Search Results (122)

Background/Objectives: Verbena officinalis L. (common vervain) is a medicinal plant traditionally used and investigated in phytotherapy for its neuroprotective, antioxidant, and anti-inflammatory properties. This study aims to investigate the phytochemical diversity and biological activity of V. officinalis extracts prepared with different ratios of butanol and ethanol. Methods: Aerial parts of V. officinalis were extracted using four solvent systems: 100% butanol (B1), 75:25 (BE7.5), 50:50 (BE5), and 25:75 (BE2.5) butanol:ethanol mixtures. Metabolite profiling was conducted using liquid chromatography–high-resolution tandem mass spectrometry (LC-HRMS/MS). Antioxidant activities were evaluated through six assays: 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), cupric ion-reducing antioxidant capacity (CUPRAC), ferric-reducing antioxidant power (FRAP), metal-chelating ability (MCA), and the phosphomolybdenum assay (PMA). Enzyme inhibition assays targeted acetylcholinesterase (AChE), butyrylcholinesterase (BChE), tyrosinase, and α-amylase. Antibacterial activity against Pseudomonas aeruginosa was tested via microdilution, while dominant phytochemicals were evaluated for binding affinity through molecular docking. Results: Seventy-five compounds, including phenolic acids, flavonoids, iridoids, phenylethanoids, and xanthones, were identified. BE5 extract exhibited the highest total phenolic content and strongest antioxidant capacity, while BE2.5 demonstrated the greatest antibacterial and metal-chelating effects. All extracts showed comparable AChE inhibition, with BE5 achieving the strongest tyrosinase and α-amylase inhibition. Docking studies confirmed high binding affinities of luteolin glucuronides to human and bacterial target enzymes. Conclusions: Solvent composition markedly influenced the chemical and biological profiles of V. officinalis extracts. BE5 and BE2.5 emerged as promising systems for obtaining bioactive fractions with therapeutic potential. Full article

Background/Objectives: The need for dual-targeted enzyme inhibitors is critical in addressing complex diseases like Alzheimer’s and glaucoma. Imidazothiadiazole and chalcone moieties are known for diverse bioactivities. This study aimed to develop novel imidazothiadiazole–chalcone hybrids as potential inhibitors of acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and human carbonic anhydrase isoforms (hCAs), specifically hCA I and hCA II. Methods: Four hybrid molecules (8a–8d) were synthesized and structurally confirmed via ¹H NMR, ¹³C NMR, FT-IR, MS, and elemental analysis techniques. Their enzyme inhibitory activities were assessed using Ellman’s and Verpoorte’s methods. Molecular docking and 100 ns molecular dynamics (MD) simulations were conducted to examine binding interactions. Absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties were predicted using the pkCSM platform. Results: All compounds showed strong enzyme inhibition: AChE (K_i: 3.86–11.35 nM), BChE (K_i: 1.01–1.78 nM), hCA I (K_i: 45.13–81.24 nM), and hCA II (K_i: 36.08–52.45 nM). Docking analyses confirmed favorable binding, particularly with active-site residues. MD simulations demonstrated stable interactions throughout 100 ns. Compound 8a exhibited the highest cholinesterase inhibition, while compounds 8d and 8c were the most potent against hCA I and hCA II, respectively. The ADMET results showed high absorption and acceptable safety, with mild mutagenicity or cardiotoxicity concerns in select compounds. Conclusions: These findings suggest that imidazothiadiazole–chalcone hybrids are promising multi-target enzyme inhibitors. Their potent activity, structural stability, and pharmacokinetic potential support their further development for therapeutic use in neurodegenerative and ocular diseases. Full article

Celery (Apium graveolens L.), one of the numerous members of the Apiaceae family, has been traditionally used as food and medicine due to its nutraceutical properties. Nevertheless, understanding the neuroprotective effects of this species requires evaluation through different mechanisms relevant to Alzheimer’s disease (AD) treatment. This study explored the neuroprotective potential of ethanolic extracts of celery leaves. Liquid chromatography and mass spectrometry-based metabolomics analysis of the extract revealed the existence of a diverse array of secondary metabolites, including phenolic acids, hydroxycinnamic acid, flavonoids, flavonoid O-glycosides, flavonol, glycosides, and isoflavones. Celery extract protects human neuroblastoma SH-SY5Y cells against 15 µM amyloid-beta (Aβ_1–42) toxicity, enhancing their vitality from 67% to 81.74% at 100 µg/mL. The extract inhibited the enzymes associated with AD, including acetylcholinesterase (AChE), butyrylcholinesterase (BChE), glycogen synthase kinase 3 beta (GSK3β), cyclooxygenase 1 (COX-1), and cyclooxygenase 2 (COX-2) with IC₅₀ values of 21.84, 61.27, 45.94, 34.1, and 52.2 µg/mL, respectively. In conclusion, celery leaf extract components may be potential therapeutic candidates for AD prevention and treatment. Full article

Background/Objectives: While various nucleoside and nucleotide analogs have been approved as anticancer and antiviral drugs, their limitations, including low bioavailability and chemotherapeutic resistance, encourage the development of novel structures. In this context, and motivated by our previous findings on bioactive 3′-O-substituted xylofuranosyl nucleosides and 5-guanidine xylofuranose derivatives, we present herein the synthesis and biological evaluation of 5′-guanidino furanosyl nucleosides comprising 6-chloropurine and uracil moieties and a 3-O-benzyl xylofuranosyl unit. Methods: The synthetic methodology was based on the N-glycosylation of a 5-azido 3-O-benzyl xylofuranosyl acetate donor with the silylated nucleobase and a subsequent one-pot sequential two-step protocol involving Staudinger reduction of the thus-obtained 5-azido uracil and N⁷/N⁹-linked purine nucleosides followed by guanidinylation with N,N′-bis(tert-butoxycarbonyl)-N′′-triflylguanidine. The molecules were evaluated for their anticancer and anti-neurodegenerative diseases potential. Results: 5′-Guanidino 6-chloropurine nucleosides revealed dual anticancer and butyrylcholinesterase (BChE)-inhibitory effects. Both N⁹/N⁷-linked nucleosides exhibited mixed-type and selective submicromolar/micromolar BChE inhibiton. The N⁹ regioisomer was the best inhibitor (K_i/K_i′ = 0.89 μM/2.96 μM), while showing low cytotoxicity to FL83B hepatocytes and no cytotoxicity to human neuroblastoma cells (SH-SY5Y). Moreover, the N⁹-linked nucleoside exhibited selective cytotoxicity to prostate cancer cells (DU-145; IC₅₀ = 27.63 μM), while its N⁷ regioisomer was active against all cancer cells tested [DU-145, IC₅₀ = 24.48 μM; colorectal adenocarcinoma (HCT-15, IC₅₀ = 64.07 μM); and breast adenocarcinoma (MCF-7, IC₅₀ = 43.67 μM)]. In turn, the 5′-guanidino uracil nucleoside displayed selective cytotoxicity to HCT-15 cells (IC₅₀ = 76.02 μM) and also showed neuroprotective potential in a Parkinson’s disease SH-SY5Y cells’ damage model. The active molecules exhibited IC₅₀ values close to or lower than those of standard drugs, and comparable, or not significant, neuro- and hepatotoxicity. Conclusions: These findings demonstrate the interest of combining guanidine moieties with nucleoside frameworks towards the search for new therapeutic agents. Full article

The growing demand for agricultural products has led to the misuse of pesticides, resulting in the use of higher concentrations of these substances. This has led to an increase in toxicity imposed on other beneficial organisms and to the bioaccumulation of toxic pesticide concentrations in the bodies of both pests and non-target organisms, as well as in their end users, including humans. In this study, the neurotoxic potential of the commonly used pesticides abamectin (an insecticide) and boscalid (a fungicide) was evaluated. Both in vitro and in silico studies showed that human butyrylcholinesterase is not a target for abamectins B1A and B1B. Boscalid showed a modest Glide score (−28.8 kJ/mol) and a considerably higher IC₅₀ (308.8 µM) against human butyrylcholinesterase than the approved inhibitor (2-((1-(benzenesulfonyl)-1H-indol-4-yl)oxy)ethyl)(benzyl)amine (IC₅₀ = 0.473 µM). However, due to its non-mutagenicity and low toxicity, structural analogues of boscalid might be considered as candidates for the symptomatic treatment of Alzheimer’s disease. Molecular dynamics simulations over 100 ns confirmed the stability of boscalid within the active site of butyrylcholinesterase, where it maintained key interactions with catalytic residues such as Trp82 and His438. These findings highlight its potential as a starting point for structure-based drug design strategies aimed at optimizing cholinesterase inhibitors with improved pharmacokinetic properties. According to absorption, distribution, metabolism, elimination, and toxicity studies, boscalid is orally active, which cannot be attributed to abamectins B1A and B1B. Full article

Schistosomiasis, a parasitic disease caused by worms of the genus Schistosoma, affects >250 million people worldwide. With no available vaccine, treatment relies solely on one drug—praziquantel—underscoring the urgent need for new therapies. We identified a tegumental, non-neuronal acetylcholinesterase (AChE) from Schistosoma mansoni—SmTAChE—as a promising drug target. RNA interference confirmed its essential role in parasite survival, as gene suppression significantly reduced parasite recovery from infected animals. Here, we produced functionally active recombinant SmTAChE by using a mammalian expression system. Biochemical characterization confirmed its identity as a true acetylcholinesterase, with the highest turnover rate (K_cat = 373 ± 39 s⁻¹) and catalytic efficiency (K_cat/K_m = 1.17 × 10⁶ M⁻¹·S⁻¹) for acetylthiocholine. Additionally, rSmTAChE was inhibited by classical AChE-specific inhibitors but not by a butyrylcholinesterase-specific inhibitor. To identify novel SmTAChE inhibitors, we developed a high-throughput chemical screening protocol (Z′ factor > 0.9) and screened a 1894-compound validation library. Twelve compounds reproducibly inhibited rSmTAChE by >30% at 7.5 µM, including known AChE inhibitors like physostigmine and new selective inhibitors. Notably, compound #2 preferentially inhibited rSmTAChE (IC₅₀ = 0.74 µM) over human AChE (IC₅₀ = 151 µM), thus providing a foundation for developing parasite-specific therapies targeting SmTAChE and potentially leading to new treatments for schistosomiasis. Full article

Background/objectives: Schistosomiasis is a parasitic disease that represents a serious public health problem. An alternative for the control of snails, intermediate hosts of schistosomiasis, is the use of molluskicides. Niclosamide, recommended by the WHO, has limitations, such as environmental toxicity, which has driven the search for safer and biodegradable alternatives, especially of plant origin. In this context, this study investigated the biological activity of Cymbopogon winterianus essential oil on embryos, juveniles, and adults of Biomphalaria glabrata and cercariae of Schistosoma mansoni. Methods: Essential oils (EOs) were extracted from fresh leaves via the Clevenger system and characterized via gas chromatography (GC/MS and GC/FID), revealing geraniol (25.0%), citronellal (29.2%), citronellol (10.5%) and elemol (9.6%) as the main components. Results: The results revealed lethal concentrations 90 (LC₉₀) for young and adult snails of 60.72 mg/L, 74.21 mg/L and 115.35 mg/L, respectively. In the histological analysis, no changes were observed in the tissues of the mollusks exposed to the lethal concentration 25 (LC₂₅). However, the lethal concentrations 50 (LC₅₀) and 75 (LC₇₅) caused crystalline concretions in proximity to the renal saccular portion. At a concentration of 60 mg/L, the oil resulted in 100% lethality in embryos and cercaricidal activity greater than 90% in 3 h. Acute toxicity tests in mice via the intraperitoneal or oral route did not reveal toxic effects, with hematological and biochemical parameters within the reference values. Furthermore, the oil did not inhibit acetylcholinesterase (AChE), indicating low toxicity to fish, and caused a slight reduction in human butyrylcholinesterase (hBChE) activity without affecting human AChE, which suggests low toxicity to mammalian tissues. In terms of environmental impact, the oil was not toxic to algae until the 75th day, with mortality observed thereafter. Conclusions: These results indicate that essential oils have great potential as biodegradable and safe alternatives for controlling mollusks and interrupting the schistosomiasis cycle. Full article

The article is devoted to the creation of enzymatic nanoreactors based on polystyrene–block–poly(acrylic acid) (PS-b-PAA) copolymers containing bioscavengers capable of neutralizing toxic esters both in the body and in the environment. Block copolymers of different amphiphilicity, hydrophilicity and molecular weights were synthesized and characterized using gel permeation chromatography, NMR and UV spectroscopy. Polymeric nanocontainers in the absence and presence of human butyrylcholinesterase were made by film hydration and characterized by dynamic light scattering and microscopy methods. Enzyme activity was determined using the Ellman method. For the first time, factors that need to be taken into account for the creation of effective enzymatic nanoreactors based on PS-b-PAA are presented. The data obtained open up the possibility of PS-b-PAA nanoreactor use for future in vivo bioscavenger studies. Full article

Acetylcholinesterase and butyrylcholinesterase are two related enzymes that represent pharmacologically suitable targets in neurodegenerative disorders, given their physiological roles in the body. The treatment of neurodegenerative disorders currently includes common reversible cholinesterase inhibitors. Resveratrol analogues, as the molecules in focus, have shown the very strong inhibition potential of cholinesterases. In this research, experimental and DFT approaches for their pK_a value determination were carried out knowing that pK_a is very important for predicting the ADMET properties of the potentially bioactive molecules and their behavior in the environment. An in silico study was used to calculate more indicators about the absorption and distribution in the human body. Among the investigated compounds, the weakest acid was experimentally detected and confirmed using three computational models. Additionally performed calculations provided access to the potential of each resveratrol analogue to engage in both π-π stacking and hydrogen bond interactions in the active site of the enzyme crucial for the stability of the ligand–enzyme complex. Full article

As some previously reported studies have proven that amodiaquine, in addition to its primary antimalarial activity, also has potential for new applications such as the inhibition of cholinesterases, in our study we focused on the evaluation of the influence of different substituents in the aminoquinoline part of the amodiaquine structure on the inhibition of human acetylcholinesterase and butyrylcholinesterase to investigate the possibility for their use as drugs for the treatment of AD. We synthesized a series of amodiaquine derivatives bearing H-, F-, CF₃-, NO₂-, CN-, CO₂H- or CH₃O- groups on the aminoquinoline ring, and determined that all of the tested derivatives were very potent inhibitors of both cholinesterases, with inhibition constants (K_i) in the nM and low μM range and with prominent selectivity (up to 300 times) for the inhibition of acetylcholinesterase. All compounds displayed an ability to chelate biometal ions Fe²⁺, Zn²⁺ and Cu²⁺ and an antioxidant power comparable to that of standard antioxidants. Most of the compounds were estimated to be able to cross the blood–brain barrier by passive transport and were nontoxic toward cells that represent the models of individual organs. Considering all these beneficial features, our study has singled out compound 5, the most potent AChE inhibitor with a CH₃O- on C(7) position, followed by 6 and 14, compounds without substituent or hydroxyl groups in the C(17) position, respectively, as the most promising compounds from the series which could be considered as potential multi-target drugs for the treatment of AD. Full article

In 2008, Brazil became the country with the highest pesticide use in the world, with over one billion liters of pesticides applied to crops in 2009. The impacts of these products on public health are wide-ranging. Vast territories are affected, involving different population groups, such as workers in various fields of activity, the population that consumes contaminated food, and people living around factories, such as traditional communities. This study aimed to assess human exposure to pesticides through epidemiological and laboratory data of residents of the Santo Antônio quilombola community in Concórdia do Pará, Amazon region, Brazil. Epidemiological data were collected using a semi-structured questionnaire, which included factors such as sex, age, length of residence, and level of exposure to pesticides. The modified Ellman method was used to assess the activity of cholinesterases, and flow cytometry was performed for cytokine analysis. Analysis of collected blood samples showed that, in most cases, there was no significant reduction in the activity of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) compared to other studies in the scientific literature. Meanwhile, there was an increase in the levels of IFN-γ cytokines, especially IL-6, in all groups. The findings of this study highlight the urgent need for a comprehensive monitoring program, considering that some conditions other than pesticide exposure can alter the activities of the biomarkers used in this study. Full article

Norbelladine derivatives have garnered attention in recent years due to their diverse biological activities and pivotal role in the biosynthetic pathway of Amaryllidaceae alkaloids. This study reports the synthesis and biological evaluation of four O,N-methylated derivatives of norbelladine. These derivatives were synthesized through a three-step process: forming imine intermediates from benzaldehydes with tyramine, hydrogenating them to secondary amines, and N-methylating these amines. The products were purified and characterized by ¹H and ¹³C NMR spectroscopy. Their biological activities were assessed by evaluating their ability to inhibit Alzheimer’s disease-related enzymes acetylcholinesterase and butyrylcholinesterase. Additionally, the cytotoxic activity of the novel derivatives was tested against cancer cell lines derived from hepatocarcinoma (Huh7), adenocarcinoma (HCT-8), and acute myeloid leukemia (THP-1) cells, and their antiviral properties against a human coronavirus (HCoV-OC43), a flavivirus (dengue virus), and a lentivirus (pseudotyped HIV-1). Docking analysis was performed to understand the impact of the N-methylation on their pharmacological relevance. The results indicate that while N-methylation does not significantly affect antiviral activity, it enhances butyrylcholinesterase inhibition for N-methylnorbelladine and 4′-O,N-dimethylnorbelladine. Overall, this work enhances our understanding of norbelladine derivatives, provides new tools for Alzheimer’s disease research, and lays the groundwork for future pharmaceutical developments. Full article

Multitarget compounds have emerged as promising drug candidates to cope with complex multifactorial diseases, like Alzheimer’s disease (AD). Most multitarget compounds are designed by linking two pharmacophores through a tether chain (linked hybrids), which results in rather large molecules that are particularly useful to hit targets with large binding cavities, but at the expense of suffering from suboptimal physicochemical/pharmacokinetic properties. Molecular size reduction by removal of superfluous structural elements while retaining the key pharmacophoric motifs may represent a compromise solution to achieve both multitargeting and favorable physicochemical/PK properties. Here, we report the stepwise structural simplification of the dihydroxyanthraquinone moiety of a rhein–huprine hybrid lead by hydroxy group removal—ring contraction—ring opening—ring removal, which has led to new analogs that retain or surpass the potency of the lead on its multiple AD targets while exhibiting more favorable drug metabolism and pharmacokinetic (DMPK) properties and safety profile. In particular, the most simplified acetophenone analog displays dual nanomolar inhibition of human acetylcholinesterase and butyrylcholinesterase (IC₅₀ = 6 nM and 13 nM, respectively), moderately potent inhibition of human BACE-1 (48% inhibition at 15 µM) and Aβ42 and tau aggregation (73% and 68% inhibition, respectively, at 10 µM), favorable in vitro brain permeation, higher aqueous solubility (18 µM) and plasma stability (100/96/86% remaining in human/mouse/rat plasma after 6 h incubation), and lower acute toxicity in a model organism (zebrafish embryos; LC₅₀ >> 100 µM) than the initial lead, thereby confirming the successful lead optimization by structural simplification. Full article

The present study was performed to determine the chemical constituents, cytotoxicity, antioxidant and enzyme inhibition activities of the aerial parts of Glaucium acutidentatum Hausskn. and Bornm. (family Papaveraceae). Methanolic and aqueous extracts were prepared by maceration, homogenizer-assisted extraction (HAE) and infusion. Results showed that the highest total phenolic and flavonoids contents were obtained from the methanol extracts obtained by HAE (53.22 ± 0.10 mg GAE/g) and maceration (30.28 ± 0.51 mg RE/g), respectively. The aporphine, beznyltetrahydroisoquinoline, and protopine types of Glaucium alkaloids have been tentatively identified. Among them, glaucine was identified in all extracts. Flavonoids, phenolic acids, coumarins, organic acids and fatty acids were also detected. Methanolic extract obtained using the HAE method displayed the highest anti-DPPH (41.42 ± 0.62 mg TE/g), total antioxidant (1.20 ± 0.17 mmol TE/g), Cu²⁺ (113.55 ± 6.44 mg TE/g), and Fe³⁺ (74.52 ± 4.74 mg TE/g) reducing properties. The aqueous extracts obtained by infusion and HAE methods exerted the best anti-ABTS (103.59 ± 1.49 mg TE/g) and chelating (19.81 ± 0.05 mg EDTAE/g) activities, respectively. Methanolic extract from HAE recorded the highest acetylcholinesterase (2.55 ± 0.10 mg GALAE/g) and α-amylase (0.51 ± 0.02 mmol ACAE/g) inhibition activities, while that obtained by maceration showed the best butyrylcholinesterase (3.76 ± 0.31 mg GALAE/g) inhibition activity. Both extracts revealed the best tyrosinase inhibitory activity (25.15 ± 1.00 and 26.79 ± 2.36 mg KAE/g, p ≥ 0.05). G. acutidentatum maceration-derived aqueous extract showed selective anticancer activity against cells originating from human hypopharyngeal carcinoma. In conclusion, these findings indicated that G. acutidentatum is a promising source of alkaloids and phenolic compounds for variable pharmaceutical formulations. Full article

Mushrooms are one of the indispensable elements of human diets. Edible mushrooms stand out with their aroma and nutritional properties. In this study, some biological activities of the wild edible mushroom Hericium erinaceus were determined. In this context, firstly, the most suitable extraction conditions of the fungus in terms of biological activity were determined. First, 64 different experiments were performed with the Soxhlet device under 40–70 °C extraction temperature, 3–9 h extraction time, and 0.5–2 mg/mL extraction conditions. As a result, a total antioxidant status (TAS) analysis was performed, and the extraction conditions were optimized so that the objective function was the maximum TAS value. The data obtained from the experimental study were modeled with artificial neural networks (ANNs), one of the artificial intelligence methods, and optimized with a genetic algorithm (GA). All subsequent tests were performed using the extract obtained under optimum extraction conditions. The antioxidant capacity of the mushroom was assessed using Rel assay kits and the DPPH and FRAP techniques. The agar dilution method was used to measure the antimicrobial activity. The anti-Alzheimer activity was assessed based on the activities of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). The antiproliferative activity was assessed against the A549 cancer cell line. The total phenolic content was measured using the Folin–Ciocalteu reagent. The measurement of total flavonoids was conducted using the aluminum chloride test. LC-MS/MS equipment was used to screen for the presence of standard chemicals. The optimum extraction conditions were found to be a 60.667 °C temperature, 7.833 h, and 1.98 mg/mL. It was determined that the mushroom has high antioxidant potential. It was determined that the substance was successful at combating common bacterial and fungal strains when used at dosages ranging from 25 to 200 µg/mL. The high antiproliferative effect of the substance was attributed to its heightened concentration. The anti-AChE value was found to be 13.85 μg/mL, while the anti-BChE value was confirmed to be 28.00 μg/mL. The phenolic analysis of the mushroom revealed the presence of 13 chemicals. This investigation found that H. erinaceus exhibits robust biological activity when extracted under appropriate circumstances. Full article