New insights into butyrylcholinesterase: Pharmaceutical applications, selective inhibitors and multitarget-directed ligands

Dual inhibitors of butyrylcholinesterase and histone deacetylase 6 for the treatment of Alzheimer's disease: design, synthesis, and biological evaluation

To address the multifactorial pathology of Alzheimer's disease (AD), eighteen butyrylcholinesterase (BChE) and histone deacetylase 6 (HDAC6) dual inhibitors were designed, synthesized, and biologically evaluated. Through structure-activity relationship studies, compound 17 emerged as the most potent candidate, with IC50 value of 0.3 nM for human BChE and 56.7 nM for HDAC6. This compound demonstrated favorable safety profiles, drug-like properties, and significant neuroprotective effects in vitro. In a mouse model of scopolamine-induced cognitive impairment, 17 (10 mg/kg) exhibited excellent safety and markedly improved cognitive deficits. These findings highlight compound 17 as a promising BChE/HDAC6 dual inhibitor, supporting its further development as a potential therapeutic agent for AD.

Design, synthesis and evaluation of novel L-tryptophan derivatives as multifunctional agents with cholinesterase inhibition, anti-β-amyloid aggregation, anti-inflammatory, antioxidant and neuroprotection properties against Alzheimer's disease

In our recent investigation, we conducted a systematic search for novel L-Tryptophan derivatives exhibiting marked inhibitory effects against human serum butyrylcholinesterase (hBuChE), an enzyme intricately implicated in the pathological cascade of Alzheimer's Disease (AD). Two lead compounds among these derivatives, Z165 and Z168 displayed IC50 values of 0.44 μM and 3.23 μM against butyrylcholinesterase, suggesting their promising potential for further structural optimization. Chemical modifications were subsequently undertaken to enhance the inhibitory activities of these leads, culminating in the development of compounds 4d-9, 4d-12, and 4d-13, which demonstrated IC50 values of 0.29 μM, 0.52 μM, and 0.13 μM, respectively. Furthermore, the following investigation revealed that these compounds exhibit exceptional antioxidant properties when juxtaposed with ascorbic acid. They are also proficient in inhibiting the aggregation of amyloid-beta (Aβ) peptides while concurrently displaying minimal cytotoxic effects towards BV-2 cell lines. Meanwhile the good blood-brain barrier permeability of these compounds was confirmed in PAMPA-BBB assay. Remarkably, compound 4d-13, which demonstrated the most potent inhibitory activity against butyrylcholinesterase, also afforded consistent neuroprotective effects compared with Galantamine against the injury induced by NMDA or L-(+)-Sodium glutamate in SH-SY5Y cells. Besides, 4d-13 could reduce the expression of inflammatory factors IL-1β and IL-6 dose-dependently in the LPS induced BV-2 inflammatory model. Morris water maze and step-down testing in vivo confirmed that 4d-13 could ameliorate scopolamine-induced cognitive deficits. These findings suggest that these compounds are promising leads for the development of therapeutic agents against AD.

Design, synthesis, and bio-evaluation of C1-aryl galantamine derivatives

For exploring the naturally-inspired anti-AD multifunctional molecules, a series of C1-aryl galantamine derivatives 4a-x were designed and synthesized. The cholinesterase inhibition activity and neuroprotection ability of 4a-x were evaluated. Among them, meta-tbutylbenzene derivative 4b (IC50 = 0.12 ± 0.03 μM) and para-hydroxybenzene derivative 4h (IC50 = 3.86 ± 0.82 μM) exhibited selective inhibition effect against EeAChE and EqBChE, respectively. Compound 4k containing meta-methylthio benzene group exhibited dual inhibitory activity against EeAChE (IC50 = 0.47 ± 0.13 μM) and EqBChE (IC50 = 2.98 ± 0.80 μM). Furthermore, the neuroprotection experiment revealed that eight synthesized derivatives had significant effect to protect SH-SY5Y cells from H2O2-induced damage at a concentration of 25 μM. Notably, the dual AChE and BChE inhibitor 4k also exhibited the good neuroprotective activity, which deserves to be further explored for developing potential multifunctional AD drug.

Discovery, Biological Evaluation and Binding Mode Investigation of Novel Butyrylcholinesterase Inhibitors Through Hybrid Virtual Screening

Butyrylcholinesterase (BChE), plays a critical role in alleviating the symptoms of Alzheimer's disease (AD) by regulating acetylcholine levels, emerging as an attractive target for AD treatment. This study employed a quantitative structure-activity relationship (QSAR) model based on ECFP4 molecular fingerprints with several machine learning algorithms (XGBoost, RF, SVM, KNN), among which the XGBoost model showed the best performance (AUC = 0.9740). A hybrid strategy integrating ligand- and structure-based virtual screening identified 12 hits from the Topscience core database, three of which were identified for the first time. Among them, piboserod and Rotigotine demonstrated the best BChE inhibitory potency (IC50 = 15.33 μM and 12.76 μM, respectively) and exhibited favorable safety profiles as well as neuroprotective effects in vitro. Notably, Rotigotine, a marketed drug, was newly recognized for its anti-AD potential, with further enzyme kinetic analyses revealing that it acts as a mixed-type inhibitor in a non-competitive mode. Fluorescence spectroscopy, molecular docking, and molecular dynamics simulations further clarified their binding modes and stability. This study provides an innovative screening strategy for the discovery of BChE inhibitors, which not only identifies promising drug candidates for the treatment of AD but also demonstrates the potential of machine learning in drug discovery.

Design and synthesis of new 1,2,3-triazole-methoxyphenyl-1,3,4-oxadiazole derivatives: selective butyrylcholinesterase inhibitors against Alzheimer's disease

Alzheimer's disease (AD) remains a significant public health challenge due to its progressive cognitive impairment and the absence of proven treatments. In this study, several novel 1,2,3-triazole-methoxyphenyl-1,3,4-oxadiazole derivatives were synthesized and evaluated for their ability to inhibit key enzymes associated with AD: acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Structure-activity relationship (SAR) analysis revealed that derivatives featuring electron-withdrawing groups, particularly nitro and fluorine substituents, exhibited remarkable inhibitory activity against BChE while showing minimal effectiveness against AChE. Among these, compound 13s (R = 4-CH3, R' = 4-NO2) demonstrated the highest potency, selectively targeting BChE with an IC50 value of 11.01 µM. Molecular docking and molecular dynamics (MD) simulations provided deeper insights into the favorable interactions between these compounds and BChE. Additionally, cytotoxicity studies confirmed the active compound's limited toxicity toward normal cells, indicating a promising therapeutic profile. These findings suggest that the synthesized selective anti-BChE compounds hold potential for consideration in the later stages of AD treatment.

A Bright Future for Photopharmaceuticals Addressing Central Nervous System Disorders: State of the Art and Challenges Toward Clinical Translation

Photopharmacology is an innovative approach that uses light to activate drugs. This method offers the potential for highly localized and precise drug activation, making it particularly promising for the treatment of neurological disorders. Despite the enticing prospects of photopharmacology, its application to treat human central nervous system (CNS) diseases remains to be demonstrated. In this review, we provide an overview of prominent strategies for the design and activation of photopharmaceutical agents in the field of neuroscience. Photocaged and photoswitchable drugs and bioactive molecules are discussed, and an instructive list of examples is provided to highlight compound design strategies. Special emphasis is placed on photoactivatable compounds for the modulation of glutamatergic, GABAergic, dopaminergic, and serotonergic neurotransmission for the treatment of neurological conditions, as well as various photoresponsive molecules with potential for improved pain management. Compounds holding promise for clinical translation are discussed in-depth and their potential for future applications is assessed. Neurophotopharmaceuticals have yet to achieve breakthrough in the clinic, as both light delivery and drug design have not reached full maturity. However, by describing the current state of the art and providing illustrative case studies, we offer a perspective on future opportunities in the field of neurophotopharmacology focused on addressing CNS disorders.

Virtual screening and molecular dynamics of anti-Alzheimer compounds from Cardiospermum halicacabum via GC-MS

Background

Ayurveda is an ancient Indian medicinal system that uses medicinal plants for their neuroprotective effects. Ayurveda claims that the (C. halicacabum) leaves possess significant neuroprotective properties. Alzheimer's is characterized by the accumulation of amyloid-β, acetylcholinesterase, and tau tangles that interfere with neural transmission and impair cognitive abilities.

Objectives

This study aimed to identify novel potential anti-Alzheimer phytoconstituents of C. halicacabum leaves using in silico methods.

Methods

This study utilized the Box-Behnken design within the response surface methodology (RSM) to optimize and combine the effects of process variables, namely powder weight, solvent volume, and extraction time, on the microwave-assisted extraction (MAE) of C. halicacabum leaves. The optimization process revealed that these variables, along with microwave usage, significantly influenced the extraction yield. The ethanolic extract was examined using gas chromatography-mass spectrometry (GC-MS) analysis, and the identified phytoconstituents were further analyzed through computer-based simulations, including docking, absorption, distribution, metabolism, excretion, and toxicity (ADMET) studies, assessment of drug-likeness, molecular dynamics, LigPlot analysis, and density functional theory (DFT) analysis.

Results

Gas chromatography-mass spectrometry (GC-MS) analysis identified 40 phytoconstituents and 37 were successfully characterized. Molecular docking and dynamics simulations revealed two lead compounds, acetic acid (dodecahydro-7-hydroxy-1,4b,8,8-tetramethyl-10-oxo-2(1H)-phenanthrenylidene)-,2-(dimethylamino)ethyl ester, [1R-(1. alpha)], and 1-(2-hydroxyethoxy)-2-methyldodecane, which exhibited superior stability in the docked complex compared to galantamine.

Conclusion

Based on computational predictions and observed pharmacological properties, these findings suggest that phytoconstituents may have therapeutic effects against selected AD targets.

Discovery of novel thiosemicarbazone-acridine targeting butyrylcholinesterase with antioxidant, metal complexing and neuroprotector abilities as potential treatment of Alzheimer's disease: In vitro, in vivo, and in silico studies

Inhibition of cholinesterases, combined with antioxidant activity, metal-chelating capacity, and neuroprotection, is recognized as an effective multitarget therapy for the treatment of Alzheimer's disease (AD). Based on our in-house thiosemicarbazone-acridine compounds, this study recognized these derivatives as possible multi-target-directed ligand (MTDL). Initial screening against cholinesterases identified CL-01, which exhibited a promising IC50 value of 0.71 μM against butyrylcholinesterase (BChE). Twelve new derivatives were designed based on CL-01 aiming to retain the BChE inhibitory activity while incorporating a MTDL profile, including antioxidant properties and metal-complexing abilities. Among the new derivatives, CL-13 maintained a good BChE inhibition (IC50 = 1.15 μM) with improved selective index against acetylcholinesterase (SI = 9.2). The acridine nucleus was important for the activity, as its saturated tetrahydroacridine analogue (TA-01) showed a decrease in cholinesterases inhibition potencies and altered the mode of inhibition, revealing for the first time distinct functional roles for the two nuclei. Moreover, CL-13 emerged as a promising lead compound, demonstrating interesting antioxidant activity (DPPH EC50 = 47.01 μM), chelating capacity of biometals involved in Aβ aggregation and/or oxidative stress, and a lack of neurotoxicity at 50 μM in SH-SY5Y cells. It also exhibited neuroprotective effects in an in vitro oxidative stress model induced by H2O2. Finally, in vivo experiments confirmed that CL-13 effectively reversed scopolamine-induced cognitive impairment, without affecting locomotor activity in the mice.

Optimization of the cardiac delirium index by including age, decrease in butyrylcholinesterase actitivity, preoperative HbA1c, and postoperative hemoglobin levels: results of a secondary analysis of a prospective observational study

Introduction

Postoperative delirium (POD) after cardiac surgery significantly affects the perioperative morbidity and mortality. Butyrylcholinesterase (BChE) is an enzyme primarily produced in the liver, which plays a crucial role in the hydrolysis of acetylcholine outside of neuronal synapses, referred to as extraneuronal hydrolysis. The integration of BChE activity into the cardiac delirium (CARDEL) index might increase its predictive power for identifying POD after cardiac surgery. Therefore, the primary aim of this study was to assess the applicability of the CARDEL index and determine whether integrating the BChE activity enables optimization of the predictive model.

Methods

This secondary analysis of a prospective observational study included patients undergoing elective coronary artery bypass graft surgery. BChE activity is expressed in units per liter (U/L), while the BChE drop refers to the percentage decrease in BChE activity from pre- to postoperative levels. POD risk factors were identified using multivariate regression analysis. The predictive power of the CARDEL index and an optimized model including BChE was calculated with receiver operating characteristic (ROC) analysis.

Results

Of 93 included patients, 20 (21.5%) developed POD. Elevated preoperative HbA1c [OR 2.5 (1.2-4.8), p = 0.01], a decrease in BChE activity [%, OR 1.1 (1.0-1.2), p = 0.04], age [1 (0.94-1.1), p = 0.55], and a postoperative hemoglobin change [OR 0.86 (0.78-0.96), p < 0.001] were identified as independent risk factors for POD. While the CARDEL index showed a moderate prediction of POD [AUCROC of 0.74 (0.60-0.87)], the optimization including BChE resulted in a significant prognostic improvement: AUCROC of 0.84 (0.72-0.94, p < 0.001).

Conclusion

Despite the small size of this derivation cohort, this study identified elevated HbA1c as the strongest risk factor for the development of POD, followed by a decrease in BChE activity, postoperative anemia, and age, respectively. By including these parameters to the CARDEL index, its predictive power for the identification of POD significantly improved in this derivation cohort. Moving forward, integrating these findings into clinical practice could enhance early risk stratification and targeted intervention for patients at high risk of POD. Therefore, further research should evaluate these results in a larger, external cohort.

The Aggravating Role of Failing Neuropeptide Networks in the Development of Sporadic Alzheimer's Disease

Alzheimer's disease imposes an increasing burden on aging Western societies. The disorder most frequently appears in its sporadic form, which can be caused by environmental and polygenic factors or monogenic conditions of incomplete penetrance. According to the authors, in the majority of cases, Alzheimer's disease represents an aggravated form of the natural aging of the central nervous system. It can be characterized by the decreased elimination of amyloid β1-42 and the concomitant accumulation of degradation-resistant amyloid plaques. In the present paper, the dysfunction of neuropeptide regulators, which contributes to the pathophysiologic acceleration of senile dementia, is reviewed. However, in the present review, exclusively those neuropeptides or neuropeptide families are scrutinized, and the authors' investigations into their physiologic and pathophysiologic activities have made significant contributions to the literature. Therefore, the pathophysiologic role of orexins, neuromedins, RFamides, corticotrope-releasing hormone family, growth hormone-releasing hormone, gonadotropin-releasing hormone, ghrelin, apelin, and natriuretic peptides are discussed in detail. Finally, the therapeutic potential of neuropeptide antagonists and agonists in the inhibition of disease progression is discussed here.

Naphthyl-functionalized acetamide derivatives: Promising agents for cholinesterase inhibition and antioxidant therapy in Alzheimer's disease

This study presents the synthesis and characterization of a series of 13 novel acetamides. These were subjected to Ellman's assay to determine the efficacy of the AChE and BChE inhibitors. Finally, we report their antioxidant activity as an alternative approach for the search for drugs to treat AD. These studies revealed that compounds 1a-1k and 2l-2m were obtained in moderate yield. Four amides (1h, 1j, 1k, and 2l) were selective for one of the enzymes (BChE); thus, those that inhibited BChE were more active than the positive control (galantamine) and showed better IC50 values (3.30-5.03 µM). The theoretical free binding energies calculated by MM-GBSA indicated that all inhibitors were more stable than rivastigmine, and the inhibition mechanisms involved the entire active site: peripheral anionic site, oxyanion hole, acyl-binding pockets, and catalytic site. We examined the cytotoxicity of compounds 1h, 1j, 1k, and 2l in human dermal cells and found that they did not exhibit any toxic effects under the tested conditions. Additionally, these compounds, which also inhibited BChE, displayed mixed inhibition and did not exhibit hemolytic effects on human erythrocytes. Furthermore, the ABTS and DPPH assays indicated that, although none of the compounds showed activity in the DPPH assay, the EC50 values for radical trapping by the ABTS method showed that compounds 1a, 1d, 1e, and 1g had EC50 values lower than 10 µg/mL, indicating their strong radical scavenging capacity. We also report the crystal structures of compounds 1c, 1d, 1f, and 1g, which are found in monoclinic crystal systems.

Pharmacokinetics and fate of free and encapsulated IRD800CW-labelled human BChE intravenously administered in mice

Human butyrylcholinesterase (BChE) is an efficient bioscavenger of toxicants. Highly purified BChE was labelled with the near infrared fluorescent IRDye800CW. The goal was to determine the pharmacokinetics and fate of enzyme in mice. BChE-IRDye800CW was encapsulated in polyethylene glycol-polypropylene sulfide-based spherical polymersome nanoreactors with the following characteristics: 140 nm diameter, ξ = -6 mV, PDI ≤ 0.2, 1 year stability. Encapsulation did not alter the functional properties of BChE. Free and encapsulated enzyme were injected intravenously to CD-1 mice (single dose of enzyme 1.5 mg/kg and PEG-PPS polymersomes 25 mg/kg) and were analyzed for 8 days using an in vivo imaging system. Results showed that the pharmacokinetic distribution α-phase of encapsulated BChE (t1/2 = 17.6 h) was longer than for free enzyme (t1/2 = 6.6 h). The mean half-time for elimination β-phase was 2-time longer for encapsulated enzyme than for free enzyme (150 vs 72 h). Transient changes in infrared fluorescence in organs showed that BChE is eliminated from liver. However, free and encapsulated enzymes were cleared via different pathways. This first study of pharmacokinetics and fate of BChE encapsulated in polymersomes initiates research of new formulations of bioscavengers aimed at increasing the residence time of enzymes in the blood stream.

Advances in Cholinesterase Inhibitor Research-An Overview of Preclinical Studies of Selected Organoruthenium(II) Complexes

Cholinesterase (ChE) inhibitors are crucial therapeutic agents for the symptomatic treatment of certain chronic neurodegenerative diseases linked to functional disorders of the cholinergic system. Significant research efforts have been made to develop novel derivatives of classical ChE inhibitors and ChE inhibitors with novel scaffolds. Over the past decade, ruthenium complexes have emerged as promising novel therapeutic alternatives for the treatment of neurodegenerative diseases. Our research group has investigated a number of newly synthesized organoruthenium(II) complexes for their inhibitory activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Three complexes (C1a, C1-C, and C1) inhibit ChE in a pharmacologically relevant range. C1a reversibly inhibits AChE and BChE without undesirable peripheral effects, making it a promising candidate for the treatment of Alzheimer's disease. C1-Cl complex reversibly and competitively inhibits ChEs, particularly AChE. It inhibits nerve-evoked skeletal muscle twitch and tetanic contraction in a concentration-dependent manner with no effect on directly elicited twitch and tetanic contraction and is promising for further preclinical studies as a competitive neuromuscular blocking agent. C1 is a selective, competitive, and reversible inhibitor of BChE that inhibits horse serum BChE (hsBChE) without significant effect on the peripheral neuromuscular system and is a highly species-specific inhibitor of hsBChE that could serve as a species-specific drug target. This research contributes to the expanding knowledge of ChE inhibitors based on ruthenium complexes and highlights their potential as promising therapeutic candidates for chronic neurodegenerative diseases.