Design, Synthesis and Investigation of New Diphenyl Substituted Pyridazinone Derivatives as Both Cholinesterase and Aβ-Aggregation Inhibitors

2019 ◽  
Vol 15 (1) ◽  
pp. 59-76 ◽  
Author(s):  
Burcu Kilic ◽  
Merve Erdogan ◽  
Hayrettin O. Gulcan ◽  
Fatma Aksakal ◽  
Nihan Oruklu ◽  
...  

Background: With respect to the increase in the average life expectancy, Alzheimer Disease (AD), the most common form of age-related dementia, has become a major threat to the population over the age of 65 during the past several decades. The majority of AD treatments are focused on cholinergic and amyloid hypotheses. Objective: In this study, three series of diphenyl-2-(2-(4-substitutedpiperazin-1-yl)ethyl)pyridazin- 3(2H)-one derivatives were designed, synthesized and investigated for their ability to inhibit both cholinesterase enzymes and amyloid-β aggregation. Method: The inhibitory activities of the synthesized compounds on AChE (from electric eel) and BChE (from equine serum) were determined by the modified Ellman’s method. The reported thioflavin T-based fluorometric assay was performed to investigate the effect of the selected compounds on the aggregation of Aβ1-42. The cytotoxic effect of the compounds (4g, 11g and 18g) was monitored in 3T3 cell lines to gain insight into therapeutic potential of the compounds by using MTT assay. The crystal structures of the AChE (1EVE) and BChE (1P0I) enzymes were retrieved from the RCSB Protein Data Bank and Molecular Operating Environment (MOE) software was used for molecular docking of the ligands. Results: Among the tested compounds, 5,6-diphenyl derivative 18g was identified as the most potent and selective AChE inhibitor (IC50 = 1.75 µM, Selectivity Index for AChE > 22.857). 4,6- Diphenyl derivative 11g showed the highest and the most selectivity for BChE (IC50= 4.97 µM, SI for AChE < 0.124). Interestingly, 4,5-diphenyl derivative 4g presented dual cholinesterase inhibition (AChE IC50= 5.11 µM; BChE IC50= 14.16 µM, SI for AChE = 2.771). Conclusion: Based on biological activity results and low toxicity of the compounds, it can be said that diphenyl substituted pyridazinone core is a valuable scaffold. Especially, dual inhibitory potencies of 4,5-diphenylpyridazin-3(2H)-one core for the cholinesterase enzymes and Aβ- aggregation makes this core a promising disease-modifying agent.

2017 ◽  
Vol 28 (7) ◽  
pp. 767-781 ◽  
Author(s):  
Alireza Majdi ◽  
Farzin Kamari ◽  
Manouchehr Seyedi Vafaee ◽  
Saeed Sadigh-Eteghad

AbstractBrain ageing is a complex process which in its pathologic form is associated with learning and memory dysfunction or cognitive impairment. During ageing, changes in cholinergic innervations and reduced acetylcholinergic tonus may trigger a series of molecular pathways participating in oxidative stress, excitotoxicity, amyloid-β toxicity, apoptosis, neuroinflammation, and perturb neurotrophic factors in the brain. Nicotine is an exogenous agonist of nicotinic acetylcholine receptors (nAChRs) and acts as a pharmacological chaperone in the regulation of nAChR expression, potentially intervening in age-related changes in diverse molecular pathways leading to pathology. Although nicotine has therapeutic potential, paradoxical effects have been reported, possibly due to its inverted U-shape dose-response effects or pharmacokinetic factors. Additionally, nicotine administration should result in optimum therapeutic effects without imparting abuse potential or toxicity. Overall, this review aims to compile the previous and most recent data on nicotine and its effects on cognition-related mechanisms and age-related cognitive impairment.


Author(s):  
Elina Berntsson ◽  
Suman Paul ◽  
Faraz Vosough ◽  
Sabrina B. Sholts ◽  
Jüri Jarvet ◽  
...  

Alzheimer’s disease (AD) is an incurable disease and the main cause of age-related dementia worldwide, despite decades of research. Treatment of AD with lithium (Li) has showed promising results, but the underlying mechanism is unclear. The pathological hallmark of AD brains is deposition of amyloid plaques, consisting mainly of amyloid-β (Aβ) peptides aggregated into amyloid fibrils. The plaques contain also metal ions of e.g. Cu, Fe, and Zn, and such ions are known to interact with Aβ peptides and modulate their aggregation and toxicity. The interactions between Aβ peptides and Li+ ions have however not been well investigated. Here, we use a range of biophysical techniques to characterize in vitro interactions between Aβ peptides and Li+ ions. We show that Li+ ions display weak and non-specific interactions with Aβ peptides, and have minor effects on Aβ aggregation. These results indicate that possible beneficial effects of Li on AD pathology are not likely caused by direct interactions between Aβ peptides and Li+ ions.


Author(s):  
Mahboubeh Bozorgi ◽  
◽  
Zahra Najafi ◽  
Sahar Omidpanah ◽  
Arash Sadri ◽  
...  

Alzheimer’s disease (AD) is an age-related neurodegenerative disorder. Sever cognitive and memory impairments, huge increase in the prevalence of the disease, and lacking definite cure have absorbed worldwide efforts to develop therapeutic approaches. Since many drugs have failed in the clinical trials due to multifactorial nature of AD, symptomatic treatments are still in the center attention and now, nootropic medicinal plants have been found as versatile ameliorators to reverse memory disorders. In this work, anti-Alzheimer’s activity of aqueous extract of areca nuts (Areca catechu L.) was investigated via in vitro and in vivo studies. It depicted good amyloid β (Aβ) aggregation inhibitory activity, 82% at 100 µg/mL. In addition, it inhibited beta-secretase 1 (BACE1) with IC50 value of 19.03 µg/mL. Evaluation of neuroprotectivity of the aqueous extract of the plant against H2O2-induced cell death in PC12 neurons revealed 84.5% protection at 1 µg/mL. It should be noted that according to our results obtained from Morris Water Maze (MWM) test, the extract reversed scopolamine-induced memory deficit in rats at concentrations of 1.5 and 3 mg/kg.


2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Gefei Chen ◽  
Yuniesky Andrade-Talavera ◽  
Simone Tambaro ◽  
Axel Leppert ◽  
Harriet E. Nilsson ◽  
...  

AbstractMolecular chaperones play important roles in preventing protein misfolding and its potentially harmful consequences. Deterioration of molecular chaperone systems upon ageing are thought to underlie age-related neurodegenerative diseases, and augmenting their activities could have therapeutic potential. The dementia relevant domain BRICHOS from the Bri2 protein shows qualitatively different chaperone activities depending on quaternary structure, and assembly of monomers into high-molecular weight oligomers reduces the ability to prevent neurotoxicity induced by the Alzheimer-associated amyloid-β peptide 1-42 (Aβ42). Here we design a Bri2 BRICHOS mutant (R221E) that forms stable monomers and selectively blocks a main source of toxic species during Aβ42 aggregation. Wild type Bri2 BRICHOS oligomers are partly disassembled into monomers in the presence of the R221E mutant, which leads to potentiated ability to prevent Aβ42 toxicity to neuronal network activity. These results suggest that the activity of endogenous molecular chaperones may be modulated to enhance anti-Aβ42 neurotoxic effects.


Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1658
Author(s):  
Fausto Queda ◽  
Sonia Calò ◽  
Karolina Gwizdala ◽  
João D. Magalhães ◽  
Sandra M. Cardoso ◽  
...  

Alzheimer’s disease (AD) is one of the most devastating neurodegenerative disorders, characterized by multiple pathological features. Therefore, multi-target drug discovery has been one of the most active fields searching for new effective anti-AD therapies. Herein, a series of hybrid compounds are reported which were designed and developed by combining an aryl-sulfonamide function with a benzyl-piperidine moiety, the pharmacophore of donepezil (a current anti-AD acetylcholinesterase AChE inhibitor drug) or its benzyl-piperazine analogue. The in vitro results indicate that some of these hybrids achieve optimized activity towards two main AD targets, by displaying excellent AChE inhibitory potencies, as well as the capability to prevent amyloid-β (Aβ) aggregation. Some of these hybrids also prevented Aβ-induced cell toxicity. Significantly, drug-like properties were predicted, including for blood-brain permeability. Compound 9 emerged as a promising multi-target lead compound (AChE inhibition (IC50 1.6 μM); Aβ aggregation inhibition 60.7%). Overall, this family of hybrids is worthy of further exploration, due to the wide biological activity of sulfonamides.


2021 ◽  
Vol 15 ◽  
Author(s):  
Giuseppe Uras ◽  
Alessia Manca ◽  
Pengfei Zhang ◽  
Zsuzsa Markus ◽  
Natalie Mack ◽  
...  

Alzheimer’s disease is a neurodegenerative disease characterized by disrupted memory, learning functions, reduced life expectancy, and locomotor dysfunction, as a result of the accumulation and aggregation of amyloid peptides that cause neuronal damage in neuronal circuits. In the current study, we exploited a transgenic Drosophila melanogaster line, expressing amyloid-β peptides to investigate the efficacy of a newly synthesized acetylcholinesterase inhibitor, named XJP-1, as a potential AD therapy. Behavioral assays and confocal microscopy were used to characterize the drug effect on AD symptomatology and amyloid peptide deposition. The symptomatology induced in this particular transgenic model recapitulates the scenario observed in human AD patients, showing a shortened lifespan and reduced locomotor functions, along with a significant accumulation of amyloid plaques in the brain. XJP-1 treatment resulted in a significant improvement of AD symptoms and a reduction of amyloid plaques by diminishing the amyloid aggregation rate. In comparison with clinically effective AD drugs, our results demonstrated that XJP-1 has similar effects on AD symptomatology, but at 10 times lower drug concentration than donepezil. It also showed an earlier beneficial effect on the reduction of amyloid plaques at 10 days after drug treatment, as observed for donepezil at 20 days, while the other drugs tested have no such effect. As a novel and potent AChE inhibitor, our study demonstrates that inhibition of the enzyme AChE by XJP-1 treatment improves the amyloid-induced symptomatology in Drosophila, by reducing the number of amyloid plaques within the fruit fly CNS. Thus, compound XJP-1 has the therapeutic potential to be further investigated for the treatment of AD.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Efrat Naaman ◽  
Sarah Ya’ari ◽  
Chen Itzkovich ◽  
Shadi Safuri ◽  
Flora Macsi ◽  
...  

AbstractAmyloid-β (Aβ), reported as a significant constituent of drusen, was implicated in the pathophysiology of age-related macular degeneration (AMD), yet the identity of the major pathogenic Aβ species in the retina has remained hitherto unclear. Here, we examined the in-vivo retinal impact of distinct supramolecular assemblies of Aβ. Fibrillar (Aβ40, Aβ42) and oligomeric (Aβ42) preparations showed clear biophysical hallmarks of amyloid assemblies. Measures of retinal structure and function were studied longitudinally following intravitreal administration of the various Aβ assemblies in rats. Electroretinography (ERG) delineated differential retinal neurotoxicity of Aβ species. Oligomeric Aβ42 inflicted the major toxic effect, exerting diminished ERG responses through 30 days post injection. A lesser degree of retinal dysfunction was noted following treatment with fibrillar Aβ42, whereas no retinal compromise was recorded in response to Aβ40 fibrils. The toxic effect of Aβ42 architectures was further reflected by retinal glial response. Fluorescence labelling of Aβ42 species was used to detect their accumulation into the retinal tissue. These results provide conceptual evidence of the differential toxicity of particular Aβ species in-vivo, and promote the mechanistic understanding of their retinal pathogenicity. Stratifying the impact of pathological Aβ aggregation in the retina may merit further investigation to decipher the pathophysiological relevance of processes of molecular self-assembly in retinal disorders.


2020 ◽  
Vol 21 (13) ◽  
pp. 4812 ◽  
Author(s):  
Yvette Akwa

Alzheimer’s disease (AD) is a multifactorial age-related neurodegenerative disease that today has no effective treatment to prevent or slow its progression. Neuroactive steroids, including neurosteroids and sex steroids, have attracted attention as potential suitable candidates to alleviate AD pathology. Accumulating evidence shows that they exhibit pleiotropic neuroprotective properties that are relevant for AD. This review focuses on the relationship between selected neuroactive steroids and the main aspects of AD disease, pointing out contributions and gaps with reference to sex differences. We take into account the regulation of brain steroid concentrations associated with human AD pathology. Consideration is given to preclinical studies in AD models providing current knowledge on the neuroprotection offered by neuroactive (neuro)steroids on major AD pathogenic factors, such as amyloid-β (Aβ) and tau pathology, mitochondrial impairment, neuroinflammation, neurogenesis and memory loss. Stimulating endogenous steroid production opens a new steroid-based strategy to potentially overcome AD pathology. This article is part of a Special Issue entitled Steroids and the Nervous System.


2021 ◽  
Author(s):  
Elina Berntsson ◽  
Suman Paul ◽  
Faraz Vosough ◽  
Sabrina B. Sholts ◽  
Jüri Jarvet ◽  
...  

AbstractAlzheimer’s disease (AD) is an incurable disease and the main cause of age-related dementia worldwide, despite decades of research. Treatment of AD with lithium (Li) has showed promising results, but the underlying mechanism is unclear. The pathological hallmark of AD brains is deposition of amyloid plaques, consisting mainly of amyloid-β (Aβ) peptides aggregated into amyloid fibrils. The plaques contain also metal ions of e.g. Cu, Fe, and Zn, and such ions are known to interact with Aβ peptides and modulate their aggregation and toxicity. The interactions between Aβ peptides and Li+ ions have however not been well investigated. Here, we use a range of biophysical techniques to characterize in vitro interactions between Aβ peptides and Li+ ions. We show that Li+ ions display weak and non-specific interactions with Aβ peptides, and have minor effects on Aβ aggregation. These results indicate that possible beneficial effects of Li on AD pathology are not likely caused by direct interactions between Aβ peptides and Li+ ions.


2014 ◽  
Vol 211 (13) ◽  
pp. 2487-2496 ◽  
Author(s):  
Jee Hoon Roh ◽  
Hong Jiang ◽  
Mary Beth Finn ◽  
Floy R. Stewart ◽  
Thomas E. Mahan ◽  
...  

Age-related aggregation of amyloid-β (Aβ) is an upstream pathological event in Alzheimer’s disease (AD) pathogenesis, and it disrupts the sleep–wake cycle. The amount of sleep declines with aging and to a greater extent in AD. Poor sleep quality and insufficient amounts of sleep have been noted in humans with preclinical evidence of AD. However, how the amount and quality of sleep affects Aβ aggregation is not yet well understood. Orexins (hypocretins) initiate and maintain wakefulness, and loss of orexin-producing neurons causes narcolepsy. We tried to determine whether orexin release or secondary changes in sleep via orexin modulation affect Aβ pathology. Amyloid precursor protein (APP)/Presenilin 1 (PS1) transgenic mice, in which the orexin gene is knocked out, showed a marked decrease in the amount of Aβ pathology in the brain with an increase in sleep time. Focal overexpression of orexin in the hippocampus in APP/PS1 mice did not alter the total amount of sleep/wakefulness and the amount of Aβ pathology. In contrast, sleep deprivation or increasing wakefulness by rescue of orexinergic neurons in APP/PS1 mice lacking orexin increased the amount of Aβ pathology in the brain. Collectively, modulation of orexin and its effects on sleep appear to modulate Aβ pathology in the brain.


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