The Ameliorative Effect of Litsea martabanica (Kurz) Hook. f. Leaf Water Extract on Chlorpyrifos-Induced Toxicity in Rats and Its Antioxidant Potentials.

Litsea martabanica root's antioxidant and acetylcholinesterase (AChE) activity showed promise as a pesticide detoxification agent in our previous study. In addition to its root, leaves can help alleviate pesticide exposure, although there is limited scientific evidence supporting their efficacy. However, the use of roots in several countries, such as Thailand, could contribute to environmental degradation, as highland communities traditionally used leaves instead of roots. This study aims to evaluate the antioxidant activity and anti-pesticide potential of water extract from L. martabanica leaves through in vitro and in vivo investigations. In the in vitro study, L. martabanica water extract and its fractions demonstrated antioxidant activity and induced apoptosis in hepatic satellite cells. In the in vivo study, treatment with the leaf extract led to increased AChE activity, decreased malondialdehyde (MDA) levels, increased superoxide dismutase (SOD) levels, and reduced glutathione in chlorpyrifos-exposed rats. Histopathological examination revealed that chlorpyrifos-treated rats exhibited liver cell damage, while treatment with the water extract of L. martabanica exhibited a protective effect on the liver. In conclusion, L. martabanica water extract exhibited antioxidant activity, enhanced AChE activity, and improved histopathological abnormalities in the liver.

Aminomethylphosphonic Acid (AMPA), a Glyphosate Metabolite, Decreases Plasma Cholinesterase Activity in Rats.

Glyphosate, a widely used herbicide, is linked to a plethora of deleterious effects in both clinical and preclinical studies. Nevertheless, the effects of its main metabolite, aminomethylphosphonic acid (AMPA), whose half-life in soil is even longer than that of glyphosate, have been little explored. On this basis, as a first approach, in this work, we report that intraperitoneal (i.p.) administration of AMPA or glyphosate (at 10, 56, and 100 mg/kg) decreased, to a similar extent, plasma cholinesterase (ChE) activity in acutely exposed rats. Moreover, we designed an experimental protocol to analyze and compare the effects of AMPA and glyphosate on human plasma ChE activity; this protocol consisted of adding these compounds to human plasma to subsequently test the effects of this plasma on the contraction to acetylcholine (ACh) in the frog rectus abdominis muscle (an indirect estimate of ChE activity). Accordingly, this muscular contraction to ACh was evaluated before and after pre-incubation of ACh with (i) plasma alone, (ii) plasma with AMPA, and (iii) plasma with glyphosate. Our results indicate that AMPA, like glyphosate, decreased ChE activity in the plasma of rats (when given i.p.) and humans (when added in vitro), suggesting that both xenobiotics may exert similar toxicological effects.

Both acute glyphosate and the aminomethylphosphonic acid intoxication decreased the acetylcholinesterase activity in rat hippocampus, prefrontal cortex and gastrocnemius muscle.

It has been reported that glyphosate, one of the most common herbicides used in agriculture, impairs locomotion and cognition. Glyphosate has a variable half-life in soil up to biotic and/or abiotic factors transform the molecule in metabolites such as the aminomethylphosphonic acid (AMPA) that has a longer half-life. In this study, female Sprague Dawley rats were acutely exposed to different doses of glyphosate or AMPA (i.e. 10, 56 or 100 mg/kg) and, subsequently, the acetylcholinesterase (AChE) activity was measured in the hippocampus, prefrontal cortex (PFC) and the gastrocnemius muscle. Both glyphosate and AMPA produced a similar decrease in the AChE activity in all the tissues tested. These results suggest that interference with normal cholinergic neurotransmission may be one of the mechanisms involved in glyphosate-induced motor alterations in rats. Moreover, our results highlight the biological importance of AMPA as a molecule with anticholinesterase action in brain and skeletal muscle. To our knowledge, this is the first report showing in vivo that AMPA, the major metabolite of glyphosate, behaves as an organophosphate.

Alcohol and Caffeine Co-Administration Increased Acetylcholinesterase Activity and Inflammatory Cytokines in Sleep-Deprived Rats: Implications for Cognitive Decline and Depressive-Like Manifestations.

Sleep deprivation is a major health problem in modern society; it has been worsened by alcohol and caffeine intake to stay awake and improve bodily activities, an experience common among night-shift workers. For the present study, 50 adult male Wistar rats weighing between 150 g and 200 g were randomly selected and divided into 5 groups of 10 rats each (n = 10). Group 1 was the control group; group 2 was the group of sleep-deprived (SD) rats; group 3 was composed SD rats submitted to the administration of 20% alcohol; group 4 comprised SD rats submitted to the administration of 200 mg/kg of caffeine; and Group 5 was composed of SD rats who underwent the co-administration of 20% alcohol and 200 mg/kg of caffeine. At the end of 28 days, the animals were euthanized, and blood samples were collected for biochemical analysis. Memory, anxiety, social behavior and locomotive activity were assessed using the Y-maze, the elevated plus maze, the hole-board and three-chambered social approach tests, and the open field test. The plasma levels of the acetylcholinesterase (AChE) enzyme and inflammatory cytokines (interleukin 6 [IL-6], interleukin 10 [IL-10], and tumor necrosis factor beta, [TNF-ß]) were also measured. Data was expressed as mean ± standard error of the mean [SEM] values, and the data were analyzed through analysis of variance (ANOVA) followed by the Tukey post hoc test, with significance set at p < 0.05 . The results revealed that sleep deprivation, and the co-administration of alcohol and caffeine impair memory in rats. Sleep deprivation also caused a significant increase in anxiety and anxiety-related behavior, with decreased social interaction, in rats. Locomotive activity was improved in SD rats, especially in those to which alcohol was administered. Sleep deprivation significantly reduced acetylcholinesterase activity among SD rats and those to which alcohol was administered when compared with the controls. The plasma levels of IL-6, IL-10 and TNF-ß were significantly increased in SD rats when compared with the controls. The administration of alcohol and caffeine separately, as well as their co-administration, significantly increased cytokine levels in rats.

Human red blood cell acetylcholinesterase activity: a revisit after fifteen years.

Human red blood cell acetylcholinesterase (RBC-AChE) activity is valuable for detecting potential exposure to cholinesterase inhibiting substances (CIS). A reliable population-based RBC-AChE activity reference range is critical for early and massive clinical and occupational toxicology screening. Previous published studies were often limited to small numbers of subjects, various testing methods, and crude statistical data analyses. We tested 4818 adult subjects with a well-established 17-minute modified Michel method over a 2-year period. We conducted a retrospective data analysis and systematically investigated on the influences to testing values from gender, age, age group, and their combinations and interactions. No significant difference was observed in the testing values between males (mean, medium, interquartile range = 0.76, 0.76, 0.71-0.80 ΔpH/h, respectively) and females (mean, medium, interquartile range = 0.76, 0.76, 0.71-0.81 ΔpH/hour, respectively), when gender was the only factor considered (p = 0.7238). However, with age progression, male testing values exhibited a consistent upward trend, while females did not show any clear patterns. Linear regression analysis of the data revealed that gender, age, and age group more or less affected testing values either as independent variables or with their combinations and interactions. However, more potential factors need to be included to achieve better testing value predictions. We recommend the toxicological testing community to adopt a new set of age group specific RBC-AChE activity reference ranges for males (0.68-0.80, 0.69-0.81, 0.70-0.83, 0.71-0.84, and 0.73-0.87 ΔpH/h for 18-29, 30-39, 40-49, 50-59, and ≥60 years old, respectively) while keeping the current reference range (0.63-0.89 ΔpH/hour) for females.

Inhibitory Actions of Antidepressants, Hypnotics, and Anxiolytics on Recombinant Human Acetylcholinesterase Activity.

Alzheimer's disease (AD) is accompanied by behavioral and psychological symptoms of dementia (BPSD), which is often alleviated by treatment with psychotropic drugs, such as antidepressants, hypnotics, and anxiolytics. If these drugs also inhibit acetylcholinesterase (AChE) activity, they may contribute to the suppression of AD progression by increasing brain acetylcholine concentrations. We tested the potential inhibitory effects of 31 antidepressants, 21 hypnotics, and 12 anxiolytics on recombinant human AChE (rhAChE) activity. At a concentration of 10-4 M, 22 antidepressants, 19 hypnotics, and 11 anxiolytics inhibited rhAChE activity by <20%, whereas nine antidepressants (clomipramine, amoxapine, setiptiline, nefazodone, paroxetine, sertraline, citalopram, escitalopram, and mirtazapine), two hypnotics (triazolam and brotizolam), and one anxiolytic (buspirone) inhibited rhAChE activity by ≥20%. Brotizolam (≥10-6 M) exhibited stronger inhibition of rhAChE activity than the other drugs, with its pIC50 value being 4.57 ± 0.02. The pIC50 values of the other drugs were <4, and they showed inhibitory activities toward rhAChE at the following concentrations: ≥3 × 10-6 M (sertraline and buspirone), ≥10-5 M (amoxapine, nefazodone, paroxetine, citalopram, escitalopram, mirtazapine, and triazolam), and ≥3 × 10-5 M (clomipramine and setiptiline). Among these drugs, only nefazodone inhibited rhAChE activity within the blood concentration range achievable at clinical doses. Therefore, nefazodone may not only improve the depressive symptoms of BPSD through its antidepressant actions but also slow the progression of cognitive symptoms of AD through its AChE inhibitory actions.

Toxicity Evaluation, Oxidative, and Immune Responses of Mercury on Nile Tilapia: Modulatory Role of Dietary Nannochloropsis oculata.

The current study evaluated the potential ameliorative effect of a dietary immune modulator, Nannochloropsis oculata microalga, on the mercuric chloride (HgCl2)-induced toxicity of Nile tilapia. Nile tilapia (45-50 g) were fed a control diet or exposed to » LC50 of HgCl2 (0.3 mg/L) and fed on a medicated feed supplemented with N. oculata (5% and 10% (50 or 100 g/kg dry feed)) for 21 days. Growth and somatic indices, Hg2+ bioaccumulation in muscles, and serum acetylcholinesterase (AChE) activity were investigated. Antioxidant and stress-related gene expression analyses were carried out in gills and intestines. Histopathological examinations of gills and intestines were performed to monitor the traits associated with Hg2+ toxicity or refer to detoxification. Hg2+ toxicity led to significant musculature bioaccumulation, inhibited AChE activity, downregulated genes related to antioxidants and stress, and elicited histopathological changes in the gills and intestine. Supplementation with N. oculata at 10% was able to upregulate the anti-oxidative-related genes while downregulated the stress apoptotic genes in gills and intestines compared to the unexposed group. In addition, minor to no histopathological traits were detected in the gills and intestines of the N. oculata-supplemented diets. Our data showed the benefit of dietary N. oculata in suppressing Hg2+ toxicity, which might support its efficacy as therapeutic/preventive agent to overcome environmental heavy metal pollution in aquatic habitats.

Cytogenotoxic potential and toxicity in adult Danio rerio (zebrafish) exposed to chloramine T.

Background: Chloramine-T (CL-T) is a synthetic sodium salt used as a disinfectant in fish farms to combat bacterial infections in fish gills and skin. While its efficacy in pathogen control is well-established, its reactivity with various functional groups has raised concerns. However, limited research exists on the toxicity of disinfection by-products to aquatic organisms. Therefore, this study aims to assess the sublethal effects of CL-T on adult zebrafish by examining biomarkers of nucleus cytotoxicity and genotoxicity, acetylcholinesterase (AChE) inhibition, and histopathological changes. Methods: Male and female adult zebrafish (wildtype AB lineage) specimens were exposed to 70, 140, and 200 mg/L of CL-T and evaluated after 96 h. Cytotoxic and genotoxic effects were evaluated by estimating the frequencies of nuclear abnormalities (NA), micronuclei (MN), and integrated optical density (IOD) of nuclear erythrocytes. Histopathological changes in the gills and liver were assessed using the degree of tissue changes (DTC). AChE activity was measured in brain samples. Results and conclusions: At a concentration of 200 mg/L, NA increased, indicating the cytogenotoxic potential of CL-T in adult zebrafish. Morphological alterations in the nuclei were observed at both 70 and 200 mg/L concentrations. Distinct IOD profiles were identified across the three concentrations. There were no changes in AChE activity in adult zebrafish. The DTC scores were high in all concentrations, and histological alterations suggested low to moderate toxicity of CL-T for adult zebrafish.

Comparative Assessment of the Toxicity of Brominated and Halogen-Free Flame Retardants to Zebrafish in Terms of Tail Coiling Activity, Biomarkers, and Locomotor Activity.

BDE-47, a flame retardant that is frequently detected in environmental compartments and human tissues, has been associated with various toxic effects. In turn, information about the effects of aluminum diethyl-phosphinate (ALPI), a halogen-free flame retardant from a newer generation, is limited. This study aims to assess and compare the toxicity of BDE-47 and ALPI to zebrafish by analyzing the tail coiling, locomotor, acetylcholinesterase activities, and oxidative stress biomarkers. At 3000 µg/L BDE-47, the coiling frequency increased at 26-27 h post-fertilization (hpf), but the burst activity (%) and mean burst duration (s) did not change significantly. Here, we considered that the increased coiling frequency is a slight neurotoxic effect because locomotor activity was impaired at 144 hpf and 300 µg/L BDE-47. Moreover, we hypothesized that oxidative stress could be involved in the BDE-47 toxicity mechanisms. In contrast, only at 30,000 µg/L did ALPI increase the catalase activity, while the motor behavior during different developmental stages remained unaffected. On the basis of these findings, BDE-47 is more toxic than ALPI.

Lycopodium Alkaloids from Huperzia serrata and Their Anti-acetylcholinesterase Activities.

One new fawcettimine-type alkaloid (1), one new miscellaneous-type alkaloid (2), four new lycodine-type alkaloids (3-6), and eight known ones (7-14) were isolated from the whole plants of Huperzia serrata. Their structures and absolute configurations were elucidated based on spectroscopic data, X-ray diffraction, ECD calculation and Mosher's method. Compound 1 was a rare C18 N2 -type Lycopodium alkaloid, possessing serratinine skeleton with an amide side chain in C-5. The absolute configuration of the 18-OH of compounds 4-6 were first determined by Mosher's method. Moreover, compounds 1-14 were assayed anti-acetylcholinesterase effect in vitro, and compound 7 showed significant anti-acetylcholinesterase activity with an IC50 value of 16.18±1.64 µM.

A novel skeleton alkaloid from Portulaca oleracea L. and its bioactivities.

A novel skeleton alkaloid was obtained from Portulaca oleracea L., which was identified as 10,11-dihydroxybenzo[5',6'] pentaleno[1',2':3,4]pyrrolo[2,1-b]oxazol-7(11bH)-one, named oleracone M, and its structure was determined using UHPLC-ESI-QTOF/MS, 1D NMR and 2D NMR spectroscopy, and circular dichroism. Then the bioactivities of the compound were investigated including the anti-inflammatory, anti-acetylcholinesterase and antioxidant activities. The results showed that the novel skeleton alkaloid exhibited the potent effect on inhibiting the secretion of IL-1ß at 10 µM, anticholinesterase activity with IC50 value of 49.58 µM, and antioxidant activity with IC50 value of 66.43 µM.

Plants of the Genus Mahonia as a Potential Traditional Chinese Medicine for the Prevention and Treatment of Alzheimer's Disease.

Alzheimer's disease (AD), a prevalent multiple neurodegenerative disease, has gained attention, particularly in the aging population. However, presently available therapies merely focus on alleviating the symptoms of AD and fail to slow disease progression significantly. Traditional Chinese medicine (TCM) has been used to ameliorate symptoms or interfere with the pathogenesis of aging-associated diseases for many years based on disease-modifying in multiple pathological roles with multi-targets, multi-systems and multi-aspects. Mahonia species as a TCM present potential for anti-inflammatory activity, antioxidant activity, anti-acetylcholinesterase activity, and antiamyloid- beta activity that was briefly discussed in this review. They are regarded as promising drug candidates for AD therapy. The findings in this review support the use of Mahonia species as an alternative therapy source for treating AD.

Electrochemical and fluorescent dual-mode sensor of acetylcholinesterase activity and inhibition based on MnO2@PD-coated surface.

We developed an electrochemical and fluorescent dual-mode sensor for assessing acetylcholinesterase (AChE) activity and inhibition by taking advantage of the high redox sensitivity of surface-coated mesoporous MnO2@polymer dot (MnO2@PD) towards AChE. The following phenomena constitute the basis of the detection mechanism: fluorescence resonance energy transfer (FRET) effect between MnO2 and PD; catalytic hydrolysis of acetylthiocholine (ATCh) to thiocholine (TCh) by AChE expressed by PC-12 cells, inducing fluorescence restoration and change in the conductivity of the system due to MnO2 decomposition; the presence of the inhibitor neostigmine preventing the conversion of ATCh to TCh. The surface-coated biosensor presents both fluorescence-based and electrochemical approaches for effectively monitoring AChE activity and inhibition. The fluorescence approach is based on the fluorescent "on/off" property of the system caused by MnO2 breakdown after interaction with TCh and the subsequent release of PDs. The conductivity of the coated electrode decreased dramatically as AChE concentration increased, resulting in electrochemical sensing of AChE activity and inhibition screening. Real-time wireless sensing can be conducted using a smartphone to monitor the resistance change, investigating the potential use of MnO2@PD nanocomposites in biological studies, and offering a real-time redox-fluorescent test for AChE activity monitoring and inhibitor screening.

How Closely Does Induced Agarwood's Biological Activity Resemble That of Wild Agarwood?

Continuous innovation in artificially-induced agarwood technology is increasing the amount of agarwood and substantially alleviating shortages. Agarwood is widely utilized in perfumes and fragrances; however, it is unclear whether the overall pharmacological activity of induced agarwood can replace wild agarwood for medicinal use. In this study, the volatile components, total chromone content, and the differences in the overall activities of wild agarwood and induced agarwood, including the antioxidant, anti-acetylcholinesterase, and anti-glucosidase activity were all determined. The results indicated that both induced and wild agarwood's chemical makeup contains sesquiterpenes and 2-(2-phenylethyl)chromones. The total chromone content in generated agarwood can reach 82.96% of that in wild agarwood. Induced agarwood scavenged 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+) radicals and inhibited acetylcholinesterase activity and α-glucosidase activity with IC50 values of 0.1873 mg/mL, 0.0602 mg/mL, 0.0493 mg/mL, and 0.2119 mg/mL, respectively, reaching 80.89%, 93.52%, 93.52%, and 69.47% of that of wild agarwood, respectively. Accordingly, the results distinguished that induced agarwood has the potential to replace wild agarwood in future for use in medicine because it has a similar chemical makeup to wild agarwood and has comparable antioxidant, anti-acetylcholinesterase, and anti-glucosidase capabilities.

Toxic effects of the cylindrospermopsin and chlorpyrifos combination on the differentiated SH-SY5Y human neuroblastoma cell line.

Due to climate change and anthropogenic activities, the levels of pollution of aquatic and terrestrial environments have increased in the last decades. In this sense, the rise of cyanobacterial blooms, which release secondary metabolites with toxic properties, and the global use of pesticides for agricultural purposes have a negative impact on ecosystems. Thus, it would be interesting to study the concomitance of both types of toxicants in the same sample, since it is possible that they appear together. The aim of the present work was to state the effects of the interaction between the cyanotoxin cylindrospermopsin and the pesticide chlorpyrifos in differentiated SH-SY5Y neuronal cells to assess how they could affect the nervous system. To this end, cytotoxicity, morphological, and acetylcholinesterase activity studies were performed during 24 and 48 h. The results revealed a concentration-dependent decrease in viability and interaction between both toxicants, together with clear signs of apoptosis and necrosis induction. In this sense, different stages on the differentiation process would lead to differences in the toxicity exerted by the compounds both isolated as in combination, which it is not observed in non-differentiated cells. Additionally, the acetylcholinesterase activity appeared not to be affected, which is a clear difference compared to non-differentiated cells. These results show the importance of studying not only the toxicants themselves, but also in combination, to assess their possible effects in a more realistic scenario.

Celastrus paniculatus oil ameliorates NF-KB mediated neuroinflammation and synaptic plasticity in the scopolamine-induced cognitive impairment rat model.

BACKGROUND AND AIM: Traditionally, Celastrus paniculatus Willd. (CP) oil has been utilized as a tranquilizer and memory enhancer. The present study investigated the neuropharmacological activity and efficacy of CP oil in ameliorating scopolamine-induced cognitive impairment in rats. EXPERIMENTAL PROCEDURE: Cognitive deficiency was induced in rats by administration of scopolamine (2 mg/kg intraperitoneal injection) for a period of 15 days. Donepezil served as a reference drug and CP oil was tested as both preventive and curative treatments. Animals' behaviour was assessed through the Morris water maze (MWM), novel object preference (NOR), and conditioned avoidance (CA) tests. Oxidative stress parameters, bioamine concentration (dopamine, noradrenaline, and 5-hydroxytryptamine), nerve growth factor (NGF), interleukin-6 (IL-6), nuclear factor kappa B (NF-кB), and tumor necrosis factor-alpha (TNFα) were estimated. Synaptophysin immunohistochemistry was performed. RESULTS: Our results showed that CP oil ameliorated behavioural deficits. It reduced latency to find a hidden platform in MWM. Reduced novel object exploration time and discrimination index (p < 0.05) in the NOR. Reduced step-down latency and normalized conditioned avoidance response (p < 0.001) in the CA test. CP oil increased dopamine, serotonin, norepinephrine, superoxide dismutase (SOD), glutathione, and catalase levels. It decreased malondialdehyde (MDA), acetylcholinesterase activity, IL-6, NF-кB (P < 0.001), TNFα, and NGF levels. Treatment showed approximate typical reactivity to synaptophysin. CONCLUSION: Our data is suggestive that CP oil treatment improves behavioural test outcomes, increases biogenic amine concentration, and decreases acetylcholinesterase activity, and neuroinflammatory biomarkers. It also restores synaptic plasticity. It thus improves cognitive functions against scopolamine-induced amnesia in rats by improving cholinergic function.

Nickel Single-Atom Catalyst-Mediated Efficient Redox Cycle Enables Self-Checking Photoelectrochemical Biosensing with Dual Photocurrent Readouts.

Developing a self-checking photoelectrochemical biosensor with dual photocurrent signals could efficiently eliminate false-positive or false-negative signals. Herein, a novel biosensor with dual photocurrent responses was established for the detection of acetylcholinesterase activity. To achieve photocurrent polarity-switchable behavior, the iodide/tri-iodide redox couple was innovatively introduced to simultaneously consume the photoexcited electrons and holes, which circumvents the inconvenience caused by the addition of different hole- and electron-trapping agents in the electrolyte. Importantly, benefiting from the high catalytic activity, the enhanced photoelectric responsivity can be realized after decorating the counter electrode with nickel single-atom catalysts, which promotes a more efficient iodide/tri-iodide redox reaction under low applied voltages. It is envisioned that the proposed photocurrent polarity switching system offers new routes to sensitive and reliable biosensing.

Cholinesterase activity as a potential biomarker for neurotoxicity induced by pesticides in vivo exposed Oreochromis niloticus (Nile tilapia): assessment tool for organophosphates and synthetic pyrethroids.

Organophosphates (OPs) and synthetic pyrethroids (SPs) are the most popular broad spectrum pesticides, used in agriculture as they have a strong pesticidal activity while also being biodegradable in the environment. The present study aimed to demonstrate the effects of these pesticides on the Acetylcholinesterase (AChE) activity in brain, gills and body muscles of Oreochromis niloticus - an important enzyme for the assessment and biomonitoring pollution caused by neurotoxins in the environment. The fish were exposed for 24 and 48 h to the LC0 concentrations of the malathion (1.425 mg/L), the chlorpyrifos (0.125 mg/L) and the λ-cyhalothrin (0.0039 mg/L), respectively. The activity of the AChE was significantly increased (p < 0.05) at 24 h and decreased at 48 h (except for the chlorpyrifos-treated brain and gills while tissues had shown no activity at 48 h's exposure) in all pesticides-treated tissues. The maximum increase in the activity and inhibition in the AChE activity were recorded as +92% and -52% in the chlorpyrifos and the lambda-cyhalothrin exposed brain tissues, respectively. Thus, the alterations in the AChE activities indicated that the applied pesticides are highly neurotoxic to fish and the enzyme (AChE) could be used as a useful biomarker for estimation of water pollution.

Synthesis, structural characterization and in vitro pharmacological properties of betanin-encapsulated chitosan nanoparticles.

Betanin, a natural food color and the only betalain, is approved for use in pharmaceutical and food industries as natural antioxidative and preservative agent, respectively. However, the antioxidant power and health-promoting properties of betanin have been disregarded due to its low stability in physiological conditions. Therefore, this study is designed to synthesize and evaluate in vitro pharmacological characteristics of betanin-encapsulated chitosan nanoparticles (ChBetNPs). ChBetNPs were synthesized by ionic gelation method and characterized by DLS, UV, FTIR, SEM and zeta potential analysis. The encapsulation efficiency (EE) and in vitro release kinetics were analyzed using spectrophotometric technique for quantifying the encapsulated amount of betanin in ChBetNPs as a function of time. The antioxidant activity of ChBetNPs was analyzed by DPPH and H2O2 radical scavenging assays, anti-inflammatory activity by protein denaturation and human RBCs stabilization assays, and anti-acetylcholinesterase activity using standard protocol with minor modifications. Unloaded chitosan nanoparticles (CSNPs) were found to be sized at 161.4 ± 5.75 nm while an increase in the size to 270.3 ± 8.50 nm was noticed upon encapsulating betanin. EE of ChBetNPs was measured to be ∼87.5%. The IC50 of ChBetNPs depicted significant free radical scavenging activities as compared to CSNPs. Similarly, a strong anti-inflammatory activity of ChBetNPs was noted. Significant decrease in acetylcholinesterase activity by ChBetNPs was measured (IC50 0.5255 µg/mL vs. control 26.09 µg/mL). The vegetables coated with 3% ChBetNPs showed decreased weight loss as compared to uncoated control. ChBetNPs was shown to exhibit strong antioxidant, anti-inflammatory and anti-acetylcholinesterase activities thus making it a significant therapeutic agent for the management of Alzheimer's disease.

Curcumin improves the ability of donepezil to ameliorate memory impairment in Drosophila melanogaster: involvement of cholinergic and cnc/Nrf2-redox systems.

One of the well-established models for examining neurodegeneration and neurotoxicity is the Drosophila melanogaster model of aluminum-induced toxicity. Anti-cholinesterase drugs have been combined with other neuroprotective agents to improve Alzheimer's disease management, but there is not much information on the combination of anti-cholinesterases with dietary polyphenols to combat memory impairment. Here, we assess how curcumin influences some of the critical therapeutic effects of donepezil (a cholinesterase inhibitor) in AlCl3-treated Drosophila melanogaster. Harwich strain flies were exposed to 40 mM AlCl3 - alone or in combination with curcumin (1 mg/g) and/or donepezil (12.5 µg/g and 25 µg/g) - for seven days. The flies' behavioral evaluations (memory index and locomotor performance) were analyzed. Thereafter, the flies were processed into homogenates for the quantification of acetylcholinesterase (AChE), catalase, total thiol, and rate of lipid peroxidation, as well as the mRNA levels of acetylcholinesterase (ACE1) and cnc/NRF2. Results showed that AlCl3-treated flies presented impaired memory and increased activities of acetylcholinesterase and lipid peroxidation, while there were decrease in total thiol levels and catalase activity when compared to the control. Also, the expression of ACE1 was significantly increased while that of cnc/NRF2 was significantly decreased. However, combinations of curcumin and donepezil, especially at lower dose of donepezil, significantly improved the memory index and biochemical parameters compared to donepezil alone. Thus, curcumin plus donepezil offers unique therapeutic effects during memory impairment in the D. melanogaster model of neurotoxicity.