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A series of coumarin‐1,3,5‐triazine derivatives were designed, synthesized and evaluated as acetylcholinesterase inhibitors. The structures of those compounds were characterized by IR, NMR, HRMS, HPLC, and X‐ray. The structures of those coumarin‐1,3,5‐triazine derivatives are the mixtures of two geometric isomers. The 1H‐NMR of compound 3 g without coumarin structure and its hydrochloride and single crystal structure of compound 3 g were studied to prove the coumarin‐1,3,5‐triazine derivatives are the mixtures of two geometric isomers. The acetylcholinesterase and butyrylcholinesterase inhibitory activities of the synthesized compounds were determinated by Ellman's method. The results showed that all the compounds could inhibit acetylcholinesterase selectively. Among them, compound 3 b was found to have the strongest inhibitory effect on acetylcholinesterase with an IC50 value of 0.018 μM, which was closest to the IC50 of the positive control donepezil (IC50=0.016 μM). Enzyme kinetic studies indicate that this compound inhibited acetylcholinesterase with a mixed mode. Molecular docking, molecular dynamics simulation study and binding free energy calculation experiments demonstrated that compound 3 b could stably interact with key amino acids in the catalytically active site and the peripheral anion site of acetylcholinesterase. According to the results, compound 3 b demonstrates promising potential as acetylcholinesterase inhibitors for the treatment of Alzheimer's disease. [ABSTRACT FROM AUTHOR]

Introduction: The Persian Gulf is home to a diverse range of marine life, including various species of fish, crustaceans, mollusks, and echinoderms. This study investigates the potential therapeutic properties of venoms from echinoderms in the Persian Gulf, specifically their ability to inhibit cholinesterases (Acetylcholinesterase and butyrylcholinesterase) and act as antioxidants. Methods: Four venoms from two echinoderm species, including the spine, gonad, and coelomic fluids of sea urchins, as well as brittle star venoms, were analyzed using various methods, including LD[sub 50] determination, protein analysis, antioxidant assays, GC-MS for secondary metabolite identification, and molecular docking simulations. Results and discussion: The study's results revealed the LD[sub 50] of the samples as follows: 2.231 ± 0.09, 1.03 ± 0.05, 1.12 ± 0.13, and 6.04 ± 0.13 mg/mL, respectively. Additionally, the protein levels were 44.037 ± 0.002, 74.223 ± 0.025, 469.97 ± 0.02, and 104.407 ± 0.025 µg/mL, respectively. SDS-PAGE and total protein studies indicated that at least part of the venom was proteinaceous. Furthermore, the study found that the brittle star samples exhibited significantly higher antioxidant activity compared to other samples, including the standard ascorbic acid, at all tested concentrations. GC-MS analysis identified 12, 23, 21, and 25 compounds in the samples, respectively. These compounds had distinct chemical and bioactive structures, including alkaloids, terpenes, and steroids. Conclusion: These venoms displayed strong cholinesterase inhibitory and antioxidant activities, likely attributed to their protein content and the presence of alkaloids, terpenes, and steroids. Notably, the alkaloid compound C7 was identified as a promising candidate for further research in Alzheimer's disease therapy. In conclusion, echinoderms in the Persian Gulf may hold significant potential for discovering novel therapeutic agents. [ABSTRACT FROM AUTHOR]

Introduction Alzheimer's disease is a neurocognitive disorder that affects elderly people by slowly impaired cognition, dementia, and gets worse with age. It slowly impacts the quality of life. Clinically, it is distinguished by a transition from episodic memory to a gradual reduction in cognitive ability leading to cognitive dysfunction. Neurofibrillary tangles and amyloid plaques are unique structures that are thought to have a role in the pathogenesis of Alzheimer's disease. In this review, we focus our attention on the risk factors, pathophysiology, etiology, epidemiology, stages, diagnosis, treatment, mechanisms, pathways, ongoing clinical trials data and risks potentially associated with the development of Alzheimer's disease. Short summary This review aims to extrapolate the information about Alzheimer's disease. Preliminary research was done by selecting reviews on PubMed, Elsevier, and Google open-access publications using the keywords like "Alzheimer, dementia, neurodegenerative, memory, amyloid β, mechanism of action, pathways". Conclusion Here we show the discussion and interpretation of several signaling pathways in the pathogenesis of Alzheimer's disease such as amyloid β plaque cleavage, Metal ion hypothesis, amyloid β degradation, initiation of amyloidogenic and non-amyloidogenic pathway, oxidative stress hypothesis, Metabolic syndrome, insulin resistance and tau phosphorylation associated apolipoprotein- cholesterol, neurofibrillary tangles accumulation, and insulin resistance which are significant for better understanding of the disease initiation and progression. On studying the ongoing clinical trials, it was found that current drugs being tested are crenezumab, gantenerumab and sodium oligonucleotide. [ABSTRACT FROM AUTHOR]

Current drugs for Alzheimer’s Disease (AD), such as cholinesterase inhibitors (ChEIs), exert only symptomatic activity. Different psychometric tools are needed to assess cognitive and non-cognitive dimensions during pharmacological treatment. In this pilot study, we monitored 33 mild-AD patients treated with ChEIs. Specifically, we evaluated the effects of 6 months (Group 1 = 17 patients) and 9 months (Group 2 = 16 patients) of ChEIs administration on cognition with the Mini-Mental State Examination (MMSE), the Montreal Cognitive Assessment (MoCA), and the Frontal Assessment Battery (FAB), while depressive symptoms were measured with the Hamilton Depression Rating Scale (HDRS). After 6 months (Group 1), a significant decrease in MoCA performance was detected. After 9 months (Group 2), a significant decrease in MMSE, MoCA, and FAB performance was observed. ChEIs did not modify depressive symptoms. Overall, our data suggest MoCA is a potentially useful tool for evaluating the effectiveness of ChEIs. [ABSTRACT FROM AUTHOR]

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Abstract The study aimed to investigate the antioxidant and cholinesterase inhibitory activities of the leaves and stems of Artocarpus sericicarpus and to analyse the phenolic compounds in the extracts. The modified Ellman's method was used to determine the cholinesterase inhibitory activities against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. The antioxidant properties were evaluated using DPPH and ABTS methods. The total phenolic content (TPC) was measured by spectrometric assay, and compound identification was carried out by LC-MS/MS analysis. The results showed that the leaf and stem extracts of A. sericicarpus exerted significant inhibitory effects against AChE and BChE, as well as antioxidant activities. The stem ethanolic extract exhibited the highest potency against AChE and BChE with IC50 values of 5.81 and 11.46 µg/mL, respectively. The leaf and stem ethanolic extracts gave higher antioxidant activities and TPC compared to the water-based extracts. The LC-MS/MS analysis indicated the presence of phenolic compounds, such as flavones, flavonols, flavanones, prenylated chalcones, and xanthones in the extracts. [ABSTRACT FROM AUTHOR]

A series of OA-tacrine hybrids with the alkylamine linker was designed, synthesized, and evaluated as effective cholinesterase inhibitors for the treatment of Alzheimer's disease (AD). Biological activity results demonstrated that some hybrids possessed significant inhibitory activities against acetylcholinesterase (AChE). Among them, compounds B4 (hAChE, IC50 = 14.37 ± 1.89 nM; SI > 695.89) and D4 (hAChE, IC50 = 0.18 ± 0.01 nM; SI = 3374.44) showed excellent inhibitory activities and selectivity for AChE as well as low nerve cell toxicity. Furthermore, compounds B4 and D4 exhibited lower hepatotoxicity than tacrine in cell viability, apoptosis, and intracellular ROS production for HepG2 cells. These properties of compounds B4 and D4 suggest that they deserve further investigation as promising agents for the prospective treatment of AD. [ABSTRACT FROM AUTHOR]

Neurodegenerative diseases such as Alzheimer's disease (AD) are multifactorial with several different pathologic mechanisms. Therefore, it is assumed that multitargeted-directed ligands (MTDLs) which interact with different biological targets relevant to the diseases, might offer an improved therapeutic alternative than using the traditional "one-target, one-molecule" approach. Herein, we describe new benzothiazole-based derivatives as a privileged scaffold for histamine H3 receptor ligands (H3R). The most affine compound, the 3-(azepan-1-yl)propyloxy-linked benzothiazole derivative 4b, displayed a Ki value of 0.012 μM. The multitargeting potential of these H3R ligands towards AChE, BuChE and MAO-B enzymes was evaluated to yield compound 3s (pyrrolidin-1-yl-(6-((5-(pyrrolidin-1-yl)pentyl)oxy)benzo[d]thiazol-2-yl)methanone) as the most promising MTDL with a Ki value of 0.036 μM at H3R and IC50 values of 6.7 µM, 2.35 µM, and 1.6 µM towards AChE, BuChE, and MAO-B, respectively. These findings suggest that compound 3s can be a lead structure for developing new multi-targeting anti-AD agents. [ABSTRACT FROM AUTHOR]

Owing to their potential to cause serious adverse health effects, significant efforts have been made to develop antidotes for organophosphate (OP) anticholinesterases, such as nerve agents. To be optimally effective, antidotes must not only reactivate inhibited target enzymes, but also have the ability to cross the blood–brain barrier (BBB). Progress has been made toward brain-penetrating acetylcholinesterase reactivators through the development of a new group of substituted phenoxyalkyl pyridinium oximes. To help in the selection and prioritization of compounds for future synthesis and testing within this class of chemicals, and to identify candidate broad-spectrum molecules, an in silico framework was developed to systematically generate structures and screen them for reactivation efficacy and BBB penetration potential. [ABSTRACT FROM AUTHOR]

Rural children in agricultural communities are thought to more likely be exposed to cholinesterase-inhibiting insecticides that may have enduring health effects than are urban children. This article shows that blood cholinesterase measures reflect these rural-urban differences that likely follow insecticide exposures. Regulations to protect rural residents from environmental insecticide exposures should be strengthened. Objective: In a 2-group prospective design, this study compared seasonal cholinesterase levels of Latinx children in rural farmworker families and comparable urban children to assess the impact of environmental exposure to cholinesterase-inhibiting insecticides. Methods: Quarterly blood samples and passive dosimeter wristbands were collected over 2 years in 8-year-old children (74 rural, 62 urban). Laboratory analysis assessed total cholinesterase, acetylcholinesterase, and butyrylcholinesterase from blood samples, and insecticides from wristbands. Results: In spring and summer, total cholinesterase and acetylcholinesterase levels were depressed in rural children compared with winter and fall. Butyrylcholinesterase was depressed in rural children in fall compared with spring and summer. Adjustment for insecticide exposure did not affect these associations. Conclusions: Environmental exposures to cholinesterase-inhibiting insecticides have measurable biochemical effects on blood cholinesterases in rural children from farmworker families. [ABSTRACT FROM AUTHOR]

An editorial is presented on the progress and challenges in Alzheimer's drug treatment over the last 30 years. Topics include the development of disease-modifying drugs, historical perspectives on treatment options, and the ongoing search for effective therapies. It reports that disease-modifying drugs have been approved, it mentions the challenges faced in developing effective treatments, and it highlights the importance of non-pharmacological preventative approaches.

Alzheimer's disease (AD) is a progressive age‐related neurodegenerative brain disorder, which leads to loss of memory and other cognitive dysfunction. The underlying mechanisms of AD pathogenesis are very complex and still not fully explored. Cholinergic neuronal loss, accumulation of amyloid plaque, metal ions dyshomeostasis, tau hyperphosphorylation, oxidative stress, neuroinflammation, and mitochondrial dysfunction are major hallmarks of AD. The current treatment options for AD are acetylcholinesterase inhibitors (donepezil, rivastigmine, and galantamine) and NMDA receptor antagonists (memantine). These FDA‐approved drugs mainly provide symptomatic relief without addressing the pathological aspects of disease progression. So, there is an urgent need for novel drug development that not only addresses the basic mechanisms of the disease but also shows the neuroprotective property. Various research groups across the globe are working on the development of multifunctional agents for AD amelioration using different core scaffolds for their design, and carbamate is among them. Rivastigmine was the first carbamate drug investigated for AD management. The carbamate fragment, a core scaffold of rivastigmine, act as a potential inhibitor of acetylcholinesterase. In this review, we summarize the last 10 years of research conducted on the modification of carbamate with different substituents which primarily target ChE inhibition, reduce oxidative stress, and modulate Aβ aggregation. [ABSTRACT FROM AUTHOR]

Purpose: This study investigates the potential impact of cholinesterase inhibitors (ChEIs) on patients with heart failure (HF) and dementia. ChEIs are known to boost acetylcholine levels and benefit cognition in patients with dementia; however, their effect on patients with HF is uncertain. This study aimed to assess whether cardiovascular events and mortality among patients with HF and dementia are altered by ChEI therapy. Methods: Data from the National Health Insurance Research Database in Taiwan were retrospectively analyzed. Dementia patients diagnosed with HF were followed for 5 years until all-cause mortality, cardiovascular mortality, hospitalization for worsening HF, or the end of the study. Multivariable Cox models and inverse probability of treatment weighting (IPTW) were employed. Results: Out of 20,848 patients with dementia, 5138 had HF. Among them, 726 were ChEI users and 4412 were non-users. Based on IPTW, the ChEI users had significantly lower estimated risks of all-cause mortality [hazard ratio (HR) 0.43; 95% confidence interval (CI) 0.38–0.49, p < 0.001] and cardiovascular mortality (HR 0.41; 95% CI 0.33–0.53, p < 0.001) compared with the non-users, but there was no significant difference in hospitalization for worsening HF (HR 0.73; 95% CI 0.51–1.05, p = 0.091) after 5 years. The survival benefits of ChEIs were consistent across subgroups. Conclusions: The results of this retrospective cohort study suggest that ChEIs may be beneficial in reducing all-cause and cardiovascular mortality in patients with dementia with HF. Further research is needed to validate these findings and explore the potential benefits of ChEIs in all patients with HF, including those without dementia. [ABSTRACT FROM AUTHOR]

Background: Cholinesterase inhibitor (ChEI) insecticide is a common cause of poisoning in developing countries. Toxicity occurs by ingestion, inhalation, or dermal absorption. However, only a few cases of parenteral poisoning have been reported, so far. The inhibition of cholinesterase itself is not enough to explain the wide range of disorders associated with ChEIs insecticide exposure. Oxidative stress is supposed to be a contributing factor to the complications of ChEIs insecticide poisoning. L-carnitine (LC) is a widely accessible antioxidant therapy that is a safe drug with fewer side effects and it could be considered as a promising adjuvant treatment in acute ChEIs insecticide poisoning. Case Presentation: The current case report describes a 60-year-old male with a homicidal intramuscular injection of ChEI insecticide, presented with chest crepitations and fasciculations. He showed an initial improvement to treatment with atropine, toxogonin, and L-carnitine (LC) and discharged. However, there was an aggressive reaplse of symptoms after five days necessitating readmission and mechanical ventilation. After two weeks of treatment with the same regimens, the patient's condition improved significantly and he was discharged with complete recovery. Conclusion: The diagnosis of ChEI toxicity by the parenteral route is a challenge, where the onset of symptoms may be delayed with atypical presentations. Even though the symptoms are mild initially, observation for a more extended period is mandatory. LC could be a promising adjuvant antioxidant treatment in acute ChEIs insecticide poisoning cases. [ABSTRACT FROM AUTHOR]

A series of new conjugates of tacrine with ethyl 2-aminomethylidene-3-oxobutanoate with a spacer length of 4, 6, and 8 methylene groups was synthesized. The synthesized conjugates were shown to be effective inhibitors of acetylcholinesterase (IC50 up to 0.143 µmol L−1) and butyrylcholinesterase (IC50 up to 0.024 µmol L−1), with the inhibitory activity increasing with the spacer elongation. The new conjugates, as their diethyl malonate analogs, demonstrated a potential ability to block the AChE-induced β-amyloid aggregation and inhibited the self-aggregation of β-amyloid (1–42) with maximum activity at the level of the standard compound myricetin for derivatives with the octamethylene spacer. For the lead compound, a conjugate of tacrine with ethyl 2-aminomethylidene-3-oxobutanoate with the (CH2)8 spacer, the ability to bind the biometal ions CuII, FeII and ZnII was also demonstrated. The obtained characteristics indicated the synthesized conjugates as promising multitarget agents for the treatment of Alzheimer's disease. [ABSTRACT FROM AUTHOR]

Chronic pain presents a major challenge in contemporary medicine, given the limited effectiveness and numerous adverse effects linked to available treatments. Recognizing the potential of the cholinergic pathway as a therapeutic target, the present work evaluates the antinociceptive activity of a combination of Cris-104, a novel α4β2* receptor agonist, and donepezil, a central anticholinesterase agent. Isobolographic analysis revealed that equimolar combination was approximately 10 times more potent than theoretically calculated equipotent additive dose. Administration of Cris-104 and donepezil combination (3 μmol/kg) successfully reversed hyperalgesia and mechanical allodynia observed in rats subjected to spinal nerve ligation (SNL). The combination also modulated neuroinflammation by reducing astrocyte activation, evident in the decreased expression of glial fibrillary acidic protein (GFAP) in the spinal cord. The observed synergism in combining a nicotinic receptor agonist with an anticholinesterase agent underscores its potential for treating chronic pain. This alternative therapeutic distinct advantage, including dose reduction and high selectivity for the receptor, contribute to a more favorable profile with minimized adverse effects. [ABSTRACT FROM AUTHOR]

Background: Cholinesterase is a biomarker for poisonings by anticholinesterase agents, but its reference values are scarce, and possible interaction with collars containing parasiticides has not been studied. Objectives: We aimed to evaluate the serum cholinesterase activity of healthy dogs without a history of contact with anticholinesterase agents and healthy animals exposed to commercial collars containing organophosphate. Methods: Ninety‐nine dogs were used and included healthy animals without recent exposure to anticholinesterase agents and healthy animals previously exposed to diazinon collars. Serum quantification of the enzyme butyrylcholinesterase (BuchE) through spectrophotometry was conducted on all samples. In experiment 1, BuchE activity was quantified at time 0 and 7 days after, a time when the samples were kept at −18°C. In experiment 2, sampling times were 0, 7, 14, 21, 28, and 56 days. Results: Time 0 values were 4622.38 ± 1311.53 U/L. After 7 days, a significant decay was observed, with a mean of 3934.45 ± 1430.45 U/L. Spearman's test was performed, finding a weak correlation between ALT, creatinine, total plasma proteins, age, weight, red blood cells, platelets, leukocytes, and BuchE activities. In experiment 2, the mean at time 0 was 4753 ± 454.8 U/L. With exposure to the collar, there was a decay of up to 93% after 14 days. Conclusions: Normality values of serum BuchE in healthy dogs without a history of exposure to anticholinesterase agents were 4360.8–4883.96 U/L. Freezing serum caused a decrease in BuchE activity. Exposure to commercial collars containing diazinon also reduced BuchE activity without clinical signs, indicating that previously exposed animals should be evaluated carefully. [ABSTRACT FROM AUTHOR]

Diisopropylfluorophosphate (DFP) is an organophosphate (OP) that is commonly used as a surrogate of OP nerve agents to study the neurotoxic effects of acute OP intoxication. In preliminary studies, we discovered abnormally high incidence of deaths in DMSO control zebrafish larvae housed in the same 96-well plate as DFP-exposed larvae and hypothesized that DFP volatilizes and cross-contaminates wells when using static waterborne exposures. Survivability and acetylcholinesterase activity assays were indicative of the presence of DFP in the tissues of zebrafish ostensibly exposed to DMSO only. These findings are consistent with DFP cross-contamination, which raises concerns for the experimental design of studies evaluating the toxicity of volatile and semi-volatile substances in zebrafish using medium-to-high throughput approaches.

With innumerable clinical failures of target-specific drug candidates for multifactorial diseases, such as Alzheimer's disease (AD), which remains inefficiently treated, the advent of multitarget drug discovery has brought a new breath of hope. Here, we disclose a class of 6-chlorotacrine (huprine)-TPPU hybrids as dual inhibitors of the enzymes soluble epoxide hydrolase (sEH) and acetylcholinesterase (AChE), a multitarget profile to provide cumulative effects against neuroinflammation and memory impairment. Computational studies confirmed the gorge-wide occupancy of both enzymes, from the main site to a secondary site, including a so far non-described AChE cryptic pocket. The lead compound displayed in vitro dual nanomolar potencies, adequate brain permeability, aqueous solubility, human microsomal stability, lack of neurotoxicity, and it rescued memory, synaptic plasticity, and neuroinflammation in an AD mouse model, after low dose chronic oral administration.

Background Femoral fracture repair surgery under general anesthesia is associated with postoperative pulmonary complications (PPCs). However, information on PPCs caused by residual neuromuscular blockade following perioperative use of neuromuscular blockers is limited. This study aimed to identify the differences in the incidence of PPCs according to the type of neuromuscular blockade reversal agent used in femoral fracture repair surgery, as well as the risk factors for PPCs. Methods We retrospectively analyzed the electronic medical records of 604 patients aged >18 years who underwent general anesthesia for femoral fracture repair surgery at a single university hospital between March 2017 and March 2022. Patients in whom sugammadex or anticholinesterase was used to reverse the neuromuscular block were subjected to propensity score matching. Multivariate logistic regression analysis was performed to identify risk factors for PPCs. Results Among the 604 patients, 108 were matched in each group. The incidence rates of PPCs overall and in the anticholinesterase and sugammadex groups were 7.0%, 8.3%, and 5.6%, respectively, with no significant differences between the groups. Older age, higher ASA (American Society of Anesthesiologists) physical status, and lower preoperative oxygen saturation were risk factors, whereas emergency surgery was a preventive factor. Conclusions Our results demonstrated that the incidence of PPC did not differ significantly between sugammadex and anticholinesterase in patients undergoing femur fracture repair under general anesthesia. Identifying the risk factors and confirming complete recovery from neuromuscular blockade might be more important.

AimsTo characterize neuroinflammatory and gut dysbiosis signatures that accompany exaggerated exercise fatigue and cognitive/mood deficits in a mouse model of Gulf War Illness (GWI).MethodsAdult male C57Bl/6N mice were exposed for 28 d (5 d/wk) to pyridostigmine bromide (P.O.) at 6.5 mg/kg/d, b.i.d. (GW1) or 8.7 mg/kg/d, q.d. (GW2); topical permethrin (1.3 mg/kg), topical N,N-diethyl-meta-toluamide (33%) and restraint stress (5 min). Animals were phenotypically evaluated as described in an accompanying article [124] and sacrificed at 6.6 months post-treatment (PT) to allow measurement of brain neuroinflammation/neuropathic pain gene expression, hippocampal glial fibrillary acidic protein, brain Interleukin-6, gut dysbiosis and serum endotoxin.Key findingsCompared to GW1, GW2 showed a more intense neuroinflammatory transcriptional signature relative to sham stress controls. Interleukin-6 was elevated in GW2 and astrogliosis in hippocampal CA1 was seen in both GW groups. Beta-diversity PCoA using weighted Unifrac revealed that gut microbial communities changed after exposure to GW2 at PT188. Both GW1 and GW2 displayed systemic endotoxemia, suggesting a gut-brain mechanism underlies the neuropathological signatures. Using germ-free mice, probiotic supplementation with Lactobacillus reuteri produced less gut permeability than microbiota transplantation using GW2 feces.SignificanceOur findings demonstrate that GW agents dose-dependently induce differential neuropathology and gut dysbiosis associated with cognitive, exercise fatigue and mood GWI phenotypes. Establishment of a comprehensive animal model that recapitulates multiple GWI symptom domains and neuroinflammation has significant implications for uncovering pathophysiology, improving diagnosis and treatment for GWI.

Organophosphate (OP) nerve agents and pesticides are a class of neurotoxic compounds that can cause status epilepticus (SE), and death following acute high-dose exposures. While the standard of care for acute OP intoxication (atropine, oxime, and high-dose benzodiazepine) can prevent mortality, survivors of OP poisoning often experience long-term brain damage and cognitive deficits. Preclinical studies of acute OP intoxication have primarily used rat models to identify candidate medical countermeasures. However, the mouse offers the advantage of readily available knockout strains for mechanistic studies of acute and chronic consequences of OP-induced SE. Therefore, the main objective of this study was to determine whether a mouse model of acute diisopropylfluorophosphate (DFP) intoxication would produce acute and chronic neurotoxicity similar to that observed in rat models and humans following acute OP intoxication. Adult male C57BL/6J mice injected with DFP (9.5 mg/kg, s.c.) followed 1 min later with atropine sulfate (0.1 mg/kg, i.m.) and 2-pralidoxime (25 mg/kg, i.m.) developed behavioral and electrographic signs of SE within minutes that continued for at least 4 h. Acetylcholinesterase inhibition persisted for at least 3 d in the blood and 14 d in the brain of DFP mice relative to vehicle (VEH) controls. Immunohistochemical analyses revealed significant neurodegeneration and neuroinflammation in multiple brain regions at 1, 7, and 28 d post-exposure in the brains of DFP mice relative to VEH controls. Deficits in locomotor and home-cage behavior were observed in DFP mice at 28 d post-exposure. These findings demonstrate that this mouse model replicates many of the outcomes observed in rats and humans acutely intoxicated with OPs, suggesting the feasibility of using this model for mechanistic studies and therapeutic screening.

In this study, heterocyclic compounds containing a benzothiophene scaffold were designed and synthetized, and their inhibitory activity against cholinesterases (ChE) and the viability of SH-SY5Y cells have been evaluated. Benzothiophenes 4a–4i and benzothiophene-chalcone hybrids 5a–5i were tested against both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), revealing interesting structure–activity relationships. In general, benzothiophene–chalcone hybrids from series 5 proved to be better inhibitors of both enzymes, with compound 5f being the best AChE inhibitor (IC50 = 62.10 μM) and compound 5h being the best BChE inhibitor (IC50 = 24.35 μM), the last one having an IC50 similar to that of galantamine (IC50 = 28.08 μM), the reference compound. The in silico ADME profile of the compounds was also studied. Molecular docking calculations were carried out to analyze the best binding scores and to elucidate enzyme–inhibitors’ interactions.

Acetylcholinesterase (EC 3.1.1.7), a key acetylcholine-hydrolyzing enzyme in cholinergic neurotransmission, is present in a variety of states in situ, including monomers, C-terminally disulfide-linked homodimers, homotetramers, and up to three tetramers covalently attached to structural subunits. Could oligomerization that ensures high local concentrations of catalytic sites necessary for efficient neurotransmission be affected by environmental factors? Using small-angle X-ray scattering (SAXS) and cryo-EM, we demonstrate that homodimerization of recombinant monomeric human acetylcholinesterase (hAChE) in solution occurs through a C-terminal four-helix bundle at micromolar concentrations. We show that diethylphosphorylation of the active serine in the catalytic gorge or isopropylmethylphosphonylation by the RP enantiomer of sarin promotes a 10-fold increase in homodimer dissociation. We also demonstrate the dissociation of organophosphate (OP)-conjugated dimers is reversed by structurally diverse oximes 2PAM, HI6, or RS194B, as demonstrated by SAXS of diethylphosphoryl-hAChE. However, binding of oximes to the native ligand-free hAChE, binding of high-affinity reversible ligands, or formation of an SP-sarin-hAChE conjugate had no effect on homodimerization. Dissociation monitored by time-resolved SAXS occurs in milliseconds, consistent with rates of hAChE covalent inhibition. OP-induced dissociation was not observed in the SAXS profiles of the double-mutant Y337A/F338A, where the active center gorge volume is larger than in wildtype hAChE. These observations suggest a key role of the tightly packed acyl pocket in allosterically triggered OP-induced dimer dissociation, with the potential for local reduction of acetylcholine-hydrolytic power in situ. Computational models predict allosteric correlated motions extending from the acyl pocket toward the four-helix bundle dimerization interface 25 Å away.

Abstract Background There are few updated studies on the prevalence and management of Alzheimer’s disease (AD), which could be underdiagnosed or undertreated. The COVID-19 pandemic may have worsened the deficiencies in the diagnosis and treatment of these patients. Electronic medical records (EMR) offer an opportunity to assess the impact and management of medical processes and contingencies in the population. Objective To estimate AD prevalence in Spain over a 6-year period, based on treated patients, according to usual clinical practice. Additionally, to describe the management of AD-treated patients and the evolution of that treatment during the 2020 COVID-19 pandemic. Methods Retrospective study using the Spanish IQVIA EMR database. Patients treated with donepezil, galantamine, rivastigmine, and/or memantine were included in the study. Annual AD prevalence (2015–2020) was estimated and extrapolated to the national population level. Most frequent treatments and involved specialties were described. To assess the effect of COVID-19, the incidence of new AD cases in 2020 was calculated and compared with newly diagnosed cases in 2019. Results Crude AD prevalence (2015–2020) was estimated at 760.5 per 100,000 inhabitants, and age-standardized prevalence (2020) was 664.6 (male 595.7, female 711.0). Monotherapy was the most frequent way to treat AD (86.2%), in comparison with dual therapy (13.8%); rivastigmine was the most prescribed treatment (37.3%), followed by memantine (36.4%) and donepezil (33.0%). Rivastigmine was also the most utilized medication in newly treated patients (46.7%), followed by donepezil (29.8%), although donepezil persistence was longer (22.5 vs. 20.6 months). Overall, donepezil 10 mg, rivastigmine 9.5 mg, and memantine 20 mg were the most prescribed presentations. The incidence rate of AD decreased from 148.1/100,000 (95% confidence interval [CI] 147.0–149.2) in 2019 to 118.4/100,000 (95% CI 117.5–119.4) in 2020. Conclusions The obtained prevalence of AD-treated patients was consistent with previous face-to-face studies. In contrast with previous studies, rivastigmine, rather than donepezil, was the most frequent treatment. A decrease in the incidence of AD-treated patients was observed during 2020 in comparison with 2019, presumably due to the significant impact of the COVID-19 pandemic on both diagnosis and treatment. EMR databases emerge as valuable tools to monitor in real time the incidence and management of medical conditions in the population, as well as to assess the health impact of global contingencies and interventions.

The therapeutic mechanism for the treatment of Alzheimer's disease (AD) is mainly by inhibiting the activity of cholinesterase (ChE) and increasing the transmission of choline and the function of neurons. In this study, two series of ChE inhibitors (CA1–CA8 and CB1–CB7) were designed and synthesized by the acylation of a cannabinoid (CBD) with bromoacetyl bromide, or the esterification of a CBD with an amino acid. All the synthesized compounds were tested for in vitro activity to evaluate the compounds as AD therapies. Compound CB7 was identified as a potential butyrylcholinesterase (BuChE) inhibitor (IC50 = 0.31 ± 0.09 μM), which did not display toxicity against HepG2 or PC12 cells at 6.25 μM. Compound CB7 showed good antioxidant behavior, effective anti-tyrosinase activity (IC50 = 0.037 ± 0.003 μM), and anti-acetylcholinesterase (AChE) activity (IC50 = 19.73 ± 0.79 μM). Kinetic studies also showed that CB7 can act as a dual inhibitor. These results provide a theoretical basis for the use of the natural product CBD in the design and development of anti-AD drugs.

Nine previously undescribed brefeldin A (BFA) derivatives (1–9), together with one known compound 4-epi-brefeldin A (10), were isolated from an endophytic fungus Penicillium brefeldianum F4a. The chemical structures were elucidated using NMR and HRESIMS. ECD analysis and Mosher's method were used to confirm the absolute configurations of 1–9. The inhibitory activity of all isolated BFA derivatives (1–10) on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) was evaluated in vitro. The bioassay results suggested that neobrefeldin (1) and brefeldin H (2) exhibited higher potent and selective AChE inhibitory activity (IC50 = 0.12 and 0.28 μM) than the therapeutic drug galantamine for Alzheimer's disease (AD) (IC50 = 0.66 µM), whereas only neobrefeldin (1) displayed weak inhibitory activity against BuChE (IC50 = 175.04 µM). Moreover, a molecular docking analyses was performed and showed compounds 1 and 2 were dual binding site AChE inhibitors. It is worth noting that neobrefeldin (1) showed a better binding affinity with the peripheral anionic site through the hydrogen bonding interaction with Tyr124 than brefeldin H (2), resulting in better AChE inhibitory activity. These findings not only provide a promising AChE inhibitor neobrefeldin (1) for developing agents against early AD, but also provide a valuable perspective for better understanding its AChE inhibition activity.

A series of OA-tacrine hybrids with the alkylamine linker was designed, synthesized, and evaluated as effective cholinesterase inhibitors for the treatment of Alzheimer’s disease (AD). Biological activity results demonstrated that some hybrids possessed significant inhibitory activities against acetylcholinesterase (AChE). Among them, compounds B4 (hAChE, IC50 = 14.37 ± 1.89 nM; SI > 695.89) and D4 (hAChE, IC50 = 0.18 ± 0.01 nM; SI = 3374.44) showed excellent inhibitory activities and selectivity for AChE as well as low nerve cell toxicity. Furthermore, compounds B4 and D4 exhibited lower hepatotoxicity than tacrine in cell viability, apoptosis, and intracellular ROS production for HepG2 cells. These properties of compounds B4 and D4 suggest that they deserve further investigation as promising agents for the prospective treatment of AD.

Neurodegenerative diseases such as Alzheimer’s disease (AD) are multifactorial with several different pathologic mechanisms. Therefore, it is assumed that multitargeted-directed ligands (MTDLs) which interact with different biological targets relevant to the diseases, might offer an improved therapeutic alternative than using the traditional “one-target, one-molecule” approach. Herein, we describe new benzothiazole-based derivatives as a privileged scaffold for histamine H3 receptor ligands (H3R). The most affine compound, the 3-(azepan-1-yl)propyloxy-linked benzothiazole derivative 4b, displayed a Ki value of 0.012 μM. The multitargeting potential of these H3R ligands towards AChE, BuChE and MAO-B enzymes was evaluated to yield compound 3s (pyrrolidin-1-yl-(6-((5-(pyrrolidin-1-yl)pentyl)oxy)benzo[d]thiazol-2-yl)methanone) as the most promising MTDL with a Ki value of 0.036 μM at H3R and IC50 values of 6.7 µM, 2.35 µM, and 1.6 µM towards AChE, BuChE, and MAO-B, respectively. These findings suggest that compound 3s can be a lead structure for developing new multi-targeting anti-AD agents.

Background: Myrtus communis L. (MC) has been used in Mesopotamian medicine. Here, the cholinesterase (ChE) inhibitory potential of its methyl alcohol extracts has been investigated and computationally dissected. Method: The ChE inhibition has been measured based on usual Ellman's colorimetric method compared to a canonical ChE inhibitor, eserine. Through a deep text mining, the structures of phytocompounds (= ligands) of MC were curated from ChemSpider, PubChem, and ZINC databases and docked into protein targets, AChE (PDB 1EVE) and BChE (PDB 1P0I) after initial in silico preparedness and binding affinity (BA; kcal/mol) reported as an endpoint. The calculation of ADMET (absorption, distribution, metabolism, excretion, and toxicity) features of phytocompounds were retrieved from SwissADME (http://www.swissadme.ch/) and admetSAR software to predict the drug-likeness or lead-likeness fitness. The Toxtree v2.5.1, software platforms (http://toxtree.sourceforge.net/) have been used to predict the class of toxicity of phytocompounds. The STITCH platform (http://stitch.embl.de) has been employed to predict ChE-chemicals interactions. Results: The possible inhibitory activities of AChE of extracts of leaves and berries were 37.33 and 70.00%, respectively as compared to that of eserine while inhibitory BChE activities of extracts of leaves and berries of MC were 19.00 and 50.67%, respectively as compared to that of eserine. Phytochemicals of MC had BA towards AChE ranging from -7.1 (carvacrol) to -9.9 (ellagic acid) kcal/mol. In this regard, alpha-bulnesene, (Z)-gamma-Bisabolene, and beta-bourbonene were top-listed low toxic binders of AChE, and (Z)-gamma-bisabolene was a more specific AChE binder. Alpha-cadinol, estragole, humulene epoxide II, (a)esculin, ellagic acid, patuletin, juniper camphor, linalyl anthranilate, and spathulenol were high class (Class III) toxic substances which among others, patuletin and alpha-cadinol were more specific AChE binders. Among intermediate class (Class II) toxic substances, beta-chamigrene was a more specific AChE binder while semimyrtucommulone and myrtucommulone A were more specific BChE binders. Conclusion: In sum, the AChE binders derived from MC were categorized mostly as antiinsectants (e.g., patuletin and alpha-cardinal) due to their predicted toxic classes. It seems that structural amendment and stereoselective synthesis like adding sulphonate or sulphamate groups to these phytocompounds may make them more suitable candidates for considering in preclinical investigations of Alzheimer's disease. [ABSTRACT FROM AUTHOR]

Alzheimer's disease (AD) is a prevalent neurodegenerative disorder. With the aging population and the continuous development of risk factors associated with AD, it will impose a significant burden on individuals, families, and society. Currently, commonly used therapeutic drugs such as Cholinesterase inhibitors, N-methyl-D-aspartate antagonists, and multiple AD pathology removal drugs have been shown to have beneficial effects on certain pathological conditions of AD. However, their clinical efficacy is minimal and they are associated with certain adverse reactions. Furthermore, the underlying pathological mechanism of AD remains unclear, posing a challenge for drug development. In contrast, natural plant molecules, widely available, offer multiple targeting pathways and demonstrate inherent advantages in modifying the typical pathologic features of AD by influencing the blood–brain barrier (BBB). We provide a comprehensive review of recent in vivo and in vitro studies on natural plant molecules that impact the BBB in the treatment of AD. Additionally, we analyze their specific mechanisms to offer novel insights for the development of safe and effective targeted drugs as well as guidance for experimental research and the clinical application of drugs for the prevention and treatment of AD. [ABSTRACT FROM AUTHOR]

A central event in the pathogenesis of Alzheimer's disease (AD) is the accumulation of senile plaques composed of aggregated amyloid-β (Aβ) peptides. The main class of drugs currently used for the treatment of AD are the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitors. In this study, it has been shown that Aβ augmented AChE activity in vitro, maximum activation of 548 ± 5% was achieved following 48 h of incubation with 10 μM of Aβ1–40, leading to a 7.7-fold increase in catalytic efficiency. The observed non-competitive type of AChE activation by Aβ1–40 was associated with increased Vmax and unchanged Km. Although BChE activity also increased following incubation with Aβ1–40, this was less efficiently achieved as compared with AChE. Ex vivo electrophysiological experiments showed that 10 μM of Aβ1–40 significantly decreased the effect of the AChE inhibitor huperzine A on the synaptic potential parameters. [ABSTRACT FROM AUTHOR]

Amaranthus dubius is a vegetable consumed for its nutritional content in Kenya. In herbal medicine, A. dubius is utilized to relief fever, anemia and hemorrhage. Additionally, it is utilized to manage cognitive dysfunction and is considered to augment brain function, but there is no empirical evidence to support this claim. The contemporary study investigated cognitive enhancing potential of A. dubius in mice model of Alzheimer's disease (AD)-like dementia induced with ketamine. Cognitively damaged mice were treated with aqueous extract of A. dubius leaf upon which passive avoidance task (PAT) was used to assess the cognitive performance. At the end of passive avoidance test, brains of the mice were dissected to evaluate the possibility of the extract to inhibit hallmarks that propagate AD namely oxidative stress and acetylcholinesterase activity. Additionally, characterization of secondary metabolites was done using liquid chromatograph- mass spectrometry analysis. During PAT test, extract-treated mice showed significantly increased step-through latencies than AD mice, depicting ability of A. dubius to reverse ketamine-induced cognitive decline. Further, the extract remarkably lowered malondialdehyde levels to normal levels and effectively inhibited acetylcholinesterase enzyme. The study showed that A. dubius extract is endowed with phytoconstituents that possess anti-oxidant and anticholinesterase activities. Thus, this study confirmed promising therapeutic effects of 200, 300 and 400 mg/kg bw of A. dubius extract with potential to alleviate cognitive disarray observed in AD. [ABSTRACT FROM AUTHOR]

Background: The acetylcholinesterase inhibitors (AChEIs) donepezil, galantamine, and rivastigmine are commonly used in the management of various forms of dementia. Objectives: While these drugs are known to induce classic cholinergic adverse events such as diarrhea, their potential to cause psychiatric adverse events has yet to be thoroughly examined. Methods: We sought to determine the risk of psychiatric adverse events associated with the use of AChEIs through a systematic review and meta-analysis of double-blind randomized controlled trials involving patients with Alzheimer's dementia and Parkinson's dementia. Results: A total of 48 trials encompassing 22,845 patients were included in our analysis. Anorexia was the most commonly reported psychiatric adverse event, followed by agitation, insomnia, and depression. Individuals exposed to AChEIs had a greater risk of experiencing appetite disorders, insomnia, or depression compared with those who received placebo (anorexia: odds ratio [OR] 2.93, 95% confidence interval [CI] 2.29–3.75; p < 0.00001; decreased appetite: OR 1.93, 95% CI 1.33–2.82; p = 0.0006; insomnia: OR 1.55, 95% CI 1.25–1.93; p < 0.0001; and depression: OR 1.59, 95% CI 1.23–2.06, p = 0.0004). Appetite disorders were also more frequent with high-dose versus low-dose therapy. A subgroup analysis revealed that the risk of insomnia was higher for donepezil than for galantamine. Conclusions: Our findings suggest that AChEI therapy may negatively impact psychological health, and careful monitoring of new psychiatric symptoms is warranted. Lowering the dose may resolve some psychiatric adverse events, as may switching to galantamine in the case of insomnia. Clinical Trial Registration: The study was pre-registered on PROSPERO (CRD42021258376). [ABSTRACT FROM AUTHOR]

Background Cholinesterase inhibitors are commonly used to treat patients with neurocognitive disorders, who often have an elevated risk of falling. Effective use of these medications requires a thoughtful assessment of risks and benefits. Objective To provide an update on previous reviews and determine the association between cholinesterase inhibitors and falls, syncope, fracture and accidental injuries in patients with neurocognitive disorders. Methods Embase, MEDLINE, Cochrane Central Register of Controlled Trials, Cumulative Index of Nursing and Allied Health Literature and AgeLine were systematically searched through March 2023 to identify all randomised controlled trials of cholinesterase inhibitors (donepezil, galantamine, rivastigmine) in patients with cognitive impairment. Corresponding authors were contacted for additional data necessary for meta-analysis. Inclusion criteria consisted of adults ≥19 years, with a diagnosis of dementia, Parkinson's disease, mild cognitive impairment or traumatic brain injury. Data were extracted in duplicate for the aforementioned primary outcomes and all outcomes were analysed using random-effects meta-analysis. Results Fifty three studies (30 donepezil, 14 galantamine, 9 rivastigmine) were included providing data on 25, 399 patients. Cholinesterase inhibitors, compared to placebo, were associated with reduced risk of falls (risk ratio [RR] 0.84 [95% confidence interval [CI] = 0.73–0.96, P = 0.009]) and increased risk of syncope (RR 1.50 [95% CI = 1.02–2.21, P = 0.04]). There was no association with accidental injuries or fractures. Conclusion In patients with neurocognitive disorders, cholinesterase inhibitors were associated with decreased risk of falls, increased risk of syncope and no association with accidental trauma or fractures. These findings will help clinicians better evaluate risks and benefits of cholinesterase inhibitors. [ABSTRACT FROM AUTHOR]

A new terrein dimer named lichtheicol A (1) and a new meroterpene named lichtheiterpene A (2), were isolated from the mangrove endophytic fungus Lichtheimia sp. J2B1, together with 10 known compounds (3–12). The planar structures and absolute configurations of 1 and 2 were established by a combination of extensive spectroscopic data analyses and electronic circular dichroism (ECD) calculations. Compounds 4 and 5 exhibited marked inhibitory effects against butyrylcholinesterase (BuChE) with IC50 values of 0.71 and 0.53 μM, respectively. [ABSTRACT FROM AUTHOR]

A series of arylated huperzine A (HPA) derivatives (1–24) were efficiently synthesized in good yields (45–88% yields) through the late-stage modification of structurally complex natural anti-Alzheimer's disease (AD) drug huperzine A (HPA), using the palladium-catalyzed Suzuki-Miyaura cross-coupling reaction. The acetylcholinesterase (AChE) inhibitory activity of all synthesized compounds was evaluated to screen the potential anti-AD bioactive molecules. The results showed that introducing the aryl groups to C-1 position of HPA resulted in the unsatisfactory AChE inhibitory activity. The present study demonstrably verifies pyridone carbonyl group could be the necessary and unchangeable pharmacophore for maintaining HPA's anti-AChE potency, and provides the helpful information on the further research for developing anti-AD HPA analogues. [ABSTRACT FROM AUTHOR]

Ferula tingitana L. is a high perennial plant and its leaf is an alternate arrangement and yellow, and its flowers are unisexual like other Apiaceae. It has been used as a spice and for various medicinal purposes in the Mediterranean region. The paper reports antidiabetic, antimicrobial, anticholinesterase, antioxidant, and genotoxic activities of leaves, flowers, stems, and fruits methanol extracts of F. tingitana. Also, quantitative determination of some secondary metabolites was also analyzed by LC-MS/MS. Moreover, chemical composition of essential oils was analyzed. Consequently, anatomical, and morphological properties of plant were investigated. Germacrene D (23.6%), 1,3,5-trimethylbenzene (18.4%), and α-pinene (50.0%) were found as the main compounds in flower, leaf, and stem oils, respectively. The cortex in stem, pedicel, and fruit is characterized by angular collenchyma cells and a distinct cambium layer. 6 compounds (quinic acid, fumaric acid, keracyanin chloride, cyanidin-3-O-glucoside, chlorogenic acid, hesperidin) were observed in samples. Leaf extract showed anticholinesterase activity. Leaf and flower extracts showed the highest % inhibition value on ABTS·+ and DPPH•. Leaf extract has the strongest antioxidant effect because it is rich in total phenolic contents. All extracts of F. tingitana were found generally effective against C. albicans. Stem extract was found effective against E. coli and flower extract was found more effective against S. enterica and C. albicans. Bacterial genotoxicity results showed that extracts did not have genotoxic activity on tester strains S. typhimurium and E. coli WP2uvrA. Thus, it revealed that extracts were genotoxic-ally safe at applied concentrations up to 3 mg/plate. [ABSTRACT FROM AUTHOR]

The synthesis of new hybrid compounds based on the domestic drug amiridine and a seven-membered cyclic homolog of tacrine combined by a thiourea-containing spacer was described. The synthesized conjugates were shown to be highly efficient inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) with a nanomolar activity exceeding that of amyridine and tacrine, which was consistent with the molecular docking results. The conjugates also demonstrated a broader spectrum of biological activity uncharacteristic of the parent pharmacophores, namely, the ability to inhibit the AChE-induced and self-aggregation of β-amyloid and antioxidant properties. [ABSTRACT FROM AUTHOR]

A new method was developed for the synthesis of 5-arylidene-2,3-disubstituted 4H-imidazol-4-ones by cyclization of N-substituted α,β-dehydroamino acid arylamides with N-trimethylsilylimidazole (TMSIM) in dimethylformamide. The process was carried out by both conventional and microwave heating. Target imidazol-4-one was also synthesized by a one-pot method based on the reaction of unsaturated 5(4H)-oxazolone, arylamine, and TMSIM. The anticholinesterase and antiradical properties of synthesized both arylamides and 4-imidazolones were studied. [ABSTRACT FROM AUTHOR]

Epidemiologic studies suggest an inverse correlation between coffee consumption and the occurrence of neurodegenerative diseases, but the role of caffeine and roasting degree are still matter of debate. The objective of this work was to evaluate the effects of caffeinated (light, medium, and dark roast) and decaffeinated instant coffee samples in acetylcholinesterase (AchE) inhibition and antioxidant assays, as well as in animal models of Parkinson's disease. Caffeinated coffees inhibited the AchE in much smaller concentrations than decaffeinated coffee. All coffee samples showed antioxidant capacity without relation with the caffeine content. Blockade in the haloperidol-induced catalepsy was observed with caffeinated coffee, but not in the decaffeinated sample. The medium-roast coffee reduced the number of rotations of rats after methamphetamine administration on the 6-hydroxydopamine unilateral lesion of the medial forebrain bundle. However, the coffee treatment did not avoid the loss of dopaminergic neurons on substantia nigra pars compact and only the smallest dose of coffee was able to avoid the decrease of dopamine levels in the lesioned side of the striatum. Altogether, these results suggest that coffee exerts moderate pro-cholinergic and pro-dopaminergic effects and caffeine seems to be the main factor responsible for these effects. [ABSTRACT FROM AUTHOR]

The results of the present work show that there are significant biochemical and neurophysiologic changes in the PRF officers when compared pre- and post-exposure moments. The real working conditions of this population are challenging and the need for periodic monitoring is indispensable. Objective: The aim of this study is to evaluate the effects of occupational exposure of federal highway police (PRF) officers to cholinesterase-inhibiting insecticides. Methods: We evaluate erythrocyte and plasma cholinesterase activity, pulse rate, systolic and diastolic pressure, and clinical evaluation through the Mini-Mental State Examination and the Diagnostic and Statistical Manual of Mental Disorders , Fifth Edition. Results: All PRF officers evaluated were male, between 22 and 49 years of age. Pulse rate of the subjects were statistically superior in the post-exposure moment when compared with pre-exposure moment. Inhibition of acetylcholinesterase and butyrylcholinesterase was significant in the post-exposure moment when compared with pre-exposure moment. Conclusions: The results of the present work show that there are significant biochemical changes, which can be the beginning of serious deleterious effects to the health of PRF officers. [ABSTRACT FROM AUTHOR]

Objective: Current treatment of Alzheimer's disease is provided by cholinesterase inhibitors. Salvia triloba L. (syn. Salvia fruticosa Mill.), a species mostly consumed as refreshing herbal tea in traditional medicine, is rich in 1,8-cineole that is known to have cholinesterase inhibiting effects. In this study, we investigated cognitive enhancer effects of S. triloba essential oil inhalation on healthy control rats and rats with scopolamine induced memory impairment. Materials and Methods: S. triloba samples from different geographical locations of Turkey were hydro-distilled and analyzed by Gas Chromatography-Mass Spectrometry (GC-MS). The optimum sample with the highest 1,8-cineole and lowest camphor, a-thujone and p-thujone content was selected. In vitro cholinergic and antioxidant potentials of the selected essential oil were calculated. Cognitive enhancer and anti-amnestic effects of the inhaled essential oil on rats were assessed by means of Morris water maze. The bioavailability of 1,8-cineole in blood of rats was measured by GC-MS. Results: The group that inhaled S. triloba significantly outperformed control group, namely faster achieving peak escape latency performance in Morris water maze. However, S. triloba inhalation failed to restore scopolamine induced learning impairment. Conclusion: In this study, we report positive effects of inhaling S. triloba essential oil as a complementary treatment for supporting cognitive functions. [ABSTRACT FROM AUTHOR]

Developing drugs for Alzheimer's disease (AD) is an extremely challenging task due to its devastating pathology. Previous studies have indicated that natural compounds play a crucial role as lead molecules in the development of drugs. Even though, there are remarkable technological advancements in the isolation and synthesis of natural compounds, the targets for many of them are still unknown. In the present study, lobeline, a piperidine alkaloid has been identified as a cholinesterase inhibitor through chemical similarity assisted target fishing method. The structural similarities between lobeline and donepezil, a known acetylcholinesterase (AChE) inhibitor encouraged us to hypothesize that lobeline may also exhibit AChE inhibitory properties. It was further confirmed by in silico, in vitro and biophysical studies that lobeline could inhibit cholinesterase. The binding profiles indicated that lobeline has a higher affinity for AChE than BChE. Since excitotoxicity is one of the major pathological events associated with AD progression, we also investigated the neuroprotective potential of lobeline against glutamate mediated excitotoxicity in rat primary cortical neurons. The cell based NMDA receptor (NMDAR) assay with lobeline suggested that neuroprotective potential of lobeline is mediated through the blockade of NMDAR activity. [ABSTRACT FROM AUTHOR]

Acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) are two important enzymes involved in the breakdown of the neurotransmitter acetylcholine and other choline esters. Coumarins are biologically active compounds naturally found in the fruit, bark, stems, and leaves of many plants, including Tonka bean, acacia, lavender, deer tongue, apricot, strawberry, cherry, and cinnamon. Coumarin and coumarin hybrids have antitumor, antioxidant, antiviral, anticonvulsant, anti-inflammatory, antimicrobial, and antiproliferative activity. AChE and BuChE enzyme inhibition effects of 12 different coumarin derivatives (Ia–Ih) and (IIa–IId) synthesized and 16 coumarin-selenophene hybrid compounds (IVa–IVh) and (Va–Vh) were investigated. Compound (Vc) and (Vg) showed the most potent inhibitor activity against AChE. [ABSTRACT FROM AUTHOR]

New 1,2,3-triazolo(thieno)stilbenes were synthesized as mixtures of isomers and efficiently photochemically transformed to their corresponding substituted thienobenzo/naphtho-triazoles in high isolated yields. The resulting photoproducts were studied as acetyl- (AChE) and butyrylcholinesterase (BChE) inhibitors without or with interconnected inhibition potential of TNF-α cytokine production. The most promising anti-inflammatory activity was shown again by naphtho-triazoles, with a derivative featuring 4-pentenyl substituents exhibiting notable potential as a cholinesterase inhibitor. To identify interactions between ligands and the active site of cholinesterases, molecular docking was performed for the best potential inhibitors. Additionally, molecular dynamics simulations were employed to assess and validate the stability and flexibility of the protein–ligand complexes generated through docking. [ABSTRACT FROM AUTHOR]