these derivatives. In the cases where sufficient information is available, some important structure-activity relationships (SAR) of their biological activities were presented, and on the strength of our expertise in medicinal chemistry and careful analysis of the recent literature, for the potential of aurones as medicinal drugs is proposed.

Topics: Alzheimer Disease; Animals; Anti-Infective Agents; Anti-Inflammatory Agents; Antinematodal Agents; Antineoplastic Agents; Antioxidants; Benzofurans; Catalysis; Drug Evaluation, Preclinical; Flavones; Humans; Hypoglycemic Agents; Metals; Structure-Activity Relationship

It is estimated that over 44 million people across the globe have dementia, and half of these cases are believed to be Alzheimer's disease (AD). As the proportion of the global population which is over the age 60 increases so will the number of individuals living with AD. This will result in ever-increasing demands on healthcare systems and the economy. AD can be either sporadic or familial, but both present with similar pathobiology and symptoms. Three prominent theories about the cause of AD are the amyloid, tau and mitochondrial hypotheses. The mitochondrial hypothesis focuses on mitochondrial dysfunction in AD, however little attention has been given to the potential dysfunction of the mitochondrial ATP synthase in AD. ATP synthase is a proton pump which harnesses the chemical potential energy of the proton gradient across the inner mitochondrial membrane (IMM), generated by the electron transport chain (ETC), in order to produce the cellular energy currency ATP. This review presents the evidence accumulated so far that demonstrates dysfunction of ATP synthase in AD, before highlighting two potential pharmacological interventions which may modulate ATP synthase.

Topics: Alzheimer Disease; Animals; Benzofurans; Brain; Curcumin; Energy Metabolism; Humans; Mitochondria; Mitochondrial Proton-Translocating ATPases; Neuroprotective Agents

Alzheimer's disease (AD) is a progressive neurodegenerative disease with no clinically accepted treatment to cure or halt its progression. The Food and Drug Administration has approved drugs (e.g., rivastigmine, donepezil, galantamine, and memantine) that at best provide marginal benefits, thus emphasizing the urgent need to explore other molecular entities as future drug candidates for AD. Looking at the wide pharmaceutical applications of heterocyclic compounds and particularly those containing benzofuran and indole ring systems, these molecular frameworks have drawn special attention from medicinal chemists for further evaluation in numerous diseases. This article focuses on the history and recent advances of benzofuran- and indole-based compounds as inhibitors of butyrylcholinesterase, acetylcholinesterase, γ-secretase, β-secretase, tau misfolding, and β-amyloid aggregation.

Topics: Alzheimer Disease; Animals; Antioxidants; Benzofurans; Cell Line, Tumor; Drug Development; Enzyme Inhibitors; Humans; Indoles; Molecular Structure; Nootropic Agents

Currently, the development of radiotracers for in vivo imaging of beta-amyloid plaques in Alzheimer's disease (AD) brains is an important, active area of molecular imaging. Postmortem brains of AD patients reveal neuropathologic features: the presence of beta-amyloid plaques and neurofibrillary tangles, which contain beta-amyloid peptides and highly phosphorylated tau proteins. Increases in the concentration of beta-amyloid in the course of the disease lead to changes in AD brains. Thus, when used in combination with positron-emission tomography/single-photon emission computed tomography (PET/SPECT), beta-amyloid imaging agents could serve as surrogate markers for the early diagnosis and neuropathogenetic studies of AD. Furthermore, quantitative evaluation of beta-amyloid plaques in the brain could facilitate the evaluation of the efficacy of antiamyloid therapies that are currently being investigated. This paper reviews our research on the development of PET/SPECT imaging agents for in vivo detection of beta-amyloid plaques in Alzheimer's brains.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Benzofurans; Brain; Flavonoids; Humans; Positron-Emission Tomography; Radiopharmaceuticals; Stilbenes; Tissue Distribution; Tomography, Emission-Computed, Single-Photon

A brief summary of the current treatment of Alzheimer disease (AD) (cholinergic replacement therapy, influence of glutamatergic neurotransmission, treatment based on the beta-amyloid cascade theory, antioxidants, anti-inflammatory drugs) clearly proves that the applied strategies are practically inefficient. We describe therefore the rationale and design of a reasonable clinical trial to test the validity of Knoll's concept that the administration of a synthetic mesencephalic enhancer substance prior to the precipitation of the symptoms is our only chance to significantly reduce the prevalence of the two main neurodegenerative disorders AD and Parkinson's disease (PD). Considering that in the population over 65 there are substantial sex (68% female, 32% male) and geographical (highest rate: 10% in USA) differences in the incidence of AD, we propose to perform the clinical trial in 75-85 year old females in the USA. Individuals without (Group 1) and with (Group 2) predisposition to AD should be selected. One third in each group should be treated daily with placebo, (-)-deprenyl (1 mg) and (-)-BPAP (1 mg), respectively. Series of studies proved already the protective effect of the synthetic mesencephalic enhancer substances against age-related neurodegenerative changes in the brain. We may therefore expect a significant difference in the placebo versus drug treated groups in the number of individuals who will precipitate with the passing of time the symptoms of AD or PD. The introduction of a safe and efficient prophylactic therapy that significantly decreases the prevalence of AD is a necessity which cannot be further postponed.

Topics: Aged; Aged, 80 and over; Alzheimer Disease; Amyloid beta-Peptides; Antiparkinson Agents; Benzofurans; Clinical Trials as Topic; Evaluation Studies as Topic; Female; Genetic Predisposition to Disease; Humans; Mesencephalon; Neuroprotective Agents; Parkinson Disease; Reproducibility of Results; Research Design; Selegiline; United States

Hundreds of millions of people now die over the age of 80 years primarily due to twentieth century progress in hygiene, chemotherapy, and immunology. With a longer average lifespan, the need to improve quality of life during the latter decades is more compelling. "Aging--The Epidemic of the New Millenium," a recent international conference (Monte Carlo, June 17-18, 2000), showed with peculiar clarity that a safe and efficient drug strategy to slow the age-related decay of brain performance is still missing. This review summarizes the physiologic and pharmacologic arguments in favor of a peculiar lifelong prophylactic medication with reasonable chances to keep in check brain aging and decrease the precipitation of age-related neurological diseases.

Topics: Aging; Alzheimer Disease; Animals; Benzofurans; Brain; Catecholamines; Depression; Humans; Neuroprotective Agents; Parkinson Disease; Propylamines; Selegiline; Serotonin

Polymerization of the amyloid beta-peptide (Abeta) has been identified as a major feature of the pathogenesis of Alzheimer's disease (AD). Inhibition of the formation of these toxic polymers of Abeta has thus emerged as an approach to developing therapeutics for AD. Techniques for studying Abeta polymerization include the use of fibril nucleation and extension assays in a variety of formats. Detection of polymeric forms of Abeta has been achieved using turbidity, dye binding, light scattering and toxicity among other methods. Direct and indirect methods have been described for the measurement of binding affinities for Abeta fibrils. Imaging techniques include electron microscopy, X-ray diffraction and atomic force microscopy. These techniques have been used to characterize different classes of compounds that inhibit the formation of Abeta polymers. These compounds include dyes such as Congo Red, the antibiotic rifampicin, the anthracycline 4'-iodo-4'-deoxydoxorubicin, and a large variety of Abeta-derived peptides and modified peptides, among other reported inhibitors.

Topics: Acridines; Alzheimer Disease; Amyloid beta-Peptides; Benzofurans; Congo Red; Doxorubicin; Drug Design; Humans; Molecular Structure; Neurofibrillary Tangles; Peptide Fragments; Polymers; Protein Binding; Rifampin

A series of novel benzofuran-based compounds 7a-s were designed, synthesized, and investigated in vitro as acetylcholinesterase inhibitors (AChEIs). Compounds 7c and 7e displayed promising inhibitory activity with IC

Topics: Acetylcholinesterase; Alzheimer Disease; Animals; Benzofurans; Cholinesterase Inhibitors; Donepezil; Glutathione; Molecular Docking Simulation; Quantitative Structure-Activity Relationship; Rats

Tauopathies, such as Alzheimer's disease, have been the subject of several hypotheses regarding the way to treat them. Hyperphosphorylation of tau protein leading to its aggregation is widely recognized as a key step in the development of these diseases resulting in neuronal dysfunction. The AcPHF6 model of tau that includes the shorter critical fragment involved in the protein aggregation was used in vitro to identify new potential inhibitors. Following a previous study on aurone derivatives, we herein compare this polyphenol family to a very close one, the benzylidene-2,3-dihydro-1H-inden-1-one (also named indanone). The structure activity relationship studies bring to light the importance of the hydroxylation pattern in both series: the more hydroxylated, the more active. In addition, the three-dimensional shape of the molecules is involved in their interaction mode with their target, thus defining their role either as inhibitors of fiber elongation or as fiber-binding molecules. Indanone 13a was identified as a promising inhibitor: its activity was confirmed by circular dichroism and atomic force microscopy studies.

Topics: Alzheimer Disease; Benzofurans; Humans; Protein Aggregates; Structure-Activity Relationship; tau Proteins

Topics: Alzheimer Disease; Benzofurans; Humans; Neurodegenerative Diseases; Neuroprotective Agents

Several fluorine-18-labeled PET β-amyloid (Aβ) plaque radiotracers for Alzheimer’s disease (AD) are in clinical use. However, no radioiodinated imaging agent for Aβ plaques has been successfully moved forward for either single-photon emission computed tomography (SPECT) or positron emission tomography (PET) imaging. Radioiodinated pyridyl benzofuran derivatives for the SPECT imaging of Aβ plaques using iodine-123 and iodine-125 are being pursued. In this study, we assess the iodine-124 radioiodinated pyridyl benzofuran derivative 5-(5-[124I]iodobenzofuran-2-yl)-N,N-dimethylpyridin-2-amine ([124I]IBETA) (Ki = 2.36 nM) for utilization in PET imaging for Aβ plaques. We report our findings on the radioiododestannylation reaction used to prepare [124/125I]IBETA and evaluate its binding to Aβ plaques in a 5 × FAD mouse model and postmortem human AD brain. Both [125I]IBETA and [124I]IBETA are produced in >25% radiochemical yield and >85% radiochemical purity. The in vitro binding of [125I]IBETA and [124I]IBETA in transgenic 5 × FAD mouse model for Aβ plaques was high in the frontal cortex, anterior cingulate, thalamus, and hippocampus, which are regions of high Aβ accumulation, with very little binding in the cerebellum (ratio of brain regions to cerebellum was >5). The in vitro binding of [125I]IBETA and [124I]IBETA in postmortem human AD brains was higher in gray matter containing Aβ plaques compared to white matter (ratio of gray to white matter was >5). Anti-Aβ immunostaining strongly correlated with [124/125I]IBETA regional binding in both the 5 × FAD mouse and postmortem AD human brains. The binding of [124/125I]IBETA in 5 × FAD mouse and postmortem human AD brains was displaced by the known Aβ plaque imaging agent, Flotaza. Preliminary PET/CT studies of [124I]IBETA in the 5 × FAD mouse model suggested [124I]IBETA was relatively stable in vivo with a greater localization of [124I]IBETA in the brain regions with a high concentration of Aβ plaques. Some deiodination was observed at later time points. Therefore, [124I]IBETA may potentially be a useful PET radioligand for Aβ plaques in brain studies.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Benzofurans; Brain; Disease Models, Animal; Humans; Iodine Radioisotopes; Mice; Mice, Transgenic; Plaque, Amyloid; Positron Emission Tomography Computed Tomography; Positron-Emission Tomography; Radiopharmaceuticals

Histamine is involved in several central nervous system processes including cognition. In the last years, H

Topics: Acetylcholine; Acetylcholinesterase; Alzheimer Disease; Benzofurans; Butyrylcholinesterase; Cholinesterase Inhibitors; Histamine; Histamine Antagonists; Humans; Ligands; Molecular Docking Simulation; Piperazines; Receptors, Histamine H3; Structure-Activity Relationship; Tryptophan

Topics: Acetylcholinesterase; Alzheimer Disease; Amyloid beta-Peptides; Animals; Anti-Inflammatory Agents; Antioxidants; Behavior, Animal; Benzofurans; Cerebral Cortex; Cognitive Dysfunction; Disease Models, Animal; Female; Hippocampus; Inflammation; Injections, Intraventricular; Interleukin-1beta; Mice; Molecular Docking Simulation; Nootropic Agents; Peptide Fragments

Alzheimer's disease (AD) is a neurodegenerative disease characterized by β-amyloid (Aβ) protein deposition, neurofibrillary tangle (NFT) formation, and neuronal loss in the brain. The current study was designed to investigate the potential mechanisms by which levistolide A affects the pathogenesis of AD in an amyloid precursor protein/presenilin 1 (APP/PS1) transgenic (Tg) mouse model of AD and N2a/APP695swe cells. Specifically, behavioral changes in levistolide A-treated APP/PS1 Tg mice were assessed by the nest-building and Morris water maze (MWM) tests. Levistolide A treatment clearly ameliorated memory deficits and cognitive decline in APP/PS1 Tg mice. Aβ generation and the inflammatory response in APP/PS1 Tg mouse brains were clearly reduced after long-term levistolide A application. Mechanistically, levistolide A concurrently stimulated the expression of α-secretase and decreased the generation of β- and γ-secretases. In addition, levistolide A inhibited the phosphorylation of tau in the brains of the Tg mice. Furthermore, in vitro and in vivo experiments suggested that peroxisome proliferator-activated receptor γ (PPARγ) is the key transcription factor that mediates the regulatory effects of levistolide A on the expression of α-, β-, and γ-secretases and phosphorylation of tau. Collectively, these findings show that levistolide A may be a candidate for the treatment of AD.

Topics: Alzheimer Disease; Amyloid beta-Protein Precursor; Animals; Benzofurans; Blotting, Western; Brain; Cognitive Dysfunction; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Female; Fluorescent Antibody Technique; Mice; Mice, Transgenic; Morris Water Maze Test; Nootropic Agents; PPAR gamma; Presenilin-1; Signal Transduction

Alzheimer's disease (AD) is the most common cause of dementia among elderly people. Despite enormous efforts, the pathogenesis of AD still remains unclear and no drug has yet been proved to be disease-modifying. As the basis of learning and memory, the plasticity of synapse and dendritic spine has been impaired during AD progression. Previous studies have showed a protective effect of L-3-n-butylphthalide (L-NBP) on cognitive deficits in AD, we wonder whether this protective effect is associated with positive alterations on synapse and dendritic spines. In this study, we first of all confirmed the anti-dementia effect of L-NBP in 13-month-old APP/PS1 mice, and then investigated the alterations in synaptic and dendritic spine plasticity due to L-NBP treatment both in vivo and in vitro. We also conducted preliminary studies and found the possible mechanisms related to the inhibition of over-activated complement cascade and the remodeling of actin cytoskeleton. Besides, we also found extra benefits of L-NBP on presynaptic dystrophic neurites and attempted to give explanations from the view of autophagy regulation. Taken together, our study added some new evidence to the application of L-NBP in AD treatment and provided deeper insight into the relevant mechanisms for future study.

Topics: Alzheimer Disease; Animals; Autophagosomes; Autophagy; Axons; Benzofurans; Biomarkers; Cells, Cultured; Cognitive Dysfunction; Dendritic Spines; Disease Models, Animal; Hippocampus; Long-Term Potentiation; Lysosomes; Male; Mice, Transgenic; Morris Water Maze Test; Neurites; Neuronal Plasticity; Synapses

Amyloid-β (Aβ) deposit in the parenchyma is a major characteristic in Alzheimer's disease (AD), and the impaired glymphatic clearance contributes to the Aβ accumulation. It was reported that L-3-n-butylphthalide (NBP) showed the potential neuroprotective effect in the rodent models of AD. The effects of NBP on the glymphatic system were explored in this study. In the wild-type mice, both CSF tracer influx and perivascular drainage increased after NBP treatment compared with vehicle treatment. Moreover, NBP promoted the perivascular drainage of Aβ via increased cerebral pulsation, which could be inhibited by propranolol. Then, we studied the potential of 3-month NBP treatment on Aβ deposits in 8-month-old APP/PS1 transgenic mice. NBP daily treatments remarkably improved cognitive behavior in Morris water maze. Furthermore, NBP could reduce Aβ deposition and decrease parenchymal Aβ levels. In addition, NBP markedly improved the perivascular AQP4 localization. Our results indicated that NBP could enhance the glymphatic clearance and reduce parenchymal Aβ deposit in the APP/PS1 mice, suggesting that it may have potential in the treatment of AD.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Benzofurans; Brain; Glymphatic System; Male; Maze Learning; Mice; Mice, Inbred C57BL; Neuroprotective Agents

Amyloid-β (Aβ) aggregated forms are highly associated with the onset of Alzheimer's disease (AD). Aβ abnormally accumulates in the brain and induces neuronal damages and symptoms of AD such as cognitive impairment and memory loss. Since an antibody drug, aducanumab, reduces Aβ aggregates and delays clinical decline, clearance of accumulated Aβ in the brain is accounted as a therapeutic approach to treat AD. In this study, we synthesized 17 benzofuran derivatives that may disaggregate Aβ oligomers and plaques into inert monomers. By a series of Aβ aggregation inhibition and aggregates' disaggregation assays utilizing thioflavin T assays and gel electrophoresis,

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Benzofurans; Brain; Disease Models, Animal; Male; Mice; Mice, Transgenic; Plaque, Amyloid

Vascular factors and mitochondria dysfunction contribute to the pathogenesis of Alzheimer's disease (AD). DL-3-n-butylphthalide (NBP) has an effect in protecting mitochondria and improving microcirculation.. The aim was to investigate the effect of donepezil combined NBP therapy in patients with mild-moderate AD.. It was a prospective cohort study. 92 mild-moderate AD patients were classified into the donepezil alone group (n = 43) or the donepezil combined NBP group (n = 49) for 48 weeks. All patients were evaluated with Alzheimer's Disease Assessment Scale-Cognitive subscale (ADAS-cog), Clinician's Interview-Based Impression of Change plus caregiver input (CIBIC-plus), Alzheimer's Disease Cooperative Study-Activities of Daily Living (ADCS-ADL), and Neuropsychiatric Inventory (NPI) every 12 weeks. All patients were monitored for adverse events (AEs). The efficacy was analyzed using multivariate logistic regression analysis.. The multivariate logistic regression analysis showed that the changes of ADAS-cog score (OR = 2.778, 95% CI: [1.087, 7. 100], p = 0.033) and ADCS-ADL score (OR = 2.733, 95% CI: [1.002, 7.459], p = 0.049) had significant difference between donepezil alone group and donepezil combined NBP group, while the changes of NPI (OR = 1.145, 95% CI: [0.463, 2.829], p = 0.769), MMSE (OR = 1.563, 95% CI: [0.615, 3.971], p = 0.348) and CIBIC-plus (OR = 2.593, 95% CI: [0.696, 9.685], p = 0.156) had no significant difference. The occurrence of AEs was similar in the two groups.. Over the 48-week treatment period, donepezil combined NBP group had slower cognitive decline and better activities of daily living in patients with mild to moderate AD. These indicated that the multi-target therapeutic effect of NBP may be a new choice for AD treatment.

Topics: Activities of Daily Living; Aged; Aged, 80 and over; Alzheimer Disease; Benzofurans; Cognitive Dysfunction; Cohort Studies; Donepezil; Drug Therapy, Combination; Female; Humans; Male; Middle Aged; Neuroprotective Agents; Neuropsychological Tests; Prospective Studies; Treatment Outcome

To discover novel multifunctional agents for the treatment of Alzheimer's disease, a series of 3-benzylidene/benzylphthalide Mannich base derivatives were designed, synthesized and evaluated. The biological screening results indicated that most of these derivatives exhibited good multifunctional activities. Among them, compound (Z)-13c raised particular interest because of its excellent multifunctional bioactivities. It displayed excellent EeAChE and HuAChE inhibition (IC

Topics: Acetylcholinesterase; Alzheimer Disease; Amyloid beta-Peptides; Animals; Antioxidants; Benzofurans; Benzylidene Compounds; Blood-Brain Barrier; Butyrylcholinesterase; Cholinesterase Inhibitors; Copper; Dose-Response Relationship, Drug; Electrophorus; Female; Humans; Male; Mannich Bases; Mice; Mice, Inbred Strains; Models, Molecular; Molecular Structure; Neuroprotective Agents; PC12 Cells; Peptide Fragments; Protein Aggregates; Rats; Structure-Activity Relationship

Many Chinese herbs are well known for their neuroprotective and anti-oxidant properties. Extracts of Salvia miltiorrhiza and Anemarrhenae asphodeloides, tanshinone IIA (tanIIA), salvianolic acid B (Sal B) and sarsasapogenin (ML-1), were selected to study their dissociation potential towards Aβ

Topics: Abietanes; Alzheimer Disease; Amyloid beta-Peptides; Anemarrhena; Benzofurans; Cell Line; China; Humans; Neuroprotective Agents; Peptide Fragments; Plant Extracts; Salvia miltiorrhiza; Spirostans

The proteolytic processing of amyloid precursor protein (APP) by β-secretase (BACE1) and γ-secretase releases amyloid-β peptide (Aβ), which deposits in amyloid plaques and contributes to the initial causative events of Alzheimer's disease (AD). In the present study, the regulatory mechanism of APP processing of three phlorotannins was elucidated in Swedish mutant APP overexpressed N2a (SweAPP N2a) cells. Among the tested compounds, dieckol exhibited the highest inhibitory effect on both intra- and extracellular Aβ accumulation. In addition, dieckol regulated the APP processing enzymes, such as α-secretase (ADAM10), β-secretase, and γ-secretase, presenilin-1 (PS1), and their proteolytic products, sAPPα and sAPPβ, implying that the compound acts on both the amyloidogenic and non-amyloidogenic pathways. In addition, dieckol increased the phosphorylation of protein kinase B (Akt) at Ser473 and GSK-3β at Ser9, suggesting dieckol induced the activation of Akt, which phosphorylated GSK-3β. The specific phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 triggered GSK-3β activation and Aβ expression. In addition, co-treatment with LY294002 noticeably blocked the effect of dieckol on Aβ production, demonstrating that dieckol promoted the PI3K/Akt signaling pathway, which in turn inactivated GSK-3β, resulting in the reduction in Aβ levels.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Amyloid beta-Protein Precursor; Animals; Benzofurans; Cell Line; Chromones; Glycogen Synthase Kinase 3 beta; Mice; Morpholines; Phosphatidylinositol 3-Kinase; Proto-Oncogene Proteins c-akt; Signal Transduction; Tannins

Alzheimer's disease perpetually demands enormous research on the development of effective treatment strategies. The present study aims to define the role of Oxyresveratrol (OXY) alone and in combination with Alkoxy glycerols (AKG) to reduce Tau protein level and improve the climbing behaviour of Drosophila fly models expressed with human-Tau protein. Oxyresveratrol, a polyphenolic stilbene, possesses a wide range of biological activities like antioxidant, anti-inflammatory, and neuroprotective effects. Nevertheless, chemical instability and low solubility of OXY in aqueous solutions reduce its bioavailability and hinder it from exerting neuroprotective activities. An inclusion complex of OXY with β- cyclodextrin (CD) (OXY-CD complex) was employed in the study for increased dissolution rate and oral availability of OXY. Fish oils and their derivatives have a plethora of applications in in vivo biological activities. Herein, we also remark on the role of AKG in reducing Tau protein level in flies by enhancing OXY-CD activity. Dietary supplementation of OXY-CD together with AKG improved the learning and memory abilities during the climbing assay in Tau flies. The study highlights OXY-CD and AKG as neuroprotective agents and put forward a plausible approach towards the increased permeability of pharmacological agents across the blood-brain barrier (BBB) for the central nervous system elicited by AKG.

Topics: Alzheimer Disease; Animals; Animals, Genetically Modified; Behavior, Animal; Benzofurans; Drosophila melanogaster; Glycerol; Humans; Learning; Memory; Neuroprotective Agents; Plant Extracts; Stilbenes; tau Proteins

A series of benzofuran piperidine derivatives were designed, synthesized and evaluated as multifunctional Aβ antiaggregant to treat Alzheimer's disease (AD). In vitro results revealed that all of them are very good Aβ antiaggregants and some of the compounds are potent acetylcholinesterase (AChE) inhibitors with moderate antioxidant property. Selected compounds were also tested for neuroprotection activity, LDH release, ATP production and inhibitory activity to prevent Aβ peptides binding to the cell membrane. The different modifications introduced in the structure of our lead compound 3 (hAChE IC

Topics: Acetylcholinesterase; Alzheimer Disease; Amyloid beta-Peptides; Benzofurans; Cholinesterase Inhibitors; Dose-Response Relationship, Drug; Humans; Models, Molecular; Molecular Structure; Neuroprotective Agents; Piperidines; Protein Aggregates; Protein Aggregation, Pathological; Structure-Activity Relationship

Recent findings unveil the pharmacological modulation of imidazoline I

Topics: Alzheimer Disease; Animals; Apoptosis; Benzofurans; Cell Line, Tumor; Dose-Response Relationship, Drug; Humans; Imidazoles; Imidazoline Receptors; Ligands; Male; Mice; Molecular Structure; Oxidative Stress; Structure-Activity Relationship

Alzheimer's disease (AD) is a type of progressive dementia caused by degeneration of the nervous system. A single target drug usually does not work well. Therefore, multi-target drugs are designed and developed so that one drug can specifically bind to multiple targets to ensure clinical effectiveness and reduce toxicity. We synthesised a series of 2-arylbenzofuran derivatives and evaluated their in vitro activities. 2-Arylbenzofuran compounds have good dual cholinesterase inhibitory activity and β-secretase inhibitory activity. The IC

Topics: Alzheimer Disease; Benzofurans; Humans; Nootropic Agents

Danshen water extract (DWE), obtained from the Salvia miltiorrhiza Bunge (Family Lamiaceae) root, is usually employed in Chinese traditional medicine as treatment to cardiovascular ailments and cerebrovascular diseases. Intriguingly, the extract was also found to contain vast beneficial properties in Alzheimer's disease (AD) treatment.. Alzheimer's disease is the most significant type of neurodegenerative disorder plaguing societies globally. Its pathogenesis encompasses the hallmark aggregation of amyloid-beta (Aβ). Of all the Aβ oligomers formed in the brain, Aβ42 is the most toxic and aggressive. Despite this, the mechanism behind this disease remains elusive. In this study, DWE, and its major components, Salvianolic acid A (SalA) and Salvianolic acid B (SalB) were tested for their abilities to attenuate Aβ42's toxic effects.. The composition of DWE was determined via Ultra-Performance Liquid Chromatography (UPLC). DWE, SalA and SalB were first verified for their capability to diminish Aβ42 fibrillation using an in vitro activity assay. Since Aβ42 aggregation results in neuronal degeneration, the potential Aβ42 inhibitors were next evaluated on Aβ42-exposed PC12 neuronal cells. The Drosophila melanogaster AD model was then employed to determine the effects of DWE, SalA and SalB.. DWE, SalA and SalB were shown to be able to reduce fibrillation of Aβ42. When tested on PC12 neuronal cells, DWE, SalA and SalB ameliorated cells from cell death associated with Aβ42 exposure. Next, DWE and its components were tested on the Drosophila melanogaster AD model and their rescue effects were further characterized. The UPLC analysis showed that SalA and SalB were present in the brains and bodies of Drosophila after DWE feeding. When human Aβ42 was expressed, the AD Drosophila exhibited degenerated eye structures known as the rough eye phenotype (REP), reduced lifespan and deteriorated locomotor ability. Administration of DWE, SalA and SalB partially reverted the REP, increased the age of AD Drosophila and improved most of the mobility of AD Drosophila.. Collectively, DWE and its components may have therapeutic potential for AD patients and possibly other forms of brain diseases.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Benzofurans; Caffeic Acids; Cell Survival; Drosophila melanogaster; Female; Lactates; Neurons; PC12 Cells; Peptide Fragments; Phytotherapy; Plant Extracts; Rats; Salvia miltiorrhiza

Pursuing the widespread interest on multi-target drugs to combat Alzheimer´s disease (AD), a new series of hybrids was designed and developed based on the repositioning of the well-known acetylcholinesterase (AChE) inhibitor, tacrine (TAC), by its coupling to benzofuran (BF) derivatives. The BF framework aims to endow the conjugate molecules with ability for inhibition of AChE (bimodal way) and of amyloid-beta peptide aggregation, besides providing metal (Fe, Cu) chelating ability and concomitant extra anti-oxidant activity, for the hybrids with hydroxyl substitution. The new TAC-BF conjugates showed very good activity for AChE inhibition (sub-micromolar range) and good capacity for the inhibition of self- and Cu-mediated Aβ aggregation, with dependence on the linker size and substituent groups of each main moiety. Neuroprotective effects were also found for the compounds through viability assays of neuroblastoma cells, after Aβ

Topics: Acetylcholinesterase; Alzheimer Disease; Animals; Benzofurans; Cholinesterase Inhibitors; Dose-Response Relationship, Drug; Electrophorus; Humans; Models, Molecular; Molecular Structure; Neuroprotective Agents; Structure-Activity Relationship; Tacrine

Accumulation of tau protein aggregation plays a crucial role in neurodegenerative diseases, such as Alzheimer's disease (AD). Uncontrollable neuroinflammation and tau pathology form a vicious circle that further aggravates AD progression. Herein, we reported the synthesis of usnic acid derivatives and evaluation of their inhibitory activities against tau-aggregation and neuroinflammation. The inhibitory activity of the derivatives against the self-fibrillation of the hexapeptide AcPHF6 was initially screened by ThT fluorescence assay. Using circular dichroism and transmission electron microscopy, compound 30 showed the most potent inhibitory activity against AcPHF6 self-fibrillation. Compound 30 was further confirmed to inhibit the aggregation of full-length 2N4R tau protein by a heparin-induced mechanism. In addition, we investigated the anti-inflammatory activity of compound 30, and showed that compared with sodium usnate, it reduced NO release in LPS-stimulated mouse microglia BV2 cells. More importantly, 30 showed significant protective effects against okadaic acid-induced memory impairment in rats. Thus, 30 was a novel tau-aggregation and neuroinflammation inhibitor that represented a potential therapeutic candidate for AD.

Topics: Alzheimer Disease; Animals; Benzofurans; Cell Line, Tumor; Disease Models, Animal; Dose-Response Relationship, Drug; Humans; Inflammation; Lipopolysaccharides; Male; Maze Learning; Mice; Models, Molecular; Molecular Structure; Nitric Oxide; Protein Aggregates; Rats; Rats, Sprague-Dawley; Structure-Activity Relationship; tau Proteins

Fluorescent small molecules are powerful tools for imaging α-synuclein pathology in vitro and in vivo. In this work, we explore benzofuranone as a potential scaffold for the design of fluorescent α-synuclein probes. These compounds have high affinity for α-synuclein, show fluorescent turn-on upon binding to fibrils, and display different binding to Lewy bodies, Lewy neurites and glial cytoplasmic inclusion pathologies in post-mortem brain tissue. These studies not only reveal the potential of benzofuranone compounds as α-synuclein specific fluorescent probes, but also have implications for the ways in which α-synucleinopathies are conformationally different and display distinct small molecule binding sites.

Topics: alpha-Synuclein; Alzheimer Disease; Benzofurans; Fluorescence; Fluorescent Dyes; Humans; Microscopy, Fluorescence; Multiple System Atrophy; Parkinson Disease

Multi-target drugs can better address the cascade of events involved in oxidative stress and the reduction in cholinergic transmission that occur in Alzheimer's disease than cholinesterase inhibitors alone. We synthesised a series of 3-arylbenzofuranone derivatives and evaluated their antioxidant activity, cholinesterase inhibitory activity, and monoamine oxidase inhibitory activity. 3-Arylbenzofuranone compounds exhibit good antioxidant activity as well as selective acetylcholinesterase inhibitory activity. The IC

Topics: Acetylcholinesterase; Alzheimer Disease; Animals; Anti-Anxiety Agents; Antioxidants; Benzofurans; Biphenyl Compounds; Cholinesterase Inhibitors; Dose-Response Relationship, Drug; Humans; Models, Molecular; Molecular Structure; Monoamine Oxidase; Monoamine Oxidase Inhibitors; Picrates; Rats; Rats, Wistar; Structure-Activity Relationship

The lack of effective Alzheimer's disease treatment is becoming a challenge for researchers and prompts numerous attempts to search for and develop better therapeutic solutions. Compounds that affect several routes of the neurodegeneration cascade leading to the development of disease are of particular interest. An example of such substances is resveratrol and its synthetic and natural derivatives, which have gained popularity in recent years and show promise as a possible new therapeutic option in the approach to Alzheimer's disease treatment. In this article, the state of the art evidence on the role of resveratrol (RSV) in neuroprotection is presented; research results are summarized and the importance of resveratrol and its derivatives in the treatment of Alzheimer's disease are underlined. It also focuses on various modifications of the resveratrol molecule that should be taken into account in the design of future research on drugs against Alzheimer's disease.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Benzofurans; Blood-Brain Barrier; Central Nervous System Diseases; Humans; Inflammation; Metabolic Diseases; Neuroprotection; Oxidative Stress; Resveratrol; Stilbenes; tau Proteins

Previously, we designed, synthesized, and evaluated a series of quinolone-benzofuran derivatives as multitargeted anti-Alzheimer's disease (anti-AD) compounds, and we discovered that WBQ5187 possesses superior anti-AD bioactivity. In this work, we investigated the pharmacokinetics of this new molecule, as well as its therapeutic efficacy in restoring cognition and neuropathology, in the APP/PS1 mouse model of AD. Pharmacokinetic analyses demonstrated that WBQ5187 possessed rational oral bioavailability, metabolic stability, and excellent blood-brain barrier (BBB) permeability. Pharmacodynamics studies indicated that a 12-week treatment with the lead compound at doses of 40 mg/kg or higher significantly enhanced the learning and memory performance of the APP/PS1 transgenic mice, and the effect was more potent than that of clioquinol (CQ). Furthermore, WBQ5187 notably reduced cerebral β-amyloid pathology, gliosis, and neuronal cell loss and increased the levels of cAMP in the hippocampus of these mice. The surrogate measures of emesis indicated that WBQ5187 had no effect at its cognitive effective doses. Overall, our results demonstrated that this compound markedly improves cognitive and spatial memory functions in AD mice and represents a promising pharmaceutical agent with potential for the treatment of AD.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Anesthetics, General; Animals; Benzofurans; Biological Availability; Blood-Brain Barrier; Brain Chemistry; Clioquinol; Cyclic AMP; Disease Models, Animal; Drug Evaluation, Preclinical; Gliosis; Hippocampus; Male; Maze Learning; Memory Disorders; Mice; Mice, Inbred C57BL; Mice, Transgenic; Nausea; Neuroprotective Agents; Phosphodiesterase 4 Inhibitors; Resorcinols; Second Messenger Systems; Vomiting

Oxidative stress and neuroinflammation play important roles in the pathology of Alzheimer's disease (AD). Thioredoxin-interacting protein (TXNIP), an endogenous inhibitor of antioxidant thioredoxin, is suspected to be an important modulator of oxidative stress and inflammation. However, the underlying mechanism involved in the abnormal homeostasis of TXNIP-thioredoxin (TrX) in AD pathogenesis remains unclear.. Using the Swedish mutant form of APP (APPswe)/PSEN1dE9 transgenic mouse (APP/PS1) and human-derived neuronal cells as model systems, we disclosed the impairment of the nuclear factor erythroid 2-related factor 2 (Nrf2)-TXNIP-TrX signaling in Alzheimer's-like pathology. We observed that the immune staining of TXNIP was increased in postmortem AD brain. The chronic accumulation of inflammatory mediator in neuronal cells facilitates interactions of TXNIP-nucleotide binding oligomerization domain-like receptor family, pyrin domain containing 3 (NLRP3) and NLRP3-ASC, which increases β-amyloid (Aβ) secretion. The antioxidant Dl-3-n-butylphthalide (Dl-NBP) is commonly used for cerebral ischemia treatment. In our study, we elucidated for new mechanisms by which Dl-NBP enhanced TrX activity, suppressed TXNIP, and ameliorated neuronal apoptosis in the APP/PS1 mouse brains. In human glioblastoma A172 cells and neuroblastoma SH-SY5Y cells, we delineated the Dl-NBP-mediated signaling pathways by which Dl-NBP-dependent upregulation of Nrf2 mediated the reciprocal regulation of reducing proinflammatory cytokine and inhibiting Aβ production in the glial and neuronal cells overexpressing APPswe.. Our data provide a novel insight into the molecular mechanism that impairments of Nrf2-TXNIP-TrX system may be involved in the imbalance of cellular redox homeostasis and inflammatory damage in the AD brain.. Dl-NBP treatment could suppress TXNIP-NLRP3 interaction and inhibit NLRP3 inflammasome activation via upregulating Nrf2. These findings may provide an instrumental therapeutic approach for AD. Antioxid. Redox Signal. 00, 000-000.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Amyloid Precursor Protein Secretases; Animals; Antioxidants; Apoptosis; Benzofurans; Carrier Proteins; Cell Line, Tumor; HEK293 Cells; Humans; Inflammasomes; Interleukin-1beta; Male; Mice; Mice, Transgenic; NF-E2-Related Factor 2; NLR Family, Pyrin Domain-Containing 3 Protein; Protein Binding; Thioredoxins

A series of novel Benzofuran-tetrazole derivatives were successfully synthesised by integrating multicomponent Ugi-azide reaction with the molecular hybridization approach. Interestingly, a number of synthesized derivatives (5c, 5d, 5i, 5l, 5q and 5s) exhibited significant reduction of aggregation of "human" amyloid beta peptide, expressing on transgenic Caenorhabditis elegans (C. elegans) strain CL4176. Further, in silico docking results have evidenced the exquisite interaction of active compounds with the help of TcAChE-E2020 complex. These findings underscore the potential of these hybrids as lead molecules against Alzheimers's disease.

Topics: Acetylcholinesterase; Alzheimer Disease; Amyloid beta-Peptides; Animals; Benzofurans; Caenorhabditis elegans; Cholinesterase Inhibitors; Dose-Response Relationship, Drug; Molecular Dynamics Simulation; Molecular Structure; Protein Aggregates; Structure-Activity Relationship; Tetrazoles

MMP13 (matrix metallopeptidase 13) plays a key role in bone metabolism and cancer development, but has no known functions in Alzheimer's disease. In this study, we used high-throughput small molecule screening in SH-SY5Y cells that stably expressed a luciferase reporter gene driven by the BACE1 (β-site amyloid precursor protein cleaving enzyme 1) promoter, which included a portion of the 5' untranslated region (5'UTR). We identified that CL82198, a selective inhibitor of MMP13, decreased BACE1 protein levels in cultured neuronal cells. This effect was dependent on PI3K (phosphatidylinositide 3-kinase) signalling, and was unrelated to BACE1 gene transcription and protein degradation. Further, we found that eukaryotic translation initiation factor 4B (eIF4B) played a key role, as the mutation of eIF4B at serine 422 (S422R) or deletion of the BACE1 5'UTR attenuated MMP13-mediated BACE1 regulation. In APPswe/PS1E9 mice, an animal model of Alzheimer's disease, hippocampal Mmp13 knockdown or intraperitoneal CL82198 administration reduced BACE1 protein levels and the related amyloid-β precursor protein processing, amyloid-β load and eIF4B phosphorylation, whereas spatial and associative learning and memory performances were improved. Collectively, MMP13 inhibition/CL82198 treatment exhibited therapeutic potential for Alzheimer's disease, via the translational regulation of BACE1.

Topics: Alzheimer Disease; Amyloid beta-Protein Precursor; Amyloid Precursor Protein Secretases; Animals; Aspartic Acid Endopeptidases; Benzofurans; Cells, Cultured; Cognitive Dysfunction; Eukaryotic Initiation Factors; Gene Knockdown Techniques; Hippocampus; Humans; Matrix Metalloproteinase 13; Matrix Metalloproteinase Inhibitors; Mice; Mice, Transgenic; Morpholines; Mutation; Oligopeptides; Phosphatidylinositol 3-Kinases; Rats

Alzheimer's disease (AD) is one of the most common neurodegenerative diseases with a multifactorial nature. β-Secretase (BACE1) and acetylcholinesterase (AChE), which are required for the production of neurotoxic β-amyloid (Aβ) and the promotion of Aβ fibril formation, respectively, are considered as prime therapeutic targets for AD. In our efforts towards the development of potent multi-target, directed agents for AD treatment, major phlorotannins such as eckol, dieckol, and 8,8'-bieckol from

Topics: ADAM17 Protein; Alzheimer Disease; Amyloid Precursor Protein Secretases; Aspartic Acid Endopeptidases; Benzofurans; Cholinesterase Inhibitors; Cholinesterases; Dioxins; Molecular Docking Simulation; Seaweed; Tannins

As Alzheimer's disease (AD) induces several cellular and molecular damages, it could be interesting to use multi-target molecules for therapeutics. We previously published that trans ε-viniferin induced the disaggregation of Aβ42 peptide and inhibited the inflammatory response in primary cellular model of AD. Here, effects of this stilbenoid were evaluated in transgenic APPswePS1dE9 mice. We report that trans ε-viniferin could go through the blood brain barrier, reduces size and density of amyloid deposits and decreases reactivity of astrocytes and microglia, after a weekly intraperitoneal injection at 10 mg/kg from 3 to 6 months of age.

Topics: Alzheimer Disease; Animals; Astrocytes; Benzofurans; Disease Models, Animal; Female; Inflammation; Male; Mice; Mice, Transgenic; Microglia; Plaque, Amyloid; Stilbenes

To address the multifactorial nature of Alzheimer's Disease (AD), a multi-target-directed ligand approach was herein developed. As a follow-up of our previous studies, a small library of newly designed 2-arylbenzofuran derivatives was evaluated towards cholinesterases and cannabinoid receptors. The two most promising compounds, 8 and 10, were then assessed for their neuroprotective activity and for their ability to modulate the microglial phenotype. Compound 8 emerged as able to fight AD from several directions: it restored the cholinergic system by inhibiting butyrylcholinesterase, showed neuroprotective activity against Aβ

Topics: Acetylcholinesterase; Alzheimer Disease; Amyloid beta-Peptides; Animals; Benzofurans; Butyrylcholinesterase; Catalytic Domain; Cell Line, Tumor; CHO Cells; Cholinesterase Inhibitors; Cricetulus; Drug Design; Humans; Immunologic Factors; Mice; Microglia; Molecular Docking Simulation; Neuroprotective Agents; Peptide Fragments; Protein Binding; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Small Molecule Libraries

Amyloid β (Aβ) is a key mediator for synaptic dysfunction and cognitive impairment implicated in Alzheimer's disease (AD). However, the precise mechanism of the toxic effect of Aβ is still not completely understood. Moreover, there is currently no treatment for AD. Protein kinase B (PKB, also termed Akt) is known to be aberrantly regulated in the AD brain. However, its potential function as a therapeutic target for AD-associated memory impairment has not been studied. Here, we examined the role of a direct Akt activator, SC79, in hippocampus-dependent memory impairments using Aβ-injected as well as 5XFAD AD model mice. Oligomeric Aβ injections into the 3rd ventricle caused concentration-dependent and time-dependent impairments in learning/memory and synaptic plasticity. Moreover, Aβ aberrantly regulated caspase-3, GSK-3β, and Akt signaling, which interact with each other in the hippocampus. Caspase-3 and GSK-3β inhibitor ameliorated memory impairments and synaptic deficits in Aβ-injected AD model mice. We also found that pharmacological activation of Akt rescued memory impairments and aberrant synaptic plasticity in both Aβ-treated and 5XFAD mice. These results suggest that Akt could be a therapeutic target for memory impairment observed in AD.

Topics: Acetates; Alzheimer Disease; Amyloid beta-Peptides; Animals; Avoidance Learning; Benzofurans; Benzopyrans; Disease Models, Animal; Enzyme Inhibitors; Evoked Potentials; Gene Expression Regulation; Hippocampus; Male; Memory Disorders; Mice; Mice, Inbred C57BL; Mice, Transgenic; Neuronal Plasticity; Oligopeptides; Oncogene Protein v-akt; Oxadiazoles; Peptide Fragments; Reaction Time; Recognition, Psychology

We developed an orally active and blood-brain-barrier-permeable benzofuran analogue (8, MDR-1339) with potent antiaggregation activity. Compound 8 restored cellular viability from Aβ-induced cytotoxicity but also improved the learning and memory function of AD model mice by reducing the Aβ aggregates in the brains. Given the high bioavailability and brain permeability demonstrated in our pharmacokinetic studies, 8 will provide a novel scaffold for an Aβ-aggregation inhibitor that may offer an alternative treatment for AD.

Topics: Administration, Oral; Alzheimer Disease; Amyloid beta-Peptides; Animals; Benzofurans; Biological Availability; Cell Line; Dogs; Humans; Mice; Protein Aggregates; Rats

A series of (3-hydroxy-4-pyridinone)-benzofuran hybrids have been developed and studied as potential multitargeting drugs for Alzheimer's disease (AD). Their design envisaged mainly to mimic the donepezil drug, a marketed inhibitor of acetylcholinesterase (AChE), and to endow the conjugate molecules with extra-properties such as metal chelation, radical scavenging and inhibition of amyloid peptide (Aβ) aggregation. Thus, a set of eleven new hybrid compounds was developed and evaluated for chemical and biological properties, in solution and in neuronal cell environment. The results are discussed in terms of the type of substituents on both main moieties and the linker size. The closest similarity with donepezil, in terms of AChE inhibitory activity, was obtained for the O-benzyl-hydroxypyridinone hybrids containing a 2-methylene linker, although still less active than the drug. However, the free-hydroxypyridinone hybrids present higher activity for the Aβ aggregation inhibition, metal chelating capacity and radical scavenging activity. Overall, some compounds demonstrated capacity to exert a multiple action by hitting three- (7d) or four- (8d, 8f) pathophysiological targets of AD. Furthermore, the compounds showed neuroprotective effects in neuronal cells subjected to model stressors of AD, but not significant dependence on the substituent groups. Importantly, the compounds evidenced drug-likeness properties, including good membrane permeability.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Benzofurans; Biphenyl Compounds; Cholinesterase Inhibitors; Copper; Free Radical Scavengers; Iron; Iron Chelating Agents; Molecular Docking Simulation; Neuroprotective Agents; Peptide Fragments; Picrates; Protein Multimerization; Pyridones

Alzheimer's disease (AD) is marked by several cellular and molecular damage. Therefore, the therapeutic interest of multi-target molecules is increasingly justified. Polyphenols presenting multiple pharmacological effects would be more efficient. In this study, beneficial effects of trans ε-viniferin, a natural polyphenol were thus evaluated. This study reported that this stilbenoid (1) induced the disaggregation of amyloid β (Aβ) peptide and (2) rescued inflammation in murine primary neuronal cultures. These both effects are higher than those of resveratrol, and so, trans ε-viniferin could be a good therapeutic multi-target candidate.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Anti-Inflammatory Agents; Benzofurans; Cells, Cultured; Disease Models, Animal; Mice; Neurons; Stilbenes

Alzheimer's disease (AD) is characterized by amyloid plaques that form due to an increase in amyloid-β peptide (Aβ) aggregation. One strategy in the search of new treatments for AD focuses on compounds that decrease Aβ accumulation. Compounds containing a benzofuran ring have been described to play an important role in decreasing Aβ-induced toxicity; however, only synthetic benzofurans have been tested thus far. The aim of the present study was to examine the in vitro neuroprotective properties of fomannoxin (Fx), a natural benzofuran isolated from cultures of the Andean-Patagonian fungi Aleurodiscus vitellinus, and evaluate its effect on Aβ peptide. We tested the effect of Fx at a wide concentration range (10-11-10-4 M) in PC-12 cells, and found the compound did not alter cellular viability. Fx also showed a concentration-dependent effect on the Aβ-induced toxicity in PC12 cells, showing viability above 100% at 10-6 M. We then measured the effect of Fx (10-7-10-5 M) on the frequency of cytosolic Ca2+ transients in rat hippocampal neurons at both acute and chronic (24 h) times. Acute incubation with Fx increased the frequency of cytosolic Ca2+ transients to values around 200%, whereas chronic incubation with Fx increased the frequency of Ca2+ transients. Finally, the Aβ-induced decrease in intracellular Ca2+ transients was prevented when Fx (10-6 M) was co-incubated with Aβ (5×10-6 M). The results suggest a potent neuroprotective effect of this naturally occurring benzofuran against Aβ peptide toxicity that could be mediated by an interference with it binding to plasma membrane, and lead Fx as new chemical entity to develop pharmacological tools against Aβ peptide neurotoxicity.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Basidiomycota; Benzofurans; Cell Survival; Hippocampus; Neurons; Neuroprotective Agents; PC12 Cells; Plaque, Amyloid; Rats

Alzheimer's disease (AD) is a neurodegenerative disorder representing the leading cause of dementia and is affecting nearly 44 million people worldwide. AD is characterized by a progressive decline in acetylcholine levels in the cholinergic systems, which results in severe memory loss and cognitive impairments. Expression levels and activity of butyrylcholinesterase (BChE) enzyme has been noted to increase significantly in the late stages of AD, thus making it a viable drug target. A series of hydroxylated 2-phenylbenzofurans compounds were designed, synthesized and their inhibitory activities toward acetylcholinesterase (AChE) and BChE enzymes were evaluated. Two compounds (15 and 17) displayed higher inhibitory activity towards BChE with IC

Topics: Acetylcholinesterase; Alzheimer Disease; Animals; Benzofurans; Binding Sites; Butyrylcholinesterase; Cell Line; Cholinesterase Inhibitors; Down-Regulation; Drug Design; GPI-Linked Proteins; Humans; Inhibitory Concentration 50; Mice; Models, Molecular; Molecular Docking Simulation

Mitochondrial dysfunction is a featured pathology underlying synaptic injury and neuronal stress in Alzheimer's disease (AD). In recent years, the vicious cycle between mitochondrial deficits and intra-neuronal Redox state imbalance has received considerable attention. In this regard, it is of great interest to determine whether antioxidants could alleviate mitochondrial dysfunction in AD-related conditions. Salvianolic acid B (SalB), a bioactive component of alvia miltiorrhiza Bge, is a potent antioxidant. Here we have determined the protective effect of SalB against Aβ-induced mitochondrial abnormalities. Our results showed that the application of SalB substantially alleviated intra-neuronal glutathione (GSH) and lipid oxidation and suppressed excess mitochondrial superoxide generation in Aβ-insulted neurons. Moreover, SalB has demonstrated strong protection on mitochondrial bioenergetics against Aβ toxicity evidenced by preserved mitochondrial membrane potential and ATP production, as well as rescued enzymatic activities of cytochrome C oxidase and F1Fo ATP synthase. In addition, Aβ-induced axonal mitochondrial fragmentation and increased dynamin-like protein 1 phosphorylation at Ser 616 were substantially mitigated by SalB. Lastly, the application of SalB restored synaptic density in Aβ-exposed neurons. The most parsimonious interpretation of the results is that intra-neuronal oxidative stress promotes mitochondrial dysfunction in AD-relevant pathological settings, and SalB has the potential to be a promising agent for AD therapy.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Benzofurans; Cells, Cultured; Mice; Mitochondria; Neurons; Oxidative Stress; Protective Agents

Alzheimer's disease (AD), the most common cause of dementia, is a neurodegenerative disorder characterized by progressive deterioration of memory and cognition. The evidenced multifactorial nature of AD has been considered the main reason for the absence of cure so far. Therefore, the development of novel hybrids to treat the disease is very much essential. Focusing on this, a novel series of coumarin-benzofuran hybrids have been designed and screened as anti-Alzheimer's disease agents. The strategy is to obtain an effective mimetic of donepezil, which is acetylcholinesterase inhibitor. Herein, the two main scaffolds namely coumarin and benzofuran are known pharmacophore moieties and we have performed their molecular design, pharmacokinetic descriptor studies for drug-likeliness. Further, in vitro studies such as antioxidant capacity, acetylcholinesterase (AChE) inhibition and amyloid-β (Aβ) self-aggregation inhibition have also been performed. Most importantly, these studies revealed that the newly synthesized hybrids can be versatile and promising drug-like moieties as efficient anti-AD agents.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Benzofurans; Binding Sites; Cholinesterase Inhibitors; Coumarins; Donepezil; Drug Design; Humans; Molecular Docking Simulation; Peptide Fragments; Structure-Activity Relationship

Alzheimer's disease (AD) is characterized by extracellular accumulation of β-amyloid peptides (Aβ) and intracellular neurofibrillary tangles, along with cognitive decline and neurodegeneration. The cognitive deficit is considered to be due to the dysfunction of hippocampal neurogenesis. Although L-3-n-butylphthalide (L-NBP) has been shown beneficial effects in multiple AD animal models, the underlying molecular mechanisms are still elusive. In this study, we investigated the effects of L-NBP on neurogenesis both in vitro and in vivo. L-NBP promoted proliferation and migration of neural stem cells and induced neuronal differentiation in vitro. In APP/PS1 mice, L-NBP induced neurogenesis in the dentate gyrus and improved cognitive functions. In addition, L-NBP significantly increased the expressions of BDNF and NGF, tyrosine phosphorylation of its cognate receptor, and phosphorylation of Akt as well as CREB at Ser133 in the hippocampus of APP/PS1 mice. These results indicated that L-NBP might stimulate the proliferation, migration, and differentiation of hippocampal neural stem cells and reversed cognitive deficits in APP/PS1 mice. BDNF/TrkB/CREB/Akt signaling pathway might be involved.

Topics: Alzheimer Disease; Amyloid beta-Protein Precursor; Animals; Benzofurans; Cell Differentiation; Cell Movement; Cell Proliferation; Embryo, Mammalian; Humans; Intercellular Signaling Peptides and Proteins; Male; Maze Learning; Mice; Mice, Inbred C57BL; Mice, Transgenic; Mutation; Nerve Tissue Proteins; Neural Stem Cells; Neurogenesis; Presenilin-1

Accumulation and oligomerization of amyloid-beta (Aβ) peptides have been known to be a potent cause of neurodegenerative diseases such as Alzheimer's disease (AD). To expand the possibilities of preventing AD, we investigated the effects of resveratrol dimers, gnetin C and ε-viniferin, on Aβ 1-42 (Aβ42) production and the reduced cell viability observed after Aβ42 treatment (monomers, 10 μM) in cultured SH-SY5Y human neuroblastoma cells. Among them, addition of gnetin C (20 μM) into the media reduced Aβ42 production most efficiently. Gnetin C suppressed the expression of β-site amyloid precursor protein-cleaving enzyme-1 (BACE1, β-secretase). Furthermore, gnetin C ameliorated the Aβ42-reduced cell viability most significantly. Concomitantly, gnetin C reduced intracellular Aβ oligomers (ca. 15 and 130 kDa) and elevated both levels of intracellular and extracellular Aβ monomers. Under the treatment with or without Aβ42, gnetin C upregulated the expression of matrix metalloproteinase-14 (MMP-14) which is assumed to be an Aβ-decomposing enzyme. Gnetin C may thereby prevent Aβ toxicity by suppressing BACE1 and enhancing MMP-14, together with reducing both internalization and oligomerization of exogenous Aβ monomers. The use of gnetin C may lead to the prevention of Aβ-mediated diseases, particularly AD.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Benzofurans; Cell Line, Tumor; Cell Survival; Gene Expression Regulation, Neoplastic; Humans; Neoplasm Proteins; Neuroblastoma; Peptide Fragments; Resveratrol; Stilbenes

Alzheimer disease (AD) is a neurodegenerative disorder characterized by excessive accumulation of amyloid-beta peptide (Aβ) and progressive loss of neurons. Therefore, the inhibition of Aβ-induced neurotoxicity is a potential therapeutic approach for the treatment of AD.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Apoptosis; Benzofurans; Cyclooxygenase 2; Dioxins; Down-Regulation; Drug Evaluation, Preclinical; MAP Kinase Signaling System; Neuroprotective Agents; NF-kappa B; Nitric Oxide Synthase Type II; PC12 Cells; Peptide Fragments; Phaeophyceae; Rats; Seaweed

A series of 2-benzylidene-benzofuran-3-ones were designed from the structures of Ebselen analogs and aurone derivatives and synthesized in good yields.. The target compounds were prepared by the condensation reaction between appropriate benzofuranones with amino alkoxy aldehydes and evaluated as cholinesterase inhibitors by Ellman's method.. The in vitro anti-acetylcholinesterase (AChE)/butyrylcholinesterase activities of the synthesized compounds revealed that 7e (IC. The anticholinesterase activities of benzylidene-benzofurane-3-ones as aurone analogs revealed that the compounds bearing piperidinylethoxy residue showed better activities against AChE, introducing these compounds for further drug discovery developments. [Formula: see text].

Topics: Acetylcholinesterase; Alzheimer Disease; Benzofurans; Benzylidene Compounds; Binding Sites; Butyrylcholinesterase; Cholinesterase Inhibitors; Drug Design; Drug Discovery; Humans; Kinetics; Models, Molecular; Molecular Docking Simulation; Structure-Activity Relationship

Alzheimer's Disease (AD) is one of the commonest neural degeneration in aging population, and has become a global health challenge. 2-(2-benzofuranyl)-2-imidazoline (2-BFI) was reported to effectively improved the damage of patients with neuropathological disorders. In the present study, we investigated the effect of 2-BFI on the improvement of antioxidative, inflammation, and apoptosis in AD rats. Sprague-Dawley rats (2 months old, n=40) were used in this study and after injection of Aβ1-42 into hippocampal CA1 (Cornu Ammonis) region, the rats were given high, moderate and low dose of 2-BFI though intraperitoneal (i.p.) injection. Then spatial memory and navigation ability were analyzed by Morrize Water Maze. For the molecular testing, chemical colorimetry, ELISA and immunoblotting were performed to measure the activities of antioxidative enzymes, the abundance of immune cytokines and expression of apoptotic proteins, respectively. Hematoxylin and Eosin staining was used to analyze the pathological changes. We observed that 2-BFI significantly ameliorated the learning and memory abilities in rat models with AD by dosage treatment, as demonstrated by the shorten learning latency and greater times of travel across the platform quadrant. Additionally, reactive oxygen species (ROS) and malondialdehyde (MDA), were decreased after treatment of 2-BFI with dosage dependency, while the activities of superoxidase dismutase (SOD) and (GPX) Glutathione peroxidase were in turn enhanced, suggesting that 2-BFI could protect the antioxidative enzymes and reduce the oxidative stress in the hippocampus. Moreover, the expression of inflammatory factors including TNF-a and IL-1β were decreased after 2-BFI treatment. Additionally, the neuronal apoptosis was also attenuated, as shown by Western blot results. Taken together, the cognitive impairment in AD rats could be significantly improved by 2-BFI in a dose-dependent manner through suppressing oxidants accumulation, inhibiting of inflammatory response, as well as enhancing the neural viability.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Anti-Inflammatory Agents, Non-Steroidal; Apoptosis; Benzofurans; Disease Models, Animal; Dose-Response Relationship, Drug; Hippocampus; Imidazoles; Inflammation; Maze Learning; Neuroprotective Agents; Nootropic Agents; Oxidative Stress; Peptide Fragments; Random Allocation; Rats, Sprague-Dawley; Spatial Memory; Spatial Navigation

Considering the complex etiology of Alzheimer's disease (AD), multifunctional agents may be beneficial for the treatment of this disease. A series of DL-3-n-butylphthalide-Edaravone hybrids were designed, synthesized and evaluated as novel dual inhibitors of amyloid-β aggregation and monoamine oxidases. Among them, compounds 9a-d exhibited good inhibition of self-induced Aβ

Topics: Alzheimer Disease; Amyloid beta-Peptides; Antioxidants; Antipyrine; Benzofurans; Binding Sites; Blood-Brain Barrier; Edaravone; Humans; Hydrogen Bonding; Inhibitory Concentration 50; Molecular Docking Simulation; Monoamine Oxidase; Monoamine Oxidase Inhibitors; Protein Binding; Protein Structure, Tertiary

Twenty-six new tacrine-benzofuran hybrids were designed, synthesized, and evaluated in vitro on key molecular targets for Alzheimer's disease. Most hybrids exhibited good inhibitory activities on cholinesterases and β-amyloid self-aggregation. Selected compounds displayed significant inhibition of human β-secretase-1 (hBACE-1). Among the 26 hybrids, 2e showed the most interesting profile as a subnanomolar selective inhibitor of human acetylcholinesterase (hAChE) (IC50 = 0.86 nM) and a good inhibitor of both β-amyloid aggregation (hAChE- and self-induced, 61.3% and 58.4%, respectively) and hBACE-1 activity (IC50 = 1.35 μM). Kinetic studies showed that 2e acted as a slow, tight-binding, mixed-type inhibitor, while X-ray crystallographic studies highlighted the ability of 2e to induce large-scale structural changes in the active-site gorge of Torpedo californica AChE (TcAChE), with significant implications for structure-based drug design. In vivo studies confirmed that 2e significantly ameliorates performances of scopolamine-treated ICR mice. Finally, 2e administration did not exhibit significant hepatotoxicity.

Topics: Alzheimer Disease; Amyloid Precursor Protein Secretases; Animals; Aspartic Acid Endopeptidases; Behavior, Animal; Benzofurans; Cell Line; Cell Survival; Chemical and Drug Induced Liver Injury; Cholinesterase Inhibitors; Crystallography, X-Ray; Drug Design; Humans; Male; Mice; Mice, Inbred ICR; Models, Molecular; Nootropic Agents; Structure-Activity Relationship; Tacrine; Torpedo

Synapse impairment in the Alzheimer's disease (AD) brain is an early event leading to cognitive dysfunction. Most oxidative stress localizes to the synapse, and synapse loss is the basis of cognitive decline in AD. Dl-3-n-butylphthalide (Dl-NBP), a small molecule compound has been shown to ameliorate oxidative stress. We evaluated the effects of a 5-month oral delivery with Dl-NBP on oxidative stress and cognitive function in APP/PS1 transgenic mice. Dl-NBP treatment reduced oxidative stress in the APP/PS1 mouse brain and alleviated learning and memory deficits. Dl-NBP supplementation meliorated synaptic plasticity, diminished soluble amyloid beta and amyloid beta oligomer in the APP/PS1 mouse brain. Dl-NBP administration caused an increase of cyclic adenosine monophosphate-response element binding protein (CREB)-binding protein (CBP)-associated Ser133-phosphorylated CREB (p-CREB) protein. Chromatin immunoprecipitation analysis revealed that Dl-NBP increased the recruitment of CBP to the promoters of best-characterized genes downstream of nuclear factor erythroid 2-related factor 2, nicotinamide adenine dinucleotide phosphate (NADPH) quinone oxidoreductase 1, and γ-glutamylcysteine synthetase modifier subunit. We demonstrate that the Dl-NBP-triggered upregulation of antioxidant defenses is involved in the enhancement of cross talk between CREB and nuclear factor erythroid 2-related factor 2 via CBP. Our results suggest that Dl-NBP may be a useful agent for the treatment of AD.

Topics: Administration, Oral; Alzheimer Disease; Amyloid beta-Peptides; Animals; Antioxidants; Benzofurans; Brain; Cognition; Cyclic AMP Response Element-Binding Protein; Disease Models, Animal; Male; Mice, Inbred C57BL; Mice, Transgenic; Neuronal Plasticity; NF-E2-Related Factor 2; Oxidative Stress; Up-Regulation

A series of 4-hydroxyl aurone derivatives were designed synthesized and evaluated as potential multifunctional agents for the treatment of Alzheimer's disease. The results demonstrated that most of the derivatives exhibited good multifunctional properties. Among them, compound 14e displayed good inhibitory activities of self- and Cu(2+)-induced Aβ1-42 aggregation with 99.2% and 84.0% at 25μM, respectively, and high antioxidant activity with a value 1.90-fold of Trolox. In addition, 14e also showed remarkable inhibitory activities of both monoamine oxidase A and B with IC50 values of 0.271μM and 0.393μM, respectively. However the 6-methoxyl aurones 15a-c revealed excellent selectivity toward MAO-B. Furthermore, the representative compounds 14e and 15b displayed good metal-chelating abilities and blood-brain barrier (BBB) permeabilities in vitro.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Antioxidants; Benzofurans; Blood-Brain Barrier; Chelating Agents; Copper; Humans; Models, Molecular; Monoamine Oxidase; Monoamine Oxidase Inhibitors; Peptide Fragments; Protein Aggregates; Swine

Alzheimer's disease (AD) is a neurodegenerative disease in humans. The accumulation of amyloid-β (Aβ) plays a critical role in the pathogenesis of AD. Previous studies indicated that Salvianolic acid B (SalB) could ameliorate Aβ-induced memory impairment. However, whether SalB could influence the generation of Aβ is unclear. Here, we show that SalB (25, 50, or 100 µM) reduces the generation of Aβ40 and Aβ42 in culture media by decreasing the protein expressions of BACE1 and sAPPβ in SH-SY5Y-APPsw cells. Meanwhile, SalB increases the levels of ADAM10 and sAPPα in the cells. However, SalB has no impact on the protein expressions of APP and PS1. Moreover, SalB attenuates oxidative stress and inhibits the activity of GSK3β, which might be related to the suppression of BACE1 expression and amyloidogenesis. Our study suggests that SalB is a promising therapeutic agent for AD by targeting Aβ generation.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Amyloid beta-Protein Precursor; Amyloid Precursor Protein Secretases; Aspartic Acid Endopeptidases; Benzofurans; Cell Line; Gene Expression Regulation, Enzymologic; Humans; Molecular Structure; Salvia miltiorrhiza

Therapeutic approach for Alzheimer's disease (AD) is still deficient. To find active compounds from herbal medicine is of interest in the alleviation of AD symptoms. This study aimed to investigate the protective effects of Tanshinone IIA (TIIA) on memory performance and synaptic plasticity in a transgenic AD model at the early phase. 25-100 mg/kg TIIA (intraperitoneal injection, i.p.) was administered to the six-month-old APP and PS1 transgenic mice for 30 consecutive days. After treatment, spatial memory, synaptic plasticity, and related mechanisms were investigated. Our result showed that memory impairment in AD mice was mitigated by 50 and 100 mg/kg TIIA treatments. Hippocampal long-term potentiation was impaired in AD model but rescued by 100 mg/kg TIIA treatment. Mechanically, TIIA treatment reduced the accumulations of beta-amyloid 1-42, C-terminal fragments (CTFs), and p-Tau in the AD model. TIIA did not affect basal BDNF but promoted depolarization-induced BDNF synthesis in the AD mice. Taken together, TIIA repairs hippocampal LTP and memory, likely, through facilitating the clearance of AD-related proteins and activating synaptic BDNF synthesis. TIIA might be a candidate drug for AD treatment.

Topics: Alzheimer Disease; Amyloid beta-Protein Precursor; Animals; Benzofurans; Disease Models, Animal; Humans; Mice; Mice, Transgenic; Presenilin-1

Our previous studies showed that L-3-n-butylphthalide (L-NBP), an extract from seeds of Apium graveolens Linn (Chinese celery), improved cognitive ability in animal models of cerebral ischemia, vascular dementia, and Alzheimer's disease (AD). It is well known that cognitive deficit of AD is caused by synaptic dysfunction. In this study, we investigated the effect of L-NBP on hippocampal synaptic function in APP/PS1 AD transgenic mice and related mechanisms.. Eighteen-month-old APP/PS1 transgenic (Tg) mice were administrated 15 mg/kg L-NBP by oral gavage for 3 months. Synaptic morphology and the thickness of postsynaptic density (PSD) in hippocampal neurons were investigated by electron microscope. The dendritic spines, Aβ plaques, and glial activation were detected by staining. The expressions of synapse-related proteins were observed by Western blotting.. L-NBP treatment significantly increased the number of synapses and apical dendritic thorns and the thickness of PSD, increased the expression levels of synapse-associated proteins including PSD95, synaptophysin (SYN), β-catenin, and GSK-3β, and attenuated Aβ plaques and neuroinflammatory responses in aged APP/PS1 Tg mice.. L-NBP may restore synaptic and spine function in aged APP Tg mice through inhibiting Aβ plaques deposition and neuroinflammatory response. Wnt/β-catenin signaling pathway may be involved in L-NBP-related restoration of synaptic function.

Topics: Alzheimer Disease; Amyloid beta-Protein Precursor; Animals; Benzofurans; beta Catenin; Dendritic Spines; Disease Models, Animal; Disks Large Homolog 4 Protein; Gene Expression Regulation; Glycogen Synthase Kinase 3 beta; Hippocampus; Humans; Intracellular Signaling Peptides and Proteins; Male; Membrane Proteins; Mice; Mice, Inbred C57BL; Mice, Transgenic; Mutation; Neuroprotective Agents; Presenilin-1; Synapses

Alzheimer's disease (AD), a progressive and neurodegenerative disorder of the brain, is the most common cause of dementia among elderly people. To date, the successful therapeutic strategy to treat AD is maintaining the levels of acetylcholine by inhibiting acetylcholinesterase (AChE). In the present study, aurone derivatives were designed and synthesized as AChE inhibitors based on the lead structure of sulfuretin. Of those synthesized, compound 10d showed ca. 1700-fold and 6-fold higher AChE inhibitory activity than sulfuretin and galantamine, respectively. This compound also ameliorated scopolamine-induced memory deficit in mice when administered orally at the dose of 1 and 2mg/kg.

Topics: Alzheimer Disease; Animals; Benzofurans; Cholinesterase Inhibitors; Male; Mice

Accumulation and deposition of amyloid-β peptide (Aβ) in the brain is a primary cause of the pathogenesis of Alzheimer's disease (AD). Aβ is generated from amyloid-β precursor protein (APP) through sequential cleavages first by β-secretase and then by γ-secretase. Inhibiting β-secretase activity is believed to be one of the most promising strategies for AD treatment. In the present study, we found that a resveratrol trimer, miyabenol C, isolated from stems and leaves of the small-leaf grape (Vitisthunbergii var. taiwaniana), can markedly reduce Aβ and sAPPβ levels in both cell cultures and the brain of AD model mice. Mechanistic studies revealed that miyabenol C affects neither protein levels of APP, the two major α-secretases ADAM10 and TACE, and the γ-secretase component Presenilin 1, nor γ-secretase-mediated Notch processing and TACE activity. In contrast, although miyabenol C has no effect on altering protein levels of the β-secretase BACE1, it can inhibit both in vitro and in vivo β-secretase activity. Together, our results indicate that miyabenol C is a prominent β-secretase inhibitor and lead compound for AD drug development.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Amyloid beta-Protein Precursor; Amyloid Precursor Protein Secretases; Animals; Benzofurans; Brain; Cell Line, Tumor; Enzyme Activation; Humans; Mice; Mice, Transgenic; Plant Extracts; Proteolysis; Solubility; Stilbenes

Five polyphenols were isolated and purified from a brown alga Ecklonia cava. These compounds showed diverse biological activities such as antioxidative, antiinflammatory, and enzyme inhibitory activities. This led us to investigate the potential of these compounds as Alzheimer's disease drugs. All of the compounds showed moderate acetylcholinesterase inhibitory activity in a micromolar range (IC50 from 16.0 to 96.3 μM). For butyrylcholinesterase, a new target for the treatment of Alzheimer's disease, phlorofucofuroeckol-A (PFF-A), showed a particularly potent inhibitory activity (IC50 0.95 μM), which is over 100-fold greater than for acetylcholinesterase. These compounds inhibited glycogen synthase kinase 3 beta, which is related to the formation of hyperphosphorylated tau and generation Aβ. Bieckol and PFF-A inhibited amyloid precursor protein biosynthesis. PFF-A also showed very strong β-secretase inhibitory activity with IC50 of submicromole. These results render these compounds as interesting potential drug candidates for Alzheimer's disease.

Topics: Acetylcholinesterase; Alzheimer Disease; Amyloid beta-Peptides; Amyloid Precursor Protein Secretases; Benzofurans; Butyrylcholinesterase; Cell Line; Cholinesterase Inhibitors; Dioxins; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Humans; Phaeophyceae; Polyphenols

A series of benzofuran-based N-benzylpyridinium derivatives 5a-o were designed and synthesized as novel AChE inhibitors. The synthetic pathway of the compounds involved the preparation of 4-(benzofuran-2-yl)pyridine intermediates via the reaction of different salicylaldehyde derivatives and 4-(bromomethyl)pyridine, followed by intramolecular cyclization. Subsequently, the 4-(benzofuran-2-yl)pyridines were N-benzylated by using appropriate benzyl bromide to afford the final product 5a-o. The results of in vitro AChE activity evaluation of synthesized compounds revealed that all compound had potent anti-AChE activity comparable or more potent than standard drug donepezil. The N-(3,5-dimethylbenzyl) derivative 5e with IC50 value of 4.1 nM was the most active compound, being 7-fold more potent than donepezil.

Topics: Acetylcholinesterase; Alzheimer Disease; Benzofurans; Cholinesterase Inhibitors; Drug Design; Humans; Molecular Docking Simulation; Molecular Structure; Pyridinium Compounds; Structure-Activity Relationship

The novel effects of artoindonesianin O, a dietary phenolic compound from mulberry, were investigated on oligomer Aβ42-, NMDA- or okadaic-acid-induced neurotoxicity and the restorative effect on the oligomer Aβ42-induced synapses dysfunction using rat hippocampus neuron cells in vitro. The phenolic compound of AIO can exert neuroprotection by blocking oligomer Aβ42- or NMDA-induced neurotoxicity and okadaic-acid-induced tau protein hyperphosphorylation through inhibiting the expression of kinase p-ERK1/2. Meanwhile, it is also beneficial to synaptic plasticity. These interesting results strongly suggest that AIO, which is rich in abundant sources of mulberry and other fruits, is suitable and possible candidate for the development of general food type neuroprotection on AD by protecting against brain damage and memory impairment.

Topics: Alzheimer Disease; Animals; Benzofurans; Brain; Cells, Cultured; Flavonoids; Humans; MAP Kinase Signaling System; Morus; Neuronal Plasticity; Neurons; Neuroprotective Agents; Plant Extracts; Rats; Rats, Sprague-Dawley

New benzofuranylthiazole derivatives containing the aryl-urea moiety were synthesized and evaluated in vitro as dual acetylcholinesterase (AChE)-butyrylcholinesterase (BuChE) inhibitors. In addition, the cupric reducing antioxidant capacities (CUPRAC) and ABTS cation radical scavenging abilities of the synthesized compounds were assayed. The result showed that all the synthesized compounds exhibited inhibitory activity on both AChE and BuChE with 1-(4-(5-bromobenzofuran-2-yl)thiazol-2-yl)-3-(2-fluorophenyl)urea (e25, IC50 value of 3.85 μM) and 1-(4-iodophenyl)-3-(4-(5-nitrobenzofuran-2-yl)thiazol-2-yl)urea (e38, IC50 value of 2.03 μM) as the strongest inhibitors against AChE and BuChE, respectively. Compound e38 was 8.5-fold more potent than galanthamine. The selectivity index of e25 and e38 was 2.40 and 0.37 against AChE and BuChE, respectively. Compound e2, e4 and e11 (IC50 = 0.2, 0.5 and 1.13 μM, respectively) showed a better ABTS cation radical scavenging ability than the standard quercetin (IC50 = 1.18 μM). Best poses of compounds e38 on BuChE and e25 on AChE indicate that the thiazole ring and the amidic moiety are important sites of interaction with both ChEs. In addition, the benzofuran ring and phenyl ring are anchored to the side chains of both enzymes by π-π(pi-pi) interactions.

Topics: Acetylcholinesterase; Alzheimer Disease; Animals; Antioxidants; Benzofurans; Butyrylcholinesterase; Cholinesterase Inhibitors; Dose-Response Relationship, Drug; Humans; Molecular Dynamics Simulation; Molecular Structure; Structure-Activity Relationship; Thiazoles; Torpedo; Urea

In order to explore novel tau-imaging agents that can selectively detect neurofibrillary tangles in Alzheimer's disease (AD) brains, we designed and synthesized a series of heterocyclic phenylethenyl and (3-pyridinyl)ethenyl derivatives with or without a dimethyl amino group. In in vitro autoradiography using AD brain sections, all radioiodinated ligands with a dimethyl amino group bound to Aβ deposits in the sections. In contrast, the ligands without a dimethyl amino group showed different patterns of radioactivity accumulation in the sections depending on the kind of heterocycle contained in their molecules. Particularly, a phenylethenyl benzimidazole derivative ([(125)I]64) showed marked radioactivity accumulation in the temporal lobe which corresponded with the distribution of tau deposits. [(125)I]64 also showed the most favorable pharmacokinetics in normal mouse brains (3.69 and 0.06% ID/g at 2 and 60 min postinjection, respectively) among all ligands in this study. Taken together, these results suggest that [(123)I]64 may be a new candidate tau-imaging agent.

Topics: Aged; Alzheimer Disease; Amyloid beta-Peptides; Animals; Autoradiography; Benzimidazoles; Benzofurans; Benzothiazoles; Benzoxazoles; Brain; Humans; Iodine Radioisotopes; Male; Mice; Neurofibrillary Tangles; Pyridines; Radionuclide Imaging; Radiopharmaceuticals; Stereoisomerism; Structure-Activity Relationship; Styrenes; tau Proteins; Temporal Lobe; Thiophenes

A novel series of clioquinol-moracin hybrids were designed and synthesized by fusing the pharmacophores of clioquinol and moracin M, and their activities as multitarget-directed ligands against Alzheimer's disease were evaluated. Biological activity results demonstrated that these hybrids possessed significant inhibitory activities against phosphodiesterase 4D (PDE4D) and Aβ aggregation as well as remarkable antioxidant effects and excellent blood-brain barrier permeability. The optimal compound, 18d (WBQ5187), exhibited excellent PDE4D inhibitory potency (IC50 = 0.32 μM), significant antioxidant effects, appropriate biometal chelating functions, and interesting properties that modulated self- and metal-induced Aβ aggregation. Two-dimensional NMR studies revealed that 18d had significant interactions with Aβ1-42 at the R5, H6, H14, Q15, and F20 residues. Furthermore, this typical hybrid possessed preeminent neuroprotective effects against inflammation in microglial cells. Most importantly, oral administration of 18d·HCl demonstrated marked improvements in cognitive and spatial memory in a rat model of Alzheimer's disease and protected hippocampal neurons from necrosis.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Antioxidants; Benzofurans; Clioquinol; Cognition; Cyclic Nucleotide Phosphodiesterases, Type 4; Inflammation; Ligands; Male; Memory; Models, Molecular; Neurons; Neuroprotective Agents; Phosphodiesterase 4 Inhibitors; Protein Aggregates; Rats; Rats, Wistar; Resorcinols

Alzheimer's disease is an irreversible neurodegenerative disorder that is characterized by the abnormal aggregation of amyloid-β into neurotoxic oligomers and plaques. Although many disease-modifying molecules are currently in Alzheimer clinical trials, a small molecule that inhibits amyloid-β aggregation and ameliorates the disorder has not been approved to date. Herein, we report the effects of a potent small molecule, 6-methoxy-2-(4-dimethylaminostyryl) benzofuran (KMS88009), that directly disrupts amyloid-β oligomerization, preserving cognitive behavior when used prophylactically and reversing declines in cognitive behavior when used therapeutically. KMS88009 exhibited excellent pharmacokinetic profiles with extensive brain uptake and a high level of safety. When orally administered before and after the onset of Alzheimer's disease symptoms, KMS88009 significantly reduced assembly of amyloid-β oligomers and improved cognitive behaviors in the APP/PS1 double transgenic mouse model. The unique dual mode of action indicates that KMS88009 may be a powerful therapeutic candidate for the treatment of Alzheimer's disease.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Benzofurans; Cognition Disorders; Disease Models, Animal; Male; Mice; Mice, Transgenic

Alzheimer's disease (AD) is a progressive neurodegenerative disease. Amyloid-β protein (Aβ), the hallmark of AD, invokes a cascade of mitochondrial dysfunction and eventually leads to neuronal death. l-3-n-Butylphthalide (l-NBP) has shown the potent neuroprotective effects in stroke and AD animal models. The present study is to evaluate the neuroprotective effect of l-NBP on Aβ25-35-induced neuronal injury and the possible mechanism in the human neuroblastoma SH-SY5Y cells. Our results showed that l-NBP significantly attenuated Aβ25-35-induced cell death and reduced neuronal apoptosis. l-NBP significantly inhibited Aβ25-35-induced mitochondrial dysfunction, including mitochondrial membrane potential reduction, and reactive oxygen species production. Furthermore, l-NBP could partially reverse the elevations of Aβ25-35-induced active caspase-3, caspase-9, and cytochrome c expressions, and the downregulation of anti-apoptosis protein Bcl-2. Moreover, l-NBP markedly inhibited the activations of p38 mitogen-activated protein kinase and c-Jun N-terminal kinase/stress-activated protein kinase signaling pathway. These results demonstrated that l-NBP was capable of protecting neuronal cells from Aβ25-35-induced toxicity through a mitochondrial-dependent apoptotic pathway. Thus, l-NBP shows promising candidate of multi-target neuronal protective agent for the treatment of AD.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Apoptosis; Benzofurans; Caspase 3; Caspase 9; Humans; MAP Kinase Signaling System; Membrane Potential, Mitochondrial; Mitochondria; Molecular Structure; Neuroblastoma; Neuroprotective Agents; p38 Mitogen-Activated Protein Kinases; Peptide Fragments; Reactive Oxygen Species; Signal Transduction

Since the imaging of β-amyloid (Aβ) plaques in the brain is believed to be a useful tool for the early diagnosis of Alzheimer's disease (AD), a number of imaging probes to detect Aβ plaques have been developed. Because the radionuclide (68)Ga (t1/2=68 min) for PET imaging could become an attractive alternative to (11)C and (18)F, we designed and synthesized a benzofuran derivative conjugated with a (68)Ga complex ((68)Ga-DOTA-C3-BF) as a novel Aβ imaging probe. In an in vitro binding assay, Ga-DOTA-C3-BF showed high affinity for Aβ(1-42) aggregates (Ki=10.8 nM). The Ga-DOTA-C3-BF clearly stained Aβ plaques in a section of Tg2576 mouse, reflecting the affinity for Aβ(1-42) aggregates in vitro. In a biodistribution study in normal mice, (68)Ga-DOTA-C3-BF displayed low initial uptake (0.45% ID/g) in the brain at 2 min post-injection. While improvement of the brain uptake of (68)Ga complexes appears to be essential, these results suggest that novel PET imaging probes that include (68)Ga as the radionuclide for PET may be feasible.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Benzofurans; Disease Models, Animal; Gallium Radioisotopes; Mice; Mice, Transgenic; Molecular Imaging; Organometallic Compounds; Peptide Fragments; Plaque, Amyloid; Positron-Emission Tomography; Radiopharmaceuticals

In the search for effective multifunctional agents for the treatment of Alzheimer's disease (AD), a series of novel hybrids incorporating benzofuran and chalcone fragments were designed and synthesized. These hybrids were screened by using a transgenic Caenorhabditis elegans model that expresses the human β-amyloid (Aβ) peptide. Among the hybrids investigated, (E)-3-(7-methyl-2-(4-methylbenzoyl)benzofuran-5-yl)-1-phenylprop-2-en-1-one (4 f), (E)-3-(2-benzoyl-7-methylbenzofuran-5-yl)-1-phenylprop-2-en-1-one (4 i), and (E)-3-(2-benzoyl-7-methylbenzofuran-5-yl)-1-(thiophen-2-yl)prop-2-en-1-one (4 m) significantly decreased Aβ aggregation and increased acetylcholine (ACh) levels along with the overall availability of ACh at the synaptic junction. These compounds were also found to decrease acetylcholinesterase (AChE) levels, reduce oxidative stress in the worms, lower lipid content, and to provide protection against chemically induced cholinergic neurodegeneration. Overall, the multifunctional effects of these hybrids qualify them as potential drug leads for further development in AD therapy.

Topics: Acetylcholine; Acetylcholinesterase; Alzheimer Disease; Amyloid beta-Peptides; Animals; Animals, Genetically Modified; Antioxidants; Benzofurans; Binding Sites; Caenorhabditis elegans; Chalcone; Chalcones; Crystallography, X-Ray; Disease Models, Animal; Humans; Microscopy, Fluorescence; Molecular Conformation; Molecular Docking Simulation; Oxidative Stress; Protein Structure, Tertiary; Structure-Activity Relationship; Thiophenes

P73 belongs to the p53 family of cell survival regulators with the corresponding locus Trp73 producing the N-terminally distinct isoforms, TAp73 and DeltaNp73. Recently, two studies have implicated the murine Trp73 in the modulation in phospho-tau accumulation in aged wild type mice and in young mice modeling Alzheimer's disease (AD) suggesting that Trp73, particularly the DeltaNp73 isoform, links the accumulation of amyloid peptides to the creation of neurofibrillary tangles (NFTs). Here, we reevaluated tau pathologies in the same TgCRND8 mouse model as the previous studies.. Despite the use of the same animal models, our in vivo studies failed to demonstrate biochemical or histological evidence for misprocessing of tau in young compound Trp73+/- + TgCRND8 mice or in aged Trp73+/- mice analyzed at the ages reported previously, or older. Secondly, we analyzed an additional mouse model where the DeltaNp73 was specifically deleted and confirmed a lack of impact of the DeltaNp73 allele, either in heterozygous or homozygous form, upon tau pathology in aged mice. Lastly, we also examined human TP73 for single nucleotide polymorphisms (SNPs) and/or copy number variants in a meta-analysis of 10 AD genome-wide association datasets. No SNPs reached significance after correction for multiple testing and no duplications/deletions in TP73 were found in 549 cases of AD and 544 non-demented controls.. Our results fail to support P73 as a contributor to AD pathogenesis.

Topics: Aged; Aged, 80 and over; Alzheimer Disease; Animals; Benzofurans; Blotting, Western; Disease Models, Animal; DNA-Binding Proteins; Female; Genetic Predisposition to Disease; Genome-Wide Association Study; Genotype; Humans; Immunohistochemistry; Male; Mice; Mice, Transgenic; Nuclear Proteins; Polymorphism, Single Nucleotide; Quinolines; tau Proteins; Tumor Protein p73; Tumor Suppressor Proteins

Salvianolic acid B (SalB) is a polyphenolic compound found in Salvia miltiorrhiza Bunge that has several anti-oxidative and anti-inflammatory effects. In the present study, we investigated whether SalB has neuroprotective effects in an amyloid β (Aβ) peptide-induced Alzheimer's disease mouse model. Mice were injected with Aβ25-35 peptide intracerebroventricularly and were subsequently administered SalB once daily for 7 days. Subchronic SalB administration (10mg/kg) significantly ameliorated the Aβ25-35 peptide-induced memory impairment in the passive avoidance task (P<0.05). SalB treatment also reduced the number of activated microglia and astrocytes that were observed during the inflammatory reaction after the administration of the Aβ25-35 peptide. Moreover, SalB markedly reduced inducible nitric oxide synthase and cyclooxygenase-2 expression levels and thiobarbituric acid reactive substances, which were increased by the administration of the Aβ25-35 peptide. Furthermore, SalB administration significantly rescued the Aβ25-35 peptide-induced decrease of choline acetyltransferase and brain-derived neurotrophic factor protein levels. These results suggest that SalB exerts neuroprotective activity via anti-inflammatory and anti-oxidative effects and that SalB may be a potential candidate for Alzheimer's disease therapy.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Anti-Inflammatory Agents; Avoidance Learning; Behavior, Animal; Benzofurans; Brain-Derived Neurotrophic Factor; Choline O-Acetyltransferase; Cognition Disorders; Cyclooxygenase 2; Disease Models, Animal; Hippocampus; Lipid Peroxidation; Male; Mice; Mice, Inbred ICR; Neuroglia; Neuroprotective Agents; Nitric Oxide Synthase Type II; Peptide Fragments

Alzheimer's disease (AD) is a progressive neurodegenerative disorder. There is a consensus that Aβ is a pathologic agent and that its toxic effects, which are at present incompletely understood, may occur through several potential mechanisms. Polyphenols are known to have wide-ranging properties with regard to health and for helping to prevent various diseases like neurodegenerative disorders. Thus inhibiting the formation of toxic Aβ assemblies is a reasonable hypothesis to prevent and perhaps treat AD METHODS: Solution NMR and molecular modeling were used to obtain more information about the interaction between the Aβ1-40 and the polyphenol ε-viniferin glucoside (EVG) and particularly the Aβ residues involved in the complex.. The study demonstrates the formation of a complex between two EVG molecules and Aβ1-40 in peptide characteristic regions that could be in agreement with the inhibition of aggregation. Indeed, in previous studies, we reported that EVG strongly inhibited in vitro the fibril formation of the full length peptides Aβ1-40 and Aβ1-42, and had a strong protective effect against PC12 cell death induced by these peptides.. For the full length peptide Aβ1-40, the binding sites observed could explain the EVG inhibitory effect on fibrillization and thus prevent amyloidogenic neurotoxicity.. Even though this interaction might be important at the biological level to explain the protective effect of polyphenols in neurodegenerative diseases, caution is required when extrapolating this in vitro model to human physiology.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Benzofurans; Binding Sites; Cell Line, Tumor; Glucosides; Magnetic Resonance Spectroscopy; Models, Molecular; PC12 Cells; Peptide Fragments; Polyphenols; Protein Conformation; Rats; Stilbenes

Activation of astrocytes is a common feature of Alzheimer's disease (AD). Proinflammatory molecules produced by activated astrocytes contribute to neuronal damage in AD. Moreover, dl-3-n-butylphthalide (NBP) has been reported to attenuate astroglial activation and exert neuroprotective effects in AD transgenic mice. However, the mechanism by which NBP inhibits activated astrocytes is poorly understood.. In this study, the primary astrocytes were obtained from the cerebral cortices of 1-day-old Sprague-Dawley rats. The levels of GFAP, COX-2, NF-κB, and IκBα were examined by Western blotting and the levels of TNF-α and IL-6 were determined by ELISA.. NBP inhibited the amyloid-β (Aβ)-induced activation of astrocytes and the up-regulation of proinflammatory molecules. Importantly, NBP markedly suppressed Aβ-induced IκBα degradation and nuclear factor-κB (NF-κB) translocation.. Our results suggest that NBP attenuates Aβ-induced activation of astrocytes and neuroinflammation via inhibition of the NF-κB signaling pathway.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Astrocytes; Benzofurans; Cells, Cultured; Cerebral Cortex; Cyclooxygenase 2; I-kappa B Proteins; Interleukin-6; Mice; Mice, Transgenic; Nerve Tissue Proteins; Neuroprotective Agents; NF-kappa B; NF-KappaB Inhibitor alpha; Rats; Rats, Sprague-Dawley; Signal Transduction; Transcription Factor RelA; Tumor Necrosis Factor-alpha; Up-Regulation

Imaging of β-amyloid (Aβ) plaques in the brain may facilitate the diagnosis of cerebral β-amyloidosis, risk prediction of Alzheimer's disease (AD), and effectiveness of anti-amyloid therapies. The purpose of this study was to evaluate novel (123)I-labeled pyridyl benzofuran derivatives as SPECT probes for Aβ imaging. The formation of a pyridyl benzofuran backbone was accomplished by Suzuki coupling. [(123)I/(125)I]-labeled pyridyl benzofuran derivatives were readily prepared by an iododestannylation reaction. In vitro Aβ binding assays were carried out using Aβ(1-42) aggregates and postmortem human brain sections. Biodistribution experiments were conducted in normal mice at 2, 10, 30, and 60 min postinjection. Aβ labeling in vivo was evaluated by small-animal SPECT/CT in Tg2576 transgenic mice injected with [(123)I]8. Ex vivo autoradiography of the brain sections was performed after SPECT/CT. Iodinated pyridyl benzofuran derivatives showed excellent affinity for Aβ(1-42) aggregates (2.4 to 10.3 nM) and intensely labeled Aβ plaques in autoradiographs of postmortem AD brain sections. In biodistribution experiments using normal mice, all these derivatives displayed high initial uptake (4.03-5.49% ID/g at 10 min). [(125)I]8 displayed the quickest clearance from the brain (1.30% ID/g at 60 min). SPECT/CT with [(123)I]8 revealed higher uptake of radioactivity in the Tg2576 mouse brain than the wild-type mouse brain. Ex vivo autoradiography showed in vivo binding of [(123)I]8 to Aβ plaques in the Tg2576 mouse brain. These combined results warrant further investigation of [(123)I]8 as a SPECT imaging agent for visualizing Aβ plaques in the AD brain.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Benzofurans; Brain; Contrast Media; Humans; Iodine Radioisotopes; Male; Mice; Mice, Transgenic; Microtomy; Peptide Fragments; Plaque, Amyloid; Pyridines; Tissue Fixation; Tomography, Emission-Computed, Single-Photon

Epidemiological evidence implies a role for chronic stress and stress-related disorders in the etiopathogenesis of sporadic Alzheimer's disease (AD). Although chronic stress exposure during various stages of life has been shown to exacerbate AD-related cognitive deficits and neuropathology in AD mouse models, the role of stress exposure during the prenatal period on AD development and progression remained to be investigated. The present study therefore explored the effects of prenatal maternal stress (PMS) in both male and female APPswe/PS1dE9 mouse offspring in terms of cognition, affect, and AD-related neuropathology. As prenatal perturbations are likely to mediate their effects via alterations in epigenetic regulation, changes in hippocampal DNA methyltransferase 3a, 5-methylcytosine and 5-hydroxymethylcytosine levels were assessed as underlying mechanisms. Repetitive restraint stress during the first week of gestation exerted a sex-dependent effect, with male PMS mice showing spatial memory deficits and a blunted hypothalamus-pituitary-adrenal axis response, while female PMS mice showed improved spatial memory performance, increased depressive-like behavior, as well as a decrease in hippocampal plaque load. In addition, sex differences were observed among APPswe/PS1dE9 mice, independent of PMS (i.e., female mice showed impaired spatial memory performance, higher hippocampal plaque load, altered amyloid precursor protein processing in the CA3 and lower DNA methyltransferase 3a immunoreactivity in the dentate gyrus when compared with male mice of the same age). In conclusion, PMS exposure impacts on the behavioral phenotype and neuropathology of APPswe/PS1dE9 mice. Moreover, given the remarkable sex differences observed, one should not overlook the impact of sex-specific responses to environmental exposures when investigating gene-environment interactions in AD.

Topics: 5-Methylcytosine; Alzheimer Disease; Amyloid beta-Protein Precursor; Animals; Behavioral Symptoms; Benzofurans; Cognition Disorders; Cytosine; Disease Models, Animal; DNA (Cytosine-5-)-Methyltransferases; DNA Methyltransferase 3A; Female; Hippocampus; Humans; Male; Memory Disorders; Mice; Mice, Transgenic; Pregnancy; Prenatal Exposure Delayed Effects; Presenilin-1; Quinolines; Space Perception; Stress, Psychological

In addition to the amyloidogenic pathway, amyloid precursor protein (APP) can be cleaved by α-secretases, producing soluble and neuroprotective APP alpha (sAPPα) (nonamyloidogenic pathway) and thus preventing the generation of pathogenic amyloid-β. However, the mechanisms regulating APP cleavage by α-secretases remain poorly understood. Here, we showed that expression of serotonin type 4 receptors (5-HT(4)Rs) constitutively (without agonist stimulation) induced APP cleavage by the α-secretase ADAM10 and the release of neuroprotective sAPPα in HEK-293 cells and cortical neurons. This effect was independent of cAMP production. Interestingly, we demonstrated that 5-HT(4) receptors physically interacted with the mature form of ADAM10. Stimulation of 5-HT(4) receptors by an agonist further increased sAPPα secretion, and this effect was mediated by cAMP/Epac signaling. These findings describe a new mechanism whereby a GPCR constitutively stimulates the cleavage of APP by α-secretase and promotes the nonamyloidogenic pathway of APP processing.

Topics: ADAM Proteins; ADAM10 Protein; Alzheimer Disease; Amyloid beta-Protein Precursor; Amyloid Precursor Protein Secretases; Benzofurans; Cerebral Cortex; Cyclic AMP; HEK293 Cells; Humans; Membrane Proteins; Neuroprotective Agents; Receptors, G-Protein-Coupled; Receptors, Serotonin, 5-HT4; Serotonin 5-HT4 Receptor Agonists

L-3-n-butylphthalide (L-NBP), an extract from seeds of Apium graveolens Linn (Chinese celery), has been shown to have neuroprotective effects on cerebral ischemic, vascular dementia and amyloid-β (Aβ)-induced animal models by inhibiting oxidative injury, neuronal apoptosis and glial activation, regulating amyloid-β protein precursor (AβPP) processing and reducing Aβ generation. The aim of the present study was to examine the effect of L-NBP on learning and memory in AβPP and presenilin 1 (PS1) double-transgenic AD mouse model (AβPP/PS1) and the mechanisms of L-NBP in reducing Aβ accumulation and tau phosphorylation. Twelve-month old AβPP/PS1 mice were given 15 mg/kg L-NBP by oral gavage for 3 months. L-NBP treatment significantly improved the spatial learning and memory deficits compared to the vehicle-treated AβPP/PS1 mice, whereas L-NBP treatment had no effect on cerebral Aβ plaque deposition and Aβ levels in brain homogenates. However, we found an L-NBP-induced reduction of tau hyperphosphorylation at Ser199, Thr205, Ser396, and Ser404 sites in AβPP/PS1 mice. Additionally, the expressions of cyclin-dependent kinase and glycogen synthase kinase 3β, the most important kinases involved in tau phosphorylation, were markedly decreased by L-NBP treatment. The effects of L-NBP on decreasing tau phosphorylation and kinases activations were further confirmed in neuroblastoma SK-N-SH cells overexpressing wild-type human AβPP695 (SK-N-SH AβPPwt). L-NBP shows promising candidate of multi-target neuronal protective agent for the treatment of Alzheimer's disease.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Amyloid beta-Protein Precursor; Analysis of Variance; Animals; Benzofurans; Brain; Cell Line, Tumor; Cognition Disorders; Cyclin-Dependent Kinase 5; Disease Models, Animal; Gene Expression Regulation; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Humans; Male; Maze Learning; Mice; Mice, Transgenic; Neuroblastoma; Neuroprotective Agents; Phosphorylation; Presenilin-1; Reaction Time; Spatial Behavior; tau Proteins; Time Factors

Pioneered with the invention of (11)C-Pittsburgh compound B, amyloid-β imaging using PET has facilitated research in Alzheimer disease (AD). This imaging approach has promise for diagnostic purposes and evaluation of disease-modifying therapies. Broad clinical use requires an (18)F-labeled amyloid-β radioligand with high specific and low nonspecific binding. The aim of the present PET study was to examine the radioligand (18)F-AZD4694 in human subjects.. Six control subjects and 10 clinically diagnosed AD patients underwent PET examination with (18)F-AZD4694 and a structural MRI scan. Of these, 4 controls and 4 patients underwent a second PET examination for test-retest analysis. Arterial sampling was done to derive a metabolite-corrected plasma input function for traditional compartment modeling. Besides, several simplified quantitative approaches were applied, including the reference Logan approach and simple ratio methods.. After intravenous injection of (18)F-AZD4694, radioactivity appeared rapidly in brain. In patients, radioactivity was high in regions expected to contain amyloid-β, whereas in controls, radioactivity was low and homogenously distributed. Binding in cerebellum, a reference region, was low and similar between the groups. Specific binding was reversible and peaked at about 27 min after injection in regions with high radioactivity. The time-activity curves could be described using the 2-tissue-compartment model. Distribution volume ratio estimates obtained using compartment models and simplified methods were highly correlated. Standardized uptake value ratios calculated at late times and distribution volume ratios estimated with the reference Logan approach were, in gray matter, significantly lower in control subjects (1.08 [11%] and 1.01 [6%], respectively) than in AD patients (2.15 [24%] and 1.62 [18%], respectively). Among noninvasive methods, the lowest test-retest variability was found with reference Logan, varying between 4% and 6% across brain regions.. Noninvasive quantitative approaches provide valid estimates of amyloid-β binding. Because of the radioisotope ((18)F) used for labeling, the radioligand has potential for wide clinical application. (18)F-AZD4694 satisfies the requirements for a promising amyloid-β radioligand both for diagnostic use and for evaluation of disease-modifying therapies in AD.

Topics: Aged; Aged, 80 and over; Alzheimer Disease; Amyloid beta-Peptides; Arteries; Benzofurans; Cerebrovascular Circulation; Diagnostic and Statistical Manual of Mental Disorders; Female; Humans; Hydrocarbons, Fluorinated; Image Processing, Computer-Assisted; Injections, Intravenous; Magnetic Resonance Imaging; Male; Middle Aged; Models, Statistical; Neuropsychological Tests; Positron-Emission Tomography; Protein Binding; Radiopharmaceuticals; Reproducibility of Results

Three novel (99m)Tc-labeled pyridyl benzofuran derivatives were tested as potential probes for imaging β-amyloid plaques using single photon emission computed tomography (SPECT). The (99m)Tc and corresponding rhenium complexes were synthesized with bis(aminoethanethiol) (BAT) as a chelating ligand. All Re complexes showed affinity for Aβ(1-42) aggregates (K(i) = 13.6-149.6 nM). Biodistribution experiments in normal mice revealed that the (99m)Tc-labeled derivatives displayed sufficient uptake in the brain (1.41-1.80% ID/g at 2 min postinjection). Notably, [(99m)Tc]BAT-Bp-2 showed a good initial uptake (1.80% ID/g at 2 min) and a reasonable washout from the brain (0.79% ID/g at 60 min). Ex vivo autoradiography with [(99m)Tc]BAT-Bp-2 revealed substantial labeling of β-amyloid plaques in sections of brain tissue from Tg2576 transgenic mice but not in the age-matched controls. [(99m)Tc]BAT-Bp-2 may be a potential SPECT probe for imaging β-amyloid plaques in Alzheimer's brains.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Benzofurans; Brain; Chelating Agents; Coordination Complexes; Mice; Mice, Transgenic; Molecular Imaging; Plaque, Amyloid; Pyridines; Radiopharmaceuticals; Rhenium; Structure-Activity Relationship; Technetium; Tissue Distribution; Tomography, Emission-Computed, Single-Photon

The synthesis and SAR of new β-amyloid binding agents are reported. Evaluation of important properties for achieving good signal-to-background ratio is described. Compounds 27, 33, and 36 displayed desirable lipophilic and pharmacokinetic properties. Compound 27 was further evaluated with autoradiographic studies in vitro on human brain tissue and in vivo in Tg2576 mice. Compound 27 showed an increased signal-to-background ratio compared to flutemetamol 4, indicating its suitability as PET ligand for β-amyloid deposits in AD patients. The preparation of the corresponding (18)F-labeled PET radioligand of compound 27 is presented.

Topics: Alzheimer Disease; Aminopyridines; Amyloid beta-Peptides; Animals; Benzofurans; Benzothiazoles; Benzoxazoles; Brain; Contrast Media; Fluorine Radioisotopes; Humans; Mice; Mice, Transgenic; Positron-Emission Tomography; Radiopharmaceuticals; Structure-Activity Relationship

The complex etiology of Alzheimer's disease prompts scientists to develop multi-target strategies to combat causes and symptoms. In line with this modern paradigm and as a follow-up to our previous studies, we designed and synthesized a focused collection of new 2-arylbenzofurans and evaluated their biological properties towards specific targets involved in AD, namely human AChE and human BuChE, and Aβ fibril formation. Selected compounds were also tested for their ability to inhibit Aβ neurotoxicity in terms of neuronal viability loss, and to prevent Aβ peptide-binding to cell membrane and intracellular reactive oxygen species (ROS) formation. The different modifications introduced in the structure of our lead compound led to an increase in activity towards one or more of the selected targets: the anticholinesterase activity of some compounds was found to be significantly higher than previously obtained related molecules, and the compounds also proved to possess Aβ anti-aggregating properties and neuroprotective effects. The most interesting multi-target compounds were 18, and 1. Interestingly, 1 also showed good selectivity and moderate affinity for CB1 receptor, opening new perspectives in the field of research on AD, since cannabinoid ligands have been widely reported to have neuroprotective properties.

Topics: Acetylcholinesterase; Alzheimer Disease; Amyloid beta-Peptides; Benzofurans; Butyrylcholinesterase; Cell Line, Tumor; Cell Survival; Cholinesterase Inhibitors; Dose-Response Relationship, Drug; Humans; Molecular Structure; Structure-Activity Relationship

Abnormal β-amyloid peptide accumulation and aggregation is considered to be responsible for the formation and cerebral deposition of senile plaques in the brains of patients with Alzheimer's disease (AD). Inhibition of the formation of β-amyloid (Aβ) fibrils would be an attractive therapeutic target for the treatment of AD. Resveratrol and its derivatives exhibit a broad range of pharmacological properties such as protection against cardiovascular diseases and cancers, as well as promoting antiaging effects. We reported previously that ε-viniferin glucoside (VG), a resveratrol-derived dimer, strongly inhibits Aβ (25-35) fibril formation in vitro. In this study, we investigated the effects of VG on the aggregation of the full-length peptides (Aβ (1-40) and Aβ (1-42)) and on the β-amyloid-induced toxicity in PC12 cells. VG inhibited Aβ cytotoxicity and the non-covalent complex between VG and Aβ was observed by electrospray ionization mass spectrometry.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Benzofurans; Humans; PC12 Cells; Rats; Spectrometry, Mass, Electrospray Ionization; Stilbenes; Vitis

A series of benzofuran-2-yl(phenyl)methanone derivatives were synthesized and evaluated as novel probes for β-amyloid plaques. These derivatives were produced by a Rap-Stoermer condensation reaction. Compounds with a N,N-dimethylamino group displayed high affinity for Aβ(1-42) aggregates with K(i) values in the nanomolar range. Autoradiography with brain sections of AD model mice (APP/PS1) revealed that a radioiodinated probe, [(125)I]10, labeled β-amyloid plaques selectively and displayed good brain uptake (3.53% ID/g) at 2 min. The results suggest that benzofuran-2-yl(phenyl)methanone derivatives should be investigated further as potential probes for detecting β-amyloid plaques in the AD brain.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Aniline Compounds; Animals; Autoradiography; Benzofurans; Brain; Iodine Radioisotopes; Ligands; Mice; Peptide Fragments; Plaque, Amyloid; Protein Binding; Radionuclide Imaging; Radiopharmaceuticals; Tissue Distribution

The objective of this study was to characterize the systemic and tissue kinetics of 2-(3,4-dimethoxyphenyl)-5-(3-methoxypropyl) benzofuran (SNU-0039), an inhibitor of β-amyloid protein aggregation, in rats. Simultaneous fitting of the data to polyexponential equations indicated that the systemic clearance and steady state volume of distribution were estimated to be 0.0220 l/min/kg and 2.33 l/kg. The clearance and volume of distribution were not dependent on the intravenous dose, in the range from 5 to 20 mg/kg. The tissue (i.e., the brain, liver, kidneys, heart, spleen, lungs, gut, muscle and adipose tissue) to plasma partition coefficients (K(p)) for SNU-0039 in rats ranged from a low of 0.779 ± 0.314 (muscle) to a high of 5.71 ± 1.66 (liver). The recoveries of DMB were less than 1% of the dose for the renal and biliary excretion, indicative of minor involvements of these pathways in overall elimination. The fraction of bound SNU-0039 to plasma protein was approximately 95.9% and the fraction of SNU-0039 distributed to blood cells was approximately 45.3%. Assuming a flow-limited distribution, the simulated concentration profiles for SNU-0039 in the physiologically based pharmacokinetic model were in reasonable agreement with the observed concentrations in plasma and nine tissues in rats.

Topics: Alzheimer Disease; Animals; Benzofurans; Computer Simulation; Injections, Intravenous; Kidney; Liver; Male; Muscles; Nootropic Agents; Protein Binding; Rats; Rats, Sprague-Dawley; Reproducibility of Results; Spleen; Tissue Distribution

Alzheimer's disease (AD) is a neurodegenerative disorder leading to a progressive loss of cognitive function and is pathologically characterized by senile plaques and neurofibrillary tangles. Glycogen synthase kinase-3 (GSK-3) is involved in AD pathogenesis. GSK-3 is reported not only to phosphorylate tau, a major component of neurofibrillary tangles, but also to regulate the production of amyloid β, which is deposited in senile plaques. Therefore, pharmacological inhibition of GSK-3 is considered an attractive therapeutic approach. In this study, we report the pharmacological effects of a novel GSK-3 inhibitor, 2-methyl-5-(3-{4-[(S)-methylsulfinyl]phenyl}-1-benzofuran-5-yl)-1,3,4-oxadiazole (MMBO), which displays high selectivity for GSK-3 and brain penetration following oral administration. MMBO inhibited tau phosphorylation in primary neural cell culture and also in normal mouse brain. When administered to a transgenic mouse model of AD, MMBO significantly decreased hippocampal tau phosphorylation at GSK-3 sites. Additionally, chronic MMBO administration suppressed tau pathology as assessed by AT8-immunoreactivity without affecting amyloid β pathology. Finally, in behavioral assessments, MMBO significantly improved memory and cognitive deficits in the Y-maze and in novel object recognition tests in the transgenic AD mouse model. These results indicate that pharmacological GSK-3 inhibition ameliorates behavioral dysfunction with suppression of tau phosphorylation in an AD mouse model, and that MMBO might be beneficial for AD treatment.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Amyloid beta-Protein Precursor; Animals; Benzofurans; Brain; Cell Culture Techniques; Cerebral Cortex; Cognition Disorders; Disease Models, Animal; Enzyme Inhibitors; Enzyme-Linked Immunosorbent Assay; Exploratory Behavior; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Humans; Maze Learning; Mice; Mice, Transgenic; Mutation; Neurons; Oxadiazoles; Peptide Fragments; Phosphorylation; Presenilin-1; tau Proteins; Time Factors

To determine the expression of glial fibrillary acidic protein(GFAP) and vascular endothelial growth factor(VEGF) in the hippocampus of rats with Alzheimer's disease(AD), and to determine the effect of butylphthalide on them and its significance.. Sixty male adult rats were randomly divided into a model group, a Butylphthalide group, and a control group. AD models were established by injecting beta-amyloid protein 1-42 into the hippocampus of rats. Sixty days later,the rats were sacrificed and both sides of the hippocampus were sectioned for immunohistochemistry.. Positive cells of GFAP in the hippocampus of the model group increased and the expression of VEGF decreased statistically, compared with the control group(P<0.01). The positive cells of GFAP in the hippocampus of the butylphthalide group decreased and the expression of VEGF increased significantly, compared with the model group(P<0.05).. Butylphthalide may protect the neuron-vascular unit of the hippocampus of Alzheimer model rats by inhibiting the expression of GFAP and increasing the expression of VEGF.

Topics: Alzheimer Disease; Animals; Benzofurans; Disease Models, Animal; Drugs, Chinese Herbal; Glial Fibrillary Acidic Protein; Hippocampus; Male; Random Allocation; Rats; Rats, Sprague-Dawley; Vascular Endothelial Growth Factor A

Positron emission tomography (PET) radioligands that bind selectively to beta-amyloid plaques (Abeta) are promising imaging tools aimed at supporting the diagnosis of Alzheimer's disease and the evaluation of new drugs aiming to modify amyloid plaque load. For extended clinical use, there is a particular need for PET tracers labeled with fluorine-18, a radionuclide with 110 min half-life allowing for central synthesis followed by wide distribution. The development of fluorinated radioligands is, however, challenging because of the lipophilic nature of aromatic fluorine, rendering fluorinated ligands more prone to have high non-specific white matter binding. We have here developed the new benzofuran-derived radioligand containing fluorine, AZD4694 that shows high affinity for beta-amyloid fibrils in vitro (K(d) = 2.3 +/- 0.3 nM). In cortical sections from human Alzheimer's disease brain [(3)H]AZD4694 selectively labeled beta-amyloid deposits in gray matter, whereas there was a lower level of non-displaceable binding in plaque devoid white matter. Administration of unlabeled AZD4694 to rat showed that it has a pharmacokinetic profile consistent with good PET radioligands, i.e., it quickly entered and rapidly cleared from normal rat brain tissue. Ex vivo binding data in aged Tg2576 mice after intravenous administration of [(3)H]AZD4694 showed selective binding to beta-amyloid deposits in a reversible manner. In Tg2576 mice, plaque bound [(3)H]AZD4694 could still be detected 80 min after i.v. administration. Taken together, the preclinical profile of AZD4694 suggests that fluorine-18 labeled AZD4694 may have potential for PET-visualization of cerebral beta-amyloid deposits in the living human brain.

Topics: Aged; Aged, 80 and over; Alzheimer Disease; Amyloid beta-Peptides; Animals; Benzofurans; Binding, Competitive; Female; Fluorine Compounds; Fluorine Radioisotopes; Humans; Hydrocarbons, Fluorinated; Injections, Intraventricular; Male; Mice; Mice, Transgenic; Plaque, Amyloid; Positron-Emission Tomography; Radioligand Assay; Rats; Rats, Sprague-Dawley

Alzheimer's disease (AD) is an age-related, progressive neurodegenerative disorder that occurs gradually and results in memory, behavior, and personality changes. L-3-n-butylphthalide (L-NBP), an extract from seeds of Apium graveolens Linn (Chinese celery), has been demonstrated to have neuroprotective effects on ischemic, vascular dementia, and amyloid-beta (Abeta)-infused animal models. In the current study, we examined the effects of L-NBP on learning and memory in a triple-transgenic AD mouse model (3xTg-AD) that develops both plaques and tangles with aging, as well as cognitive deficits. Ten-month-old 3xTg-AD mice were given 15 mg/kg L-NBP by oral gavage for 18 weeks. L-NBP treatment significantly improved learning deficits, as well as long-term spatial memory, compared with vehicle control treatment. L-NBP treatment significantly reduced total cerebral Abeta plaque deposition and lowered Abeta levels in brain homogenates but had no effect on fibrillar Abeta plaques, suggesting preferential removal of diffuse Abeta deposits. Furthermore, we found that L-NBP markedly enhanced soluble amyloid precursor protein secretion (alphaAPPs), alpha-secretase, and PKCalpha expression but had no effect on steady-state full-length APP. Thus, L-NBP may direct APP processing toward a non-amyloidogenic pathway and preclude Abeta formation in the 3xTg-AD mice. The effect of l-NBP on regulating APP processing was further confirmed in neuroblastoma SK-N-SH cells overexpressing wild-type human APP(695) (SK-N-SH APPwt). L-NBP treatment in 3xTg-AD mice also reduced glial activation and oxidative stress compared with control treatment. L-NBP shows promising preclinical potential as a multitarget drug for the prevention and/or treatment of Alzheimer's disease.

Topics: ADAM Proteins; Alzheimer Disease; Amyloid beta-Peptides; Amyloid beta-Protein Precursor; Animals; Benzofurans; Cell Line, Tumor; Cell Survival; Cognition Disorders; Disease Models, Animal; Enzyme Inhibitors; Enzyme-Linked Immunosorbent Assay; Female; Humans; Indoles; Leukocyte Common Antigens; Male; Maleimides; Malondialdehyde; Maze Learning; Mice; Mice, Inbred C57BL; Mice, Transgenic; Mutation; Nerve Tissue Proteins; Neuroblastoma; Neuroglia; Neuroprotective Agents; Oxidative Stress; Presenilin-1; Reaction Time; Spatial Behavior; Statistics, Nonparametric; tau Proteins; Time Factors; Transfection

Two (99m)Tc/Re complexes based on flavone and aurone were tested as potential probes for imaging β-amyloid plaques using single photon emission computed tomography. Both (99m)Tc-labeled derivatives showed higher affinity for Aβ(1-42) aggregates than did (99m)Tc-BAT. In sections of brain tissue from an animal model of AD, the Re-flavone derivative 9 and Re-aurone derivative 19 intensely stained β-amyloid plaques. In biodistribution experiments using normal mice, (99m)Tc-labeled flavone and aurone displayed similar radioactivity pharmacokinetics. With additional modifications to improve their brain uptake, (99m)Tc complexes based on the flavone or aurone scaffold may serve as probes for imaging cerebral β-amyloid plaques.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Benzofurans; Brain; Coordination Complexes; Disease Models, Animal; Flavones; Mice; Molecular Probes; Organotechnetium Compounds; Peptide Fragments; Plaque, Amyloid; Radiopharmaceuticals; Rhenium; Tissue Distribution; Tomography, Emission-Computed, Single-Photon

A potential probe for PET targeting β-amyloid plaques in Alzheimer's disease (AD) brain, FPYBF-1 (5-(5-(2-(2-(2-fluoroethoxy)ethoxy)ethoxy)benzofuran-2-yl)-N,N-dimethylpyridin-2-amine), was synthesized and evaluated. In experiments in vitro, FPYBF-1 displayed high affinity for Aβ(1-42) aggregates (K(i)=0.9 nM), and substantial labeling of β-amyloid plaques in sections of postmortem AD brains but not control brains. In experiments in vivo, [(18)F]FPYBF-1 displayed good initial uptake (5.16%ID/g at 2 min postinjection) and rapid washout from the brain (2.44%ID/g at 60 min postinjection) in normal mice, and excellent binding to β-amyloid plaques in a murine model of AD. Furthermore, the specific labeling of plaques labeling was observed in autoradiographs of autopsied AD brain sections. [(18)F]FPYBF-1 may be a useful probe for imaging β-amyloid plaques in living brain tissue.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Autopsy; Autoradiography; Benzofurans; Brain; Fluorine Radioisotopes; Humans; Male; Mice; Mice, Transgenic; Plaque, Amyloid; Positron-Emission Tomography; Radiopharmaceuticals

To determine the effect of butylphthalide on the expressions of protein disulfide isomerase (PDI) and P53 in the brain tissue of rats with Alzheimer's disease (AD).. Sixty male adult rats were randomly divided into AD model group, butylphthalide group and control group (n = 20). AD models were established by injecting beta-amyloid protein 1-42 into the hippocampus of rats. Sixty days later, the learning and memory abilities of the rats were evaluated using Y-maze test, and the expressions of PDI and P53 in the brain tissue of the rats were measured by immunohistochemistry.. Compared with the control group, the rats in AD model group exhibited significantly reduced learning and memory abilities, lowered expressions of PDI in the hippocampus and increased expression of P53 in the cortex (P > 0.01). In comparison with the model group, the rats in the butylphthalide group showed significantly increased PDI-positive cells in the hippocampus and decreased expression of P53 in the cortex (P < 0.01).. Butylphthalide improves the learning and memory abilities of rats with experimental AD, the mechanism of which may involve inhibition of P53 expression and enhancement of PDI expression in the brain tissues.

Topics: Alzheimer Disease; Animals; Apoptosis; Benzofurans; Brain; Disease Models, Animal; Learning; Male; Memory; Protein Disulfide-Isomerases; Random Allocation; Rats; Rats, Sprague-Dawley; Tumor Suppressor Protein p53

This study investigated a methanol extract from the leaf and stem of Vitis amurensis (Vitaceae) for possible neuroprotective effects on neurotoxicity induced by amyloid β protein (Aβ) (25-35) in cultured rat cortical neurons and also for antidementia activity in mice. Exposure of cultured cortical neurons to 10 μM Aβ (25-35) for 36 h induced neuronal apoptotic death. At concentrations of 1-10 μg/mL, V. amurensis inhibited neuronal death, the elevation of intracellular calcium ([Ca(2+)](i)) and the generation of reactive oxygen species (ROS), all of which were induced by Aβ (25-35) in primary cultures of rat cortical neurons. Memory loss induced by intracerebroventricular injection of ICR mice with 16 nmol Aβ (25-35) was inhibited by chronic treatment with V. amurensis extract (50 and 100 mg/kg, p.o. for 7 days), as measured by a passive avoidance test. Amurensin G, r-2-viniferin and trans-ɛ-viniferin isolated from V. amurensis also inhibited neuronal death, the elevation of [Ca(2+)](i) and the generation of ROS induced by Aβ (25-35) in cultured rat cortical neurons. These results suggest that the neuroprotective effect of V. amurensis may be partially attributable to these compounds. These results suggest that the antidementia effect of V. amurensis is due to its neuroprotective effect against Aβ (25-35)-induced neurotoxicity and that the leaf and stem of V. amurensis have possible therapeutic roles for preventing the progression of Alzheimer's disease.

Topics: Acetylcholinesterase; Alzheimer Disease; Amyloid beta-Peptides; Animals; Apoptosis; Benzofurans; Cells, Cultured; Cerebral Cortex; Dibenzocycloheptenes; Dose-Response Relationship, Drug; Embryo, Mammalian; GPI-Linked Proteins; Male; Memory Disorders; Mice; Mice, Inbred ICR; Neurons; Neuroprotective Agents; Peptide Fragments; Phytotherapy; Plant Extracts; Plant Leaves; Plant Stems; Rats; Rats, Sprague-Dawley; Resorcinols; Stilbenes; Vitis

During a synthesis of coumarins to obtain new candidates for treating Alzheimer's Disease (AD), an unusual rearrangement of a benzopyran group to a benzofuran group occurred, offering a novel synthesis pathway of these benzofuran derivatives. The possible mechanism of the novel rearrangement was also discussed. All of the benzofuran derivatives have weak anti-AChE activities compared with the reference compound, donepezil.

Topics: Acetylcholinesterase; Alzheimer Disease; Animals; Benzofurans; Cholinesterase Inhibitors; GPI-Linked Proteins; Humans; Rats

We report a novel series of radioiodinated aurone derivatives as probes for imaging Abeta plaques in the brains of patients with Alzheimer's disease (AD) using single photon emission computed tomography (SPECT). In binding experiments in vitro, aurone derivatives showed very good affinity for Abeta aggregates (K(i) = 1.1 to 3.4 nM). No-carrier-added radioiodinated aurones were successfully prepared through an iododestannylation reaction from the corresponding tributyltin derivatives. In biodistribution experiments using normal mice, aurone derivatives displayed high brain uptake (1.7-4.5% ID/g at 2 min) and rapid clearance from the brain (0.1-0.4% ID/g at 30 min), especially [125I]15. Furthermore, a specific plaque labeling signal was observed in in vitro autoradiography of postmortem AD brain sections using [125I]15. [125I]15 may be a useful SPECT imaging agent for detecting Abeta plaques in the brain of AD.

Topics: Alzheimer Disease; Animals; Autoradiography; Benzofurans; Brain; Iodine Radioisotopes; Mice; Plaque, Amyloid; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

To determine the effect of butylphthalide on the expressions of p38 mitogen-activated protein kinase and extra-cellular signal regulated kinases (ERKs) in the brain tissue of rats with Alzheimer's disease (AD).. Sixty male adult rats were randomly divided to AD model group, butylphthalide group, and control group (n=20). AD models were established by injecting beta-amyloid protein 1-42 into the hippocampus of rats. Sixty days later, the learning and memory abilities of the rats were evaluated using Y-maze test, and the expressions of p38 and ERKs in the brain tissue of the rats were measured by immunohistochemistry. RESULTS Compared with the control group, the rats in AD model group exhibited significantly reduced learning and memory abilities, increased expressions of P38 in the hippocampus and lowered expression of ERK in the cortex (P<0.01). In comparison with the model group, the rats in the butylphthalide group showed significantly decreased P38-positive cells in the hippocampus and increased expression of ERK in the cortex (P<0.01).. Butylphthalide improves the learning and memory abilities of rats with experimental AD, the mechanism of which may involve inhibition of P38 expression and enhancement of ERK expression in the brain tissues.

Topics: Alzheimer Disease; Animals; Benzofurans; Extracellular Signal-Regulated MAP Kinases; Gene Expression Regulation, Enzymologic; Hippocampus; Male; Memory; Neuroprotective Agents; p38 Mitogen-Activated Protein Kinases; Rats; Rats, Sprague-Dawley

To determine the expression of S100-beta protein and glial fibrillary acidic protein (GFAP) in hippocampal astrocytes of rats with Alzheimer disease (AD) model rats, and observe the effect of butylphthalide on their expression.. Sixty male adult rats were randomized equally into model group, butylphthalide group, and control group, and in the former two groups, AD models were established by injecting beta-amyloid protein 1-40 into the hippocampus. Sixty days later, the rats were sacrificed and the bilateral hippocampuses were taken for immunohistochemistry.. The number of cells positive for S100 and GFAP in the hippocampus in butylphthalide group were significantly higher than that in the control group (P/0.01), but lower than that in the model group (P/0.05).. The expression of S100 protein and glial fibrillary acidic protein increased significantly in the hippocampal astrocytes of rats with AD, and butylphthalide can inhibit the increase of their expression.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Benzofurans; Disease Models, Animal; Glial Fibrillary Acidic Protein; Hippocampus; Male; Nerve Growth Factors; Neuroprotective Agents; Peptide Fragments; Random Allocation; Rats; Rats, Sprague-Dawley; S100 Calcium Binding Protein beta Subunit; S100 Proteins

The synthesis of a novel series of aminostyrylbenzofuran derivatives 1a-w and their inhibitory activities for Abeta fibril formation were described. All the synthesized compounds were evaluated by thioflavin T (ThT) assay and displayed potent inhibitory activities for Abeta fibril formation. Among them, compounds 1i and 1q exhibited excellent inhibitory activities (IC(50)=0.07 and 0.08 microM, respectively) than those of Curcumin (IC(50)=0.80 microM) and IMSB (IC(50)=8.00 microM) as reference compounds. Both compounds were selected as promising candidates for further biological evaluation.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Benzofurans; Benzothiazoles; Benzoxazoles; Chemistry, Pharmaceutical; Curcumin; Drug Design; Electrons; Humans; Inhibitory Concentration 50; Models, Chemical; Peptide Fragments; Structure-Activity Relationship; Styrenes; Thiazoles

A novel series of aurone derivatives for in vivo imaging of beta-amyloid plaques in the brain of Alzheimer's disease (AD) were synthesized and characterized. When in vitro binding studies using Abeta(1-42) aggregates were carried out with aurone derivatives, they showed high binding affinities for Abeta(1-42) aggregates at the K(i) values ranging from 1.2 to 6.8 nM. When in vitro plaque labeling was carried out using double transgenic mice brain sections, the aurone derivatives intensely stained beta-amyiloid plaques. Biodistribution studies in normal mice after i.v. injection of the radioiodinated aurones displayed high brain uptake (1.9-4.6% ID/g at 2 min) and rapid clearance from the brain (0.11-0.26% ID/g at 60 min), which is highly desirable for amyloid imaging agents. The results in this study suggest that novel radiolabeled aurones may be useful amyloid imaging agents for detecting beta-amyloid plaques in the brain of AD.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Benzofurans; Benzylidene Compounds; Brain; Disease Models, Animal; Mice; Mice, Transgenic; Microscopy, Fluorescence; Peptide Fragments; Plaque, Amyloid; Radiopharmaceuticals

A novel series of benzofuran derivatives as potential positron emission tomography (PET) tracers targeting amyloid plaques in Alzheimer's disease (AD) were synthesized and evaluated. The syntheses of benzofurans were successfully achieved by an intramolecular Wittig reaction between triphenylphosphonium salt and 4-nitrobenzoyl chloride. When in vitro binding studies using AD brain gray matter homogenates were carried out with a series of benzofuran derivatives, all the derivatives examined displayed high binding affinities with K(i) values in the subnanomolar range. Among these benzofuran derivatives, compound 8, 5-hydroxy-2-(4-methyaminophenyl)benzofuran, showed the lowest K(i) value (0.7 nM). In vitro fluorescent labeling of AD sections with compound 8 intensely stained not only amyloid plaques, but also neurofibrillary tangles. The (11)C labeled compound 8, [(11)C]8, was prepared by reacting the normethyl precursor, 5-hydroxy-2-(4-aminophenyl)benzofuran, with [(11)C]methyl triflate. The [(11)C]8 displayed moderate lipophilicity (log P = 2.36), very good brain penetration (4.8%ID/g at 2 min after iv injection in mice), and rapid washout from normal brains (0.4 and 0.2%ID/g at 30 and 60 min, respectively). In addition, this PET tracer showed in vivo amyloid plaque labeling in APP transgenic mice. Taken together, the data suggest that a relatively simple benzofuran derivative, [(11)C]8, may be a useful candidate PET tracer for detecting amyloid plaques in the brains of patients with Alzheimer's disease.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Benzofurans; Mice; Mice, Transgenic; Molecular Structure; Positron-Emission Tomography

5-HT(4) receptors are widely distributed in both peripheral and central nervous systems where they couple, via a G-protein, to the activation of adenylate cyclase. In the brain, the highest 5-HT(4) receptor densities are found in the limbic system, including the hippocampus and frontal cortex. It has been suggested that activation of these receptors may be of therapeutic benefit in diseases that produce cognitive deficits such as Alzheimer's disease (AD). Previous electrophysiological studies have shown that the 5-HT(4) agonist, Zacopride, can increase population spike amplitude recorded in region CA1 of rat hippocampal slices in a cyclic AMP (cAMP)/cAMP-dependent protein kinase A-dependent manner. We report here that the 5-HT(4) agonist, Prucalopride, and the 5-HT(4) partial agonist, SL65.0155, produce a similar effect in rat hippocampal slices and that the specific 5-HT(4) antagonist, GR113808, blocks these effects. To investigate the potential use of 5-HT(4) agonists in the treatment of AD, Prucalopride was applied to hippocampal slices from a transgenic mouse line that overexpresses the Abeta peptide. Despite the deficit in synaptic transmission present in these mice, the percentage increase of the CA1 population spike induced by Prucalopride was the same as that observed in wild-type mice. These data support 5-HT(4) receptors as a target for cognitive enhancement and suggest that a partial agonist would be sufficient to produce benefits, while reducing potential peripheral side effects. In addition, we show that 5-HT(4) receptors remain functional in the presence of excess Abeta peptide and may therefore be a useful target in AD.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Animals, Genetically Modified; Benzofurans; Dioxanes; Disease Models, Animal; Excitatory Postsynaptic Potentials; Hippocampus; Humans; Indoles; Male; Neurons; Organ Culture Techniques; Oxadiazoles; Patch-Clamp Techniques; Rats; Receptors, Serotonin, 5-HT4; Serotonin Antagonists; Serotonin Receptor Agonists; Sulfonamides

The purpose of this study is to develop potential I-123 labeled diagnostic imaging agents targeting amyloid plaques in Alzheimer's disease (AD). Formation and accumulation of aggregates of beta-amyloid (Abeta) peptides in the brain are critical factors in the development and progression of AD. Small molecule-based benzofuran derivatives were designed and synthesized. Both 5- and 6-iodobenzofuran derivatives displayed excellent competition for I-125 TZDM binding to Abeta40 aggregates with K(i) values in the subnanomolar range. The radioiodinated ligands, with a high specific activity, were successfully prepared through an iododestannylation reaction from the corresponding tributyltin derivatives using hydrogen peroxide as the oxidant in high yields (60-80%) and with high radiochemical purities (greater than 95%). After an iv injection, all four radioiodinated ligands displayed high brain uptakes ranging from 0.5 to 1.5% initial dose/organ in normal mice. The radioactivity washed out from the mouse brain slowly (less than 50% at 2 h post injection), suggesting high in vivo non-specific binding. In conclusion, the benzofuran ligands displayed excellent binding affinity for Abeta aggregates. The long retention of these ligands in the normal mouse brain suggests that there may be high binding for these probes in the brain not associated with Abeta plaques. Additional modifications are necessary to improve the in vivo imaging properties for plaque detection.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Benzofurans; Biomarkers; Brain; In Vitro Techniques; Iodine Radioisotopes; Isotope Labeling; Mice; Models, Chemical; Models, Molecular; Radionuclide Imaging; Radiopharmaceuticals

The serotonin 5-HT(4) receptor has recently gained a lot of attention for its functional roles in central processes such as memory and cognition. In this study, we show that activation of the human 5-HT(4) (h5-HT(4)) receptor stimulates the secretion of the non-amyloidogenic soluble form of the amyloid precursor protein (sAPPalpha). 5-HT enhanced the level of secreted sAPPalpha in a time- and dose-dependent manner in Chinese hamster ovary cells stably expressing the h5-HT(4(e)) receptor isoform. The increase was inhibited by the selective 5-HT(4) receptor antagonist, GR113808. The 5-HT(4) selective agonists, prucalopride and renzapride, also increased secreted sAPPalpha in IMR32 human neuroblastoma cells. The stimulatory effect of 5-HT was mimicked by forskolin, a direct activator of adenylyl cyclase, and 8-bromo-cAMP, a membrane-permeant cAMP analogue. On the contrary, inhibition of protein kinase A (PKA) by H89 potentiated the 5-HT-induced increase in both secreted and cellular sAPPalpha. This phenomenon involves a novel PKA-independent stimulatory process that overcomes a PKA-dependent inhibitory one. Finally, activation of the h5-HT(4(e)) receptor did not modify extracellular amyloid beta-protein in Chinese hamster ovary cells transfected with the human APP695. Given the neuroprotective and enhancing memory effects of sAPPalpha, our results may open a new avenue for the treatment of Alzheimer's disease.

Topics: 8-Bromo Cyclic Adenosine Monophosphate; Adenylyl Cyclases; Alzheimer Disease; Amyloid beta-Protein Precursor; Animals; Benzamides; Benzofurans; Blotting, Western; Bridged Bicyclo Compounds, Heterocyclic; CHO Cells; Colforsin; Cricetinae; Cyclic AMP-Dependent Protein Kinases; Dose-Response Relationship, Drug; Humans; Indoles; Ligands; Memory; Polymerase Chain Reaction; Protein Binding; Protein Isoforms; Radioimmunoassay; Receptors, Serotonin; Receptors, Serotonin, 5-HT4; Serotonin; Sulfonamides; Time Factors; Transfection; Tumor Cells, Cultured

This work has explored the relationship between excitotoxicity and the amyloid precursor protein gene (APP) which may be relevant to future therapeutic developments in Alzheimer's disease. The excitotoxic effects of kainic acid (KA) and pentylenetetrazole (PTZ) have been compared and contrasted on the two major mRNA isoforms of APP using in situ hybridization and quantitative analysis of gene expression in rat brain. The Kunitz Protease Inhibitor containing isoform APP 770 KPI+, the major glial cell isoform, has been shown to be stimulated after KA and was related to neuronal loss and astrocyte activation as gauged by GFAP mRNA. This was associated with reduced expression of APP695 KPI- isoform, the major neuronal isoform. These changes were not observed after PTZ where there was no neuronal loss and no glial reaction. The KA induced changes in APP were prevented by pretreatment with the non-competitive NMDA receptor antagonist dizocilpine and the barbiturate pentobarbitone, but not with the kappa-opioid receptor agonist enadoline. These findings were related to the suppression of seizures and the survival of neurons. In conclusion, excitotoxic stimulation leading to neuronal death was associated with increased expression of APP KPI+ mRNA and decreased APP KPI- mRNA, a finding which may relate to the plasticity of the central nervous system.

Topics: Alzheimer Disease; Amyloid beta-Protein Precursor; Animals; Benzofurans; Brain; Dizocilpine Maleate; Gene Expression Regulation; Glial Fibrillary Acidic Protein; Humans; Kainic Acid; Male; Neuroprotective Agents; Neurotoxins; Organ Specificity; Pentobarbital; Pentylenetetrazole; Pyrrolidines; Rats; Rats, Wistar; RNA, Messenger; Transcription, Genetic; Trypsin Inhibitor, Kunitz Soybean