piperidines and Protein-Aggregation--Pathological

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

The multitarget-directed strategy offers an effective and promising paradigm to treat the complex neurodegenerative disorder, such as Alzheimer's disease (AD). Herein, a series of N-benzylpiperidine analogs (17-31 and 32-46) were designed and synthesized as multi-functional inhibitors of acetylcholinesterase (AChE) and β-secretase-1 (BACE-1) with moderate to excellent inhibitory activities. Among the tested inhibitors, 25, 26, 40, and 41 presented the most significant and balanced inhibition against both the targets. Compounds 40 and 41 exhibited high brain permeability in the PAMPA-BBB assay, significant displacement of propidium iodide from the peripheral anionic site (PAS) of AChE, and were devoid of neurotoxicity towards SH-SY5Y neuroblastoma cell lines up to the maximum tested concentration of 80 μM. Meanwhile, both these compounds inhibited self- and AChE-induced Aβ aggregation in thioflavin T assay, which was also re-affirmed by morphological characterization of Aβ aggregates using atomic force microscopy (AFM). Moreover, 40 and 41 ameliorated the scopolamine-induced cognitive impairment in elevated plus and Y-maze experiments. Ex vivo and biochemical analysis established the brain AChE inhibitory potential and antioxidant properties of these compounds. Further, improvement in Aβ

Topics: Alzheimer Disease; Amyloid Precursor Protein Secretases; Animals; Aspartic Acid Endopeptidases; Blood-Brain Barrier; Cell Line, Tumor; Cholinesterase Inhibitors; Cognitive Dysfunction; Drug Design; Humans; Mice; Piperidines; Protein Aggregation, Pathological; Structure-Activity Relationship

Soluble epoxide hydrolase (sEH) is widely expressed in the mammalian brain and possesses dual enzymatic activities, including C-terminal epoxide hydrolase (C-EH) which degrades epoxyeicosatrienoic acid (EET), a beneficial arachidonic acid metabolite. In the present study, the neuroprotective effect of sEH inhibition on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurodegeneration of nigrostriatal dopaminergic system was investigated using genetic and pharmacological approaches. MPTP (15 mg/kg) was intraperitoneally injected in sEH knockout (KO) mice and C57BL/6J mice as wild-type (WT) mice. Compared with the MPTP-treated WT mice, MPTP-induced reductions in striatal dopamine content and nigral tyrosine hydroxylase level (TH, a biomarker of dopaminergic neurons) were less significant in the treated sEH mice. Furthermore, MPTP-induced HO-1 elevation (a redox-regulated protein), α-synuclein aggregation, and caspase 12 activation (a hallmark of ER stress) were less prominent in sEH KO mice than in WT mice. These data indicate that sEH KO mice are more resistant to MPTP-induced neurotoxicity. The pharmacological effect of N-[1-(1-oxopropyl)-4-piperidinyl]-N0-[4-(trifluoromethoxy)phenyl)-urea (TPPU, an sEH inhibitor) on MPTP-induced neurotoxicity was investigated in WT mice. TPPU (1 mg/kg, i.p.) attenuated MPTP-induced reduction in striatal dopamine content, TH-positive cell numbers, TH, and pro-caspase 9 protein levels (an initiator caspase of apoptosis) in mouse SN. Moreover, TPPU reduced MPTP-induced HO-1 elevation, α-synuclein aggregation and caspase 12 activation, indicating that TPPU is effective in attenuating MPTP-induced oxidative stress, apoptosis, protein aggregation, and ER stress. In conclusion, our study suggests that sEH is a potential target for developing therapies for parkinsonism. Furthermore, sEH inhibitors may be of clinical significance for treating CNS neurodegenerative diseases.

Topics: alpha-Synuclein; Animals; Corpus Striatum; Dopaminergic Neurons; Endoplasmic Reticulum Stress; Epoxide Hydrolases; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; MPTP Poisoning; Neuroprotective Agents; Phenylurea Compounds; Piperidines; Protein Aggregation, Pathological; Substantia Nigra

Accumulation of alpha-synuclein (ASYN) in neurons and other CNS cell types may contribute to the underlying pathology of synucleinopathies including Parkinson's disease (PD), dementia with Lewy bodies (DLB) and Multiple Systems Atrophy (MSA). In support of this hypothesis for PD, ASYN immunopositive aggregates are a prominent pathological feature of PD, and mutations and gene multiplications of human wild type (WT) ASYN cause rare familial autosomal-dominant forms of PD. Targeted therapeutics that reduce the accumulation of ASYN could prevent or slow the neurodegenerative processes in PD and other synucleinopathies. NPT200-11 is a novel small molecule inhibitor of ASYN misfolding and aggregation. The effects of NPT200-11 on ASYN neuropathology were evaluated in animal models over expressing human alpha synuclein. Longitudinal studies using retinal imaging in mice expressing a hASYN::GFP fusion protein revealed that 2 months of once daily administration of NPT200-11 (5 mg/kg IP) resulted in a time-dependent and progressive reduction in retinal ASYN pathology. The effects of NPT200-11 on ASYN pathology in cerebral cortex and on other disease-relevant endpoints was evaluated in the Line 61 transgenic mouse model overexpressing human wild type ASYN. Results from these studies demonstrated that NPT200-11 reduced alpha-synuclein pathology in cortex, reduced associated neuroinflammation (astrogliosis), normalized striatal levels of the dopamine transporter (DAT) and improved motor function. To gain insight into the relationship between dose, exposure, and therapeutic benefit pharmacokinetic studies were also conducted in mice. These studies demonstrated that NPT200-11 is orally bioavailable and brain penetrating and established target plasma and brain exposures for future studies of potential therapeutic benefit.

Topics: alpha-Synuclein; Animals; Cerebral Cortex; Disease Models, Animal; Gene Expression Regulation; Humans; Inflammation; Lewy Body Disease; Mice; Mice, Transgenic; Multiple System Atrophy; Neurons; Parkinson Disease; Piperidines; Protein Aggregation, Pathological; Protein Folding; Pyrazines; Pyrimidines; Retina

A novel series of donepezil-trolox hybrids were designed, synthesized, and evaluated as multifunctional ligands against Alzheimer's disease (AD). Biological assays showed that these derivatives possessed moderate to good inhibitory activities against acetylcholinesterase (AChE) and monoamine oxidase B (MAO-B) as well as remarkable antioxidant effects. The optimal compound 6d exhibited balanced functions with good inhibition against hAChE (IC

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Antioxidants; Blood-Brain Barrier; Cell Line; Central Nervous System Agents; Chelating Agents; Cholinesterase Inhibitors; Chromans; Copper; Donepezil; Drug Design; Drug Evaluation, Preclinical; Humans; Indans; Male; Mice, Inbred ICR; Microglia; Molecular Docking Simulation; Monoamine Oxidase Inhibitors; Neurotoxins; Oxidants; PC12 Cells; Peptide Fragments; Piperidines; Protein Aggregation, Pathological; Rats; Structure-Activity Relationship

A novel series of donepezil based multi-functional agents "(E)-5,6-dimethoxy-2-(4-(4-substituted piperazin-1-yl)benzylidene)-2,3-dihydro-1H-inden-1-ones" have been designed and synthesized as potential anti-Alzheimer's agents. In-vitro studies revealed that these compounds demonstrated moderate to good AChE and Aβ aggregation inhibitory activity. These derivatives are also endowed with admirable antioxidant activity. Among the entire series compounds IP-9, IP-13 and IP-15 appeared as most active multi-functional agents and displayed marked AChE inhibitory, Aβ disaggregation and antioxidant activity. Studies indicate that IP-13 and IP-15 showed better AChE inhibitory activity than the standard drug donepezil and IP-9, IP-13 as well as IP-15 exhibited better Aβ aggregation inhibitory activity than curcumin. These compounds (IP-9, IP-13 and IP-15) successfully diminished H

Topics: Acetylcholine; Alzheimer Disease; Cell Line; Donepezil; Drug Delivery Systems; Drug Design; Humans; Indans; Ligands; Microscopy, Electron, Transmission; Molecular Dynamics Simulation; Molecular Structure; Neuroprotective Agents; Piperidines; Protein Aggregation, Pathological; Protein Binding

A series of 7-substituted coumarin derivatives were designed and synthesised to display ChE and MAO-B inhibitory activity. The compounds consisted out of a coumarin structure (MAO-B inhibitor) and benzyl-, piperidine-, N-benzylpiperidine- or p-bromo-N-benzylpiperizine moiety, resembling the N-benzylpiperidine function of donepezil (ChE inhibitor), connected via an alkyl ether linkage at the 7 position. The biological assay results indicated that all the compounds (1-25) displayed selective inhibition to hMAO-B over hMAO-A, with the benzyloxy series (1-8, 10-13) showing nano-molar hMAO-B inhibition (IC

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Benzyl Compounds; Binding Sites; Cholinesterase Inhibitors; Coumarins; Dose-Response Relationship, Drug; Humans; Monoamine Oxidase; Monoamine Oxidase Inhibitors; Peptide Fragments; Piperidines; Protein Aggregation, Pathological; Protein Binding; Structure-Activity Relationship

The dyshomeostasis of transition metal ions, accumulation of amyloid-β (Aβ) senile plaques and neuroinflammatory response found in the brain of patients with Alzheimer's disease (AD) have been suggested to be involved in AD pathogenesis. Novel compounds capable of targeting metal-Aβ species and neuroinflammation would be valuable. AD-35 is such a patented small-molecule compound derived from innovative modification of the chemical structure of donepezil. This compound could moderately inhibit acetylcholinesterase and metal-induced Aβ aggregation in vitro and showed disassembly of Aβ aggregates. The effects of AD-35 on cognitive impairments and neuroinflammatory changes caused by intracerebroventricular injection of Aβ25-35 were studied in rats. Compared to sham group, Aβ25-35 injection significantly led to learning and memory deficits, astrocyte activation, and pro-inflammatory cytokines releases (TNF-α and IL-1β). Further studies indicated that the phosphorylation of extracellular signal-regulated kinase was involved in astrocyte activation and pro-inflammatory cytokines production. Oral administration of AD-35 could markedly attenuate Aβ25-35 injection-induced astrocyte activation, pro-inflammatory cytokines TNF-α and IL-1β release, and memory deficits. On the contrary, donepezil only showed inhibition of IL-1β production, but failed to block astrocyte activation and TNF-α production. These results showed that AD-35 would be a novel multi-mechanism drug for the prevention and/or treatment of AD.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Astrocytes; Brain; Cell Line, Tumor; Cholinesterase Inhibitors; Cognitive Dysfunction; Disease Models, Animal; Donepezil; Humans; Indans; Interleukin-1beta; Male; Memory Disorders; Nootropic Agents; Peptide Fragments; Piperidines; Protein Aggregation, Pathological; Random Allocation; Rats, Sprague-Dawley; Tumor Necrosis Factor-alpha

Parkinson's disease (PD) is the most widespread form of dementia where there is an age related degeneration of dopaminergic neurons in the substantia nigra region of the brain. Accumulation of α-synuclein (αS) protein aggregate, mitochondrial dysfunction, oxidative stress, and neuronal cell death are the pathological hallmarks of PD. In this context, amalgamation of curcumin and piperine having profound cognitive properties, and antioxidant activity seems beneficial. However, the blood-brain barrier (BBB) is the major impediment for delivery of neurotherapeutics to the brain. The present study involves formulation of curcumin and piperine coloaded glyceryl monooleate (GMO) nanoparticles coated with various surfactants with a view to enhance the bioavailability of curcumin and penetration of both drugs to the brain tissue crossing the BBB and to enhance the anti-parkinsonism effect of both drugs in a single platform. In vitro results demonstrated augmented inhibition of αS protein into oligomers and fibrils, reduced rotenone induced toxicity, oxidative stress, and apoptosis, and activation of autophagic pathway by dual drug loaded NPs compared to native counterpart. Further, in vivo studies revealed that our formulated dual drug loaded NPs were able to cross BBB, rescued the rotenone induced motor coordination impairment, and restrained dopaminergic neuronal degeneration in a PD mouse model.

Topics: Alkaloids; alpha-Synuclein; Animals; Antiparkinson Agents; Benzodioxoles; Blood-Brain Barrier; Capillary Permeability; Curcumin; Drug Delivery Systems; Drug Therapy, Combination; Liposomes; Male; Mice, Inbred BALB C; Mice, Inbred C57BL; Nanoparticles; Neuroprotective Agents; Parkinsonian Disorders; PC12 Cells; Piperidines; Polyunsaturated Alkamides; Protein Aggregation, Pathological; Random Allocation; Rats; Rotenone; Surface-Active Agents