Synthesis of novel hybrids of 1,2,3-triazoles-hydrazone: targeting cholinesterases and Alzheimer's related genes.

Aim: A new series of 1,2,3-triazole-hydrazone derivatives were developed to evaluate their anti-Alzheimer's activity. Materials & methods: All compounds were screened toward cholinesterases via the modified Ellman's method. The toxicity assay on SH-SY5Y cells was performed using the MTT assay, and the expression levels of GSK-3α, GSK-3ß, DYRK1 and CDK5 were assessed in the presence of compounds 6m and 6p.Results:6m and 6p; acting as mixed-type inhibitors, exhibited promising acetylcholinesterase and butyrylcholinesterase inhibitory activity, respectively. 6m demonstrated no toxicity under tested concentrations on the SH-SY5Y cells and positively impacted neurodegenerative pathways. Notably, 6m displayed a significant downregulation in mRNA levels of GSK-3α, GSK-3ß and CDK5.Conclusion: The target compounds could be considered in developing anti-Alzheimer's disease agents.

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In vitro anti-HSV1 activity of aqueous extract of Areca catechu L.

Background and Objectives: HSV-1 is known as a very contagious virus and the main cause of cold sores or fever blisters. Herein, the aqueous extract of Areca catechu L. was evaluated for its anti-HSV-1 activity, compared to the standard control (acyclovir). Also, the effect of extract on the expression of UL46 and US6 genes that accumulate late in viral infection, was studied. Materials and Methods: The aqueous extract was obtained by the maceration of powdered plant in boiling water. Its antiviral activity was evaluated on Vero cells infected with HSV-1 at different times: 2 h pre-infection, simultaneous infection, and 4 h post-infection, using MTT assay. The effect of extract on the expression of genes was investigated with quantitative real-time PCR. Results: The aqueous extract of A. catechu induced the inhibition of infection with the IC50 value of 110.52 ± 1.36 µg/ml. Also, it reduced the expression of UL46 when it was added 2 h pre-infection at 100 µg/ml. Moreover, reduction of expression of US6 was observed at the same concentration when the extract was used simultaneously with the occurrence of infection and 4 h post-infection. Conclusion: A. catechu can be considered an essential element of natural-based anti-HSV-1 agents.

Novel N'-substituted benzylidene benzohydrazides linked to 1,2,3-triazoles: potent α-glucosidase inhibitors.

Herein, various N'-substituted benzylidene benzohydrazide-1,2,3-triazoles were designed, synthesized, and screened for their inhibitory activity toward α-glucosidase. The structure of derivatives was confirmed using 1H- and 13C-NMR, FTIR, Mass spectrometry, and elemental analysis. All derivatives exhibited good inhibition with IC50 values in the range of 0.01 to 648.90 µM, compared with acarbose as the positive control (IC50 = 752.10 µM). Among them, compounds 7a and 7h showed significant potency with IC50 values of 0.02 and 0.01 µM, respectively. The kinetic study revealed that they are noncompetitive inhibitors toward α-glucosidase. Also, fluorescence quenching was used to investigate the interaction of three inhibitors 7a, 7d, and 7h, with α-glucosidase. Accordingly, the binding constants, the number of binding sites, and values of thermodynamic parameters were determined for the interaction of candidate compounds toward the enzyme. Finally, the in silico cavity detection plus molecular docking was performed to find the allosteric site and key interactions between synthesized compounds and the target enzyme.

Cedrus deodara: In Vivo Investigation of Burn Wound Healing Properties.

Objective: Cedrus deodara (Roxb. Ex Lamb.) G. Don possesses various biological activities, which have been documented in modern and traditional medicine. In this study, burn wound healing activity of the methanol extract of C. deodara wood was evaluated via a burn wound model in Wistar rats. Methods: The methanol extract of C. deodara was evaluated for the contents of phenolic compounds, flavonoids, and tannins. Also, its antioxidant activity was determined using the DPPH assay. Then, a topical ointment containing the methanol extract of C. deodara (10%) was used to evaluate the healing effects on a model of second-degree thermal burn in 4 groups of 7 rats within 21 days. In this respect, average wound surface area, wound closure, and various histological features were examined. Results: Our findings revealed that the wounds treated with the methanol extract of C. deodara showed higher wound contraction (33.6, 87.1, and 93.4% on days 7, 14, and 21, respectively) compared with the positive control (27.6, 80.7, and 88.3% on days 7, 14, and 21, respectively) and the negative control (20.1, 77.9, and 80.2% on days 7, 14, and 21, respectively). According to the results from epitheliogenesis score, the number of inflammatory cells, neovascularization, and collagen density, good burn wound healing activity of the methanol extract of C. deodarawas demonstrated. Conclusion: Using the methanol extract of C. deodara in an ointment formulation can be developed to prevent or reduce burn injury progression.

Quinazolinone-1,2,3-triazole-acetamide conjugates as potent α-glucosidase inhibitors: synthesis, enzyme inhibition, kinetic analysis, and molecular docking study.

In this study, new hybrids of quinazolinone-1,2,3-triazole-acetamide were designed, synthesized, and screened for their α-glucosidase inhibitory activity. The results obtained from the in vitro screening indicated that all analogs exhibited significant inhibitory activity against α-glucosidase (IC50 values ranging from 4.8-140.2 µM) in comparison to acarbose (IC50 = 750.0 µM). The limited structure-activity relationships suggested the variation in the inhibitory activities of the compounds affected by different substitutions on the aryl moiety. The enzyme kinetic studies of the most potent compound 9c, revealed that it inhibited α-glucosidase in a competitive mode with a K i value of 4.8 µM. In addition, molecular docking studies investigated the structural perturbation and behavior of all derivatives inside the α-glucosidase active site. Next, molecular dynamic simulations of the most potent compound 9c, were performed to study the behavior of the 9c-complex during the time. The results showed that these compounds can be considered as potential antidiabetic agents.

Phytochemical investigation and biological activity of Doronicum pardalianches L. roots against Alzheimer's disease.

The methanol extract of Doronicum pardalianches L. was fractionated using n-hexane, chloroform, and ethyl acetate to evaluate their cholinesterase (ChE) inhibitory activity via modified Ellman's method. It was perceived that only the ethyl acetate fraction was active toward acetylcholinesterase (AChE) with IC50 value of 172.21 µg/mL. Also, all fractions showed no butyrylcholinesterase (BChE) inhibitory activity. The ethyl acetate fraction was also investigated for its neuroprotectivity and metal chelating ability (Zn2+, Fe2+, and Cu2+) which demonstrated desired activity. Phytochemical analysis of the ethyl acetate fraction led to isolation and identification of formononetin 7-O-ß-D-glucopyranoside which has not been previously reported for this plant.

Cinnamomum verum J. Presl. Bark essential oil: in vitro investigation of anti-cholinesterase, anti-BACE1, and neuroprotective activity.

BACKGROUND: Cinnamomum verum J. Presl. (Lauraceae), Myrtus communis L. (Myrtaceae), Ruta graveolens L. (Rutaaceae), Anethum graveolens L. (Apiaceae), Myristica fragrans Houtt. (Myristicaceae), and Crocus sativus L. (Iridaceae) have been recommended for improvement of memory via inhalation, in Iranian Traditional Medicine (ITM). In this respect, the essential oils (EOs) from those plants were obtained and evaluated for cholinesterase (ChE) inhibitory activity as ChE inhibitors are the available drugs in the treatment of Alzheimer's disease (AD). METHODS: EOs obtained from the plants under investigation, were evaluated for their potential to inhibit acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) in vitro based on the modified Ellman's method. The most potent EO was candidate for the investigation of its beta-secretase 1 (BACE1) inhibitory activity and neuroprotectivity. RESULTS: Among all EOs, C. verum demonstrated the most potent activity toward AChE and BChE with IC50 values of 453.7 and 184.7 µg/mL, respectively. It also showed 62.64% and 41.79% inhibition against BACE1 at the concentration of 500 and 100 mg/mL, respectively. However, it depicted no neuroprotective potential against ß-amyloid (Aß)-induced neurotoxicity in PC12 cells. Also, identification of chemical composition of C. verum EO was achieved via gas chromatography-mass spectrometry (GC-MS) analysis and the major constituent; (E)-cinnamaldehyde, was detected as 68.23%. CONCLUSION: Potent BChE inhibitory activity of C. verum EO can be considered in the development of cinnamon based dietary supplements for the management of patients with advanced AD.

Ultrasound-assisted synthesis of kojic acid-1,2,3-triazole based dihydropyrano[3,2-b]pyran derivatives using Fe3O4@CQD@CuI as a novel nanomagnetic catalyst.

The magnetic nanoparticles coated with carbon quantum dot and copper (I) iodide (Fe3O4@CQD@CuI) were used as eco-friendly heterogeneous Lewis / Brønsted acid sites and Cu (I) nanocatalysts. In the first step, it was applied in the synthesis of kojic acid-based dihydropyrano[3,2-b]pyran derivatives in a three-component reaction and in the second step, as a recyclable catalyst for the synthesis of kojic acid-1,2,3-triazole based dihydropyrano[3,2-b]pyran derivatives in the CuI-catalyzed azide/alkyne cycloaddition (CuAAC) reaction. The catalyst was characterized fully by using the different techniques including fourier transform infrared spectroscopy (FT-IR), elemental mapping analysis, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), X-ray spectroscopy (EDX), transmission electron microscopy (TEM), thermal gravimetric (TG) and value-stream mapping (VSM) methods. The final synthesized derivatives were identified by 1H- and 13C-NMR spectroscopy.

Phytochemical analysis and anticholinesterase activity of aril of Myristica fragrans Houtt.

In this study, the ethyl acetate fraction of Myristica fragrans Houtt. was investigated for its in vitro anticholinesterase activity as well as neuroprotectivity against H2O2-induced cell death in PC12 neuronal cells and the ability to chelate bio-metals (Zn2+, Fe2+, and Cu2+). The fraction was inactive toward acetylcholinesterase (AChE); however, it inhibited the butyrylcholinesterase (BChE) with IC50 value of 68.16 µg/mL, compared with donepezil as the reference drug (IC50 = 1.97 µg/mL) via Ellman's method. It also showed good percentage of neuroprotection (86.28% at 100 µg/mL) against H2O2-induced neurotoxicity and moderate metal chelating ability toward Zn2+, Fe2+, and Cu2+. The phytochemical study led to isolation and identification of malabaricone A (1), malabaricone C (2), 4-(4-(3,4-dimethoxyphenyl)-2,3-dimethylbutyl)benzene-1,2-diol (3), nectandrin B (4), macelignan (5), and 4-(4-(benzo[d][1,3]dioxol-5-yl)-1-methoxy-2,3-dimethylbutyl)-2-methoxyphenol (6) which were assayed for their cholinesterase (ChE) inhibitory activity. Compounds 1 and 3 were not previously reported for M. fragrans. Among isolated compounds, compound 2 showed the best activity toward both AChE and BChE with IC50 values of 25.02 and 22.36 µM, respectively, compared with donepezil (0.07 and 4.73 µM, respectively).

Novel 3-aminobenzofuran derivatives as multifunctional agents for the treatment of Alzheimer's disease.

A novel multifunctional series of 3-aminobenzofuran derivatives 5a-p were designed and synthesized as potent inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). The target compounds 5a-p were prepared via a three-step reaction, starting from 2-hydroxy benzonitrile. In vitro anti-cholinesterase activity exhibited that most of the compounds had potent acetyl- and butyrylcholinesterase inhibitory activity. In particular, compound 5f containing 2-fluorobenzyl moiety showed the best inhibitory activity. Furthermore, this compound showed activity on self- and AChE-induced Aß-aggregation and MTT assay against PC12 cells. The kinetic study revealed that compound 5f showed mixed-type inhibition on AChE. Based on these results, compound 5f can be considered as a novel multifunctional structural unit against Alzheimer's disease.

Cyanoacetohydrazide linked to 1,2,3-triazole derivatives: a new class of α-glucosidase inhibitors.

In this work, a novel series of cyanoacetohydrazide linked to 1,2,3-triazoles (9a-n) were designed and synthesized to be evaluated for their anti-α-glucosidase activity, focusing on the fact that α-glucosidase inhibitors have played a significant role in the management of type 2 diabetes mellitus. All synthesized compounds except 9a exhibited excellent inhibitory potential, with IC50 values ranging from 1.00 ± 0.01 to 271.17 ± 0.30 µM when compared to the standard drug acarbose (IC50 = 754.1 ± 0.5 µM). The kinetic binding study indicated that the most active derivatives 9b (IC50 = 1.50 ± 0.01 µM) and 9e (IC50 = 1.00 ± 0.01 µM) behaved as the uncompetitive inhibitors of α-glucosidase with Ki = 0.43 and 0.24 µM, respectively. Moreover, fluorescence measurements were conducted to show conformational changes of the enzyme after binding of the most potent inhibitor (9e). Calculation of standard enthalpy (ΔHm°) and entropy (ΔSm°) values confirmed the construction of hydrophobic interactions between 9e and the enzyme. Also, docking studies indicated desired interactions with important residues of the enzyme which rationalized the in vitro results.

Novel tacrine-based acetylcholinesterase inhibitors as potential agents for the treatment of Alzheimer's disease: Quinolotacrine hybrids.

A new series of quinolotacrine hybrids including cyclopenta- and cyclohexa-quinolotacrine derivatives were designed, synthesized, and assessed as anti-cholinesterase (ChE) agents. The designed derivatives indicated higher inhibitory effect on the acetylcholinesterase (AChE) with IC50 values of 0.285-100 µM compared to butyrylcholinesterase (BChE) with IC50 values of > 100 µM. Of these compounds, cyclohexa-quinolotacrine hybrids displayed a little better anti-AChE activity than cyclopenta-quinolotacrine hybrids. Compound 8-amino-7-(3-hydroxyphenyl)-5,7,9,10,11,12-hexahydro-6H-pyrano[2,3-b:5,6-c'] diquinolin-6-one (6m) including 3-hydroxyphenyl and cyclohexane ring moieties exhibited the best AChE inhibitory activity with IC50 value of 0.285 µM. The kinetic and molecular docking studies indicated that compound 6m occupied both the catalytic anionic site (CAS) and peripheral anionic site (PAS) of AChE as a mixed inhibitor. Using neuroprotective assay against H2O2-induced cell death in PC12 cells, the compound 6h illustrated significant protection among the assessed compounds. In silico ADME studies estimated good drug-likeness for the designed compounds. As a result, these quinolotacrine hybrids can be very encouraging AChE inhibitors to treat Alzheimer's disease. A novel series of quinolotacrine hybrids were designed, synthesized, and evaluated against AChE and BChE enzymes as potential agents for the treatment of AD. The hybrids showed good to significant inhibitory activity against AChE (0.285-100 µM) compared to butyrylcholinesterase (BChE) with IC50 values of > 100 µM. Among them, compound 8-amino-7-(3-hydroxyphenyl)-5,7,9,10,11,12-hexahydro-6H-pyrano[2,3-b:5,6-c'] diquinolin-6-one (6 m) bearing 3-hydroxyphenyl moiety and cyclohexane ring exhibited the highest anti-AChE activity with IC50 value of 0.285 µM. The kinetic and molecular docking studies illustrated that compound 6 m is a mixed inhibitor and binds to both the catalytic anionic site (CAS) and peripheral anionic site (PAS) of AChE.

Phytochemical investigation and anticholinesterase activity of ethyl acetate fraction of Myristica fragrans Houtt. seeds.

In this work, n-hexane, chloroform, and ethyl acetate fractions of the methanol extract of Myristica fragrans Houtt. seeds were evaluated against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) via Ellman's method. It was found that all fractions depicted no anti-AChE activity, however, they were active toward BChE with IC50 values of 361.8, 215.0, and 145.8 µg/mL, respectively comparing with donepezil as the reference drug (IC50 = 1.97 µg/mL). The ethyl acetate fraction which also showed high neuroprotectivity and metal chelating ability was selected for the phytochemical analysis. Our results confirmed the presence of trimyristin and 5,7-diacetyl chrysin (reported for the first time in M. fragrans) in the corresponding fraction.

Synthesis and evaluation of novel arylisoxazoles linked to tacrine moiety: in vitro and in vivo biological activities against Alzheimer's disease.

Alzheimer's disease (AD) is now ranked as the third leading cause of death after heart disease and cancer. There is no definite cure for AD due to the multi-factorial nature of the disease, hence, multi-target-directed ligands (MTDLs) have attracted lots of attention. In this work, focusing on the efficient cholinesterase inhibitory activity of tacrine, design and synthesis of novel arylisoxazole-tacrine analogues was developed. In vitro acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibition assay confirmed high potency of the title compounds. Among them, compounds 7l and 7b demonstrated high activity toward AChE and BChE with IC50 values of 0.050 and 0.039 µM, respectively. Both compounds showed very good self-induced Aß aggregation and AChE-induced inhibitory activity (79.4 and 71.4% for compound 7l and 61.8 and 58.6% for compound 7b, respectively). Also, 7l showed good anti-BACE1 activity with IC50 value of 1.65 µM. The metal chelation test indicated the ability of compounds 7l and 7b to chelate biometals (Zn2+, Cu2+, and Fe2+). However, they showed no significant neuroprotectivity against Aß-induced damage in PC12 cells. Evaluation of in vitro hepatotoxicity revealed comparable toxicity of compounds 7l and 7b with tacrine. In vivo studies by Morris water maze (MWM) task demonstrated that compound 7l significantly reversed scopolamine-induced memory deficit in rats. Finally, molecular docking studies of compounds 7l and 7b confirmed establishment of desired interactions with the AChE, BChE, and BACE1 active sites.

Anti-Helicobacter pylori Compounds from Oliveria decumbens Vent. through Urease Inhibitory In-vitro and In-silico Studies.

Oliveria decumbens Vent. has been used by indigenous people of southwest Iran for treating peptic ulcers and gastrointestinal infections. This study aimed to investigate the antibacterial activity of Oliveria decumbens extract and fractions and to analyze the bioactive components of the fractions. Total plant extract and different fractions of Oliveria decumbens Vent. were prepared. Antibacterial activities were evaluated against the clinical strain of Helicobacter pylori and standard strains of Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, and Pseudomonas aeruginosa using agar dilution and disc diffusion methods. Phytochemical analysis of the fractions was performed using silica gel chromatography and 1D and 2D NMR spectroscopy. Moreover, the urease inhibitory effects of the isolated compounds were assessed in-vitro and in-silico. Three novel kaempferol derivatives and two thymol derivatives were isolated from Oliveria decumbens aerial parts, and the structures were determined by comparison with published data. The n-hexane fraction was found to exert the most significant anti-H. pylori activity with the minimum inhibitory concentration of 50 µg/mL. All fractions demonstrated antibacterial activity toward S. aureus. In-vitro urease inhibition assay showed that stigmasterol, tiliroside, and carvacrol were found to be the most potent enzyme inhibitors in the isolated compounds. Molecular interactions of the compounds with the active site of urease were supported by the molecular docking analysis. Novel bioactive compounds in Oliveria decumbens were described in this study. The antibacterial effects suggested the potential use of the compounds in pharmaceutical formulations inconsistent with the traditional use of the plant in the treatment of gastrointestinal infections.

Design, Synthesis, and In Vitro and In Vivo Evaluation of Novel Fluconazole-Based Compounds with Promising Antifungal Activities.

Demand has arisen for developing new azole antifungal agents with the growth of the resistant rate of infective fungal species to current azole antifungals in recent years. Accordingly, the present study reports the synthesis of novel fluconazole (FLC) analogues bearing urea functionality that led to discovering new azole agents with promising antifungal activities. In particular, compounds 8b and 8c displayed broad-spectrum activity and superior in vitro antifungal capabilities compared to the standard drug FLC against sensitive and resistant Candida albicans (C. albicans). The highly active compounds 8b and 8c had potent antibiofilm properties against FLC-resistant C. albicans species. Additionally, these compounds exhibited very low toxicity for three mammalian cell lines and human red blood cells. Time-kill studies revealed that our synthesized compounds displayed a fungicidal mechanism toward fungal growth. Furthermore, a density functional theory (DFT) calculation, additional docking, and independent gradient model (IGM) studies were performed to analyze their structure-activity relationship (SAR) and to assess the molecular interactions in the related target protein. Finally, in vivo results represented a significant reduction in the tissue fungal burden and improvements in the survival rate in a mice model of systemic candidiasis along with in vitro and in silico studies, demonstrating the therapeutic efficiency of compounds 8b and 8c as novel leads for candidiasis drug discovery.

Phytochemical Analysis and Evaluation of Biological Activity of Lawsonia inermis Seeds Related to Alzheimer's Disease.

Using Lawsonia inermis L. (henna) seeds has been frequently recommended for the improvement of memory in Iranian Traditional Medicine (ITM). In this respect, different fractions of the plant were prepared and evaluated for their in vitro biological assays related to Alzheimer's disease (AD), including acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity as well as metal chelating ability and DPPH antioxidant activity. The dichloromethane and ethyl acetate fractions were able to inhibit the BChE selectively with IC50 values of 113.47 and 124.90 µg/mL, respectively, compared with donepezil as the reference drug (IC50 = 1.52 µg/mL). However, all fractions were inactive toward AChE. Phytochemical analysis of the dichloromethane fraction indicated the presence of ß-sitosterol (1), 3-O-ß-acetyloleanolic acid (2), 3-O-(Z)-coumaroyl oleanolic acid (3), betulinic acid (4), and oleanolic acid (5). The inhibitory activity of isolated compounds was also evaluated toward AChE and BChE. Among them, compounds 2 and 5 showed potent inhibitory activity toward BChE with IC50 values of 77.13 and 72.20 µM, respectively. However, all compounds were inactive toward AChE. Moreover, molecular docking study confirmed desired interactions between those compounds and the BChE active site. The ability of fractions and compounds to chelate biometals (Cu2+, Fe2+, and Zn2+) was also investigated. Finally, DPPH antioxidant assay revealed that the ethyl acetate (IC50 = 3.08 µg/mL) and methanol (IC50 = 3.64 µg/mL) fractions possessed excellent antioxidant activity in comparison to BHA as the positive control (IC50 = 3.79 µg/mL).

Investigation of anti-Alzheimer's activity of aqueous extract of areca nuts (Areca catechu L): in vitro and in vivo studies / Investigación de la actividad anti-Alzheimer del extracto acuoso de nueces de areca (Areca catechu L): estudios in vitro e in vivo

Alzheimer's disease (AD) is an age-related neurodegenerative disorder. Sever cognitive and memory impairments, huge increase in the prevalence of the disease, and lacking definite cure have absorbed worldwide efforts to develop therapeutic approaches. Since many drugs have failed in the clinical trials due to multifactorial nature of AD, symptomatic treatments are still in the center attention and now, nootropic medicinal plants have been found as versatile ameliorators to reverse memory disorders. In this work, anti-Alzheimer's activity of aqueous extract of areca nuts (Areca catechu L.) was investigated via in vitro and in vivo studies. It depicted good amyloid ß (Aß) aggregation inhibitory activity, 82% at 100 µg/mL. In addition, it inhibited beta-secretase 1 (BACE1) with IC50 value of 19.03 µg/mL. Evaluation of neuroprotectivity of the aqueous extract of the plant against H2O2-induced cell death in PC12 neurons revealed 84.5% protection at 1 µg/mL. It should be noted that according to our results obtained from Morris Water Maze (MWM) test, the extract reversed scopolamine-induced memory deficit in rats at concentrations of 1.5 and 3 mg/kg.

La enfermedad de Alzheimer (EA) es un trastorno neurodegenerativo relacionado con la edad. Los severos deterioros cognitivos y de la memoria, el enorme aumento de la prevalencia de la enfermedad y la falta de una cura definitiva han absorbido los esfuerzos mundiales para desarrollar enfoques terapéuticos. Dado que muchos fármacos han fallado en los ensayos clínicos debido a la naturaleza multifactorial de la EA, los tratamientos sintomáticos siguen siendo el centro de atención y ahora, las plantas medicinales nootrópicas se han encontrado como mejoradores versátiles para revertir los trastornos de la memoria. En este trabajo, se investigó la actividad anti-Alzheimer del extracto acuoso de nueces de areca (Areca catechu L.) mediante estudios in vitro e in vivo. Representaba una buena actividad inhibidora de la agregación de amiloide ß (Aß), 82% a 100 µg/mL. Además, inhibió la beta-secretasa 1 (BACE1) con un valor de CI50 de 19,03 µg/mL. La evaluación de la neuroprotección del extracto acuoso de la planta contra la muerte celular inducida por H2O2 en neuronas PC12 reveló una protección del 84,5% a 1 µg/mL. Cabe señalar que, de acuerdo con nuestros resultados obtenidos de la prueba Morris Water Maze (MWM), el extracto revirtió el déficit de memoria inducido por escopolamina en ratas a concentraciones de 1,5 y 3 mg/kg.

Novel 1,2,4-oxadiazole derivatives as selective butyrylcholinesterase inhibitors: Design, synthesis and biological evaluation.

Alzheimer's disease (AD) is a progressive mental disorder that brings a huge economic burden to the healthcare systems. During this illness, acetylcholine levels in the cholinergic systems gradually diminish, which results in severe memory loss and cognitive impairments. Moreover, Butyrylcholinesterase (BuChE) enzyme participates in cholinergic neurotransmission regulation by playing a prominent role in the latter phase of AD. In this study, based on donepezil, which is an effective acetylcholinesterase (AChE) inhibitor, a series of 1,2,4-oxadiazole compounds were designed, synthesized and their inhibitory activities towards AChE and BuChE enzymes were evaluated. Some structures exhibited a higher selectivity rate towards BuChE in comparison to donepezil. Notably, compound 6n with an IC50 value of 5.07 µM and an SI ratio greater than 19.72 showed the highest potency and selectivity towards BuChE enzyme. The docking result revealed that compound 6n properly fitted the active site pocket of BuChE enzyme, and formed desirable lipophilic interactions and hydrogen bonds. Moreover, according to in silico ADME studies, these compounds have proper potential for being developed as new oral anti-Alzheimer's agents (Figure 1(Fig. 1)).