Anticholinesterase Activity Research Articles

Investigation of the Anticholinesterase and Antioxidant Activity of Several Iranian Thymus caramanicus Populations

Background: Thymus extracts have become attractive targets for screening bioactive compounds with potential applications in pharmaceuticals, food, and cosmetics industries. Objectives: This is the first report assessing the anticholinesterase and antioxidant activities, along with total phenolic and flavonoid contents (TPC and TFC), of hydroethanolic extracts from six populations of Thymus caramanicus Jalas at vegetative and flowering stages, collected from different regions in Kerman province, Iran. Methods: The anticholinesterase and antioxidant activity, as well as TPC and TFC of T. caramanicus hydroethanolic extracts, were evaluated using Ellman, DPPH, Folin-Ciocalteu, and aluminum chloride assays, respectively. Results: All extracts inhibited both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) enzymes, with most showing a stronger effect on AChE. The extract T2-F exhibited the highest anti-AChE (IC50: 28.74 ± 0.21 µg/mL) and anti-BuChE (IC50: 65.49 ± 0.81 µg/mL) activities. The DPPH results indicated overall suitable antioxidant activity, with T4-F showing the highest antioxidant capacity (IC50: 16.22 ± 0.07 µg/mL), though about 4.2 times lower than ascorbic acid. The TPC (76.60 ± 0.98 - 211.73 ± 2.13 mg GAE/g extract) and TFC (19.15 ± 0.09 - 53.90 ± 0.13 mg QE/g extract) analyses revealed that T6-V and T5-F are rich sources of polyphenolic and flavonoid compounds. Pearson’s correlation analysis showed no direct correlation between TPC and TFC with their anticholinesterase and antioxidant activities. Conclusions: The hydroethanolic extracts of T. caramanicus demonstrated significant anticholinesterase and antioxidant activities, making them promising candidates for further studies aimed at developing therapeutic compounds with dual anticholinesterase and antioxidant properties, potentially for treating Alzheimer's disease (AD).

Synthesis of newly designed hydrazones, in vitro and in silico studies, and structure-activity relationship

Herein, new N'-(substituted benzylidene)-3,5-dihydroxybenzohydrazide (1–13) series were synthesized, and their antioxidant, anticholinesterase, anti-tyrosinase, anti-urease, and antidiabetic activities were investigated together with in silico studies. The synthesized derivates were characterized using molecular spectroscopy, and the structure-activity relationships (SAR) were discussed for all tested biological assays. According to activity results, compound 3 exhibited excellent antioxidant activity in all tests, while compound 1 demonstrated the best acetylcholinesterase (AChE) inhibitory and butyrylcholinesterase (BChE) inhibitory activities. On the other hand, compound 11 showed excellent tyrosinase inhibitory (IC50:3.02±0.10 mM) and urease inhibitory (IC50:9.21±0.27 µM) activity. Moreover, among the synthesized compounds, compound 6 was detected as the best antidiabetic compound by inhibiting α-amylase (IC50:30.68±0.94 µM) and α-glycosidase (IC50:41.35±0.03 µM) enzymes, which were related with the antidiabetic activity. Molecular docking analysis confirmed AChE, BChE, tyrosinase, urease, α-amylase, and α-glucosidase inhibitory activities. In line with the findings obtained from in vitro bioactivity results and molecular docking analysis, hydrazone compounds are a suitable class of organic compounds for developing acetylcholinesterase, butyrylcholinesterase, urease, α-amylase, and α-glucosidase inhibitors.

Anti-cholinesterase profile of Murraya koenigii (L.) Spreng essential oil and its chemical constituents

Traditionally, Murraya koenigii (L.) Spreng has been used as an ingredient in medicinal formulations. Several studies have reported on the potential of M. koenigii leaves to enhance learning and memory functions in animal models. This study aimed to identify the chemical constituents and evaluate the anti-cholinesterase activity of the essential oil extracted from M. koenigii leaves. The essential oil extracted via hydrodistillation was analyzed using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). A total of 41 constituents were identified, with β-phellandrene (35.42%), β-caryophyllene (16.79%) and α-pinene (17.75%) predominating in the essential oil. Using Ellman’s colorimetric method, the M. koenigii essential oil demonstrated potent inhibitory activity against acetylcholinesterase (AChE), with an IC50 value of 36.89 μg/mL. Interestingly, a mixture of the three major constituents (β-phellandrene, β-caryophyllene, and α-pinene) was more effective than the individual constituents (β-caryophyllene and α-pinene). In conclusion, the study on the neuroprotective effects of M. koenigii essential oil has yielded promising results.

Conchocarpus J. C. Mikan (Rutaceae): Chemical Constituents and Biological Activities.

Rutaceae Juss. stands out as a botanical family recognized for its remarkable diversity in taxonomy, worldwide distribution, chemical composition, and biological activity exhibited by its compounds. Conchocarpus J. C. Mikan is one of the main genera of this family, comprising 50 species distributed throughout the Neotropical America. Brazil is the main center of diversity for this genus, hosting 72% of the species as endemic. This is the first review concerning the genus Conchocarpus, emphasizing its chemical composition and biological activities. The selected papers for this review cover studies on 11 species, of which were identified 88 compounds. Among these, quinoline and acridone alkaloids predominate (57%), followed by flavonoids, amides, coumarins and terpenoids. The biological activities of extracts and compounds indicate trypanocidal and leishmanicidal actions, as well as cytotoxic, fungicidal, molluscicidal, insecticidal, anticholinesterase and antioxidant activities.

Holistic exploration of silver nanoparticles synthesized from Carthamus oxycantha leaf extracts: Characterization and assessment of antioxidant, anti-α-amylase, and anti-cholinesterase activities using comprehensive statistical methods

In the burgeoning field of nanotechnology, plant-mediated nanoparticles (NPs) have attracted significant attention due to their small size, favorable chemical properties, and eco-friendly nature. We utilized Carthamus oxycantha leaf extract to synthesize silver nanoparticles (AgNPs) and evaluate their potential as antioxidants and inhibitors of acetylcholinesterase (AChE) and alpha-amylase (α-amylase). The AgNPs were characterized using advanced techniques. The UV–Vis spectrum recorded at 410 nm, with an absorbance of 2.3 a.u., confirmed the presence of AgNPs. Fourier transform infrared spectroscopy (FT-IR) indicated that functional groups from the extract were attached to the AgNP surface, aiding in their formation and stabilization. X-ray diffraction analysis (XRD) revealed four major peaks at 37, 43, 64, and 77, confirming AgNP synthesis. Scanning electron microscopy (SEM) showed that 80 % of the AgNPs were spherical, measuring 25–50 nm, while energy dispersive X-ray (EDX) analysis indicated that silver constituted 83 % of the material. The AgNPs demonstrated significant scavenging activity: 59.3 % with ABTS, 67.2 % with ammonium molybdate, 60.35 % with DPPH, 65.2 % with ferric chloride, and 55.2 % with H2O2. Both α-amylase and AChE were inhibited by AgNPs, exhibiting uncompetitive inhibition characteristics. For glucophage, Km decreased from 143 to 75 µg, and Vmax decreased from 45 % to 72 % as concentrations increased from 50 to 150 µg. The Km of AgNPs decreased from 25 to 17 µg, and Vmax decreased from 16 % to 37 %. The extract showed noncompetitive inhibition against α-amylase, while AgNPs caused noncompetitive inhibition in AChE. These findings highlight the potential of AgNPs as therapeutic agents for managing oxidative stress and enzyme-related disorders, paving the way for future research and applications in medicinal chemistry.

LC-MS and GC-MS Analyses on Green Algae Penicillus Capitatus: Cytotoxic, Antimicrobial and Anticholinesterase Activity Screening Enhanced by Molecular Docking & Dynamics and ADME Studies.

In this comprehensive screening study, the chemical composition, and cytotoxic, antimicrobial, and anticholinergic activities of the green algae Penicillus capitatus, collected from Antalya-Türkiye, were determined as in vitro and in silico. GC-MS analysis of the hexane extract revealed a high content of fatty acids, with hexadecanoic acid constituting half of the total fatty acid content. LC-HRMS analysis of the DCM:MeOH extract identified ascorbic acid as the most abundant compound, followed by (-)-epigallocatechin and salicylic acid. The DCM:MeOH extract exhibited potent cytotoxicity against MDA-MB-231 and MCF7 breast cancer cell lines, outperforming doxorubicin with lower IC50 values and a higher selectivity index. Additionally, the extract demonstrated significant antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans, along with selective inhibition of acetylcholinesterase (hAChE) over butyrylcholinesterase (hBChE). Molecular docking and dynamics studies revealed that apigenin-7-O-glucoside and epigallocatechin form stable interactions with estrogen receptor alpha (ERα) and hAChE, suggesting their potential as inhibitors. In silico ADME studies indicated favorable pharmacokinetic profiles for the detected compounds, supporting their potential as drug candidates. The promising cytotoxic activity of the P. capitatus extracts, coupled with significant antimicrobial properties and selective hAChE inhibition, highlights their therapeutic potential for breast cancer treatment, infection management, and neurodegenerative disease intervention.

Design, Synthesis and Cholinesterase Inhibitory Activity of Novel 1,3,4-Thiadiazole Derivatives

Inhibition of the cholinesterases (AChE and BChE) plays a pivotal role in the symptomatic treatment of Alzheimer’s disease. The present study reports the synthesis and anticholinesterase activity of five novel thiadiazole analogs in search of anti-Alzheimer agents. The structures of the newly synthesized compounds were characterized using 1H NMR, 13C NMR and HRMS. Tested compounds inhibited acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes with IC50 values in the range of 8.250-20.382 μM and 14.143-0.986 μM, respectively. N-(4-Chlorophenyl)-2-[(5-(allylamino)-1,3,4-thiadiazol-2-yl)thio]-N-(3-nitrobenzyl)acetamide (6e) was determined as the most potent inhibitor against both tested enzymes when compared with standard drug tacrine. Molecular docking study was carried out to reveal the binding interactions between compound 6e and the active site of AChE

Design, Synthesis, Anticholinesterase and Antidiabetic Inhibitory Activities, and Molecular Docking of Novel Fluorinated Sulfonyl Hydrazones.

In this study, it was aimed to synthesize (E)-N'-(2-hydroxybenzylidene)-substituted benzenesulfonohydrazide (1-7) from the 2-hydroxybenzaldehyde reaction of different substituted fluorinated sulfonyl hydrazides. The structures of the synthesized molecules were characterized by elemental analysis, FTIR, 1H NMR, 13C NMR, 19F NMR, and 2D NMR (HMBC, correlation spectroscopy, and HQSC). The anticholinesterase (AChE and BChE) and antidiabetic (α-glucosidase, α-amylase) inhibition activities of the synthesized compounds were evaluated. According to biological activity test results, (E)-N'-(2-hydroxybenzylidene)-4-(trifluoromethoxy)benzenesulfonohydrazide (compound 7 among hydrazone derivatives 1-7) demonstrated better BChE inhibitor activity than galantamine in anticholinesterase inhibition; and in the α-glucosidase and α-amylase assay, it exhibited more antidiabetic inhibition activity than the reference standard.

Mistletoe (Loranthus europaeus Jacq.): antioxidant, antimicrobial and anticholinesterase activities

Plants are natural resources responsible for different biological activities. Determining the biological activities of plants is very important. In our study, some biological activities and total phenolic and flavonoid contents of Loranthus europaeus Jacq. were determined. In this context, ethanol and methanol extracts of the plant were obtained using the soxhlet device. Total antioxidant, total oxidant, and oxidative stress statuses were determined using Rel Assay kits. Antimicrobial activity was tested against standard bacterial and fungal strains using the agar dilution test. Anticholinesterase activity was determined by detecting acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities. Determination of total phenolic content was determined using the Folin-Ciocalteu reagent. Total flavonoid quantification was performed using an aluminum chloride assay. As a result of the study, TAS values (Total antioxidant status) of ethanol and methanol extracts of the plant were determined as 5.620±0.134 and 6.384±0.134 mmol/L, respectively. TOS values (Total oxidant status) were determined as 10.997±0.183 and 13.368±0.222 µmol/L, respectively. OSI values (Oxidative stress index) were measured as 0.196±0.004 and 0.209±0.003, respectively. TPC (Total phenolic content) value was determined as 34.49±1.78 and 55.82±2.34 mg/g, respectively, and TFC (Total flavonoid content) value was determined as 46.10±2.40 and 55.49±1.15 mg/g, respectively. Ethanol and methanol extracts of the plant were found to be effective against bacterial and fungal strains at concentrations between 50-200 µg/mL. In addition, the anti-AChE values of ethanol and methanol extracts were determined as 13.51±0.81 and 22.79±1.86 µg/mL, respectively, and the anti-BChE values were determined as 27.84±0.62 and 33.08±1.63 µg/mL, respectively. According to the results obtained, it was determined that L. europaeus has antioxidant, antimicrobial, and anticholinesterase activity. In this context, it is thought that it can be used as a natural material in pharmacological designs.

A Compressive Review on Source, Toxicity and Biological Activity of Flavonoid.

Flavonoids are biologically active chemicals in various fruits, plants, vegetables, and leaves, which have promising uses in medicinal science. The health properties of these natural chemicals are widely accepted, and efforts are underway to extract the specific components referred to as flavonoids. Flavonoids demonstrate a diverse range of bio-activities, anticancer, antioxidant activity, anti-cholinesterase activity, antiinflammatory activity, antimalarial activity, antidiabetic activity, neurodegenerative disease, cardiovascular effect, hepatoprotective effects, and antiviral and antimicrobial activity. This study aims to examine the prevailing trends in flavonoid investigation studies, elucidate the activity of flavonoids, examine their various functions and uses, assess the potential of flavonoids as preventive medications for chronic diseases, and outline future research opportunities in this field. This review explores the diverse functions of flavonoids in preventing and managing various diseases.

Polyphenols Investigation and Antioxidant and Anticholinesterase Activities of Rosmarinus officinalis L. Species from Southwest Romania Flora.

Rosemary is one of the most important medicinal plants for natural therapy due to its multiple pharmacological properties, such as antioxidant, anti-inflammatory, neuroprotective, antiproliferative, antitumor, hepato- and nephroprotective, hypolipidemic, hypocholesterolemic, antihypertensive, anti-ischemic, hypoglycemic, radioprotective, antimicrobial, antiviral, antiallergic, and wound healing properties. Our study reports for the first time, over a 12-month period, the identification and quantification of polyphenols and the investigation of the antioxidant and acetylcholinesterase (AChE) inhibitory activities of the Rosmarinus officinalis L. species harvested at flowering from the flora of southwestern Romania (Oltenia Region). Identification and quantification of polyphenolic acids was made by ultra-high-performance liquid chromatography/mass spectrometry (UHPLC/MS). Total phenolic content was determined using the spectrophotometric method. In situ antioxidant and anticholinesterase activities were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and AChE inhibitory assay, respectively, on high-performance thin-layer chromatography (HPTLC) plates. DPPH radical scavenging activity was also assessed spectrophotometrically. The results revealed significant correlations between specific polyphenolic compounds and the measured biological activities, understanding the role of seasonal variations and providing insights into the optimal harvesting times and medicinal benefits of rosemary. Our research brings new information on the phytochemical profile of R. officinalis as a natural source of polyphenols with antioxidant and AChE inhibitory properties.

Rooted in therapeutics: comprehensive analyses of Cannabis sativa root extracts reveals potent antioxidant, anti-inflammatory, and bactericidal properties.

Following the legalization of recreational Cannabis in Canada in 2018, the associated waste, including Cannabis roots, has significantly increased. Cannabis roots, comprising 30%-50% of the total plant, are often discarded despite their historical use in Ayurvedic medicine for treating inflammatory and infectious disorders. This study evaluates the phytochemical and therapeutic properties of Cannabis root extracts from a high tetrahydrocannabinolic acid, low cannabidiolic acid cultivar (variety Alien Gorilla Glue). We performed ultra high-performance liquid chromatography coupled with mass spectrometry (UPLC-QTOF-MS) to identify the chemical components of the Cannabis roots. Extracts using water, ethanol and acid-base solvents were tested for antioxidant activity through free radical scavenging, metal chelation, and lipoperoxidation inhibition assays. Mitochondrial membrane protection was assessed using flow cytometry with the MitoPerOx probe in THP-1 monocytic leukemia cells. Anti-inflammatory potential was evaluated by measuring interleukin-6 levels in lipopolysaccharide-stimulated THP-1 cells. Bactericidal/fungicidal efficacy against Escherichia coli, Staphylococcus aureus, and Candida albicans was determined using the p-iodonitrophenyltetrazolium assay. Additionally, we investigated the anticholinesterase activity of Cannabis root extracts, given the potential role of plant alkaloids in inhibiting cholinesterase, an enzyme targeted in Alzheimer's disease treatments. UPLC-QTOF-MS analysis suggested the presence of several phenolic compounds, cannabinoids, terpenoids, amino acids, and nitrogen-containing compounds. Our results indicated significant antioxidant, bactericidal, and anticholinesterase properties of Cannabis root extracts from both soil and hydroponic cultivation. Extracts showed strong antioxidant activity across multiple assays, protected mitochondrial membrane in THP-1 cells, and exhibited anti-inflammatory and bactericidal/fungicidal efficacy. Notably, soil-cultivated roots displayed superior anti-inflammatory effects. These findings demonstrate the remarkable antioxidant, anti-inflammatory, and anti-microbial activities of Cannabis roots, supporting their traditional uses and challenging their perception as mere waste. This study highlights the therapeutic potential of Cannabis roots extracts and suggests avenues for further research and application.

Some heterocycles connected to substituted piperazine by 1,3,4-oxadiazole linker: Design, synthesis, anticholinesterase and antioxidant activity

AD is a multifactorial neurodegenerative disease that has caused morbidity and mortality on a global scale. Currently, there are only a few drugs used in the treatment of AD. Although many compounds that aim at new targets have reached clinical trials, none have been approved. However, discovering efficient drugs for AD treatment is one of the biggest challenges for pharmaceutical research and requires strong support. In this paper, we aim to design a series of indole, benzothiophene, and thiophene bearing 1,3,4-oxadiazole linker to the piperazine basic center and evaluate for their antioxidant and inhibitory activity against both cholinesterase enzymes. Among the compounds, 6a, 7b, and 8b exhibited moderate cationic radical scavenging activities with IC50 values ranging from 20.39 to 30.10 μM. The inhibitory activity results revealed that compounds 5c (IC50 for AChE = 53.91 μM and for BChE = 55.81 μM) and 6c (IC50 for AChE = 54.42 μM and BChE = 45.82 μM) bearing 2-fluorophenyl piperazine moiety showed both AChE and BChE inhibition with moderate IC50 values. To explore the binding properties of the target compounds into the active site of the enzyme, a molecular docking study was carried out using MOE software. The docking study showed that compound 6c targeted both the catalytic active site (CAS) and the peripheral anionic site (PAS) of AChE/BChE and formed important interactions with key residues. Moreover, theoretical physicochemical properties of the best active compound 6c were calculated by the SwissADME web service. It obeyed Lipinski's rule of five and had high GI absorption (gastrointestinal absorption) and good permeating to the blood-brain barrier (BBB). The compound 6c can be considered a promising compound and provides us directions for further research of anti-AD agent development.

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.

Multi-modal neuroprotection of Argemone mexicana L. against Alzheimer’s disease: In vitro and in silico study

Argemone mexicana L. is a medicinal plant, but its impact on Alzheimer's disease (AD) is right now undetermined. We intended to investigate the in-vitro anti-AD potential of leaves and flowers of A. mexicana methanol, ethanol, and ethyl extracts and to identify multi-modal anti-AD phytochemicals by computational approaches. Molecular docking of 196 phytochemicals identified three hit phytochemicals (protoberberine, protopine, and codeine) with higher binding affinity and multi-targeting ability toward AChE, BChE, BACE-1, and GSK-3β. Further MM-GBSA assays confirmed the integrity of these phytochemicals as the hit phytochemicals. However, these phytochemicals demonstrated favorable pharmacokinetics (PK) and drugable properties having no toxicity. Molecular dynamics simulations confirmed the binding strength of the hit phytoconstituents in the active pockets of AChE, BChE, BACE-1, and GSK-3β with multi-targeting inhibitory activities. All the extracts exhibited dose-dependent antioxidant and anti-cholinesterase activities supporting the insilico results in the context of oxidative stress and cholinergic pathways. Our results offer scientific validation of the anti-AD properties of Argemone mexicana L. and identified protoberberine, protopine, and codeine that could be used for the development of multi-modal inhibitors of AChE, BChE, BACE-1, and GSK-3β to combat AD. Additional in vivo validation is recommended to ensure a thorough assessment in the present research.

Metabolites profiling, in-vitro and molecular docking studies of five legume seeds for Alzheimer’s disease

Even though legumes are valuable medicinal plants with edible seeds that are extensively consumed worldwide, there is little information available on the metabolic variations between different dietary beans and their influence as potential anti-cholinesterase agents. High-resolution liquid chromatography coupled with mass spectrometry in positive and negative ionization modes combined with multivariate analysis were used to explore differences in the metabolic profiles of five commonly edible seeds, fava bean, black-eyed pea, kidney bean, red lentil, and chickpea. A total of 139 metabolites from various classes were identified including saponins, alkaloids, phenolic acids, iridoids, and terpenes. Chickpea showed the highest antioxidant and anti-cholinesterase effects, followed by kidney beans. Supervised and unsupervised chemometric analysis determined that species could be distinguished by their different discriminatory metabolites. The major metabolic pathways in legumes were also studied. Glycerophospholipid metabolism was the most significantly enriched KEGG pathway. Pearson’s correlation analysis pinpointed 18 metabolites that were positively correlated with the anti-cholinesterase activity. Molecular docking of the biomarkers to the active sites of acetyl- and butyryl-cholinesterase enzymes revealed promising binding scores, validating the correlation results. The present study will add to the metabolomic analysis of legumes and their nutritional value and advocate their inclusion in anti-Alzheimer’s formulations.

Optimization of bioactivities of solvent extracts of bark and heartwood of Pterocarpus marsupium and exploration of neuroprotective effect linking to the major Phytoconstituents

The study aims to evaluate the neuroprotective properties of Pterocarpus marsupium Roxb. The bioactive optimized hydroalcohol-extracted fractions of bark (PMBHA) and heartwood (PMHHA) at 300 and 400 mg/kg were examined in rats with scopolamine-induced neurotoxicity to study oxidative, neurochemical, and neuroinflammation biomarkers. Phenol and flavonoid-rich radical scavengers in contributing total antioxidant capacities of PMBHA and PMHHA quenched peroxyl radicals and protected the cellular membrane and lipoproteins from ROS in DPPH, ORAC, and CAP-e tests. In anticholinesterase activities, PMBHA inhibited AChE (IC50: 54.40 ± 0.98 µg/mL) and BChE (IC50: 50.95 ± 0.98 µg/mL) mixed-competitively, while PMHHA inhibited cholinesterase activities (AChE: 42.23 ± 0.54, and BChE: 47.19 ± 0.65 µg/mL) competitively. Dosage at 300 and 400 mg/kg of PMBHA and PMHHA improved serum and brain oxidative indicators (MDA, SOD, CAT, and GSH), and restored proinflammatory cytokines (TNF-α, and IL-6) leading to enhanced brain cholinesterase and β-secretase levels in neurotoxic rats. GC-MS reported antioxidant, anti-inflammatory, and neuroprotective compounds of PMBHA catechol, thiamet-G, d-Gala-l-ido-octonic amide, falcarinol, D-mannose, ribitol, 1,2,4-cyclopentanetrione, 3-(2-pentenyl)-, hexadecanoic acid methyl ester, n-hexadecanoic acid, oleic acid, and 3,5-Dimethoxybenzyl alcohol, α-epi-7-epi-5-Eudesmol, 1 R,4aR,7 R,8aR)-7-(2-Hydroxypropan-2-yl)-1,4a-dimethyldecahydro naphthalen-1-ol, arctiol, 1,1,4,7-tetramethyldecahydro-1 H-cyclopropa[e]azulene-4,7-diol, 2-Propen-1-ol, 3-(2,6,6-trimethyl-1-cyclohexen-1-yl), 4-t-Butyl-2-[4-nitrophenyl]phenol in PMHHA were responsible in neuroprotection in neurotoxic rats. However, heartwood demonstrated better neuroprotective activities than the bark of P. marsupium due to some of the key compounds (1 R,4aR,7 R,8aR)-7-(2-Hydroxypropan-2-yl)-1,4a-dimethyldecahydronaphthalen-1-ol, 2-Propen-1-ol, 3-(2,6,6-trimethyl-1-cyclohexen-1-yl)-, 4-t-Butyl-2-[4-nitrophenyl]phenol, 1,1,4,7-Tetramethyldecahydro-1 H-cyclopropa[e]azulene-4,7-diol.

Synthesis and biological evaluation of novel aminoquinolines with an n-octyl linker: Impact of halogen substituents on C(7) or a terminal amino group on anticholinesterase and BACE1 activity

Alzheimer’s disease is age-related multifactorial neurodegenerative disease manifested by gradual loss of memory, cognitive decline and changes in personality. Due to rapid and continuous growth of its prevalence, the treatment of Alzheimer’s disease calls for development of new and efficacies drugs, especially those that could be able to simultaneously act on more than one of possible targets of action. Aminoquinolines have proven to be a highly promising structural scaffold in the design of such a drug as cholinesterases and β-secretase 1 inhibitors. In this study, we synthesised twenty-two new 4-aminoquinolines with different halogen atom and its position in the terminal N-benzyl group or with a trifluoromethyl or a chlorine as C(7)-substituents on the quinoline moiety. All compounds were evaluated as multi-target-directedligands by determining their inhibition potency towards human acetylcholinesterase, butyrylcholinesterase and β-secretase 1. All of the tested derivatives were very potent inhibitors of human acetylcholinesterase and butyrylcholinesterase with inhibition constants (Ki) in the nM to low μM range. Most were estimated to be able to cross the blood–brain barrier by passive transport and were nontoxic toward cells that represented the main models of individual organs.

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.

Design, Synthesis, and Biological Evaluation of Ferulic Acid-Piperazine Derivatives Targeting Pathological Hallmarks of Alzheimer's Disease.

Alzheimer's disease (AD) is the most prevalent cause of dementia and is characterized by low levels of acetyl and butyrylcholine, increased oxidative stress, inflammation, accumulation of metals, and aggregations of Aβ and tau proteins. Current treatments for AD provide only symptomatic relief without impacting the pathological hallmarks of the disease. In our ongoing efforts to develop naturally inspired novel multitarget molecules for AD, through extensive medicinal chemistry efforts, we have developed 13a, harboring the key functional groups to provide not only symptomatic relief but also targeting oxidative stress, able to chelate iron, inhibiting NLRP3, and Aβ1-42 aggregation in various AD models. 13a exhibited promising anticholinesterase activity against AChE (IC50 = 0.59 ± 0.19 μM) and BChE (IC50 = 5.02 ± 0.14 μM) with excellent antioxidant properties in DPPH assay (IC50 = 5.88 ± 0.21 μM) over ferulic acid (56.49 ± 0.62 μM). The molecular docking and dynamic simulations further corroborated the enzyme inhibition studies and confirmed the stability of these complexes. Importantly, in the PAMPA-BBB assay, 13a turned out to be a promising molecule that can efficiently cross the blood-brain barrier. Notably, 13a also exhibited iron-chelating properties. Furthermore, 13a effectively inhibited self- and metal-induced Aβ1-42 aggregation. It is worth mentioning that 13a demonstrated no symptom of cytotoxicity up to 30 μM concentration in PC-12 cells. Additionally, 13a inhibited the NLRP3 inflammasome and mitigated mitochondrial-induced reactive oxygen species and mitochondrial membrane potential damage triggered by LPS and ATP in HMC-3 cells. 13a could effectively reduce mitochondrial and cellular reactive oxygen species (ROS) in the Drosophila model of AD. Finally, 13a was found to be efficacious in reversing memory impairment in a scopolamine-induced AD mouse model in the in vivo studies. In ex vivo assessments, 13a notably modulates the levels of superoxide, catalase, and malondialdehyde along with AChE and BChE. These findings revealed that 13a holds promise as a potential candidate for further development in AD management.