2',6'-dihydroxy-4'-methoxy dihydrochalcone improves the cognitive impairment of Alzheimer's disease: a structure-activity relationship study

Author(s):  
Ana E. Gonçalves ◽  
Ângela Malheiros ◽  
Camila A. Cazarin ◽  
Lara de França ◽  
David L. Palomino-Salcedo ◽  
...  

Background: Chalcones and dihydrochalcones present potent inhibition of acetylcholinesterase, which is currently considered the most efficient approach for symptomatic treatment of Alzheimer’s disease. Objective: The present study aimed to explore the potential benefits of 2',6'-dihydroxy-4'-methoxy dihydrochalcone on the cognitive deficits of animals submitted to the streptozotocin-induced Alzheimer's model, as well as to evaluate the possible mechanisms of action. Methods: Learning and memory functions of different groups of animals were submitted to the streptozotocin-induced Alzheimer's model (STZ 2.5 mg/mL, i.c.v.) and subsequently treated with 2',6'-dihydroxy-4'-methoxy dihydrochalcone (DHMDC) administered at doses 5, 15, and 30 mg/kg (p.o.), rivastigmine (0,6 mg/kg, i.p.) and vehicle were evaluated in aversive memory test (inhibitory avoidance test) and spatial memory test (object recognition test). Molecular docking simulations were performed to predict the binding mode of DHMDC at the peripheral site of AChE to analyze noncovalent enzyme-ligand interactions. DFT calculations were carried out to study well-known acetylcholinesterase inhibitors and DHMDC. Results: DHMDC markedly increased the learning and memory of mice. STZ caused a significant decline of spatial and aversive memories in mice, attenuated by DHMDC (15 and 30 mg/kg). Furthermore, STZ conspicuously increased lipid peroxidation and compromised the antioxidant levels in mice brains. DHMDC pretreatment significantly increased GSH activity and other oxidative stress markers and decreased TBARS levels in the brain of STZ administered mice. AChE activity was significantly decreased by DHMDC in the brain of mice. Conclusion: The results together point that DHMDC may be a useful drug in the management of dementia.

Author(s):  
Krishna Chinthapalli

Pharmacological treatment of Alzheimer’s disease is an important part of management of the condition. There are only four drugs available for treatment of the disease and none halt the disease process, however they have a benefit on cognition, behaviour, activities of daily living, and global function. Acetylcholinesterase inhibitors are thought to work by enhancing cholinergic transmission in the brain and are particularly effective in mild and moderate AD, with recent evidence suggesting donepezil is also effective in severe AD. Memantine is the only glutamate antagonist that is available for AD and is limited for use in moderate or severe AD. The choice of drug depends on route of administration, adverse effects, and medical comorbidities. There is intense research on alternative treatments especially those that may stop the underlying disease process.


2019 ◽  
Vol 25 (33) ◽  
pp. 3519-3535 ◽  
Author(s):  
Md. Tanvir Kabir ◽  
Md. Sahab Uddin ◽  
Mst. Marium Begum ◽  
Shanmugam Thangapandiyan ◽  
Md. Sohanur Rahman ◽  
...  

: In the brain, acetylcholine (ACh) is regarded as one of the major neurotransmitters. During the advancement of Alzheimer's disease (AD) cholinergic deficits occur and this can lead to extensive cognitive dysfunction and decline. Acetylcholinesterase (AChE) remains a highly feasible target for the symptomatic improvement of AD. Acetylcholinesterase (AChE) remains a highly viable target for the symptomatic improvement in AD because cholinergic deficit is a consistent and early finding in AD. The treatment approach of inhibiting peripheral AChE for myasthenia gravis had effectively proven that AChE inhibition was a reachable therapeutic target. Subsequently tacrine, donepezil, rivastigmine, and galantamine were developed and approved for the symptomatic treatment of AD. Since then, multiple cholinesterase inhibitors (ChEIs) have been continued to be developed. These include newer ChEIs, naturally derived ChEIs, hybrids, and synthetic analogues. In this paper, we summarize the different types of ChEIs which are under development and their respective mechanisms of actions.


2021 ◽  
Vol 11 (11) ◽  
pp. 5044
Author(s):  
Giovanni Ribaudo ◽  
Maurizio Memo ◽  
Alessandra Gianoncelli

Alzheimer’s disease is a memory-related neurodegenerative condition leading to cognitive impairment. Cholinergic deficit, together with other underlying mechanisms, leads the to onset and progression of the disease. Consequently, acetylcholinesterase inhibitors are used for the symptomatic treatment of dementia, even if limited efficacy is observed. More recently, some specific phosphodiesterase isoforms emerged as promising, alternative targets for developing inhibitors to contrast neurodegeneration. Phosphodiesterase isoforms 4,5 and 9 were found to be expressed in brain regions that are relevant for cognition. Given the complex nature of Alzheimer’s disease and the combination of involved biochemical mechanisms, the development of polypharmacological agents acting on more than one pathway is desirable. This review provides an overview of recent reports focused on natural and Nature-inspired small molecules, or plant extracts, acting as dual cholinesterase and phosphodiesterase inhibitors. In the context of the multi-target directed ligand approach, such molecules would pave the way for the development of novel agents against neurodegeneration. More precisely, according to the literature data, xanthines, other alkaloids, flavonoids, coumarins and polyphenolic acids represent promising scaffolds for future optimization.


2020 ◽  
pp. 149-160
Author(s):  
Maha Z. Rizk ◽  
Hanan F. Aly

Alzheimer’s disease (AD) is a progressive, neurodegenerative pathology that primarily affects the elderly population, and is estimated to account for 50-60% of dementia cases in persons over 65 years of age. The main characteristics connected with AD implicate the dysfunction of cognitive role, mainly loss of memory. While, the main features linked with AD at later stages include deficits of language, depression and problems associated with behavior. One of the most important approaches for medication of this disease is to improve level of the acetylcholine in the brain tissues using inhibitors of acetylcholinesterase (AChE). The present work reviews the literature on natural products from plants and plant-derived compounds inhibitors of enzyme acetylcholinesterase. Keywords: Alzheimer’s disease; Acetylcholinesterase inhibitors; Secondary metabolites; Plant extracts; essential oils


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. SCI-2-SCI-2 ◽  
Author(s):  
Mark P. Mattson

Abstract Abstract SCI-2 Brain cells are influenced in health and disease by several types of bone marrow-derived cells (BMDC) that either reside in, or are recruited to, the brain. Microglia are macrophage-like cells that continuously surveil the brain, and respond to injury, infection or disease by endocytosing damaged/dead cells and microorganisms, and by producing pro-inflammatory cytokines. Lymphocytes of various phenotypes enter the brain in large numbers in response to acute injury (stroke, severe epileptic seizures, trauma) or chronic disease (multiple sclerosis, Alzheimer's disease). While microglia and lymphocytes are best known for their adverse effects on neuronal function and survival in injury or disease (Arumugam et al., Nat Med. 2006; 12:621-3), recent findings suggest that these cells may also serve important beneficial roles in processes such as learning and memory (Ziv et al. Nat Neurosci. 2006; 9:268-75). Here I describe how BMDC can affect neuronal excitability and mitochondrial function in normal physiological settings and in disease states. We have found that low concentrations of tumor necrosis factor (TNF), which is produced by microglia/macrophages and lymphocytes, can promote neuronal survival and synaptic plasticity by activating the transcription factor NF-kB to induce the expression of glutamate receptor subunits, mitochondrial SOD2 and Bcl2 (Mattson and Meffert, Cell Death Differ. 2006; 13:852-60). When bone marrow from TNF receptor-deficient mice was transplanted into irradiated wild type mice, neurons in the brain were more vulnerable to epileptic seizures, suggesting that TNF suppresses neuronal excitability (Guo et al., Neuromolecular Med. 2004; 5:219-34). In other studies we found that a mutation in presenilin-1 (PS1) that causes early-onset inherited Alzheimer's disease (AD) perturbs lymphocyte signaling (Morgan et al., Neuromolecular Med. 2007; 9:35-45). Splenic T cells isolated from PS1 mutant knockin mice respond poorly to proliferative signals and have downregulated cluster designation 3 and interleukin (IL)- 2-receptor expression necessary for a normal T-cell immune response. The adverse effect of mutant PS1 involves perturbed calcium regulation and cytokine signaling in lymphocytes, and associated sensitivity of lymphocytes to mitochondria-mediated apoptosis. These findings suggest that abnormalities in immune function might play roles in the pathogenesis of AD. Finally, I describe very recent findings that suggest roles for toll-like receptor signaling in learning and memory processes, and in neuronal responses to energy deprivation (Tang et al., Proc Natl Acad Sci U S A. 2007; 104:13798-803). Emerging findings therefore suggest that both innate and humoral signaling from BMDC to neurons play interesting roles in regulating neuronal plasticity and energy metabolism in health and disease. Disclosures No relevant conflicts of interest to declare.


2021 ◽  
Vol 13 ◽  
pp. 117957352110291
Author(s):  
Immacolata Vecchio ◽  
Luca Sorrentino ◽  
Annamaria Paoletti ◽  
Rosario Marra ◽  
Mariamena Arbitrio

Alzheimer’s disease (AD) is a chronic disabling disease that affects the central nervous system. The main consequences of AD include the decline of cognitive functions and language disorders. One of the causes leading to AD is the decrease of neurotransmitter acetylcholine (ACh) levels in the brain, in part due to a higher activity of acetylcholinesterase (AChE), the enzyme responsible for its degradation. Many acetylcholinesterase inhibitors (AChEIs), both natural and synthetic, have been developed and used through the years to counteract the progression of the disease. The first of such drugs approved for a therapeutic use was tacrine, that binds through a reversible bond to the enzyme. However, tacrine has since been withdrawn because of its adverse effects. Currently, donepezil and galantamine are very promising AChEIs with clinical benefits. Moreover, rivastigmine is considered a pseudo-irreversible compound with anti-AChE action, providing similar effects at the clinical level. The purpose of this review is to provide an overview of what has been published over the last decade on the effectiveness of AChEIs in AD, analysing the most relevant issues under the clinical and methodological profiles and the consequent possible welfare effects for the whole world. Furthermore, novel drugs and possible therapeutic approaches are also discussed.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Mona Mehta ◽  
Abdu Adem ◽  
Marwan Sabbagh

Acetylcholinesterase (AChE) remains a highly viable target for the symptomatic improvement in Alzheimer's disease (AD) because cholinergic deficit is a consistent and early finding in AD. The treatment approach of inhibiting peripheral AchE for myasthenia gravis had effectively proven that AchE inhibition was a reachable therapeutic target. Subsequently tacrine, donepezil, rivastigmine, and galantamine were developed and approved for the symptomatic treatment of AD. Since then, multiple cholinesterase inhibitors (ChEI) continue to be developed. These include newer ChEIs, naturally derived ChEIs, hybrids, and synthetic analogues. In this paper, we summarize the different types of ChEIs in development and their respective mechanisms of actions. This pharmacological approach continues to be active with many promising compounds.


2022 ◽  
Vol 67 (4) ◽  
pp. 106-114
Author(s):  
Syed Sayeed Ahmad ◽  
Haroon Khan ◽  
Mohammad Khalid ◽  
Abdulraheem SA Almalki

Alzheimer's disease is a chronic neurodegenerative ailment and the most familiar type of dementia in the older population with no effective cure to date. It is characterized by a decrease in memory, associated with the mutilation of cholinergic neurotransmission. Presently, acetylcholinesterase inhibitors have emerged as the most endorsed pharmacological medications for the symptomatic treatment of mild to moderate Alzheimer's disease. This study aimed to research the molecular enzymatic inhibition of human brain acetylcholinesterase by a natural compound emetine and I3M. Molecular docking studies were used to identify superior interaction between enzyme acetylcholinesterase and ligands. Furthermore, the docked acetylcholinesterase-emetine complex was validated statistically using an analysis of variance in all tested conformers. In this interaction, H-bond, hydrophobic interaction, pi-pi, and Cation-pi interactions played a vital function in predicting the accurate conformation of the ligand that binds with the active site of acetylcholinesterase. The conformer with the lowest free energy of binding was further analyzed. The binding energy for acetylcholinesterase complex with emetine and I3M was -9.72kcal/mol and -7.09kcal/mol, respectively. In the current study, the prediction was studied to establish a relationship between binding energy and intermolecular energy (coefficient of determination [R2 linear = 0.999), and intermolecular energy and Van der wall forces (R2 linear = 0.994). These results would be useful in gaining structural insight for designing novel lead compounds against acetylcholinesterase for the effective management of Alzheimer's disease.


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