Acetylcholinesterase Activity Research Articles

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

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

Components in SLPE Alleviate AD Model Nematodes by Up-Regulating Gene gst-5.

Salvia leucantha is a perennial herb of the genus Salvia in the family Labiatae, which has a wide range of biological activities, mainly including inhibition of acetylcholinesterase, antibacterial, and anti-inflammatory activity. To explore the protective effects and mechanism of action of S. leucantha on Alzheimer's disease (AD), the anti-AD activity of SLE (extracts of S. leucantha) was determined by using a transgenic Caenorhabditis elegans (C. elegans) model (CL4176). Analyses included paralysis assay, phenotypic experiments, transcriptome sequencing, RNA interference (RNAi), heat shock assays, and gas chromatography-mass spectrometry (GC-MS). SLPE (S. leucantha petroleum ether extract) could significantly delay CL4176 paralysis and extend the longevity of C. elegans N2 without harmful effects. A total of 927 genes were significantly changed by SLPE treatment in C. elegans, mainly involving longevity regulatory pathways-nematodes, drug metabolism-cytochrome P450, and glutathione metabolic pathways. RNAi showed that SLPE exerted its anti-AD activity through up-regulation of the gene gst-5; the most abundant compound in SLPE analyzed by GC-MS was 2,4-Di-tert-butylphenol (2,4-DTBP), and the compound delayed nematode paralysis. The present study suggests that active components in S. leucantha may serve as new-type anti-AD candidates and provide some insights into their biological functions.

Drosophila melanogaster as a model organism for screening acetylcholinesterase reactivators

ABSTRACT The widely used insecticide chlorpyrifos (CP) is known to inhibit acetylcholinesterase (AChE) activity attributed to result in various neurological disorders and acetylcholine-dependent organ functions including heart, skeletal muscle, lung, gastrointestinal tract, and central nervous systems. Enzyme reactivators, such as oximes, are known to restore AChE activity and mitigate adverse effects. The identification of compounds that reactivate AChE constitute agents with important therapeutic beneficial effects in cases of pesticide poisoning. However, the screening of novel drugs using traditional models may raise ethical concerns. This study aimed to investigate the potential of Drosophila melanogaster as a model organism for screening AChE reactivators, with a focus on organophosphate poisoning. The efficacy of several oximes, including pralidoxime, trimedoxime, obidoxime, methoxime, HI-6, K027, and K048, against CP-induced AChE activity inhibition in D. melanogaster was determined in silico, in vitro, and in vivo experiments. Molecular docking studies indicated a strong interaction between studied oximes and the active-site gorge of AChE. Data showed that selected oximes (100 μM) are effective in the reactivation of AChE inhibited by CP (10 μM) in vitro. Finally, in vivo investigations demonstrated that selected oximes, pralidoxime and K048 (1.5 ppm), reversed the locomotor deficits, inhibition of AChE activity as well as lowered the mortality rates induced by CP (0.75 ppm). Our findings contribute to utilization of D. melanogaster as a robust model for determination of actions of identified new AChE inhibitory agents with more effective therapeutic properties that those currently in use in the clinical practice in treatment of AChE associated disorders.

Insights into the neurotoxicity and oxidative stress to the freshwater amphipod Hyalella azteca induced by hexafluoropropylene oxide trimer acid

With the regulation and phase-out of conventional per- and polyfluoroalkyl substances (PFAS), there is a growing trend towards seeking alternatives that are less toxic and less persistent. Hexafluoropropylene oxide trimer acid (HFPO-TA) is one of the alternatives to perfluorooctanoic acid (PFOA), the latter being widely present in the environment globally. However, there is limited information regarding the biological toxicity of HFPO-TA to aquatic organisms. In this study, the freshwater benthic amphipod, Hyalella azteca, was used to assess the acute and chronic toxicity of HFPO-TA in both water and sediment. HFPO-TA was found to be more toxic to H. azteca than PFOA, as indicated by greater production of reactive oxygen species (p < 0.05) and increasing catalase activity (p < 0.05). In addition, exposure to HFPO-TA affected the swimming behavior and the acetylcholinesterase (AChE) activity of the amphipod. Molecular docking models revealed that HFPO-TA can bind to AChE with a stronger binding affinity than PFOA. Furthermore, an integrated biomarker response index indicated that environmentally relevant concentration (1–100 μg/L) of HFPO-TA may cause toxicity to H. azteca, encompassing oxidative stress and neurotoxicity. This study provides new insights into the toxicity mechanisms of HFPO-TA and is valuable for assessing the ecological safety of this compound.

Discovery of thiourea based acetylcholinesterase inhibitors and antibacterial agents: Synthesis, in vitro, structure-activity relationship and in silico study

In current work, we have synthesized a novel class of compounds (1-6) and assessed their acetylcholinesterase and antibacterial investigations to find out the most potent analogs. In this series, only two analogs were found to be the most potent against acetylcholinesterase and antibacterial activity. Analog (1, 25.35 ± 0.21 µM for acetylcholinesterase, ZOI 18.167 ± 0.7638 mm & MIC 149 μg/cm3 for antibacterial) & (6, 45.81 ± 0.02 µM acetylcholinesterase, ZOI 13.10 ± 0.5568 mm & MIC 180 μg/cm3 for antibacterial) shown to be the highest activity against both of them. In order to investigate the binding affinity of active residue molecular docking study. While the docking score energy for compounds 5, and 6 were the highest ones obtained for compound 5 was -8.2214 kcal/mol with an RMDS refine of 1.5843, while compound 6 was -8.0047 kcal/mol, with an RMDS refine of 1.3806.All of the above results confirm the analogue 5 & 6 are index as more potent than the others. Furthermore, all of the synthesized are characterized through modern spectroscopic techniques such as NMR and FTIR. In the future these are further assessed their cytotoxic effects and many more.

Fluorescent Iron-Doped Polymer Dot Nanozyme-Based Cascade System for Dual-Mode Detection of Acetylcholinesterase Activity and Its Inhibitors.

The advancement of acetylcholinesterase (AChE) activity and its inhibitor assays is crucial for clinical diagnosis, drug screening, and environmental monitoring. A nanozyme-mediated cascade reaction system could offer promising prospects for a wide range of applications in such biosensing; however, the creation of nanozyme catalysts with diverse functionalities remains a significant challenge. Herein, we have proposed a multifunctional iron-doped polymer dots (Fe-PDs) nanozyme possessing excellent fluorescence and peroxidase (POD)-mimicking activity. Notably, the Fe-PDs nanozyme is capable of catalyzing H2O2 to produce a series of reactive oxygen species, which can simultaneously quench the fluorescence of Fe-PDs and induce a chromogenic reaction of 3,3',5,5'-tetramethylbenzidine (TMB), enabling the dual-mode detection of H2O2 through both fluorescence turn-off and absorbance turn-on signals. Furthermore, by integrating acetylcholine (ACh) and choline oxidase (ChOx), we have developed a three-enzyme (AChE-ChOx-POD) cascade-based fluorometric and colorimetric dual-mode sensing platform for monitoring AChE activity and its inhibitors. The sensitive and convenient dual-mode sensor has achieved low limits of detection with 0.5 mU/mL (fluorometry) and 0.014 mU/mL (colorimetry) for AChE, respectively, which are superior to the traditional Ellman's assay. More significantly, this sensor can also be extended to detect the reversible and irreversible inhibitors of AChE, such as tacrine (IC50 = 23.3 nM) and carbaryl (LOD = 0.8 nM). We firmly believe that this innovative dual-mode nanozyme-involved multienzyme cascade system-based sensing strategy will stimulate further exploration and serve as a versatile and practical tool for biochemical sensing applications.

Green synthesis of silver nanoparticles using carob leaf extract: Characterization and analysis of toxic effects in model organism Galleria mellonella L. (The greater wax moth).

Silver nanoparticles (Ag NPs) have been used in many studies due to their inhibitory properties on microorganisms such as bacteria and viruses. In recent years, due to global problems such as environmental pollution, the green synthesis (biosynthesis) method is frequently preferred because it is simple and low cost and does not require the use of toxic substances. The aim of this study is to synthesize silver nanoparticles (Ag NPs) from Ceratonia siliqua L. leaves and investigate their antioxidant and immunotoxic properties using Galleria mellonella last instar larvae. The UV spectrophotometer, TEM, XRD and FTIR measurements were used to characterize the Ag NPs. In this study, it was determined that the effects on antioxidant enzyme activities (SOD, CAT, GPx, GST), acetylcholinesterase (AChE) and total hemocyte count (THC) as well as phenoloxidase activity determine their effect on antioxidant defence and the immune system in model organism G. mellonella larvae. We observed that green synthesized Ag NPs accumulate in the midgut of the larvae and led to the increasing of CAT and SOD activities. GST and AChE activities were increased in the fat body of the larvae; otherwise, it was decreased in the midgut. Moreover, increases were found in THC and phenoloxidase activity. Consequently, green synthesized silver nanoparticles led to oxidative stress and immunotoxic effects on G. mellonella larvae.

Different mulch films, consistent results: soil fauna responses to microplastic

Agricultural activities contribute to plastic pollution, with unintentional introduction and intentional use of plastic mulch films leading to the accumulation of microplastic particles in soils. The lack of removal techniques and scarce information on the effects on soil organisms, especially for biodegradable mulch films, necessitate an assessment of potential effects. This study aimed to elucidate the effects of mulch film microplastic on soil fauna by investigating reproduction output and subcellular responses before and after recovery from exposure. Two common soil organisms, Folsomia candida and Eisenia fetida, were exposed to petroleum-based polyethylene (PE) and biodegradable polylactic acid/polybutylene adipate terephthalate (PLA/PBAT) microplastic for 28 days, according to OECD guidelines 232 and 222, respectively. Juvenile numbers revealed no polymer- or concentration-dependent effects on E. fetida and F. candida reproduction after exposure to up to 5 and 10 g/kgdw soil, respectively. To provide a more sensitive and early indication of sublethal effects, subcellular responses in E. fetida were analyzed. Glutathione S-transferase (GST) activity increased with rising microplastic concentration; however, catalase (CAT), acetylcholine esterase (AChE) activity, and reactive oxygen species (ROS) did not differ from control levels. Further, the more environmentally relevant PE polymer was chosen for in-depth assessment of subcellular response after 28-day microplastic exposure and subsequent 28 days in uncontaminated soil with E. fetida. No significant differences in biomarker activity and stress levels were observed. We conclude that mulch film–derived microplastic did not adversely affect earthworm and collembolan species in this scenario, except for a slight induction in the detoxification enzyme glutathione S-transferase.

Potential of insect growth regulators for the control of Musca domestica (Diptera: Muscidae) with respect to their biochemical and histological effects

BackgroundHousefly causes a variety of health problems to humans and animals. Therefore, it is crucial to find out effective methods for the control of housefly larvae to avoid health problems associated with the presence this disease vector insect. Efficacy of insect growth regulators (IGRs), chlorfluazuron, lufenuron, methoxyfenozide and pyriproxyfen, against larvae of Musca domestica (Diptera: Muscidae), was assessed. The IGRs were mixed with food media at concentrations of 2.5, 5.0, 10.0, 25.0, 50.0, 75.0 and 100.0 mg/kg (ppm).ResultsThe highest larvicidal activity was obtained by chlorfluazuron and pyriproxyfen with LC50 values of 6.79 and 7.10 ppm, respectively, 72 h post-treatment. Also, 25.0 ppm of chlorfluazuron and 75.0 ppm of methoxyfenozide as well as lufenuron were shown to fully suppress adult emergence and survival percentages (0.0%). Moreover, the activity of three digestive enzymes suppressed in the treated larvae with pyriproxyfen and chlorfluazuron: amylase (enzyme ratio (ER) = 0.71 and 0.78), lipase (ER = 0.54 and 0.63) and proteases (ER = 0.62 and 0.66), respectively. Also, methoxyfenozide and pyriproxyfen inhibited acetylcholinesterase (AChE) and general-esterase (GE) activity with ER (0.28 and 0.59) and (0.61 and 0.72), respectively. The histological examination of M. domestica larvae treated with IGRs showed changes in midgut; for example, the epithelial cells were broken, deformed and loss their columnar structure. Also, the peritrophic membrane disappeared completely.ConclusionsThe findings of the current study indicate that the tested IGRs have a potential to be applied in IPM programs of M. domestica.

Exploring the neuroprotective potential of KC14 peptide from Cyprinus carpio against oxidative stress-induced neurodegeneration by regulating antioxidant mechanism.

Oxidative stress, a condition characterized by excessive production of reactive oxygen species (ROS), can cause significant damage to cellular macromolecules, leading to neurodegeneration. This underscores the need for effective antioxidant therapies that can mitigate oxidative stress and its associated neurodegenerative effects. KC14 peptide derived from liver-expressed antimicrobial peptide-2A (LEAP 2A) from Cyprinus carpio L. has been identified as a potential therapeutic agent. This study focuses on the antioxidant and neuroprotective properties of the KC14 peptide is to evaluate its effectiveness against oxidative stress and neurodegeneration. The antioxidant capabilities of KC14 were initially assessed through in silico docking studies, which predicted its potential to interact with oxidative stress-related targets. Subsequently, the peptide was tested at concentrations ranging from 5 to 45 µM in both in vitro and in vivo experiments. In vivo studies involved treating H2O2-induced zebrafish larvae with KC14 peptide to analyze its effects on oxidative stress and neuroprotection. KC14 peptide showed a protective effect against the developmental malformations caused by H2O2 stress, restored antioxidant enzyme activity, reduced neuronal damage, and lowered lipid peroxidation and nitric oxide levels in H2O2-induced larvae. It enhanced acetylcholinesterase activity and significantly reduced intracellular ROS levels (p < 0.05) dose-dependently. Gene expression studies showed up-regulation of antioxidant genes with KC14 treatment under H2O2 stress. This study highlights the potent antioxidant activity of KC14 and its ability to confer neuroprotection against oxidative stress can provide a novel therapeutic agent for combating neurodegenerative diseases induced by oxidative stress.

Carvacrol improves cognitive dysfunction by decreasing amyloid-β accumulation and regulating neuroinflammation in ovariectomized renovascular hypertensive rats.

Hypertension contributes to both the development and progression of brain damage and cognitive dysfunction in the postmenopausal period in women. Carvacrol (CAR), which can easily cross the blood-brain barrier, exhibits neuroprotective properties due to its antioxidant, anti-inflammatory, and anti-apoptotic effects. In the present study, we have examined the effect of CAR treatment on learning-memory impairment in a post-menopausal hypertensive rat model that was induced by ovariectomy following two-kidney, one-clip renovascular hypertension surgery. From the third week after the establishment of renovascular hypertension in ovariectomized rats, CAR (40 mg/kg) was administered once daily for consecutive 7 weeks by gastric gavage. Systolic blood pressure was estimated by the tail-cuff method once a week. At the end of the study, cognitive functions were evaluated with behavioral tests and also neurochemical changes were measured in serum, cortex, and hippocampus by ELISA test. Blood pressure was decreased with CAR treatment in hypertensive rats. Serum estrogen levels decreased in ovariectomized rats and did not change with CAR treatment. CAR demonstrated beneficial effects on learning and memory tests as determined by increased recognition index, the number of platforms crossed, and time spent in the target quadrant. Due to CAR treatment, there was a marked reduction in the hippocampal and cortex amyloid-β, osteopontin, interleukin-6 and tumor necrosis factor-alpha levels, and acetylcholinesterase activity, while an increment in neprilysin and interleukin-10 levels was found. In conclusion, since CAR suppressed amyloid-β deposition and neuroinflammation in ovariectomized-hypertensive rats, it is thought that it may be protective against memory disorders in postmenopausal hypertensive women.

Protective effects of betanin, a novel acetylcholinesterase inhibitor, against H2O2-induced apoptosis in PC12 cells.

Dysfunction of the cholinergic system and increased oxidative stress have a crucial role in cognitive disorders including Alzheimer's disease (AD). Here, we have investigated the protective effects of betanin, a novel acetylcholinesterase (AChE) inhibitor, on hydrogen peroxide (H2O2)-induced cell death in PC12 cells. The protective effects were assessed by measuring cell viability, the amount of reactive oxygen species (ROS) production, AChE activity, cell damage, and apoptosis using resazurin, 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA), Ellman method, lactate dehydrogenase (LDH) release, propidium iodide (PI) staining and flow cytometry, and Western blot analysis. H2O2 (150µM) resulted in cell viability reduction and apoptosis induction while, pretreatment with the betanin (10, 20, and 50μM) and N-Acetyl-L-cysteine (NAC) (2.5 and 5mM) significantly increased the viability (P < 0.05, P < 0.01 and P < 0.001) and at 5-50μM betanin decreased ROS amount (P < 0.05, P < 0.01 and P < 0.001). Whereas, pretreatment with the betanin (10, 20, and 50μM) decreased AChE activity (P < 0.001), also at 20 and 50μM betanin reduced the release of LDH (P < 0.001), and at 10-50μM decreased the percentage of apoptotic cells (P < 0.001). Apoptosis biomarkers such as cleaved poly (ADP-ribose) polymerase (PARP) (P < 0.01 and P < 0.001) and cytochrome c (P < 0.05 and P < 0.001) were attenuated after pretreatment of PC12 cells with betanin at 10-20μM and 10-50μM respectively. Indeed, survivin (P < 0.001) increased after pretreatment of cells with betanin at 10-20μM. Overall, betanin may use the potential to delay or prevent cell death caused by AD through decreasing the activity of AChE as well as attenuating the expression of proteins involved in the apoptosis pathway.

Bioactive Properties of Enzymatic Gelatin Hydrolysates Based on In Silico, In Vitro, and In Vivo Studies.

This current study aims to analyze the potential bioactivities possessed by the enzymatic hydrolysates of commercial bovine, porcine, and tilapia gelatins using bioinformatics in combination with in vitro and in vivo studies. The hydrolysate with superior inhibition of angiotensin converting enzyme (ACE) activity was used to treat the D-galactose (DG)-induced amnesic mice. In silico digestion of the gelatins led to the identification of peptide sequences with potential antioxidant, ACE-inhibitory, and anti-amnestic properties. The results of in vitro digestion revealed that the <1 kDa peptide fraction of porcine gelatin hydrolysate obtained after 1 h digestion with papain (PP) (PP1, <1 kDa) potently inhibited ACE, acetylcholinesterase, and prolyl endopeptidase activities at 87.42%, 21.24%, and 48.07%, respectively. Administering the PP1 to DG-induced amnesic mice ameliorated the spatial cognitive impairment and Morris water maze learning abilities. The dentate area morphology in the PP1-treated mice was relatively similar to the control group. In addition, PP1 enhanced the antioxidant capacity in the DG-induced amnesic mice. This study suggests that PP1 could serve as a potential treatment tool against oxidative stress, hypertension, and neurodegenerative diseases.

Biosynthesis and biological activities of magnesium hydroxide nanoparticles using Tinospora cordifolia leaf extract.

The synthesis of magnesium hydroxide nanoparticles (Mg(OH)2 NPs) using plant extracts are known to be a practical, economical, and an environmentally friendly approach. In this work, Mg(OH)2 NPs were synthesized using aqueous leaf extract of Tinospora cordifolia, a medicinal plant commonly found in India. The synthesized Mg(OH)2 NPs were characterized using various spectroscopic techniques. The ultraviolet-visible (UV-Vis) absorption peak of the Mg(OH)2 NPs was detected at 289nm, Fourier transform infrared (FTIR) analysis confirmed the presence of various functional groups, and X-ray diffraction (XRD) patterns revealed the well-crystallized structure of the Mg(OH)2 NPs. High-resolution transmission electron microscopy (HR-TEM) and scanning electron microscopy (SEM) analyses depicted spherical morphology and an average particle size (PS) of 27.71nm. The energy-dispersive X-ray (EDX) analysis confirmed the presence of C, O, and Mg elements, and the X-ray photoelectron spectroscopy (XPS) survey spectrum confirmed the elements for the Su 1s peak at 280.2eV. The dynamic light scattering (DLS) analysis displayed an average PS of 54.3nm, and the Zeta potential (ZP) was of 9.89mV. The fabricated Mg(OH)2 NPs displayed notable antibacterial activity against S. epidermidis, E. coli, and S. aureus. In addition, these NPs exhibited strong antioxidant properties (> 75%) based on DPPH, ABTS, and hydrogen peroxide (H2O2) assays. Further, the same NPs exerted a potent anti-inflammatory activity (> 65%) based on COX-1 and COX-2 evaluations. The anti-Alzheimer' disease (AD) potential of Mg(OH)2 NPs was assessed through effective inhibition (> 70%) of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities. Molecular docking (MD) studies confirmed that caryophyllene has higher binding affinity with AChE (-5.3kcal/mol) and BuChE (-6.4kcal/mol) enzymes. This study emphasizes the green synthesis of Mg(OH)2 NPs using T. cordifolia as a plant source and highlights their potential for biomedical applications.

Therapeutic effects of alpha lipoic acid and/or caffeine-loaded chitosan nanoparticles on memory impairment and neurochemical changes in high-fat diet-induced obese rats

The therapeutic effects of alpha lipoic acid (LA) and/or caffeine-loaded chitosan nanoparticles (CCNPs) on obesity-induced memory impairment were evaluated in the present study. Rats were divided into control rats, obese rats induced by high fat diet (HFD) and obese rats treated with LA and/or CCNPs. Obesity was confirmed by measuring the body mass index (BMI). Memory and cognitive functions were evaluated by novel object recognition test (NORT). The levels of serotonin (5-HT), dopamine (DA), norepinephrine (NE), lipid peroxidation (MDA), nitric oxide (NO), reduced glutathione (GSH), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), leptin (LEP) and ghrelin (GHR) and the activities of monoamine oxidase (MAO), acetylcholinesterase (AchE) and Na+,K+,ATPase were determined in the cortex and hippocampus. The cerebral histopathological alterations were examined in obese rats.Obese rats showed impaired memory and exhibited significant neurochemical changes, including decreased levels of 5-HT, DA, GSH, GHR, and Na+,K+-ATPase activity, as well as an increase in AchE, MAO, MDA, NO, IL-1β, TNF-α, and LEP. LA and/or CCNPs treatment reduced BMI and improved memory. LA or CCNPs alleviated the cortical and hippocampal neurochemical changes and histopathological changes induced by obesity. Furthermore, LA and CCNPs exhibited antioxidant and anti-inflammatory properties, which likely contributed to their effects. However, no synergistic effect was observed between LA and CCNPs. These findings suggest that LA or CCNPs may be a potential therapy against obesity and its adverse effects on memory, mediated by their ability to restore monoamine levels and exhibit antioxidant and anti-inflammatory properties.

Effects of diphenhydramine on crayfish cytochrome P450 activity and antioxidant defence mechanisms: First evidence of CYP2C- and CYP3A-like activity in marbled crayfish

Growing evidence has reported that diphenhydramine (DPH), an ionisable antihistamine, is widely present in surface waters across the world. Relative to vertebrates studied, its impact on invertebrates, particularly concerning cytochrome P450 (CYP) metabolism and oxidative stress, remains poorly understood. In this study, we aimed to investigate the effects of 2, 20, and 200 µg/L DPH on marbled crayfish (Procambarus virginalis) after 96-h exposure. Specifically, we assessed CYP activity, antioxidant enzyme responses, and acetylcholinesterase (AChE) activity in gills, muscle, and hepatopancreas. The crayfish CYP metabolised fluorogenic CYP-metabolic substrates of 7-benzyloxy-4-trifluoromethylcoumarin (BFC) and dibenzylfluorescein (DBF), which evidenced the activity of CYP2C and CYP3A isoforms, well known in mammalian detoxification metabolism. Both BFC and DBF dealkylations showed a positive correlation with each other but were negatively correlated to water and haemolymph DPH concentrations. Exposure to 200 µg/L DPH elicited an apparent inhibition trend, albeit not significant, in BFC- and DBF-transformation activities in crayfish. Other tested 7-benzyloxyresorufin and 7-pentoxyresorufin substrates were poorly metabolised, suggesting their relatively low activity or the lack of mammalian-like CYP1A and CYP2B isoforms in marbled crayfish. The significant modulation of antioxidant enzymes was demonstrated in gills and hepatopancreas. The exposure to DPH did not alter the activity of AChE. Integrated biomarker response version 2 showed the highest cumulative effect of DPH exposure on gills, implying that gill tissue is the most reliable matrix for evaluating DPH toxicity. Activities of glutathione peroxidase and glutathione-S-transferase were the most deviated determinants among the investigated biomarkers, providing insights into the DPH toxicity in crayfish. This study brought the first insight into utilising the fluorogenically active substrates BFC and DBF to demonstrate the CYP involvement in the detoxification metabolism in marbled crayfish. Further, our results provided information on valuable antioxidant defence mechanisms and biomarker responses for a future DPH toxicity assessment in aquatic organisms.

Blackcurrant (Ribes nigrum L.) improves cholinergic signaling and protects against chronic Scopolamine-induced memory impairment in mice.

Blackcurrant (Ribes nigrum L.) is a berry rich in anthocyanins, bioactive compounds known for their antioxidant and neuroprotective properties that benefit human health. This study aimed to investigate the effects of blackcurrant and its association with Donepezil on memory impairment, cholinergic neurotransmission, and antioxidant systems in a mouse model of amnesia induced by chronic administration of Scopolamine. Adult male Swiss mice were given saline, blackcurrant (50 mg/kg, orally), and/or Donepezil (5 mg/kg, orally) and/or Scopolamine (1 mg/kg, intraperitoneally). Behavioral tests revealed that blackcurrant and/or Donepezil prevented the learning and memory deficits induced by Scopolamine. In the cerebral cortex and hippocampus, blackcurrant and/or Donepezil treatments prevented the increase in acetylcholinesterase and butyrylcholinesterase activities induced by Scopolamine. Scopolamine also disrupted the glutathione redox system and increased levels of reactive species; nevertheless, blackcurrant and/or Donepezil treatments were able to prevent oxidative stress. Furthermore, these treatments prevented the increase in gene expression and protein density of acetylcholinesterase and the decrease in gene expression of the choline acetyltransferase enzyme induced by Scopolamine. Findings suggest that blackcurrant and Donepezil, either alone or in combination, have anti-amnesic effects by modulating cholinergic system enzymes and improving the redox profile. Therefore, blackcurrant could be used as a natural supplement for the prevention and treatment of memory impairment in neurodegenerative diseases.

Metabolic variation and oxidative stress responses of clams (Ruditapes philippinarum) perturbed by ofloxacin exposure

Ofloxacin (OFL), one of the most widely used fluoroquinolone antibiotics, has been frequently detected in marine environments. Nonetheless, researchers are yet to focus on the effects of OFL on the benthos. In the present study, marine clams (Ruditapes philippinarum) were exposed to OFL (0.5, 50, and 500 μg/L) for 14 d, followed by a 7 d depuration period. The accumulation of OFL, antioxidative defense responses, neurotoxicity, burrowing behavior, and metabolomic changes in clams were evaluated. The results indicated that OFL could accumulate in clams, albeit with a low bioaccumulation capacity. The intermediate (50 μg/L) and high (500 μg/L) levels of OFL induced significant antioxidative responses in the gills and digestive glands of clams, mainly manifesting as the inhibition of catalase activities and the induction of superoxide dismutase and glutathione S-transferase activities, which ultimately elevated the content of malondialdehyde, causing oxidative damage. Furthermore, the significant induction of acetylcholinesterase activities was observed, coinciding with a significant increase in burrowing rates of clams. The high level of OFL affected glycerophospholipid, arachidonic acid, steroid hormone biosynthesis, unsaturated fatty acids biosynthesis, and glycolysis/glycogenesis metabolism. In conclusion, this study has contributed to the understanding of the physiological and biochemical effects and molecular toxicity mechanisms of OFL to marine bivalves.

Assessment of sub-lethal effects of Celcron on Java barb through erythrocyte morphology and acetylcholinesterase activity: Implications for environmental health in aquatic ecosystems

Industrialization and the extensive use of chemicals have raised significant concerns about their environmental impacts, particularly on aquatic ecosystems. This study evaluated the sub-lethal effects of Celcron (Cec), an organophosphate insecticide, on the Java barb (Barbonymus gonionotus) through erythrocyte morphology and acetylcholinesterase (AChE) activity, aiming to refine biomarkers for environmental health assessments. We hypothesized that sub-lethal Cec exposure would induce significant erythrocyte abnormalities and decrease AChE activity in Java barb, with variable recovery rates between gill and kidney tissues. To test this, we exposed the juvenile Java barbs to two sub-lethal Cec concentrations - 0.01 ppm (10 % of the LC50) and 0.05 ppm (50 % of the LC50) -for 60 days. After the exposure period, the fish were placed in pesticide-free water to allow for recovery. Results indicated a significant decline in AChE activity in both liver and kidney tissues, with activity levels showing gradual recovery over time. Erythrocyte abnormalities, including nuclear and cellular changes, were significantly elevated in response to Cec exposure. The frequency of nuclear abnormalities such as micronuclei and binucleation increased in a concentration- and duration-dependent manner, with the gill blood exhibiting higher sensitivity and slower recovery compared to kidney blood. Cellular abnormalities such as twin, teardrop and spindle-shaped cells were also more prevalent in Cec-treated fish. Recovery from these abnormalities was observed but varied between gill and kidney blood, with gill blood showing higher sensitivity and slower recovery compared to kidney blood. This study underscores the utility of AChE activity and erythrocyte abnormalities as biomarkers for assessing pesticide impacts on aquatic organisms. The findings highlight the sensitivity of fish erythrocytes to environmental contaminants and emphasize the need for continued research to better understand the long-term effects of pesticide exposure on aquatic health and ecosystem stability.

Zeaxanthin and Lutein Ameliorate Alzheimer's Disease-like Pathology: Modulation of Insulin Resistance, Neuroinflammation, and Acetylcholinesterase Activity in an Amyloid-β Rat Model.

Alzheimer's disease (AD) is characterized by impaired insulin/insulin-like growth factor-1 signaling in the hippocampus. Zeaxanthin and lutein, known for their antioxidant and anti-inflammatory properties, have been reported to protect against brain damage and cognitive decline. However, their mechanisms related to insulin signaling in AD remain unclear. This study investigated the efficacy and mechanisms of zeaxanthin, lutein, and resveratrol in modulating an AD-like pathology in an amyloid-β rat model. Rats were administered hippocampal infusions of 3.6 nmol/day amyloid-β (Aβ)(25-35) for 14 days to induce AD-like memory deficits (AD-CON). Normal control rats received Aβ(35-25) (Normal-CON). All rats had a high-fat diet. Daily, AD rats consumed 200 mg/kg body weight of zeaxanthin (AD-ZXT), lutein (AD-LTN), and resveratrol (AD-RVT; positive-control) or resistant dextrin as a placebo (AD-CON) for eight weeks. The AD-CON rats exhibited a higher Aβ deposition, attenuated hippocampal insulin signaling (reduced phosphorylation of protein kinase B [pAkt] and glycogen synthase kinase-3β [pGSK-3β]), increased neuroinflammation, elevated acetylcholinesterase activity, and memory deficits compared to the Normal-CON group. They also showed systemic insulin resistance and high hepatic glucose output. Zeaxanthin and lutein prevented memory impairment more effectively than the positive-control resveratrol by suppressing acetylcholinesterase activity, lipid peroxidation, and pro-inflammatory cytokines (TNF-α, IL-1β). They also potentiated hippocampal insulin signaling and increased brain-derived neurotrophic factor (BDNF) and ciliary neurotrophic factor (CTNF) mRNA expression to levels comparable to the Normal-CON rats. Additionally, zeaxanthin and lutein improved glucose disposal, reduced hepatic glucose output, and normalized insulin secretion patterns. In conclusion, zeaxanthin and lutein supplementation at doses equivalent to 1.5-2.0 g daily in humans may have practical implications for preventing or slowing human AD progression by reducing neuroinflammation and maintaining systemic and central glucose homeostasis, showing promise even when compared to the established neuroprotective compound resveratrol. However, further clinical trials are needed to evaluate their efficacy and safety in human populations.