Search Results (738)

Iridoids are compounds recognized for their neuroprotective properties and their potential application in the treatment of neurodegenerative diseases. Geniposide (GP) and asperuloside (ASP) are iridoids that have demonstrated some biological activities. In this study, the potential neuroprotective effects of these iridoids were evaluated through in silico and in vivo assays, using Caenorhabditis elegans (C. elegans) strains CF1553 (sod-3::GFP), GA800 (cat::GFP), and CL2166 (gst-4::GFP). The results suggested that neither compound appears to have good passive permeability through the blood–brain barrier (BBB). However, an active transport mechanism involving the glucose transporter GLUT-1 may be present, as both compounds contain glucose in their molecular structure. In addition, they can inhibit the activity of both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). GP at 1 and 2 mM reversed the H₂O₂-induced increase in sod-3 expression, while ASP at 1 and 2 mM reversed the increase in gst-4 expression. Worm survival was more adversely affected by higher concentrations of GP than ASP, although both similarly reduced acetylcholinesterase activity. These findings suggest that GP and ASP exhibit very low toxicity both in silico and in vivo in C. elegans, and positively modulate key enzymes involved in antioxidant pathways, highlighting their potential for neuroprotective applications. Full article

Increased consumer awareness on food safety has spurred the development of detection techniques for pesticide residues. In this study, a rapid detection card on the basis of enzyme action was developed for the visual detection of pesticides, in which the thermally crosslinked and surface-decorated polyvinyl alcohol/citric acid nanofiber mat (PCNM) was employed as a novel immobilization matrix for acetylcholinesterase (AChE). The PCNM, crosslinked at 130 °C for 50 min, exhibited appropriate microstructure and water stability, making it suitable for AChE immobilization. The activation of carboxyl groups by surface decoration resulted in a 2.5-fold increase in enzyme loading capacity. Through parameter optimization, the detection limits for phoxim and methomyl were determined to be 0.007 mg/L and 0.10 mg/L, respectively. The detection card exhibited superior sensitivity and a reduced detection time (11 min) when compared to a commercially available pesticide detection card. Furthermore, the detection results of pesticide residues in fruit and vegetable samples confirmed its feasibility and superiority over commercial alternatives, suggesting its great potential for practical application in the on-site detection of pesticide residues. Full article

Black Chiloe’s giant garlic is a functional food produced by a mild Maillard reaction that contains relevant bioactive molecules like organosulfur compounds (OSCs) and (poly)phenols (PPs). Compared with raw garlic, black garlic has a higher content of PPs and S-allyl cysteine (SAC), a key OSC due to its bioactivities. The objective of the present work was to optimize by chemometric tools a green microwave-assisted extraction (MAE) of SAC and PPs present in black Chiloe’s giant garlic to detect and identify novel bioactive molecules with antioxidant and/or inhibitory activities over cyclooxygenase, α-glucosidase, and acetylcholinesterase enzymes. The MAE factors were optimized using a central composite design, establishing optimal PP and SAC yields at 67 °C, 0% ethanol, 12 min and 30 °C, 40% ethanol, 3 min, respectively. PP and SAC values were 9.19 ± 0.18 mg GAE/g DW and 2.55 ± 0.10 mg SAC/g DW. Applying effect-directed analysis using high-performance thin layer chromatography-bioassay and mass spectrometry, the bioactive molecules present in the MAE extract with antioxidant and inhibitory activities over cyclooxygenase, α-glucosidase, and acetylcholinesterase enzymes were identified as N-fructosyl-glutamyl-S-(1-propenyl)cysteine, N-fructosyl-glutamylphenylalanine, and Harmane. Full article

The search for selective anticholinergic agents stems from varying cholinesterase levels as Alzheimer’s Disease progresses from the mid-to-late stage and from butyrylcholinesterase’s (BChE) role in β-amyloid plaque formation. While structure-based and pharmacophore-based virtual screening could search from large libraries in a short time, these methods do not consider dynamic features that result from a ligand’s inhibition of the enzyme and consequently may under- or overexaggerate enzyme selectivity of a given ligand. In this computational study, we probed the selectivity of representative secondary metabolite compounds against acetylcholinesterase and BChE through molecular dynamics simulations. The results were evaluated by analysis of the root mean squared deviation of ligand heavy atoms, the radius of gyration of each inhibited and uninhibited enzyme, root mean squared fluctuation of residues, intermolecular interaction energy, and linear interaction energy approximation of the Gibbs free energy of binding. These considerations further reveal the induced-fit characteristics contributing to ChE selectivity that are predominantly due to the greater flexibility of BChE’s active site gorge. Full article

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

Alzheimer’s disease (AD) is characterized by β-amyloid plaques, neurofibrillary tangles, neuroinflammation, and oxidative stress—pathological features that pose significant challenges for the development of therapeutic interventions. Given these challenges, this review comprehensively evaluates the neuroprotective mechanisms of bioactive compounds derived from red algae, including polysaccharides and phycobiliproteins, which are considered a promising source of natural therapeutics for AD. Red algal constituents exhibit neuroprotective activities through multiple mechanisms. Sulfated polysaccharides (e.g., carrageenan, porphyran) suppress NF-κB-mediated neuroinflammation, modulate mitochondrial function, and enhance brain-derived neurotrophic factor (BDNF) expression. Phycobiliproteins (phycoerythrin, phycocyanin) and peptides derived from their degradation scavenge reactive oxygen species (ROS) and activate antioxidant pathways (e.g., Nrf2/HO-1), thus mitigating oxidative damage. Carotenoids (lutein, zeaxanthin) improve cognitive function through the inhibition of acetylcholinesterase and pro-inflammatory cytokines (TNF-α, IL-1β), while phenolic compounds (bromophenols, diphlorethol) provide protection by targeting multiple pathways involved in dopaminergic system modulation and Nrf2 pathway activation. Emerging extraction technologies—including microwave- and enzyme-assisted methods—have been shown to optimize the yield and maintain the bioactivity of these compounds. However, the precise identification of molecular targets and the standardization of extraction techniques remain critical research priorities. Overall, red algae-derived compounds hold significant potential for multi-mechanism AD interventions, providing novel insights for the development of therapeutic strategies with low toxicity. Full article

This study investigated the impact of sublethal concentrations of dinotefuran on the predatory behavior and detoxification enzyme activity of Harmonia axyridis, aiming to establish a theoretical foundation for the conservation and utilization of natural enemies and the effective management of wheat aphids. This study treated wheat aphids with sublethal concentrations (LC₂₀ and LC₃₀) of dinotefuran via the leaf dipping method and subsequently used them as prey for the fourth-instar larvae of H. axyridis. The predation amount, instantaneous attack rate, handling time, daily maximum predation amount, and detoxification enzyme activity of H. axyridis were statistically analyzed. The results indicated that the predation of H. axyridis on wheat aphids conformed to the Holling II disc equation. Moreover, in comparison to the control group, the handling time of H. axyridis on wheat aphids was extended, and at the same time, the instantaneous attack rate, maximum daily predation amount, and predation efficiency were all diminished. After the ingestion of LC₂₀- and LC₃₀-dinotefuran-treated aphids, the carboxylesterase levels in H. axyridis were not significantly different from the control, with levels 0.97-fold and 0.94-fold that of the control, respectively. Glutathione-S-transferase (GST) demonstrated an induction impact compared to the control, reaching 1.96- and 1.47-fold higher than the control, respectively. The activity of mixed-functional oxidase (MFO) demonstrated an induction effect compared to the control, measuring 1.98- and 3.04-fold higher than that of the control, respectively. Consequently, the predation function and detoxification enzyme activity of H. axyridis were influenced when consuming wheat aphids treated with sublethal concentrations of dinotefuran, with significant variations across different concentrations, potentially reflecting the survival strategy of insects under dinotefuran stress. 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

Aluminum (Al) is one of the most abundant metals on Earth and is well known as an environmental neurotoxic agent in the pathogenesis of Alzheimer’s disease. Aluminum toxicity is associated with oxidative stress, reduction of antioxidant enzymes, and disruption of the balance of cellular metals, such as iron (Fe), calcium (Ca), and copper (Cu), which causes structural and functional changes in the nervous tissue of the brain or peripheral nervous system. The intake of functional foods, rich in antioxidants, such as quercetin, may be beneficial in combating oxidative stress and neurodegenerative changes in the brain. The aim of this study was to provide deeper insight into the cellular and molecular neuroprotective effects of quercetin in regulating amyloid-beta (Aβ) accumulation, tau pathology, and neuroinflammation in the Al/D-galactose-induced rat model (Al/D-gal) of AD. The results showed that quercetin successfully modulated the impaired homeostatic and neuropathological consequences of aluminum chloride and D-galactose administration over 28 days: it directly protected neurons by regulating the level of oxidative stress and antioxidants, reduced Aβ aggregation by inhibiting the activity of acetylcholinesterase (AChE), increased the survival, growth, and differentiation of nerve cells by maintaining the level of brain-derived neurotrophic factor (BDNF), and regulated microglial immunoreactivity and neuroinflammation by reducing the level of proinflammatory cytokines. The multiple effects confirm that quercetin can be applied as an alternative non-pharmaceutical approach in reducing Al-induced neurotoxicity and maintaining adaptive homeostasis, which consequently affects the functioning of the central nervous system and the whole organism. Full article

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by synaptic dysfunction and neuronal loss due to the accumulation of amyloid-β peptides and tau proteins. In the pursuit of novel neuroprotective strategies, organotin(IV) compounds have garnered attention due to their unique chemical and biological properties. This study evaluates the inhibitory potential of two triphenyltin(IV) derivatives—(3-propan-1-ol)triphenyltin(IV) (Ph₃SnL₁) and (4-butan-1-ol)triphenyltin(IV) (Ph₃SnL₂)—in both free form and immobilized into mesoporous silica SBA-15~Cl, targeting acetylcholinesterase (AChE), a key enzyme involved in AD pathophysiology. The SBA-15~Cl|Ph₃SnL₂ nanostructures exhibited the most potent inhibitory activity against AChE (IC₅₀ = 0.58 μM), significantly outperforming the standard drug galantamine. Molecular docking, molecular dynamics simulations, and MM/GBSA and MM/PBSA analyses confirmed the stability and selectivity of interactions with AChE, primarily driven by hydrophobic interactions. Compound transport was also simulated using a multi-scale 3D mouse brain model to evaluate brain tissue distribution and blood–brain barrier permeability. The results highlight the strong potential of SBA-15-loaded organotin(IV) compounds as biocompatible neuroprotective agents for novel treatments of neurodegenerative diseases. Full article

The incorporation of selenium into tacrine derivatives has been explored as a novel strategy to enhance therapeutic efficacy while minimizing toxicity in the treatment of neurodegenerative diseases such as Alzheimer’s. This study utilized computational and experimental approaches, including Density Functional Theory (DFT), molecular docking, pharmacokinetic profiling, and toxicological predictions, to evaluate the potential of these derivatives. The selenium-modified compounds demonstrated improved electronic properties, such as narrower HOMO–LUMO gaps and optimized electronegativity, resulting in enhanced stability and reactivity. Pharmacokinetic analyses revealed favorable absorption, distribution, and blood–brain barrier penetration, while toxicological assessments indicated reduced hepatotoxicity and skin sensitization risks compared to tacrine. Molecular docking and dynamic simulations highlighted strong and stable interactions of the derivatives with critical enzymes, including acetylcholinesterase (AChE) and beta-secretases (BACE1 and BACE2). Compounds 12 and 13, in particular, emerged as the most promising candidates due to their superior stability and binding affinity. These findings underscore the potential of selenium-modified tacrine derivatives as safer and more effective therapeutic agents for Alzheimer’s disease, warranting further experimental validation. Full article

In this study, the ranking of the multifaceted activity of rutin (Ru), quercetin (Q), and quercetin’s glucosides (Q3G, Q4′G and Q3,4′G) was addressed. The antioxidant potency was determined by electrochemical methods, whereas the ability of these compounds to inhibit angiotensin-converting enzyme (ACE) activity, acetylcholinesterase (AChE) activity, and advanced glycation endproduct (AGE) formation was examined in bovine serum albumin (BSA)/glucose and BSA/methylglyoxal (MGO) model systems to show their importance against hypertension, Alzheimer-type dementia, and diabetic complication, respectively. Then, the relationship between the biological activities of these compounds and their antioxidant potential provided by the cyclic voltammetry (CV) method was evaluated. The ranking of the ACE inhibitory activity was Q > Q3,4′G > Ru > Q3G > Q4′G. The correlation coefficient between ACE enzyme inhibitory activities and antioxidant potentials had a value of r = −0.68, thus clearly indicating the impact of antioxidant potential and chemical structure on ACE inhibitory activity. The ranking of the AChE enzyme inhibitory activity was Q ≈ Q3G ≈ Q4′G ≈ Ru > Q3,4′G, and the correlation between their antioxidant potentials and AChE inhibitory activities (r = −0.77) also indicated the impact of chemical structure. The quercetin glucosides displayed strong inhibitory capacity on AGE formation, as the ranking of anti-AGE activity in the BSA/MGO model system was Q3,4′G ≈ Q4′G ≈ Q3G > Ru ≈ Q > AG. The anti-AGE activity of rutin, quercetin, and quercetin’s glucosides was negatively correlated with their IC₅₀ values for ACE inhibition (r = −0.67) and AChE inhibition (r = −0.81), whereas no correlation was found between their ACE and AChE inhibition activities. These effects of rutin, quercetin, and quercetin’s glucosides expand our knowledge of the multifunctional activity of biologically active compounds of plant origin. Full article

In aquaculture, pre-slaughter fasting reduces stress and improves muscle quality. Fasting periods of 55–58 degree days (°C d) enhance muscle structure and post-mortem biochemistry in rainbow trout (Oncorhynchus mykiss), although optimal durations vary with temperature. This study investigated the effects of fasting from none to extended durations on 495 rainbow trout under summer (22 °C) and winter (8 °C) conditions. In summer, elevated temperatures increased muscle glycogen, leading to lower pH and delayed rigor mortis (RM), especially in fasted groups, where RM peaked at 24 h post-mortem. In winter, RM occurred earlier. Prolonged fasting increased acetylcholinesterase (AChE) activity, with high baseline levels in non-fasted summer fish. Muscle lightness at 0 h post-mortem was highest in non-fasted winter fish but declined to summer levels in fasted groups. Antioxidant enzyme activity (glutathione-S-transferase, glutathione peroxidase) increased with fasting in winter, while summer heat masked responses. The expression of genes for mineralocorticoid receptors and heat shock proteins remained stable in warm conditions. Summer delayed metabolic decline due to higher glycogen-triggered excessive AChE activity from heat stress. Winter supported faster metabolic adjustment and more regulated enzyme activity. These findings highlight the need to adjust fasting strategies seasonally to optimize muscle traits, especially under thermal variations. Full article

Erica spiculifolia Salisb. (formerly Bruckenthalia spiculifolia Benth.) (Balkan heath) is renowned for its traditional usage as a diuretic, anti-inflammatory and antioxidant agent. For the first time, acylquinic acids, flavonoids and numerous proanthocyanidin oligomers were annotated/dereplicated by liquid chromatography–high-resolution mass spectrometry in methanol–aqueous extracts from E. spiculifolia aerial parts harvested at the early and full flowering stage. Chlorogenic acid and proanthocyanidin tetra- and trimer A, B-type together with quercitrin and (+) catechin were the predominant compounds in the semi-quantitative analysis. Neutral triterpenoids, triterpenoid acids and phytosterols were determined in apolar extracts by gas chromatography–mass spectrometry. Triterpenoid acids accounted for 80% of the total triterpenoid content, dominated by ursolic and oleanolic acid, reaching up to 32.2 and 6.1 mg/g dw, respectively. Ursa/olean-2,12-dien-28-oic acids and 3-keto-derivatives together with α-amyrin acetate as a chemotaxonomic marker, α-amyrenone, α- and β-amyrin were evaluated. Total phenolic and flavonoid contents were 83.85 ± 0.89 mg gallic acid equivalents/g and 78.91 ± 0.41 mg rutin equivalents/g, respectively. The extract actively scavenged DPPH and ABTS radicals (540.01 and 639.11 mg Trolox equivalents (TE)/g), possessed high potential to reduce copper and iron ions (660.32 and 869.22 mg TE/g, respectively), and demonstrated high metal chelating capacity (15.57 Ethylenediaminetetraacetic acid equivalents/g). It exhibited prominent anti-lipase (18.32 mg orlistat equivalents/g) and anti-tyrosinase (71.90 mg kojic acid equivalents/g) activity. The extract inhibited α-glucoside (1.35 mmol acarbose equivalents/g) and acetylcholinesterase (2.56 mg galanthamin equivalents/g), and had moderate effects on α-amylase, elastase, collagenase and hyaluronidase. Balkan heath could be recommended for raw material production with antioxidant and enzyme inhibitory properties. Full article

Artemisia schmidtiana Maxim., a plant belonging to the Asteraceae family, is renowned for its extensive ethnomedicinal applications and distinctive aromatic qualities. This study evaluated the chemical composition, antioxidant capacity, and inhibitory effects on acetylcholinesterase (AChE), α-glucosidase, and β-lactamase of its essential oil (EO). The major constituents of the EO were identified as germacrene D (16.29%), falcarinol (11.02%), β-caryophyllene (9.43%), α-zingiberene (7.93%), phytol (6.06%), and α-humulene (4.04%). The EO demonstrated radical scavenging activity against DPPH (44.9% at 5 mg/mL) and ABTS (IC₅₀ = 0.72 ± 0.02 mg/mL) radicals, with a FRAP antioxidant capacity of 126.61 ± 0.59 μmol·g⁻¹. Additionally, the EO exhibited modest AChE inhibition (16.7% at 250 μg/mL) and significant inhibition of α-glucosidase and β-lactamase, with IC₅₀ values of 178.80 ± 17.02 μg/mL and 40.06 ± 8.22 μg/mL, respectively. Molecular docking revealed favorable interactions between the major EO compounds and the tested enzymes, providing a theoretical foundation for future drug development. These findings suggest that A. schmidtiana EO holds potential for applications in the food and pharmaceutical industries, warranting further investigation. Full article