Lead optimization based design, synthesis, and pharmacological evaluation of quinazoline derivatives as multi-targeting agents for Alzheimer's disease treatment.

The complexity and multifaceted nature of Alzheimer's disease (AD) have driven us to further explore quinazoline scaffolds as multi-targeting agents for AD treatment. The lead optimization strategy was utilized in designing of new series of derivatives (AK-1 to AK-14) followed by synthesis, characterization, and pharmacological evaluation against human cholinesterase's (hChE) and ß-secretase (hBACE-1) enzymes. Amongst them, compounds AK-1, AK-2, and AK-3 showed good and significant inhibitory activity against both hAChE and hBACE-1 enzymes with favorable permeation across the blood-brain barrier. The most active compound AK-2 revealed significant propidium iodide (PI) displacement from the AChE-PAS region and was non-neurotoxic against SH-SY5Y cell lines. The lead molecule (AK-2) also showed Aß aggregation inhibition in a self- and AChE-induced Aß aggregation, Thioflavin-T assay. Further, compound AK-2 significantly ameliorated Aß-induced cognitive deficits in the Aß-induced Morris water maze rat model and demonstrated a significant rescue in eye phenotype in the Aꞵ-phenotypic drosophila model of AD. Ex-vivo immunohistochemistry (IHC) analysis on hippocampal rat brains showed reduced Aß and BACE-1 protein levels. Compound AK-2 suggested good oral absorption via pharmacokinetic studies and displayed a good and stable ligand-protein interaction in in-silico molecular modeling analysis. Thus, the compound AK-2 can be regarded as a lead molecule and should be investigated further for the treatment of AD.

Acetylcholinesterase is regulated by exposure of ultraviolet B in skin keratinocytes: A potential inducer of cholinergic urticaria.

Cholinergic urticaria is a dermatological disease characterized by the presence of large patches of red skin and transient hives triggered by factors, such as exercise, sweating, and psychological tension. This skin problem is hypothesized to be attributed to a reduced expression of acetylcholinesterase (AChE), an enzyme responsible for hydrolyzing acetylcholine (ACh). Consequently, ACh is thought to the leak from sympathetic nerves to skin epidermis. The redundant ACh stimulates the mast cells to release histamine, triggering immune responses in skin. Here, the exposure of ultraviolet B in skin suppressed the expression of AChE in keratinocytes, both in in vivo and in vitro models. The decrease of the enzyme was resulted from a declined transcription of ACHE gene mediated by micro-RNAs, that is, miR-132 and miR-212. The levels of miR-132 and miR-212 were markedly induced by exposure to ultraviolet B, which subsequently suppressed the transcriptional rate of ACHE. In the presence of low level of AChE, the overflow ACh caused the pro-inflammatory responses in skin epidermis, including increased secretion of cytokines and COX-2. These findings suggest that ultraviolet B exposure is one of the factors contributing to cholinergic urticaria in skin.

The protective effect of Astaxanthin on scopolamine - induced Alzheimer's model in mice.

OBJECTIVES: To investigate the fundamental mechanisms of the neuroprotective impact of Astaxanthin (AST) in a mouse model of Alzheimer's disease (AD) induced by scopolamine. METHODS: This research constituted an in vivo animal study encompassing 36 adult male mice, divided into 6 groups: Control, 100 mg/kg AST, 2 mg/kg scopolamine (AD group), 100 mg/kg AST+2 mg/kg scopolamine, 3 mg/kg galantamine+2 mg/kg scopolamine, and 100 mg/kg AST+3 mg/kg galantamine+2 mg/kg scopolamine. After 14 days, the mice's short-term memory, hippocampus tissue, oxidative and inflammatory markers were evaluated. RESULTS: The AST demonstrated a beneficial influence on short-term memory and a reduction in acetylcholinesterase activity in the brain. It exhibited neuroprotective and anti-amyloidogenic properties, significantly decreased pro-inflammatory markers and oxidative stress, and reversed the decline of the Akt-1 and phosphorylated Akt pathway, a crucial regulator of abnormal tau. Furthermore, AST enhanced the effect of galantamine in reducing inflammation and oxidative stress. CONCLUSION: The findings indicate that AST may offer therapeutic benefits against cognitive dysfunction in AD. This is attributed to its ability to reduce oxidative stress, control neuroinflammation, and enhance Akt-1 and pAkt levels, thereby underscoring its potential in AD treatment strategies.

Amyloid Beta Leads to Decreased Acetylcholine Levels and Non-Small Cell Lung Cancer Cell Survival via a Mechanism That Involves p38 Mitogen-Activated Protein Kinase and Protein Kinase C in a p53-Dependent and -Independent Manner.

Several studies have shown an inverse correlation between the likelihood of developing a neurodegenerative disorder and cancer. We previously reported that the levels of amyloid beta (Aß), at the center of Alzheimer's disease pathophysiology, are regulated by acetylcholinesterase (AChE) in non-small cell lung cancer (NSCLC). Here, we examined the effect of Aß or its fragments on the levels of ACh in A549 (p53 wild-type) and H1299 (p53-null) NSCLC cell media. ACh levels were reduced by cell treatment with Aß 1-42, Aß 1-40, Aß 1-28, and Aß 25-35. AChE and p53 activities increased upon A549 cell treatment with Aß, while knockdown of p53 in A549 cells increased ACh levels, decreased AChE activity, and diminished the Aß effects. Aß increased the ratio of phospho/total p38 MAPK and decreased the activity of PKC. Inhibiting p38 MAPK reduced the activity of p53 in A549 cells and increased ACh levels in the media of both cell lines, while opposite effects were found upon inhibiting PKC. ACh decreased the activity of p53 in A549 cells, decreased p38 MAPK activity, increased PKC activity, and diminished the effect of Aß on those activities. Moreover, the negative effect of Aß on cell viability was diminished by cell co-treatment with ACh.

Assessment of antioxidant, acetylcholinesterase, paraoxonase inhibition activities and phenolic content of Alchemilla lithophila.

In the present study, antioxidant activity and inhibition of acetylcholinesterase (AChE) and paraoxonase (hPON 1) of Alchemilla lithophila extracts were evaluated for the first time. Besides, there is no research on the contents of phenolic compounds except for fatty acids. In this context, phenolic compounds of A. lithophila were investigated by liquid chromatography/ mass spectrometry (LC-MS/MS). The methanol extract of the A. lithophila exhibited significant inhibition on the AChE (IC50 value for methanol extract 0.162 ± 0.25 mg /mL, R2:0.992). Besides, antioxidant activities of the A. lithophila extracts were examined using by the methods ABTS•+ and DPPH• free radical scavenging potentials, FRAP and CUPRAC metal-reducing activities. ABTS•+ and DPPH• scavenging activities were found for methanol extract at 70.67% and water extract at 75.38%, respectively. Also, FRAP and CUPRAC metal-reducing were determined for water extract 0.796 and hexane extract 1.570 as absorbance. According to LC-MS/MS analyses, the amounts of ellagic acid, catechin hydrate, gallic acid, fumaric acid, luteolin, quercetin, kaempferol, acetohydroxamic acid, caffeic acid, syringic acid, hydroxybenzoic acid and salicylic acid were determined by LC-MS/MS, respectively. As a consequence, this study will be a useful resource for determining bioactivity and phenolic compound profile for natural medicine research.

Two Fluorescent Probes for Recognition of Acetylcholinesterase: Design, Synthesis, and Comparative Evaluation.

In this study, two "on-off" probes (BF2-cur-Ben and BF2-cur-But) recognizing acetylcholinesterase (AChE) were designed and synthesized. The obtained probes can achieve recognition of AChE with good selectivity and pH-independence with a linear range of 0.5~7 U/mL and 0.5~25 U/mL respectively. BF2-cur-Ben has a lower limit of detection (LOD) (0.031 U/mL), higher enzyme affinity (Km = 16 ± 1.6 µM), and higher inhibitor sensitivity. A responsive mechanism of the probes for AChE was proposed based on HPLC and mass spectra (MS) experiments, as well as calculations. In molecular simulation, BF2-cur-Ben forms more hydrogen bonds (seven, while BF2-cur-But has only four) and thus has a more stable enzyme affinity, which is mirrored by the results of the comparison of Km values. These two probes could enable recognition of intracellular AChE and probe BF2-cur-Ben has superior cell membrane penetration due to its higher log p value. These probes can monitor the overexpression of AChE during apoptosis of lung cancer cells. The ability of BF2-cur-Ben to monitor AChE in vivo was confirmed by a zebrafish experiment.

Characterization of Phenolic Compounds in Extra Virgin Olive Oil from Granada (Spain) and Evaluation of Its Neuroprotective Action.

The olive oil sector is a fundamental food in the Mediterranean diet. It has been demonstrated that the consumption of extra virgin olive oil (EVOO) with a high content of phenolic compounds is beneficial in the prevention and/or treatment of many diseases. The main objective of this work was to study the relationship between the content of phenolic compounds and the in vitro neuroprotective and anti-inflammatory activity of EVOOs from two PDOs in the province of Granada. To this purpose, the amounts of phenolic compounds were determined by liquid chromatography coupled to mass spectrometry (HPLC-MS) and the inhibitory activity of acetylcholinesterase (AChE) and cyclooxygenase-2 (COX-2) enzymes by spectrophotometric and fluorimetric assays. The main families identified were phenolic alcohols, secoiridoids, lignans, flavonoids, and phenolic acids. The EVOO samples with the highest total concentration of compounds and the highest inhibitory activity belonged to the Picual and Manzanillo varieties. Statistical analysis showed a positive correlation between identified compounds and AChE and COX-2 inhibitory activity, except for lignans. These results confirm EVOO's compounds possess neuroprotective potential.

Exposure to hull cleaning wastewater induces mortality through oxidative stress and cholinergic disturbance in the marine polychaete Perinereis aibuhitensis.

While wastewater and paint particles discharged from the in-water cleaning process of ship hulls are consistently released into benthic ecosystems, their hazardous effects on non-target animals remain largely unclear. In this study, we provide evidence on acute harmful effects of hull cleaning wastewater in marine polychaete Perinereis aibuhitensis by analyzing physiological and biochemical parameters such as survival, burrowing activity, and oxidative status. Raw wastewater samples were collected during ship hull cleaning processes in the field. Two wastewater samples for the exposure experiment were prepared in the laboratory: 1) mechanically filtered in the in-water cleaning system (MF) and 2) additionally filtered with a 0.45 µm filter in the laboratory (LF). These wastewater samples contained high concentrations of metals (zinc and copper) and metal-based booster biocides (copper pyrithione and zinc pyrithione) compared to those analyzed in seawater. Polycheates were exposed to different concentrations of the two wastewater samples for 96 h. Higher mortality was observed in response to MF compared to LF-exposed polychaetes. Both wastewater samples dose-dependently decreased burrowing activity and AChE activity. Drastic oxidative stress was observed in response to the two wastewater samples. MDA levels were significantly increased by MF and LF samples. Significant GSH depletion was observed with MF exposure, while increased and decreased GSH contents were observed in LF-exposed polychaetes. Enzymatic activities of antioxidant components, catalase, superoxide dismutase, and glutathione S-transferase were significantly modulated by both wastewater samples. These results indicate that even filtered hull cleaning wastewater can have deleterious effects on the health status of polychaetes.

Structural Insights into the Marine Alkaloid Discorhabdin G as a Scaffold towards New Acetylcholinesterase Inhibitors.

In this study, Antarctic Latrunculia sponge-derived discorhabdin G was considered a hit for developing potential lead compounds acting as cholinesterase inhibitors. The hypothesis on the pharmacophore moiety suggested through molecular docking allowed us to simplify the structure of the metabolite. ADME prediction and drug-likeness consideration provided valuable support in selecting 5-methyl-2H-benzo[h]imidazo[1,5,4-de]quinoxalin-7(3H)-one as a candidate molecule. It was synthesized in a four-step sequence starting from 2,3-dichloronaphthalene-1,4-dione and evaluated as an inhibitor of electric eel acetylcholinesterase (eeAChE), human recombinant AChE (hAChE), and horse serum butyrylcholinesterase (BChE), together with other analogs obtained by the same synthesis. The candidate molecule showed a slightly lower inhibitory potential against eeAChE but better inhibitory activity against hAChE than discorhabdin G, with a higher selectivity for AChEs than for BChE. It acted as a reversible competitive inhibitor, as previously observed for the natural alkaloid. The findings from the in vitro assay were relatively consistent with the data available from the AutoDock Vina and Protein-Ligand ANTSystem (PLANTS) calculations.

Effects of imidacloprid on the survival and biomarker responses of Eristalis tenax larvae (Diptera: Syrphidae): a comparative study between indoor and outdoor exposures.

Imidacloprid is a widely used pesticide in agriculture. It is being found in aquatic ecosystems in agricultural regions. This study aimed to evaluate its effects on the survival rates, acetylcholinesterase (AChE) and catalase (CAT) responses of larval Eristalis tenax hoverflies. The larvae were exposed for 3, 7 and 14 days to increasing concentrations of imidacloprid (0, 0.1, 0.5 and 2 mg L-1) both indoors at a constant temperature of 20 °C and outdoors under varying environmental conditions. The results revealed that indoors and outdoors, the mortality of E. tenax significantly increased with increasing imidacloprid concentration and duration of exposure. Median lethal concentrations (LC50) varied from 0.03 to 0.17 mg L-1 depending on the duration and conditions of exposure. Indoors, AChE activity decreased in all the treatments for all three exposure durations, whereas outdoors the decrease was observed after the short (3-day) and long (14-day) exposure durations. AChE inhibition ranged from 6% to 62% (indoors) and 12% to 62% (outdoors). Variations in CAT activity were observed for both experimental setups, with a decrease outdoors in larvae exposed to 0.5 mg L-1 for 7 days and a gradual dose-dependent increase indoors for exposure lasting 3 and 7 days. This study sheds light on the potential ecological implications of imidacloprid contamination which may cause the decline of aquatic insect populations and pollination rates, leading to disruptions of the food chain and the overall decline of aquatic and terrestrial ecosystem health.

Design, synthesis, and biological evaluation of some 2-(3-oxo-5,6-diphenyl-1,2,4-triazin-2(3H)-yl)-N-phenylacetamide hybrids as MTDLs for Alzheimer's disease therapy.

Inspite of established symptomatic relief drug targets, a multi targeting approach is highly in demand to cure Alzheimer's disease (AD). Simultaneous inhibition of cholinesterase (ChE), ß secretase-1 (BACE-1) and Dyrk1A could be promising in complete cure of AD. A series of 18 diaryl triazine based molecular hybrids were successfully designed, synthesized, and tested for their hChE, hBACE-1, Dyrk1A and Aß aggregation inhibitory potentials. Compounds S-11 and S-12 were the representative molecules amongst the series with multi-targeted inhibitory effects. Compound S-12 showed hAChE inhibition (IC50 value = 0.486 ± 0.047 µM), BACE-1 inhibition (IC50 value = 0.542 ± 0.099 µM) along with good anti-Aß aggregation effects in thioflavin-T assay. Only compound S-02 of the series has shown Dyrk1A inhibition (IC50 value = 2.000 ± 0.360 µM). Compound S-12 has also demonstrated no neurotoxic liabilities against SH-SY5Y as compared to donepezil. The in vivo behavioral studies of the compound S-12 in the scopolamine- and Aß-induced animal models also demonstrated attanuation of learning and memory functions in rats models having AD-like characteristics. The ex vivo studies, on the rat hippocampal brain demonstrated reduction in certain biochemical markers of the AD brain with a significant increase in ACh level. The Western blot and Immunohistochemistry further revealed lower tau, APP and BACE-1 molecular levels. The drosophilla AD model also revealed improved eyephenotype after treatment with compound S-12. The molecular docking studies of the compounds suggested that compound S-12 was interacting with the ChE-PAS & CAS residues and catalytic dyad residues of the BACE-1 enzymes. The 100 ns molecular dynamics simulation studies of the ligand-protein complexed with hAChE and hBACE-1 also suggested stable ligand-protein confirmation throughout the simulation run.

The Repellent Capacity against Sitophilus zeamais (Coleoptera: Curculionidae) and In Vitro Inhibition of the Acetylcholinesterase Enzyme of 11 Essential Oils from Six Plants of the Caribbean Region of Colombia.

The repellent capacity against Sitophilus zeamais and the in vitro inhibition on AChE of 11 essential oils, isolated from six plants of the northern region of Colombia, were assessed using a modified tunnel-type device and the Ellman colorimetric method, respectively. The results were as follows: (i) the degree of repellency (DR) of the EOs against S. zeamais was 20-68% (2 h) and 28-74% (4 h); (ii) the IC50 values on AChE were 5-36 µg/mL; likewise, the %inh. on AChE (1 µg/cm3 per EO) did not show any effect in 91% of the EO tested; (iii) six EOs (Bursera graveolens-bark, B. graveolens-leaves, B. simaruba-bark, Peperomia pellucida-leaves, Piper holtonii (1b*)-leaves, and P. reticulatum-leaves) exhibited a DR (53-74%) ≥ C+ (chlorpyrifos-61%), while all EOs were less active (8-60-fold) on AChE compared to chlorpyrifos (IC50 of 0.59 µg/mL). Based on the ANOVA/linear regression and multivariate analysis of data, some differences/similarities could be established, as well as identifying the most active EOs (five: B. simaruba-bark, Pep. Pellucida-leaves, P. holtonii (1b*)-leaves, B. graveolens-bark, and B. graveolens-leaves). Finally, these EOs were constituted by spathulenol (24%)/ß-selinene (18%)/caryophyllene oxide (10%)-B. simaruba; carotol (44%)/dillapiole (21%)-Pep. pellucida; dillapiole (81% confirmed by 1H-/13C-NMR)-P. holtonii; mint furanone derivative (14%)/mint furanone (14%)-B. graveolens-bark; limonene (17%)/carvone (10%)-B. graveolens-leaves.

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.

BACKGROUND: Polyalthia 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. METHODS: The 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. RESULTS: A total of 125 compounds were identified where D-limonene (0.07 - 24.7%), α-copaene (2.25 - 15.49%), E-ß-caryophyllene (5.17 - 14.42%), 24-noroleana-3,12-diene (12.92%), ß-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. CONCLUSIONS: From these findings, it is concluded that P. suberosa leaf oil should be evaluated as a food supplement for enhancing memory.

New Charged Cholinesterase Inhibitors: Design, Synthesis, and Characterization.

Triazoles and triazolium salts are very common subunits in the structures of various drugs. Medicaments with a characteristic 1,2,3-triazole core are also being developed to treat neurodegenerative disorders associated with cholinesterase enzyme activity. Several naphtho- and thienobenzo-triazoles from our previous research emerged as being particularly promising in that sense. For this reason, in this research, new naphtho- and thienobenzo-triazoles 23-34, as well as 1,2,3-triazolium salts 44-51, were synthesized and tested. Triazolium salts 44-46 showed excellent activity while salts 47 and 49 showed very good inhibition toward both butyrylcholinesterase (BChE) and acetylcholinesterase (AChE) enzymes. In contrast, neutral photoproducts were shown to be selective towards BChE but with very good inhibition potential as molecules 24-27. The representative of newly prepared compounds, 45 and 50, were stable in aqueous solution and revealed intriguing fluorimetric properties, characterized by a strong Stokes shift of >160 nm. Despite their condensed polycyclic structure shaped similarly to well-known DNA-intercalator ethidium bromide, the studied compounds did not show any interaction with ds-DNA, likely due to the unfavorable steric hindrance of substituents. However, the studied dyes bind proteins, particularly showing very diverse inhibition properties toward AChE and BChE. In contrast, neutral photoproducts were shown to be selective towards a certain enzyme but with moderate inhibition potential. The molecular docking of the best-performing candidates to cholinesterases' active sites identified cation-π interactions as the most responsible for the stability of the enzyme-ligand complexes. As genotoxicity studies are crucial when developing new active substances and finished drug forms, in silico studies for all the compounds synthesized have been performed.

Mechanochemical Approach to Obtaining a Multicomponent Fisetin Delivery System Improving Its Solubility and Biological Activity.

In this study, binary amorphous solid dispersions (ASDs, fisetin-Eudragit®) and ternary amorphous solid inclusions (ASIs, fisetin-Eudragit®-HP-ß-cyclodextrin) of fisetin (FIS) were prepared by the mechanochemical method without solvent. The amorphous nature of FIS in ASDs and ASIs was confirmed using XRPD (X-ray powder diffraction). DSC (Differential scanning calorimetry) confirmed full miscibility of multicomponent delivery systems. FT-IR (Fourier-transform infrared analysis) confirmed interactions that stabilize FIS's amorphous state and identified the functional groups involved. The study culminated in evaluating the impact of amorphization on water solubility and conducting in vitro antioxidant assays: 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)-ABTS, 2,2-diphenyl-1-picrylhydrazyl-DPPH, Cupric Reducing Antioxidant Capacity-CUPRAC, and Ferric Reducing Antioxidant Power-FRAP and in vitro neuroprotective assays: inhibition of acetylcholinesterase-AChE and butyrylcholinesterase-BChE. In addition, molecular docking allowed for the determination of possible bonds and interactions between FIS and the mentioned above enzymes. The best preparation turned out to be ASI_30_EPO (ASD fisetin-Eudragit® containing 30% FIS in combination with HP-ß-cyclodextrin), which showed an improvement in apparent solubility (126.5 ± 0.1 µg∙mL-1) and antioxidant properties (ABTS: IC50 = 10.25 µg∙mL-1, DPPH: IC50 = 27.69 µg∙mL-1, CUPRAC: IC0.5 = 9.52 µg∙mL-1, FRAP: IC0.5 = 8.56 µg∙mL-1) and neuroprotective properties (inhibition AChE: 39.91%, and BChE: 42.62%).

Astragaloside IV as a Memory-Enhancing Agent: In Silico Studies with In Vivo Analysis and Post Mortem ADME-Tox Profiling in Mice.

Many people around the world suffer from neurodegenerative diseases associated with cognitive impairment. As life expectancy increases, this number is steadily rising. Therefore, it is extremely important to search for new treatment strategies and to discover new substances with potential neuroprotective and/or cognition-enhancing effects. This study focuses on investigating the potential of astragaloside IV (AIV), a triterpenoid saponin with proven acetylcholinesterase (AChE)-inhibiting activity naturally occurring in the root of Astragalus mongholicus, to attenuate memory impairment. Scopolamine (SCOP), an antagonist of muscarinic cholinergic receptors, and lipopolysaccharide (LPS), a trigger of neuroinflammation, were used to impair memory processes in the passive avoidance (PA) test in mice. This memory impairment in SCOP-treated mice was attenuated by prior intraperitoneal (ip) administration of AIV at a dose of 25 mg/kg. The attenuation of memory impairment by LPS was not observed. It can therefore be assumed that AIV does not reverse memory impairment by anti-inflammatory mechanisms, although this needs to be further verified. All doses of AIV tested did not affect baseline locomotor activity in mice. In the post mortem analysis by mass spectrometry of the body tissue of the mice, the highest content of AIV was found in the kidneys, then in the spleen and liver, and the lowest in the brain.

Synthesis, structural, molecular docking, and in vitro biological activities of Cu-doped ZnO nanomaterials.

Copper-doped ZnO nanoparticles with the formula Zn1-x(Cu)O, where x = 0.0, 0.03, 0.05, and 0.07 were produced using the co-precipitation process. Physical, chemical, and structural properties were properly examined. Powdered X-ray diffraction (P-XRD) patterns revealed the formation of hexagonal wurtzite crystal structure in all samples, through atomic substitutional incorporation in the Cu-doped ZnO lattice. The presence of Cu ions and their dissolution in the host ZnO crystal structure was supported by FT-IR spectra. HR-TEM images were used to assess the average size, morphology, and shape regularity of the synthesized samples. The form and homogeneity of the ZnO changed when Cu ions were substituted, as evidenced by FE-SEM/EDX analysis. The presence of copper signals in the Cu-doped samples indicates that the doping was successful. The decrease in zeta potential with an increased copper doping percentage designates that the nanoparticles (NPs) are more stable, which could be attributed to an increase in the ionic strength of the aqueous solution. The synthesized NPs were evaluated for their substantial in vitro antioxidant properties. In addition, the antimicrobial efficacy of the materials was tested against pathogenic microorganisms. Regarding the anti-diabetic activity, the 7Cu ZnO sample showed the highest inhibitory effect on the α-amylase enzyme. No variations were observed in the activities of the acetylcholinesterase enzyme (AChE) and proteinase enzymes with ZnO and samples doped with different concentrations of Cu. Therefore, further studies are recommended to reveal the in-vitro anti-diabetic activity of the studied doped samples. Finally, molecular docking provided valuable insights into the potential binding interactions of Cu-doped ZnO with α-amylase, FabH of E. coli, and Penicillin-binding proteins of S. aureus. These outcomes suggest that the prepared materials may have an inhibitory effect on enzymes and hold promise in the battle against microbial infections and diabetes.

Diosmetin derivatives as multifunctional anti-AD ligands: Design, synthesis, and biological evaluation.

With the increasing aging population, rational design of drugs for Alzheimer's disease (AD) treatment has become an important research area. Based on the multifunctional design strategy, four diosmetin derivatives (1-4) were designed, synthesized, and characterized by 1H NMR, 13C NMR, and MS. Docking study was firstly applied to substantiate the design strategies and then the biological activities including cholinesterase inhibition, metal chelation, antioxidation and ß-amyloid (Aß) aggregation inhibition in vitro were evaluated. The results showed that 1-4 had good acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibition, metal chelation (selective chelation of Cu2+ ions), antioxidation, self-induced, Cu2+-induced, and AChE-induced Aß aggregation inhibition activities, and suitable blood-brain barrier (BBB) permeability. Especially, compound 3 had the strongest inhibitory effect on AChE (10-8 M magnitude) and BuChE (10-7 M magnitude) and showed the best inhibition on AChE-induced Aß aggregation with 66.14% inhibition ratio. Furthermore, compound 3 could also reduce intracellular reactive oxygen species (ROS) levels in Caenorhabditis elegans and had lower cytotoxicity. In summary, 3 might be considered as a potential multifunctional anti-AD ligand.

The role of the cholinergic system in the memory-protecting effects of metformin in a model of scopolamine-induced memory impairment in aged rats.

PURPOSE: As the elderly population grows, the prevalence of dementia is also rapidly increasing worldwide. Metformin, an antidiabetic drug, has been shown to have ameliorative effects on impaired cognitive functions in experimental models. However, studies have generally used young animals. Additionally, although it has a major role in Alzheimer's disease (AD) and memory, literature information about the effects of metformin on the cholinergic system is limited. In this study, we investigated the effects of metformin on memory in a model of scopolamine-induced memory impairment in aged rats. We also examined the effects of metformin on the cholinergic system, which is very important in cognitive functions. METHODS: Metformin was administered orally to male Wistar rats (20-22 months old) at 100 mg/kg/day for three weeks. Morris water maze (MWM) tests were performed to assess spatial memory. Before the probe test of the MWM test, scopolamine was injected intraperitoneally at a dose of 1 mg/kg. After testing, animals were sacrificed, whole brains were removed, and hippocampus samples were separated for biochemical analysis. RESULTS: Impaired memory associated with scopolamine administration was reversed by metformin. In addition, metformin administration ameliorated scopolamine-induced changes in acetylcholine (ACh) levels, acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), and choline acetyltransferase (ChAT) activity. CONCLUSION: Our results show that metformin may have protective effects in a scopolamine-induced memory impairment model in aged animals by improving cholinergic function. Metformin shows promise in preventing dementia with its dual cholinesterase inhibition and ChAT activation effect.

Transcriptome analyses in juvenile yellow perch (Perca flavescens) exposed in vivo to clothianidin and chlorantraniliprole: Possible sampling bias.

The St. Lawrence River is an important North American waterway that is subject to anthropogenic pressures including intensive urbanization, and agricultural development. Pesticides are widely used for agricultural activities in fields surrounding the yellow perch (Perca flavescens) habitat in Lake St. Pierre (Quebec, Canada), a fluvial lake of the river where the perch population has collapsed. Clothianidin and chlorantraniliprole were two of the most detected insecticides in surface waters near perch spawning areas. The objectives of the present study were to evaluate the transcriptional and biochemical effects of these two pesticides on juvenile yellow perch exposed for 28d to environmental doses of each compound alone and in a mixture under laboratory/aquaria conditions. Hepatic mRNA-sequencing revealed an effect of chlorantraniliprole alone (37 genes) and combined with clothianidin (251 genes), but no effects of clothianidin alone were observed in perch. Dysregulated genes were mostly related to circadian rhythms and to Ca2+ signaling, the latter effect has been previously associated with chlorantraniliprole mode of action in insects. Moreover, chronic exposure to clothianidin increased the activity of acetylcholinesterase in the brain of exposed fish, suggesting a potential non-target effect of this insecticide. Further analyses of three clock genes by qRT-PCR suggested that part of the observed effects of chlorantraniliprole on the circadian gene regulation of juvenile perch could be the result of time-of-day of sacrifice. These results provide insight into biological effects of insecticides in juvenile perch and highlight the importance of considering the circadian rhythm in experimental design and results analyses.