Inhibition Of Enzyme Acetylcholinesterase Research Articles

Evaluating Quinolines: Molecular Dynamics Approach to Assess Their Potential as Acetylcholinesterase Inhibitors for Alzheimer's Disease.

Quinoline represents a promising scaffold for developing potential drugs because of the wide range of biological and pharmacological activities that it exhibits. In the present study, quinoline derivatives obtained from CADMA-Chem docking protocol were investigated in the mean of molecular dynamics simulations as potential inhibitors of acetylcholinesterase enzyme. The examined species can be partitioned between neutral, dq815 (2,3 dihydroxyl-quinoline-4-carbaldehyde), dq829 (2,3 dihydroxyl-quinoline-8-carboxylic acid methane ester), dq1356 (3,4 dihydroxyl-quinoline-6-carbaldehyde), dq1368 (3,4 dihydroxyl-quinoline-8-carboxylic acid methane ester) and dq2357 (5,6 dihydroxyl-quinoline-8-carboxylic acid methane ester), and deprotonated, dq815_dep, dq829_dep, dq1356_dep and dq2357_dep. Twelve molecular dynamics simulations were performed including those of natural acetylcholine, of the well-known donepezil inhibitor and of the founder quinoline chosen as reference. Key intermolecular interactions were detected and discussed to describe the different dynamic behavior of all the considered species. Binding energies calculation from MMPBSA well accounts for the dynamic behavior observed in the simulation time proposing dq1368 as promising candidate for the inhibition of acetylcholinesterase. Retrosynthetic route for the production of the investigated compounds is also proposed.

Synthesis and characterization of tannic acid–copper complex: A promising anticholinesterase drug

This study aimed to present an optimized synthetic pathway for a complex formed between copper (II) metal ion and tannic acid (TA), which have a variety of pharmacological properties. The study also focused on characterizing this metallodrug, carrying out in vitro antioxidant and acetylcholinesterase enzyme (AChE) inhibition assays, and performing in vivo toxicity assay against zebrafish (Danio rerio), thus expanding the area of study involving syntheses of metal complexes to act as therapeutic agents. Through various characterization techniques, including UV–Vis Absorption Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Thermal Analysis (TG and DTG), 1H Nuclear Magnetic Resonance (1H NMR), Inductively Coupled Plasma with Optical Emission Spectrometry (ICP-OES), and Electron Paramagnetic Resonance (EPR), it was confirmed that the metal ion is coordinated to the ligand, exhibiting distorted planar square geometry with mononuclear copper (3.10 ± 0.10 % copper by ICP-OES). In vitro tests demonstrated that the TA–Cu complex presents antioxidant activity against DPPH (IC50 = 2.26 ± 0.01 µg mL−1) and ABTS (IC50 = 1.91 ± 0.07 µg mL−1) radical scavenging assays. These results were more promising than those obtained for the TA (4.25 ± 0.03 µg mL−1 and 3.37 ± 0.03 µg mL−1, respectively). In the in vitro inhibition of AChE assay, the TA–Cu complex (4.07 ± 0.04 µg mL−1) presented a lower IC50 value than TA (5.80 ± 0.09 µg mL−1), indicating that coordination to the metal center Cu (II) was able to improve the anticholinesterase activity of the free ligand. Furthermore, the TA–Cu complex did not show toxicity in the in vivo test with adult zebrafish for 96 h at the tested doses of 4–40 mg kg−1, with LD50 >40 mg kg−1. Thus, it is estimated that the TA–Cu complex is a metallodrug with anticholinesterase potential, representing a promising strategy for conducting future pre-clinical studies in models of Alzheimer’s disease.

2-amino-6-ethoxy-4-arylpyridine-3,5-dicarbonitrile Scaffolds as potential acetylcholinesterase and butyrylcholinesterase inhibitors

Inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes are of prime importance for treating Alzheimerʼs disease (AD). Apart from many organic scaffolds, pyridine-based compounds have previously been reported as potential α-glucosidase inhibitors. The current study reports a series of pyridine-based synthetic molecules for their acetylcholinesterase AChE and butyrylcholinesterase BChE inhibitory potential assessed via in vitro, kinetics, and in silico studies. For this purpose, 2-amino-6-ethoxy-4-arylpyridine-3,5-dicarbonitrile analogs 1–23 were synthesized by using a two-step reaction scheme. In the first step, different aryl aldehydes were treated with malononitrile to afford the 2-benzylidenemalononitrile in the presence of catalyst ammonium acetate. In the next step, 2-benzylidenemalononitrile intermediates were reacted again with malononitrile, catalyzed by potassium hydroxide, to synthesize a range of functionalized pyridine scaffolds in good yields. Compounds were subjected to in vitro screening against AChE and BChE enzymes. Several derivatives, including 2, 3, 11, 14–16, 19, 20, and 22, showed many folds of increased inhibitory potential and binding affinity in the ranges of Ki = 1.62 ± 0.13 nM to 15.84 ± 0.10 nM for AChE and Ki = 1.35 ± 0.31 nM to 13.52 ± 0.61 nM for BChE, as compared to the standard tacrine Ki = 53.31 ± 11.32 nM for AChE, and Ki = 58.16 ± 7.24 nM for BChE. Further, molecular docking studies deduced key interactions between the ligands (compounds) and the active pocket of enzymes. The current research study has identified several potential AChE and BChE inhibitors that may serve as lead candidates after targeted advanced research for exploring anti-Alzheimer agents.

Computational exploration of bioactive compounds from Albizia procera: Molecular docking, dynamics, and pharmacokinetics for AchE and BchE inhibition in Alzheimer's disease treatment

Current treatments for Alzheimer's disease (AD) are inadequate and primarily target inhibition of butyrylcholinesterase (BchE) and acetylcholinesterase (AChE) enzymes. This study focused on identifying potential anti-AD compounds from the leaf extract of Albizia procera using gas chromatography-tandem mass spectrometry (GC-MS) analysis and computational approaches. Ethanol seed extract analysis revealed 10 phytoconstituents, which were evaluated for their binding affinities using Autodock Vina and Desmond software against AD-related targets (PDB IDs: 4PQE, 2WJO, and 2POA). Five compounds, along with the control drug, showed significant docking energies. Subsequent in silico ADMET analysis assessed parameters such as intestinal absorption, blood-brain barrier permeability, gastrointestinal absorption, carcinogenicity, and acute oral toxicity. The results extract showed notable affinity for BchE and acetylcholinesterase targets. Molecular dynamics (MD) simulations supported the involvement of hydrogen bonding with ASP207 and GLY75 residues in binding these ligands, demonstrating that disrupting these forces causes destabilization. A ligand plot study also presented a two-dimensional plot of these interactions. The docking results indicate that 7-Oxabicyclo [4.1.0] heptan-2-one could be a promising agent for the treatment of AD because of its higher stability with respect to the two best ligands among all compounds tested. Therefore, from this study, it can be concluded that the compounds present in the leaf extract of A. procera have potential as targets linked to AD and may be helpful for the development of new drugs. Therefore, these data draw a focus on non-synthetic compounds during drug discovery and could possibly provide approaches for exploring existing therapies for AD.

Essential oils of Plumeria alba L. and Plumeria rubra L. growing in Egypt: GC/MS analysis, molecular dynamics and in-vitro anti-cholinesterase activity

AimEssential oils (EOs) from Plumeria species exhibit noteworthy chemical compositions and diverse biological activities, rendering them valuable constituents for use in medicine, cosmetics, and perfumery. Our aim is to investigate the chemical profiles of P. alba L. and P. rubra L. cultivated in Egypt as biologically active crops. MethodsThe EOs of the flowers of P. alba and P. rubra cultivated in Egypt were prepared by steam distillation and headspace and analyzed by GC/MS. Principal components analysis (PCA) was used to assess the correlation between the chemical composition of the EOs and those reported for EOs of Plumeria species in other countries. ResultsThe score plot revealed a notable difference in the components of EOs prepared by steam distillated and headspace. Geranyl benzoate (27.55 %) was the major compound identified in steam distillated sample of P. alba and linalool (32.52 %) was the major in that prepared by headspace. On the other hand, 1-heptacosanol (23.86 %) was the major compound in the steam distillated sample of P. rubra and 2-methyl-butyl aldoxime (36.38 %) was the major compound in that prepared by headspace. Both EOs demonstrated in-vitro inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. Docking study revealed that aromatic compounds have better fitting, while aliphatic compounds have better stability with lower docking interaction energy, and geranyl benzoate showed docking results and binding mode similar to that of the ligands of both enzymes; its stability after docking was confirmed by molecular dynamics. ConclusionEOs from Plumeria species are highly recommended for developing natural and effective aromatherapy products for Alzheimer’s disease.

Preparation and characterization of AChE immobilized magnetic bio-nanocomposites (Fe3O4@Cht/Au) for pesticide detection

Free enzymes cause difficulties in many applications due to their insufficient stability, loss of activity in a short time, and most importantly, although they are costly, they are used only once in reactions, lose their effect and cannot be recovered from the environment. Magnetic nanoparticles coated with biocompatible polymeric material are potential candidates for promising enzyme carriers due to their multifunctional pore surfaces, easy removal from the environment provided by the magnetization, ability to main stability under various harsh conditions. This study prepared a biosensor candidate based on the inhibiting acetylcholinesterase enzyme by organophosphate pesticides from chitosan-coated magnetic nanoparticles doped with gold. Transmission electron microscopy, scanning electron microscopy, X-ray diffraction diffractometry, and Fourier transform infrared spectroscopy analysis confirmed the structure of synthesized nanocomposites. Magnetic characteristics of the nanocomposites were assessed using VSM. Bio-nanocomposite (Fe3O4@Cht/Au/AChE) was used to determine environmental pollutants qualitatively. Remediation of organophosphate-containing wastewater is an essential issue for environmental sustainability. In this work, Dichlorvos and Chlorpyrifos were selected as organic pollutants to assess the enzymatic activity of immobilized Fe3O4@Cht/Au/AChE. Optimum conditions for AChE enzyme were immobilized nanostructures (Fe3O4@Cht/Au/AChE) were determined. The optimum pH for the immobilized enzyme was found to be 8, and the optimum temperature was found to be 60 °C. Retained immobilized enzyme activity is found to be around 50% for the 20th reuse. In the presence of 150 µL pesticide, retained immobilized enzyme activity is found to be around 25%. Method validation was performed for pesticides. When using immobilized AChE, the LOD (limit of detection)-LOQ (limit of quantitation) values for Dichlorovos and Chlorpyrifos was obtained in the range of 0.0087–0.029 nM and 0.0014–0.0046 nM, respectively. The relative standard deviation (RSD%) values, which are indicators of precision, were found to be below 2%.

Competitive Inhibition and Synergistic Effects of Nutraceutical and Metabolite Molecules on Anti-Acetylcholinesterase Activity

The rapidly increasing prevalence of Alzheimer's disease (AD) poses a significant global public health threat. While medications such as Donepezil, Galantamine, and Rivastigmine are used, their serious side effects and limited healing fail to provide a definite cure. Consequently, combination therapies are being explored to enhance the efficacy of existing drugs. This study aims to evaluate the anti-acetylcholinesterase activities of previously identified nutraceutical and metabolite compounds, namely Queuine, Etoperidone, and Thiamine. Combined use of Queuine with Donepezil, Etoperidone, and Thiamine on acetylcholinesterase enzyme inhibition is also evaluated. The effects of the drug combinations on cell viability and acetylcholinesterase inhibition were investigated by using safe doses determined for each drug. The cytotoxic effect of drug combinations was investigated on the SH-SY5Y cell line using the RTCA method. All the individual or drug combinations were non-toxic to neuronal cells. Anti-acetylcholinesterase activities were estimated by Ellman’s method yielding the inhibition percentages as 70%, 61%, 45%, and 51% for Donepezil, Etoperidone, Queuine, and Thiamine, respectively. When drug combinations were analyzed, competitive inhibition resulted for Queuine+Donepezil and Queuine+Thiamine, the enzyme inhibition percentages being diminished to 47% and 21%, respectively. A significant synergistic effect was observed for Queuine+Etoperidone with the highest inhibition of 74%. This study provides the first evidence of the nutraceutical molecule Queuine's impact on acetylcholinesterase inhibition and the synergistic effect of Queuine and Etoperidone as a potent drug combination surpassing the effectiveness of Donepezil. Queuine and Etoperidone synergism may serve as a potential AD treatment by further in vivo validations.

Neuroprotective properties of UV-C treated Bacopa floribunda leaves: in vitro and in vivo studies

This study investigated the effect of UV-C irradiation on antioxidant, cholinergic and neuroprotective properties of Bacopa floribunda leaves in scopolamine-induced rats. In vitro study was done by the determination of phenolics, flavonoid, total antioxidant capacity, 2, 2-diphenyl-1-picrylhydrazyl scavenging activity, inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. Loss of memory was induced in Wistar rats pre-treated with extracts of Bacopa floribunda using scopolamine (2 mg/kg) administered intraperitoneally. Behavioural studies using elevated plus maze (EPM) and biochemical analysis on the were carried out. Exposure to UV-C radiation increased the phenolics, flavonoid, antioxidant and inhibitory properties against AChE and BChE of the Bacopa floribunda leaves. The administration of scopolamine caused significant increase in the activities of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes, but decrease in the activities of antioxidant enzymes and enhanced generation of malondialdehyde and nitric oxide in vivo. The loss of memory and Biochemical analysis in scopolamine-induced rats was ameliorated by treatment with UV-C treated Bacopa floribunda (TBF) extracts. Treatment with TBF improved memory retention and ameliorated oxidative damage in hippocampus of scopolamine treated rats.

The impact of seasonal variation on the composition of the volatile oil of Polyalthia suberosa (Roxb.) Thwaites leaves and evaluation of its acetylcholinesterase inhibitory activity

BackgroundPolyalthia suberosa (Roxb.) Thwaites (Annonaceae) is a medicinal plant that has been reported for its various pharmacological potentials, such as its anti-inflammatory, analgesic, antioxidant, and neuropharmacological activities. This study aimed to analyze the leaf essential oils of P. suberosa (PSLO) collected in different seasons, to evaluate the acetylcholinesterase inhibitory activity, and to corroborate the obtained results via in-silico molecular docking studies.MethodsThe leaf essential oils of P. suberosa collected in different seasons were analyzed separately by GC/MS. The acetylcholinesterase inhibitory activity of the leaves oil was assessed via colorimetric assay. In-silico molecular docking studies were elucidated by virtual docking of the main compounds identified in P. suberosa leaf essential oil to the active sites in human acetylcholinesterase crystal structure.ResultsA total of 125 compounds were identified where D-limonene (0.07 − 24.7%), α-copaene (2.25 − 15.49%), E-β-caryophyllene (5.17 − 14.42%), 24-noroleana-3,12-diene (12.92%), β-pinene (0.14 − 8.59%), and α-humulene (2.49–6.9%) were the most abundant components. Results showed a noteworthy influence of the collection season on the chemical composition and yield of the volatile oils. The tested oil adequately inhibited acetylcholinesterase enzyme with an IC50 value of 91.94 µg/mL. Additionally, in-silico molecular docking unveiled that palmitic acid, phytol, p-cymene, and caryophyllene oxide demonstrated the highest fitting scores within the active sites of human acetylcholinesterase enzyme.ConclusionsFrom these findings, it is concluded that P. suberosa leaf oil should be evaluated as a food supplement for enhancing memory.

CG-MS, Radical Scavenging, Acetylcholinesterase Inhibition, Antifungal and Molecular Docking Studies of Essential Oil from the Leaves of Tapirira guianensis Aubl

The species Tapirira guianensis Aubl is used in folk medicine to treat leprosy, diarrhea, and syphilis. The present study aims to evaluate the chemical composition and the antioxidant, anticholinesterase, and antifungal potential of the essential oil from T. guianensis leaves. The plant material was collected at Arco Estadual do Cocó, with prior authorization from the Municipal Environment Department. The essential oil was extracted through the hydrodistillation process with a Clevenger-type apparatus, and the constituents were evaluated through Gas Chromatography coupled to Mass Spectrometry (GC-MS). The antioxidant potential was assessed through free radicals: DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS+ (2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)) in a 96-well plate. Antifungal activity was evaluated using the Clinical Laboratory Standards Institute - M38-A protocol (CLSI, 2018). Gas chromatography coupled with mass spectrometry revealed the presence of constituents such as eugenol (59.00%), α-copaene (0.40%), β-caryophyllene (29.91%), α-humulene in T. guianensis. The essential oil demonstrated very promising antioxidant and anticholinesterase potential in In vitro studies. Molecular docking regarding acetylcholinesterase enzyme inhibition revealed that α-copaene has superior action compared to the drug physostigmine. The results of molecular docking for Candida albicans showed that α-copaene and α-humulene interacted in the same binding region as the PepA inhibitor against SAP5. This indicates their action is similar to the aspartic protease inhibitor, in addition to the possibility of a synergistic effect with the drug fluconazole. This is the first study of the biological potential of the essential oil from T. guianensis leaves, thus revealing its high potential for future studies in the scientific community. Therefore, we can infer that the essential oil of T. guianensis is a source of antioxidant, anticholinesterase, and antifungal constituents, with promising therapeutic potential in the management of Alzheimer's disease and Candida infections.

In Silico Investigation of Novel Compounds as Inhibitors of Acetylcholinesterase Enzyme for the Treatment of Alzheimer's Diseases.

Alzheimer's disease (AD) is a "progressive, neurodegenerative disease that occurs when nerve cells in the brain die." There are only 4 drugs approved by the United States Food and Drug Administration (FDA). Three (donepezil, rivastigmine, and galantamine) out of these four drugs are anticholinesterase inhibitors, while the fourth one memantine is an N-methyl-D-aspartate (NMDA) receptor inhibitor. Currently, two immunotherapy drugs that target amyloid protein (donanemab and lecanemab) are being considered for the treatment of Alzheimer's disease at an early stage. All these drug molecules are still not the complete answer to the treatment of Alzheimer's disease. A recent report from the Office of National Statistics showed that AD is the leading cause of death in 2022. Therefore, there is an urgency to develop more drugs that can treat AD. Based on this urgency, we aim to investigate how bioactive and already approved drugs could be repurposed for inhibiting the anticholinesterase enzyme using computational studies. To achieve this, the data science tool-Python coding was compiled on Jupyter Notebook to mine bioactive compounds from the ChEMBL database. The most bioactive compounds obtained were further investigated using Molecular Operating Environment (MOE) software to carry out molecular docking and ligand analysis, and this was followed by molecular dynamics simulation production at 35 ns using GROMACS 2022.4 on Archer 2 machine. The molecular dynamic analysis was carried out using HeroMDanalysis software. Data mining of the ChEMBL database was carried out for lipase inhibitors, and this gave CHEMBL-ID 1240685, a peptide molecule, the most active compound at the time of data mining. Further literature studies gave Zoladex an FDA-approved drug for the treatment of breast cancer as another compound of interest. The in silico studies were carried out against the anticholinesterase enzyme using two FDA-approved drugs donepezil and galantamine as a template for comparing the in silico activities of the repurposed drugs. A very useful receptor for this study was PDB-1DX6, a cocrystallized galantamine inhibitor of acetylcholinesterase enzyme. The molecular docking analysis (using ligand interactions) and molecular dynamic analysis (root mean square deviation (RMSD) and root mean square fluctuation (RMSF)) showed that the two peptide molecules CHEMBL-1240685 and Zoladex gave the best binding energy and stability when compared to the FDA-approved drugs (donepezil and galantamine). Finally, further literature studies revealed that Zoladex affects memory reduction; therefore, it was dropped as a possible repurposed drug. Our research showed that CHEMBL-1240685 is a potential compound that could be investigated for the inhibition of anticholinesterase enzyme and might be another drug molecule that could be used to treat Alzheimer's disease.

Content analysis, nanoparticle forming potential and acaricidal effects on Tick (Hyalomma marginatum) of essential oils from two common Thymbra species

In this study, the fatty acid, essential oil and aroma composition of Thymbra sintenisii Bornm. & Aznav. subsp. sintenisii Bornm. & Aznav (TSS) and Thymbra sintenisii Bornm. & Azn. subsp. isaurica P.H.Davis (TSI) were determined by GC-MS. The cytotoxic activity was determined with MTT assay and antioxidant activities were determined with DPPH, ABTS, CUPRAC methods. Urease, acetyl, butyryl, angiotensin, α-amylase, tyrosinase, elastase, and collagenase enzyme inhibition activities of these species were also determined. The acaricidal effects of essential oils from aerial parts of TSS and TSI on ticks and the nanoparticle formation potential of their essential oils with AgNO3 were determined and compared. The main components of TSS essential oil and aroma were determined as carvacrol and o-cemen (66.78 and 35.44%, respectively), the major components of TSI essential oil and aroma were carvacrol and γ-terpinene (63.78 and 31.44%, respectively). The species exhibited remarkably high antioxidant activity, particularly in the ABTS and CUPRAC methods. It was also determined that the butyrylcholinesterase and acetylcholinesterase enzyme inhibition activities (Inhibition%: 76.12±0.83 and 74.13±0.33, respectively) of the species were quite high. Moderate antimicrobial activity against the bacteria was observed for both essential oils, with MIC values ranging from 312 to 1250 μg/mL. Moreover, essential oils of these species showed good acaricidal activity on Hyalomma marginatum (LC50: 11.82 μg/mL for TSS; LC50: 57.64 μg/mL for TSI). The high antioxidant, anticholinesterase, and acaracidal activities observed in both species are attributed to the presence of carvacrol in their essential oils. The species have potential to be used in food supplements-preservatives, pharmaceutical industry.

Investigation, scaffold hopping of novel donepezil-based compounds as anti-Alzhiemer's agents: synthesis, in-silico and pharmacological evaluations.

Alzheimer's disease (AD) is a multifaceted neurodegenerative condition. The pathogenesis of AD is highly intricate and the disease is apparent in the aged population ~ 50-70years old. Even after > 100years of research, the root origin of AD and its pathogenesis is unclear, complex and multifaceted. Herein, we have designed and synthesized 9 novel molecules with three different heterocyclic scaffolds namely pyrrolidone-2-one, quinoline & indoline-2-one to imitate and explore the novel chemical space around donepezil. The synthesized molecules were evaluated for their potential as anti-Alzheimer's agents through in-vitro and in-vivo studies in appropriate animal models. To further understand their interaction with acetylcholinesterase enzyme (AChE), extra-precision docking, and molecular dynamics simulation studies were carried out. As the number of compounds was limited to thoroughly explore the structure-activity relationship, atom-based 3D-quantitative structure-activity relationships (QSAR) studies were carried out to get more insights. All the designed compounds were found to inhibit AChE with IC50 in the micromolar range. From pyrrolidone-2-one series, 6-chloro-N-(1-(1-(3,4-dimethoxybenzyl)-2-oxopyrrolidin-3-yl)piperidin-4-yl)pyridine-3-sulfonamide (9), 2-(1-benzylpiperidin-4-yl)-6,7-dimethoxy-4-(4-methoxyphenyl)quinoline (18) from quinoline series and N-(1-benzylpiperidin-4-yl)-2-(2-oxoindolin-3-yl)acetamide (23) from indolin-2-one series inhibited AChE with an IC50 value of 0.01µM. Based on other biochemical studies like lipid peroxidation, reduced glutathione, superoxide dismutase, catalase, nitrite, and behavioural studies (Morris water maze), compound 9 was found to be a potent AChE inhibitor which can be further explored as a lead molecule to design more potent and effective anti-Alzheimer's agents.

Repurposing of USFDA-approved drugs to identify leads for inhibition of acetylcholinesterase enzyme: a plausible utility as an anti-Alzheimer agent.

In the quest to identify new anti-Alzheimer agents, we employed drug repositioning or drug repositioning techniques on approved USFDA small molecules. Herein, we report the structure-based virtual screening (SBVS) of 1880 USFDA-approved drugs. The in silico-based identification was followed by calculating Prime MMGB-SA binding energy and molecular dynamics simulation studies. The cumulative analysis led to identifying domperidone as an identified hit. Domperidone was further corroborated in vitro using anticholinesterase-based assessment, keeping donepezil as a positive control. The analysis revealed that the identified lead (domperidone) could induce an inhibitory effect on AChE in a dose-dependent manner with an IC50 of 3.67 μM as compared to donepezil, which exhibited an IC50 of 1.37 μM. However, as domperidone is known to have poor BBB permeability, we rationally proposed new analogues utilizing the principles of bioisosterism. The bioisostere-clubbed analogues were found to have better BBB permeability, affinity, and stability within the catalytic domain of AChE via molecular docking and dynamics studies. The proposed bioisosteres may be synthesized in the future. They may plausibly be explored for their implication in the developmental progress of new anti-Alzheimer agent achieved via repurposing techniques in future.

Optimization of the Extraction Process of Bioactive Compounds from Zingiber officinale Roscoe, Evaluation of Acetylcholinesterase Enzyme Inhibition and Cytotoxic Activity of the Free and Encapsulated Extract

The present study optimized the extraction process of bioactive compounds present in ginger (Zingiber officinale) dried at 80 °C, using ethanol:water 70:30 (v/v) as solvent. The extracts were evaluated for antioxidant activity by the 2,2’-azino-bis(3-ethylbenzothiazoline6-sulfonic acid (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical reduction methods and by the chelating activity of FeII ions. It was found that the extraction condition with a temperature of 60 °C and an extraction time of 12 h showed better responses to the tests. Then, the characterization of the compounds was carried out by mass spectrometry and thermal analysis (thermogravimetric (TG), differential thermal analysis (DTA), and differential scanning calorimetry (DSC)), identifying that the main compounds of ginger were gingerols and shogaols, being confirmed by the intensities and characteristics of the thermal graphs. The inhibition of the enzyme acetylcholinesterase (AChE) was evaluated using the Ellman test, which did not show an inhibitory action. Regarding cytotoxic activity, the free extract and encapsulated in liposomes were tested, showing antiproliferative effect at different concentrations for human kidney tumor cells (786-0), liver cells (HUH7.5), and Macaca mullata normal kidney cells (LLC-MK2). Given the results obtained, ginger presents itself as a renewable source of bioactive compounds and can be indicated for applications in the pharmaceutical industry

Larvicidal Activity of Ethanol Extract of Cinnamomum sintoc Blume Bark against Aedes aegypti: Role of the Extract as an Acetylcholinesterase Enzyme Inhibitor

The display ponders evaluated the larvicidal exercises of ethanol bark extricates of Cinnamomum sintoc BI against the third instar hatchlings of Aedes aegypti. For superior understanding, this show ponders moreover examined the instrument of plant extricates against the hatchlings through in silico examination. Larvicidal exercises of plant extricate were considered within the extent of 0.01 to 0.1% and two control bunch with aquades and temephos within the research facility bioassays against early third instar hatchlings of A. aegypti. The mortality was checked and subjected to probit investigation to decide the deadly concentrations (LC50 and LC90) to murder 50 and 90% of the treated hatchlings of the particular species. Also, to examine the instrument, four dynamic compounds within the plant extricate with the most noteworthy substance analyzed in silico with the acetylcholinesterase protein in A. aegypti. The appears about appear expanding the concentration will increment the passing of the hatchlings and the viability of the extricate is found to be superior to temephos. The comes about of in silico investigation appeared that the two dynamic compounds in plant extricates, specifically α-copaene and γ-muurolene have a component of activity comparable to temephos. Both of these compounds work as inhibitors of acetylcholinesterase chemicals. Our information recommends that the bark ethanol extricate of C. sintoc BI have the potential to be utilized as a larvicidal operator for the control of the A. aegypti.

In-vitro and in-silico cholinesterase inhibitory activity of bioactive molecules isolated from the leaves of Andrographis nallamalayana J.L. Ellis and roots of Andrographis beddomei C.B. Clarke

Cholinesterase inhibitors remain the best therapeutic strategies to treat Alzheimer's disease. In search for the potent and long-acting cholinesterase (AChE/BChE) inhibitors, we studied the inhibitory activities of three species of Andrographis genus viz, Andrographis paniculata (Burm.f.) Nees Andrographis nallamalayana J.L. Ellis , and Andrographis beddomei C.B. Clarke. It was demonstrated that the methanolic extract of these plants was able to inhibit acetylcholinesterase and butyrylcholinesterase. Furthermore, the phytochemical investigation led to the isolation of 11 known compounds. Echioidinin (1), skullcapflavone I (2), 5,2′,6′-trihydroxy-7-methoxyflavone (3), 5.,2′,6′-trihydroxy-7-methoxyflavone 2′-O-β-D-glucopyranoside (4), and chrysin 7-glucuronide (5) were isolated from leaves of A. nallamalayana whereas 7-O-methylwogonin (9), wogonin (10), viscidulin II (11), andrographidine C (12), andrographidine G (13), 5,8,2′-trihydroxy-7-methoxyflavone-5-O-ß-D glucopyranoside (14) were isolated from roots of A. beddomei. Their structures were elucidated by 1H, 13CNMR spectra, mass spectrometry, and X-ray single crystal diffraction experiments. The SC-XRD and Hirshfeld Surface analysis of eight flavonoids (Compound 1, 2, 4, 6, 9, 11, 12, 13 and positive control drug galantamine hydrobromide is reported for the first time. Compound 6, 4, 10, 9 were potent inhibitors of acetylcholinesterase enzyme with IC50 values of 1.86 ± 0.139 μM, 3.37 ± 0.086 μM, 6.38 ± 0.098 μM, 9.11 ± 0.116 μM respectively. Compound 6 was more potent than the positive control, galantamine (IC50 = 4.68 ± 0.032 μM). All these compounds showed moderate to weak inhibitory activity against BChE. In addition, molecular docking studies were performed to explore the binding mode of the compounds, and the results were in good agreement with the experimental results. These results clearly indicate the potential of these compounds as powerful lead molecules for further investigations.

Antioxidant, AChE inhibitory, and anticancer effects of Verbascum thapsus extract.

Verbascum thapsus (VT) is a medicinal plant that is used in folk medicine to treat a variety of ailments. For this study, the biological functions of VT methanol extract were determined in vitro. The plant's methanol extract was created through the maceration process. The phytochemical composition of plant extracts was investigated using liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). The antioxidant capacity of the extract was determined using the DPPH (2,2-diphenyl-1-picrylhydrazil) and ABTS (2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) tests and its cytotoxicity was assessed using the MTT ((3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, a tetrazole)) assay on the Caco-2 (human colorectal adenocarcinoma cells), LNCaP (Lymph Node Carcinoma of the Prostate), and HEK293 cell lines (Human embryonic kidney 293 cells) used to model colon, prostate, and non-cancerous cells. VT extract showed low DPPH and ABTS radical scavenging activities compared to standard antioxidants at 30 mg/ml concentration. In addition, it was determined that VT extract inhibited acetylcholinesterase enzyme.

Hesperidin counteracts chlorpyrifos-induced neurotoxicity by regulating oxidative stress, inflammation, and apoptosis in rats.

Chlorpyrifos (CPF), considered one of the most potent organophosphates, causes a variety of human disorders including neurotoxicity. The current study was designed to evaluate the efficacy of hesperidin (HSP) in ameliorating CPF-induced neurotoxicity in rats. In the study, rats were treated with HSP (orally, 50 and 100mg/kg) 30min after giving CPF (orally, 6.75mg/kg) for 28 consecutive days. Molecular, biochemical, and histological methods were used to investigate cholinergic enzymes, oxidative stress, inflammation, and apoptosis in the brain tissue. CPF intoxication resulted in inhibition of acetylcholinesterase (AChE) and butrylcholinesterase (BChE) enzymes, reduced antioxidant status [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione (GSH)], and elevation of malondialdehyde (MDA) levels and carbonic anhydrase (CA) activities. CPF increased histopathological changes and immunohistochemical expressions of 8-OHdG in brain tissue. CPF also increased levels of glial fibrillary acidic protein (GFAP) and nuclear factor kappa B (NF-κB) while decreased levels of nuclear factor erythroid 2-related factor 2 (Nrf-2), heme oxygenase-1 (HO-1) and peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α). Furthermore, CPF increased mRNA transcript levels of caspase-3, Bax, PARP-1, and VEGF, which are associated with apoptosis and endothelial damage in rat brain tissues. HSP treatment was found to protect brain tissue by reducing CPF-induced neurotoxicity. Overall, this study supports that HSP can be used to reduce CPF-induced neurotoxicity.

Design, synthesis, in vitro acetylcholinesterase, butyrylcholinesterase activities, and in silico molecular docking study of oxindole-oxadiazole hybrid analogues

Alzheimer's disease is a neurological disorder characterized by cognitive dysfunction and deficits in activities of daily living. There is no drug available for Alzheimer's at the moment, and the inhibition of acetylcholinesterase and butyrylcholinesterase enzymes are a good target to treat Alzheimer's disease. In this study, a series of new oxindole-oxadiazole hybrid analogues (1–18) have been synthesized and evaluated for acetylcholinesterase and butyrylcholinesterase inhibitory activities. All compounds showed a varied degree of inhibition, ranging from 0.80 ± 0.20 to 12.50 ± 0.40 µM (against acetylcholinesterase) and 1.10 ± 0.20 to 20.30 ± 0.10 µM (against butyrylcholinesterase), as compared to the standard inhibitor donepezil (IC50 values of 2.16 ± 0.12 & 4.5 ± 0.11 µM, respectively). In the case of acetylcholinesterase, analogue 17 (IC50 = 0.80 ± 0.20 µM) while in case of butyrylcholinesterase, analogue 5 (IC50 = 1.10 ± 0.20 µM) was found the most potent among the whole series. Structure-activity relationship has been established for all compounds, which mainly depended upon the nature, number, position, and electron-donating or -withdrawing effect of the substituent(s) on the phenyl ring. A molecular docking study was carried out to investigate the interaction of the most potent compounds with the active site of enzymes. The stability of each drug-like hit in complex with acetylcholinesterase and butyrylcholinesterase was determined by computing their RMSD, RMSF analysis. Among all the compounds, compound 17 and compound 5 respectively, revealed a good interactions and stability during the entire simulation procedure.