Design, synthesis, molecular modeling, in vitro evaluation of novel piperidine-containing hydrazone derivatives as cholinesterase inhibitors.

In an effort to develop new and effective therapeutic agents for Alzheimer's disease, a series of hydrazone derivatives bearing piperidine rings have been designed and synthesized. The chemical structures of the compounds were characterized by various spectroscopic techniques. In vitro antioxidant and cholinesterase activities of the compounds were evaluated. Among the compounds, N12 exhibited the most antioxidant activity in all methods (CUPRAC, FRAP, DPPH, ABTS). In vitro acetylcholinesterase (AChE) activity results of the compounds showed good IC50 values between 14.124 ± 0.084 and 49.680 ± 0.110 µM were obtained (IC50 = 38.842 ± 0.053 µM for Donepezil). Among the compounds, N7 and N6 are much more effective derivatives than the standard compound donepezil with IC50 values of 14.124 ± 0.084 and 17.968 ± 0.072 µM, respectively. In vitro, butyrylcholinesterase (BChE) inhibition values of the compounds were between 13.505 ± 0.025 and 52.230 ± 0.027 µm. Among the compounds, N6 has the highest BChE inhibition with an IC50 value of 13.505 µm in the series. The cytotoxicity and AChE inhibitory activity of the compounds on SH-SY5Y cell lines were also evaluated. Kinetic studies were also performed to determine the behavior of the compounds as competitive or noncompetitive inhibitors. The binding modes of N6, which was determined to be highly effective according to in vitro analyses, with AChE and BChE were investigated using molecular docking studies, and the stability of the complexes was determined by molecular dynamics simulations. These findings indicated that AChE and BChE enzymes maintained their overall structural stability and compactness during interactions with compound N6.

New Sulfonate Ester-Linked Fluorinated Hydrazone Derivatives as Multitarget Carbonic Anhydrase and Cholinesterase Inhibitors: Design, Synthesis, Biological Evaluation, Molecular Docking and ADME Analysis.

In this study, some new hydrazone derivatives (2a-g) was designed, synthesized for first time, and evaluated as multitarget inhibitors of AChE, BChE, hCA I and hCA II. The chemical structures of new hybrids were confirmed by elemental analysis and some spectroscopic techniques. All tested compounds showed low nanomolar inhibition with IC50 values of in the range of 30.4 to 264.0 nM against hCA I, 23.2 to 251.6 nM against hCA II, 12.1 to 114.3 nM against AChE, and 76.4 to 134.0 nM against BChE. These compounds inhibited hCA I and AChE more than acetazolamide (AZA) and neostigmine. Among them, compounds 2c and 2e, which have a linear structure, were determined to be the most active inhibitor candidates against these selected enzymes. Molecular docking studies were carried out on the compounds (2a-g), revealing their binding interactions with the active site of AChE, BChE, hCA I and hCA II thus supporting the experimental findings. Additionally, in silico absorption, distribution, metabolism, and excretion (ADME) prediction studies of the obtained compounds (2a-g) with in silico approaches were carried out to determine their solubility, whether they have the potential to cross the blood-brain barrier (BBB), values ​​such as GI absorption and drug likeness principles.

Inhibitory Effects of Aspirin and Ibuprofen Overdose on Cholinesterase Activity: In Vivo and In Vitro Studies.

BACKGROUND: In recent years, it has been reported that long-term use of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) may have protective effects against neurodegenerative diseases by inhibiting the activity of cholinesterase enzymes. The exact biological mechanism of these protective effects is not yet known. This study aims to assess the in vivo and in vitro effects of aspirin and ibuprofen injection on the activity of acetylcholinesterase and butyrylcholinesterase. MATERIALS AND METHODS: In this experimental study, 70 adult male mice (20-25 g) were divided randomly into 7 groups (n= 10) including a control group that received normal saline and other groups that received different dosages of aspirin and ibuprofen (100, 200, and 300 mg/kg) in the form of intraperitoneal injection. Mice were anesthetized by ether, and blood samples were taken from the heart. Ellman´s methods were used to measure cholinesterase, erythrocytes, and serum, respectively. RESULTS: The activity of cholinesterase enzymes in serum and erythrocytes decreased significantly (P<0.0001) in treated groups with aspirin and ibuprofen compared to the control samples after 3 and 24 hours. However, these inhibitory effects were variable depending on the dose of the injected drugs, and they were statistically significant at higher injection doses in vitro and in vivo analysis. CONCLUSION: The result of this study showed that non-steroidal anti-inflammatory drugs can inhibit the activity of the cholinesterase enzymes in both in vivo and in vitro conditions compared to the control group.

Pesticide exposure and blood cholinesterase levels among adolescents from farming families in Northern Thailand.

BACKGROUND: Adolescents living in agricultural communities may be at risk for the adverse effects of pesticide exposure because they are involved in agriculture either as a career or to support their families. OBJECTIVE: The purpose of this study was to investigate the association of farm activities related to pesticide exposure on blood cholinesterase (ChE) levels among adolescents from farming families in the north of Thailand. MATERIAL AND METHODS: This cross-sectional study included 336 adolescents aged 12-19 years from farming families in Chiang Dao District, Chiang Mai Province. Data on pesticide exposure was collected using a questionnaire, and blood ChE activity was assessed using a ChE reactive paper test kit via fingerstick blood sampling. RESULTS: Overall, 51.2% of participants had abnormal blood ChE levels. Univariable logistic regression analysis revealed that pesticide-related activities on farms associated with abnormal ChE levels were mixing/spraying (OR=10.54; 95%CI=4.63-23.99), assisting or working in areas with pesticide application (OR=5.54; 95%CI=3.45-8.89), and harvesting (OR=3.70; 95%CI=2.35-5.82). In a multivariable model (Nagelkerke R2=0.374), mixing/spraying (OR=4.90; 95%CI=2.03-11.83) and assisting or working in areas with pesticide application (OR=2.61; 95%CI=1.49-4.57) were significantly associated with abnormal ChE levels, but harvesting (OR=1.48; 95%CI=0.84-2.61) was not significant after adjusting for sex, age in years, and entering or walking through a farm. CONCLUSIONS: The findings indicated that Thai adolescents living in farming families are at risk of pesticide exposure, particularly those involved in agricultural activities such as pesticide applicators. An intervention and measure to raise awareness and reduce the risk of pesticide exposure in adolescents is required.

Discovery of New Highly Potent Histamine H3 Receptor Antagonists, Calcium Channel Blockers, and Acetylcholinesterase Inhibitors.

At present, one of the most promising strategies to tackle the complex challenges posed by Alzheimer's disease (AD) involves the development of novel multitarget-directed ligands (MTDLs). To this end, we designed and synthesized nine new MTDLs using a straightforward and cost-efficient one-pot Biginelli three-component reaction. Among these newly developed compounds, one particular small molecule, named 3e has emerged as a promising MTDL. This compound effectively targets critical biological factors associated with AD, including the simultaneous inhibition of cholinesterases (ChEs), selective antagonism of H3 receptors, and blocking voltage-gated calcium channels. Additionally, compound 3e exhibited remarkable neuroprotective activity against H2O2 and Aß1-40, and effectively restored cognitive function in AD mice treated with scopolamine in the novel object recognition task, confirming that this compound could provide a novel and innovative therapeutic approach for the effective treatment of AD.

Moderation of Amyloid-ß Deposition on the Effect of Cholinesterase Inhibitors on Cognition in Mild Cognitive Impairment.

Background: Clinical trial findings on cholinesterase inhibitors (ChEIs) for mild cognitive impairment (MCI) are inconclusive, offering limited support for their MCI treatment. Given that nearly half of amnestic MCI cases lack cerebral amyloid-ß (Aß) deposition, a hallmark of Alzheimer's disease; this Aß heterogeneity may explain inconsistent results. Objective: This study aimed to assess whether Aß deposition moderates ChEI effects on amnestic MCI cognition. Methods: We examined 118 individuals with amnestic MCI (ages 55-90) in a longitudinal cohort study. Baseline and 2-year follow-up assessments included clinical evaluations, neuropsychological testing, and multimodal neuroimaging. Generalized linear models were primarily analyzed to test amyloid positivity's moderation of ChEI effects on cognitive change over 2 years. Cognitive outcomes included Mini-Mental Status Examination score, the total score of the Consortium to Establish a Registry for Alzheimer's Disease neuropsychological battery, and Clinical Dementia Rating-sum of boxes. Results: The analysis found no significant ChEI use x amyloid positivity interaction for all cognitive outcomes. ChEI use, irrespective of Aß status, was associated with more cognitive decline over the 2-year period. Conclusions: Aß pathology does not appear to moderate ChEI effects on cognitive decline in MCI.

Evaluation of genotoxic effects in workers and residents of rural areas exposed to pesticides in Brazil.

Brazil is one of the world's largest consumers of pesticides. This intense use impacts the environment and exposes a wide range of individuals to pesticides, including rural workers who are occupationally exposed and rural residents who are environmentally exposed. We aimed to evaluate the effects of occupational exposure to pesticides on the health of rural workers and rural residents. We conducted an epidemiological study with 104 farmers and 23 rural residents of Casimiro de Abreu (Rio de Janeiro, Brazil). A comparison group (urban residents) comprised 103 residents of the urban area of the same city. We determined the activity of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) using a modified version of Ellman's method to evaluate exposure. In addition, we performed genotoxic and mutagenic analyses with the comet assay and the cytokinesis-block micronucleus (CBMN) assay. There was a reduction in cholinesterase activity, mainly BChE, in rural workers and rural residents compared with urban residents (p = 0.002). There was an increase in genotoxic effects in rural workers compared with urban residents (comet assay, p < 0.001; CBMN assay, p < 0.001). In addition, there was a greater chance of genotoxic changes in rural workers exposed to pesticides based on the comet assay (odds ratio [OR] 7.6, 95 % confidence interval [CI] 6.6-15.9) and the CBMN assay (OR 22.7, 95 % CI 10.3-49.9). We found that individuals occupationally exposed to pesticides are more likely to have genotoxic effects. These findings are useful for the development of programs to monitor populations exposed to genotoxic substances and allow the development of strategies for the prevention, control, and surveillance of effects that result from occupational and environmental exposures to pesticides.

Evaluation of XQ528 tartrate on embryo-fetus developmental toxicity in SD rats and genotoxicity.

The effects of XQ528 tartrate on the embryonic and fetal development of fertile Sprague-Dawley (SD) rats, along with their embryos and littermates, were evaluated using an embryo-fetus developmental toxicity assay. fertile SD rats exhibited no significant general toxic effects when administered doses of 0.25, 1.25, and 5.0 mg/kg intranasally from days 6 to 15 of gestation. The genotoxicity of the compound was evaluated through an amalgam of tests that included the Ames test, the Chinese hamster ovary (CHO) cell chromosome aberration test, and the micronucleus test in ICR mice. The results from the Ames test indicated non-mutagenicity at concentrations of 5000, 500, 50.0, 5.0, and 0.5 µg/dish across strains TA97, TA98, TA100, TA102, and TA1535. Additionally, the chromosomal aberration rates in CHO cells were not significantly altered at concentrations of 50.5, 101.0, and 202.0 µg/mL. No micronuclei induction was observed in ICR mice at dosage levels of 11.25, 22.50, and 45.00 mg/kg post intranasal administration. In conclusion, the no observed adverse effect level (NOAEL) for developmental toxicity of XQ528 tartrate in fertile SD rats, embryos, and littermates under the test conditions in this study was established at 5.0 mg/kg/day. Under these test conditions, XQ528 tartrate did not exhibit any significant genotoxic or carcinogenic potential.

A New Class of Benzo[b]thiophene-chalcones as Cholinesterase Inhibitors: Synthesis, Biological Evaluation, Molecular Docking and ADME Studies.

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.

Neuroprotective Effects of Phenolic Constituents from Drynariae Rhizoma.

This study aimed to provide scientific data on the anti-Alzheimer's disease (AD) effects of phenolic compounds from Drynariae Rhizoma (DR) extract using a multi-component approach. Screening of DR extracts, fractions, and the ten phenolic compounds isolated from DR against the key AD-related enzymes acetylcholinesterase (AChE), butyrylcholinesterase (BChE), ß-site amyloid precursor protein cleaving enzyme 1 (BACE1), and monoamine oxidase-B (MAO-B) confirmed their significant inhibitory activities. The DR extract was confirmed to have BACE1-inhibitory activity, and the ethyl acetate and butanol fractions were found to inhibit all AD-related enzymes, including BACE1, AChE, BChE, and MAO-B. Among the isolated phenolic compounds, compounds (2) caffeic acid 4-O-ß-D-glucopyranoside, (6) kaempferol 3-O-rhamnoside 7-O-glucoside, (7) kaempferol 3-o-b-d-glucopyranoside-7-o-a-L-arabinofuranoside, (8) neoeriocitrin, (9) naringin, and (10) hesperidin significantly suppressed AD-related enzymes. Notably, compounds 2 and 8 reduced soluble Amyloid Precursor Protein ß (sAPPß) and ß-secretase expression by over 45% at a concentration of 1.0 µM. In the thioflavin T assay, compounds 6 and 7 decreased Aß aggregation by approximately 40% and 80%, respectively, and degraded preformed Aß aggregates. This study provides robust evidence regarding the potential of DR as a natural therapeutic agent for AD, highlighting specific compounds that may contribute to its efficacy.

Anti-oxidant activity of coenzyme Q10 against AlCl3/D-galactose in albino rat induced cognitive dysfunctions: Behavioral, biochemical, and BACE-1/GSK-3ß alterations.

The relationship between amyloid beta (Aß) and oxidative stress (OS), both prominent factors in Alzheimer's disease-related neural degeneration, is deeply interconnected. The cleavage of the extracellular domain of Amyloid precursor protein (APP) and phosphorylating different substrates, respectively, the ß-site amyloid precursor protein cleaving enzyme-1 (BACE-1) and Glycogen synthase kinase-3-beta (GSK-3ß) enzymes initiate the synthesis of Aß, which causes cognitive deficits in AD. This study aimed to explore the protective potential of Coenzyme Q10 (CoQ10). It also sought to uncover any synergistic effects when combined with donepezil, an acetylcholinesterase inhibitor, in treating Alzheimer's disease in male albino rats, focusing on the modulation of the BACE-1/GSK-3ß pathway. The experiment involved 70 rats categorized into different groups: control, donepezil alone, CoQ10 alone, AD-model, donepezil co-treatment, CoQ10 co-treatment, and CoQ10 + donepezil combination. Various assessments, such as cholinesterase activity, oxidative stress, serum iron profile, Brain Derived Neurotrophic Factor (BDNF), Tau protein, ß-site amyloid precursor protein cleaving enzyme-1 (BACE-1), phosphatase and tensin homolog (Pten), and Glycogen synthase kinase-3-beta (GSK-3ß), were conducted on behavioral and biochemical aspects. CoQ10 treatment demonstrated memory improvement, enhanced locomotion, and increased neuronal differentiation, mainly through the inhibition of the dual BACE-1/GSK-3ß. These findings were substantiated by histological and immunohistological examinations of the hippocampus.

Long-term effects of cholinesterase inhibitors and memantine on cognitive decline, cardiovascular events, and mortality in dementia with Lewy bodies: An up to 10-year follow-up study.

INTRODUCTION: We aimed to assess the impact of cholinesterase inhibitors (ChEIs) and memantine on cognition, major adverse cardiovascular events (MACE) and mortality in dementia with Lewy bodies (DLB). METHODS: A total of 1,095 incident DLB patients from the Swedish Registry on cognitive/dementia disorders were included. Using an inverse probability of treatment weighting, the effect of initiating ChEI or memantine within 90 days of DLB diagnosis and nonuse was evaluated on cognitive trajectories and risks of MACE and death. RESULTS: The use of ChEIs significantly slowed cognitive decline at follow-ups (Mini-Mental State Examination [MMSE] -0.39 points/y; 95% confidence interval [CI], -0.96 to 0.18) compared to memantine (-2.49 points/y; -4.02 to -0.97) and nonuse (-2.50 points/y; -4.28 to -0.73). Treatment groups did not differ in MACE events. ChEI use was associated with lower risk of death in the first year after DLB diagnosis (adjusted hazard ratio [HR] 0.66, 95% CI 0.46, 0.94). DISCUSSION: Our findings illuminate the potential benefits of ChEI treatment in DLB patients. HIGHLIGHTS: Cholinesterase inhibitors slow cognitive decline over a 5-year follow-up period when compared to both memantine treatment and nonuse in patients with dementia with Lewy bodies. Cholinesterase Inhibitors reduce risk of mortality within the initial year, but this effect is not sustained after 1 year in patients with dementia with Lewy bodies.

Barbiturate-sulfonate hybrids as potent cholinesterase inhibitors: design, synthesis and molecular modeling studies.

Aim: Design and synthesis of a series of 5-benzylidene(thio)barbiturates 3a-r.Methodology: Evaluation of the inhibitory activity of the new chemical entities on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) using Donepezil as the standard reference.Results & Conclusion: Compound 3r emerged as the most potent AChE inhibitor (IC50 = 9.12 µM), while compound 3q exhibited the highest inhibitory activity against BChE (IC50 = 19.43 µM). Toxicological bioassays confirmed the absence of cytotoxicity for the most potent compounds at the tested doses. Molecular docking analysis demonstrated that the tested derivatives effectively bind to the active sites of both enzymes. Overall, this study sheds light on the potential of barbiturate-sulfonate conjugates as promising drug candidates.

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Cholinesterase Inhibitory Activity and Molecular Docking Studies of Isocryptolepine-Triazole Adducts.

Due to the rising prevalence of Alzheimer's disease (AD), there is a pressing need for more effective drugs to treat or manage AD's symptoms. Studies have shown that cholinesterase inhibition can improve cognitive and behavioral symptoms associated with AD, by addressing the cholinergic deficit. Based on the recent development of cholinesterase inhibitors with indoloquinoline and triazole moiety, we rationalized that compounds with an isocryptolepine-triazole scaffold may also have the same biological targets. In this study, eighteen previously synthesized isocryptolepine-triazole compounds were assessed for their ability to inhibit acetylcholinesterase (AChE) and butyrylcholine esterase (BChE). The majority of these compounds demonstrated potent selective AChE inhibition. Furthermore, our molecular docking and molecular dynamic simulation studies reveal that the isocryptolepine and triazole moieties are important for the binding of the compounds with the periphery of the AChE's binding pocket. While reductions in molecular weights and lipophilicities may be necessary to improve their pharmacokinetic properties, this work provides valuable insights for designing future AChE inhibitors, based on the novel isocryptolepine-triazole scaffold.

Effect of curcumin-donepezil combination on spatial memory, astrocyte activation, and cholinesterase expressions in brain of scopolamine-treated rats.

BACKGROUND: The study investigated the effect of co-administration of curcumin and donepezil on several markers of cognitive function (such as spatial memory, astrocyte activation, cholinesterase expressions) in the brain cortex and hippocampus of scopolamine-treated rats. METHOD AND RESULTS: For seven consecutive days, a pre-treatment of curcumin (50 mg/kg) and/or donepezil (2.5 mg/kg) was administered. On the seventh day, scopolamine (1 mg/kg) was administered to elicit cognitive impairment, 30 min before memory test was conducted. This was followed by evaluating changes in spatial memory, cholinesterase, and adenosine deaminase (ADA) activities, as well as nitric oxide (NO) level were determined. Additionally, RT-qPCR for glial fibrillary acidic protein (GFAP) and cholinesterase gene expressions was performed in the brain cortex and hippocampus. Also, GFAP immunohistochemistry  of the brain tissues for neuronal injury were performed in the brain cortex and hippocampus. In comparison to the control group, rats given scopolamine had impaired memory, higher levels of acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and ADA activities, as well as elevated markers of oxidative stress. In addition to enhanced GFAP immunoreactivity, there was also overexpression of the GFAP and BChE genes in the brain tissues. The combination of curcumin and donepezil was, however, observed to better ameliorate these impairments in comparison to the donepezil-administered rat group. CONCLUSION: Hence, this evidence provides more mechanisms to support the hypothesis that the concurrent administration of curcumin and donepezil mitigates markers of cognitive dysfunction in scopolamine-treated rat model.

Exploring the Bioactive Properties and Therapeutic Benefits of Pear Pomace.

The fruit juice industry generates a significant amount of waste, with a strong impact on the environment and the economy. Therefore, researchers have been focusing on the characterization of resources considered as food waste. This work provides information about the lipophilic and polar metabolites of pear pomace flours (PPFs) as a tool that can shed more light on the bioactive potential of this residue. Using UPLC-PDA, UPLC-FLR, and GC-MS, the study identified and quantified PPF's polar and non-polar metabolites. Essential, conditional, and non-essential amino acids were found, with asparagine being the most abundant. Isoprenoids, including lutein, zeaxanthin, and carotene isomers, ranged from 10.8 to 22.9 mg/100 g dw. Total flavonoids and phenolic compounds were 520.5-636.4 mg/100 g dw and 536.9-660.1 mg/100 g dw, respectively. Tocotrienols and tocopherols were identified, with concentrations of 173.1-347.0 mg/100 g dw and 468.7-913.4 mg/100 g dw. Fatty acids were the major non-polar compounds. All fractions significantly reduced matrix metalloproteinase-9 (MMP-9) activity. Although PPF had lower antioxidant potential (3-6 mmol Trolox/100 g dw), it inhibited AChE and BuChE by 23-30% compared to physostigmine salicylate. These findings suggest that pear pomace waste can be repurposed into functional products with valuable bioactive properties by re-introducing it in the food chain.

Synthesis, biological evaluation, molecular docking, and MD simulation of novel 2,4-disubstituted quinazoline derivatives as selective butyrylcholinesterase inhibitors and antioxidant agents.

Alzheimer's disease is the most prevalent neurodegenerative disorder characterized by significant memory loss and cognitive impairments. Studies have shown that the expression level and activity of the butyrylcholinesterase enzyme increases significantly in the late stages of Alzheimer's disease, so butyrylcholinesterase can be considered as a promising therapeutic target for potential Alzheimer's treatments. In the present study, a novel series of 2,4-disubstituted quinazoline derivatives (6a-j) were synthesized and evaluated for their inhibitory activities against acetylcholinesterase (AChE) and butyrylcholinestrase (BuChE) enzymes, as well as for their antioxidant activities. The biological evaluation revealed that compounds 6f, 6h, and 6j showed potent inhibitory activities against eqBuChE, with IC50 values of 0.52, 6.74, and 3.65 µM, respectively. These potent compounds showed high selectivity for eqBuChE over eelAChE. The kinetic study demonstrated a mixed-type inhibition pattern for both enzymes, which revealed that the potent compounds might be able to bind to both the catalytic active site and peripheral anionic site of eelAChE and eqBuChE. In addition, molecular docking studies and molecular dynamic simulations indicated that potent compounds have favorable interactions with the active sites of BuChE. The antioxidant screening showed that compounds 6b, 6c, and 6j displayed superior scavenging capabilities compared to the other compounds. The obtained results suggest that compounds 6f, 6h, and 6j are promising lead compounds for the further development of new potent and selective BuChE inhibitors.

Advances in Understanding and Managing Alzheimer's Disease: From Pathophysiology to Innovative Therapeutic Strategies.

Alzheimer's disease (AD) is a debilitating neurodegenerative disorder characterized by the presence of amyloid-ß (Aß) plaques and tau-containing neurofibrillary tangles, leading to cognitive and physical decline. Representing the majority of dementia cases, AD poses a significant burden on healthcare systems globally, with onset typically occurring after the age of 65. While most cases are sporadic, about 10% exhibit autosomal forms associated with specific gene mutations. Neurofibrillary tangles and Aß plaques formed by misfolded tau proteins and Aß peptides contribute to neuronal damage and cognitive impairment. Currently, approved drugs, such as acetylcholinesterase inhibitors and N-methyl D-aspartate receptor agonists, offer only partial symptomatic relief without altering disease progression. A promising development is using lecanemab, a humanized IgG1 monoclonal antibody, as an immune therapeutic approach. Lecanemab demonstrates selectivity for polymorphic Aß variants and binds to large soluble Aß aggregates, providing a potential avenue for targeted treatment. This shift in understanding the role of the adaptive immune response in AD pathogenesis opens new possibilities for therapeutic interventions aiming to address the disease's intricate mechanisms. This review aims to summarize recent advancements in understanding Alzheimer's disease pathology and innovative therapeutic approaches, providing valuable insights for both researchers and clinicians.

Pyridostigmine for the Management of Neurogenic Orthostatic Hypotension: A Systemic Review.

BACKGROUND: Pyridostigmine is hypothesized to improve neurogenic orthostatic hypotension (nOH) symptoms without causing or exacerbating supine hypertension. The objective of this review was to evaluate the safety and efficacy of pyridostigmine for management of nOH. METHODS: A literature search of PubMed, Embase, and CENTRAL was performed in December 2023 for prospective trials with a placebo or active comparator. RESULTS: Four randomized and two non-randomized studies were reviewed. Three studies utilizing a single dose, crossover design found significant differences of orthostatics using adjunctive pyridostigmine. Two studies assessing longer-term endpoints demonstrated conflicting efficacy of pyridostigmine with one trial finding significant improvement in orthostatics and symptoms after three months of therapy. Use of pyridostigmine did not lead to supine hypertension with most adverse effects being cholinergic. CONCLUSION: Pyridostigmine may be considered as an adjunctive medication in individuals with nOH refractory to standard treatment options as it carries a favorable safety profile with low risk for supine hypertension.

The association between preoperative serum cholinesterase and all-cause mortality in geriatric patients with hip fractures: a cohort study of 2387 patients.

OBJECTIVE: This study is to evaluate the association between preoperative cholinesterase levels and all-cause mortality in geriatric hip fractures. METHODS: Elderly patients with hip fractures were screened between Jan 2015 and Sep 2019. Demographic and clinical characteristics of patients were collected. Linear and nonlinear multivariate Cox regression models were used to identify the association between preoperative cholinesterase levels and mortality in these patients. Analyses were performed using EmpowerStats and the R software. RESULTS: Two thousand three hundred eighty-seven patients were included in this study. The mean follow-up period was 37.64 months. Seven hundred eighty-seven (33.0%) patients died due to all-cause mortality. Preoperative cholinesterase levels were 5910 ± 1700 U/L. Linear multivariate Cox regression models showed that preoperative cholinesterase level was associated with mortality (HR = 0.83, 95% CI: 0.78-0.88), P < 0.0001) for every 1000 U/L. However, the linear association was unstable, and nonlinearity was identified. A cholinesterase concentration of 5940 U/L was an inflection point. When preoperative cholinesterase level < 5940 U/L, the mortality decreased by 28% for every 1000 U/L increase in cholinesterase (HR = 0.72, 95%CI: 0.66-0.79, P < 0.0001). When cholinesterase was > 5940 U/L, the mortality was no longer decreased with the rise of cholinesterase (HR = 1.01, 95%CI: 0.91-1.11, P = 0.9157). We found the nonlinear association was very stable in the propensity score-matching sensitive analysis. CONCLUSIONS: Preoperative cholinesterase levels were nonlinearly associated with mortality in elderly hip fractures, and cholinesterase was a risk indicator of all-cause mortality. TRIAL REGISTRATION: This study is registered on the website of the Chinese Clinical Trial Registry (ChiCTR: ChiCTR2200057323) (08/03/2022).