A new amide from the fruiting bodies of Tricholoma bakamatsutake.

A new amide tricholomine C was isolated from the dried fruiting bodies of Tricholoma bakamatsutake. Its structure was identified by a combination of nuclear magnetic resonance spectroscopic analysis and electronic circular dichroism (ECD) calculations. The ethyl alcohol crude extract and tricholomines A-C from T. bakamatsutake were evaluated for neuroprotective activities. Of these substances, the crude extract showed weak neurite outgrowth-promoting activity in rat pheochromocytoma (PC12) cells, as well as weak inhibitory activities against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE).

Co, N co-doped porous carbon-based nanozyme as an oxidase mimic for fluorescence and colorimetric biosensing of butyrylcholinesterase activity.

A Co, N co-doped porous carbon-based nanozyme (Co-N-C nanozyme) has been fabricated. Taking advantages of the excellent oxidase catalytic activity and significant stability of Co-N-C nanozyme, we propose a fluorescence and colorimetric system based on Co-N-C nanozyme and red-emitting carbon quantum dots (RCDs) for butyrylcholinesterase (BChE) sensing. As the chromogenic substrate 3,3',5,5'-tetramethylbenzidine (TMB) was catalyzed and oxidized by Co-N-C nanozyme, the generated oxTMB had a new absorption peak at 652 nm, which resulted in the significant quenching of the fluorescence of the carbon quantum dots at 610 nm. Under the catalysis of BChE, thiocholine was generated from the hydrolysis of S-butyrylthiocholine iodide (BTCh), and the as-generated thiocholine effectively inhibited the oxidation of TMB catalyzed by Co-N-C nanozyme, leading to a decrease of the absorption of oxTMB at 652 nm and effective fluorescence recovery of RCDs. By measuring the absorbance of produced oxTMB at 652 nm and the fluorescence of RCDs at 610 nm, the fluorescence and colorimetric system both exhibited an outstanding linear response to the activity of BChE in the range 0.5 to 40 U L-1, with a detection limit of 0.16 U L-1 and 0.21 U L-1, respectively. Furthermore, this established dual-channel biosensing strategy has been successfully applied to the determination of BChE in human serum samples. The present work has effectively expanded the development and application of nanozyme in biosensing.

UPLC-PDA-ESI-QTOF-MS/MS fingerprint of purified flavonoid enriched fraction of Bryophyllum pinnatum; antioxidant properties, anticholinesterase activity and in silico studies.

CONTEXT: Bryophyllum pinnatum (Lam.) Oken (Crassulaceae) is used traditionally to treat many ailments. OBJECTIVES: This study characterizes the constituents of B. pinnatum flavonoid-rich fraction (BPFRF) and investigates their antioxidant and anticholinesterase activity using in vitro and in silico approaches. MATERIALS AND METHODS: Methanol extract of B. pinnatum leaves was partitioned to yield the ethyl acetate fraction. BPFRF was isolated from the ethyl acetate fraction and purified. The constituent flavonoids were structurally characterized using UPLC-PDA-MS2. Antioxidant activity (DPPH), Fe2+-induced lipid peroxidation (LP) and anticholinesterase activity (Ellman's method) of the BPFRF and standards (ascorbic acid and rivastigmine) across a concentration range of 3.125-100 µg/mL were evaluated in vitro for 4 months. Molecular docking was performed to give insight into the binding potentials of BPFRF constituents against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). RESULTS: UPLC-PDA-MS2 analysis of BPFRF identified carlinoside, quercetin (most dominant), luteolin, isorhamnetin, luteolin-7-glucoside. Carlinoside was first reported in this plant. BPFRF significantly inhibited DPPH radical (IC50 = 7.382 ± 0.79 µg/mL) and LP (IC50 = 7.182 ± 0.60 µg/mL) better than quercetin and ascorbic acid. Also, BPFRF exhibited potent inhibition against AChE and BuChE with IC50 values of 22.283 ± 0.27 µg/mL and 33.437 ± 1.46 µg/mL, respectively compared to quercetin and rivastigmine. Docking studies revealed that luteolin-7-glucoside, carlinoside and quercetin interact effectively with crucial amino acid residues of AChE and BuChE through hydrogen bonds. DISCUSSION AND CONCLUSIONS: BPFRF possesses an excellent natural source of cholinesterase inhibitor and antioxidant. The material could be further explored for the potential treatment of oxidative damage and cholinergic dysfunction in Alzheimer's disease.

Expression of cholinesterases and their anchoring proteins in rat heart.

Acetylcholine (ACh)-mediated vagal transmission as well as nonneuronal ACh release are considered cardioprotective in pathological situations with increased sympathetic drive such as ischemia-reperfusion and cardiac remodeling. ACh action is terminated by hydrolysis by the cholinesterases (ChEs), acetylcholinesterase, and butyrylcholinesterase. Both ChEs exist in multiple molecular variants either soluble or anchored by specific anchoring proteins like collagen Q (ColQ) anchoring protein and proline-rich membrane anchoring protein (PRiMA). Here we assessed the expression of specific ChE molecular forms in different heart compartments using RT-qPCR. We show that both ChEs are expressed in all heart compartments but display different expression patterns. The acetylcholinesterase-T variant together with PRiMA and ColQ is predominantly expressed in rat atria. Butylcholinesterase is found in all heart compartments and is accompanied by both PRiMA and ColQ anchors. Its expression in the ventricular system suggests involvement in the nonneuronal cholinergic system. Additionally, two PRiMA variants are detected throughout the rat heart.

Gold Nanoclusters/Iron Oxyhydroxide Platform for Ultrasensitive Detection of Butyrylcholinesterase.

The combination of gold nanoclusters (AuNCs) and nanomaterial-based quencher creates an innovative method for sensors design. In this work, we report a fluorescent sensing platform for sensitive detection of butyrylcholinesterase (BChE). The fluorescence of AuNCs can be quenched by iron oxyhydroxide (FeOOH) nanomaterials. In the presence of BChE and acetylthiocholine (ATCh), nano-FeOOH can be effectively decomposed by the enzymatic hydrolysate (thiocholine), leading to the recovery of AuNCs fluorescence. The Au/FeOOH exhibits the highest fluorescence quenching efficiency compared with other transition metal oxyhydroxide-based sensing systems, e.g., Au/CoOOH and Au/NiOOH. The corresponding fluorescence recovery efficiency is also the best for Au/FeOOH. The large surface area of nanomaterials and thin nanostructure provide a favorable platform for the reaction of enzymatic hydrolysate and eventually improve the high sensitivity of the probe. A linear detection range for BChE is achieved within 5-100 ng mL-1 along with a detection limit of 4 ng mL-1. By taking advantage of the high sensitivity, the Au/FeOOH was successfully used for BChE quantification in 2 µL of finger blood.

Multi-charged bis(p-calixarene)/pillararene functionalized gold nanoparticles for ultra-sensitive sensing of butyrylcholinesterase.

A series of supramolecular assemblies based on multi-charged calixarene (SC4A), bis(p-calixarene) (BSC4A) and pillararene (CP5A) modified gold nanoparticles (AuNP) was constructed to realize colorimetric sensing of both succinylcholine (SuCh) and butyrylcholinesterase (BChE). With the high binding affinity of BSC4A and CP5A towards SuCh, BSC4A-AuNPs and CP5A-AuNPs could assemble with micromolar level SuCh as SuCh-BSC4A/CP5A-AuNPs. More interestingly, the enzymatic hydrolysis of SuCh by BChE could lead to the disassembly of SuCh-BSC4A/CP5A-AuNPs and provide a sensitive time-dependent color change from blue to red which could be observed by the naked eye and used to monitor BChE activity. As BChE activity is an important biomarker for diseases and poor health conditions, this novel supramolecular tandem colorimetric sensing strategy may have potential use for early diagnosis of diseases.

A Nanozyme- and Ambient Light-Based Smartphone Platform for Simultaneous Detection of Dual Biomarkers from Exposure to Organophosphorus Pesticides.

A transparent, lateral-flow test strip coupled with a smartphone-based ambient light sensor was first proposed for detecting enzymatic inhibition and phosphorylation. The principle of the platform is based on the simultaneous measurement of the total amount of the enzyme and enzyme activity to biomonitor exposure to organophosphorus (OP) pesticides. In this study, butyrylcholinesterase (BChE) was adopted as the model enzyme and ethyl paraoxon was chosen as an analyte representing OP pesticides. The total amount of BChE was quantified by a sensitive colorimetric signal originating from a sandwich immunochromatographic assay utilizing PtPd nanoparticles as a colorimetric probe, which exhibited excellent catalytic activity for phenols. In the sandwich immunoassay, only one antibody against BChE was simultaneously utilized as the recognition antibody and the labeling antibody due to the tetrameric structure of native BChE. The BChE activity was estimated by another colorimetric signal using the Ellman assay. Both colorimetric signals on two separated test strips were detected by the smartphone-based ambient light sensor. The proposed sensor operated with an LED in a 3D-printed substrate, which emitted excitation light and transmitted it through a transparent, lateral-flow test strip. With the increase in the colorimetric signal in the test line of the test strip, the intensity of the transmitted light decreased. The smartphone-based sensor showed excellent linear responses for assaying the total amount of BChE and active BChE ranging from 0.05 to 6.4 nM and from 0.1 to 6.4 nM, respectively. A high portability and low detection limit were simultaneously realized in the common smartphone-based device. This low-cost, portable, easy-operation, and sensitive immunoassay strategy shows great potential for online detection of OP exposure and monitoring other disease biomarkers.

Involvement of oxidative stress, cholinergic and adenosinergic systems on renal damage caused by Trypanosoma evansi infection: Relationship with lipid peroxidation.

The aim of this study was to evaluate the oxidative stress variables, and enzymes of cholinergic (acetylcholinesterase (AChE) and butyrylcholinesterase (BChE)) and adenosinergic (adenosine deaminase (ADA)) systems in renal tissue, as well as the relationship between these systems and lipid peroxidation. The animals were divided into two groups with six animals each: uninfected (negative control) and infected (positive control). On day 4 post-infection (PI), animals were euthanized and the kidney was collected. Thiobarbituric acid reactive species (TBARS) and lipid peroxidation (FOX) levels increased, while the catalase (CAT), AChE, BChE and ADA activities decreased in kidney tissue on day 4 PI. A negative correlation between AChE and TBARS (r = -0.750), AChE and FOX (r = -0.650), as well as ADA and TBARS (r = -0.345) and ADA and FOX (r = -0.540) were observed (p < 0.05). In summary, the T. evansi infection cause lipid peroxidation in the renal tissue, altering the antioxidant-oxidant status, alterations compatible to oxidative stress and oxidative damage. Also, the T. evansi decrease the activities of AChE, BChE and ADA in order to reduce the oxidative damage increasing the levels of ACh, BCh and adenosine. These alterations in the kidney may be contribute on pathophysiology of T. evansi infection.

Involvement of cholinergic and purinergic systems during the inflammatory response caused by Aeromonas hydrophila in Rhamdia quelen.

The aim of this study was to evaluate the cholinergic (acetylcholinesterase (AChE) and butyrylcholinesterase (BChE)) and purinergic (adenosine deaminase (ADA)) systems in head kidney, spleen, total blood and serum samples in experimentally infected fish with A. hydrophila, and the involvement of these systems during the inflammatory process. Silver catfish (Rhamdia quelen) juveniles were divided into two groups with seven fish each: uninfected (negative control) and infected (positive control). On day 2 post-infection, animals were euthanized and the head kidney, spleen, total blood and serum were collected. AChE and ADA activities in head kidney and spleen decreased in infected animals compared to uninfected animals, as well as AChE in total blood and seric ADA activities. BChE activity was not expressed in the evaluated tissues. Therefore, our results lead to the hypothesis that cholinergic and purinergic systems play an important role on the immune response against A. hydrophila with an anti-inflammatory effect. In summary, AChE and ADA activities reduced probably in order to protect against tissue inflammatory damage caused by infection.

Hepatic cholinesterase of laying hens naturally infected by Salmonella Gallinarum (fowl typhoid).

Salmonella is a facultative intracellular pathogen that may cause foodborne gastroenteritis in humans and animals consisting of over 2000 serovars. The serovar Salmonella Gallinarum is an important worldwide pathogen of poultry. However, little is known on the mechanisms of pathogenesis of Salmonella in chickens. The aim of this study was to evaluate cholinesterase and myeloperoxidase activities in hepatic tissue of laying hens naturally infected by S. Gallinarum. Twenty positive liver samples for S. Gallinarum were collected, in addition to seven liver samples from healthy uninfected laying hens (control group). The right liver lobe was homogenized for analysis of acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and myeloperoxidase (MPO), and the left lobe was divided into two fragments, one for histopathology and the other for Salmonella isolation. The results showed changes in AChE and BchE activity in the liver of infected laying hens compared to the control group (P < 0.05), i.e. reduced AChE and increased BChE activities in liver samples. Infected animals showed increased MPO activity compared to healthy animals (P < 0.05). Furthermore, the histopathological findings showed fibrinoid necrosis associated to the infiltration of lymphocytes, plasma cells, macrophages,heterophils in the liver of infected hens. These findings suggest that the inflammatory process was attenuated providing a pro-inflammatory action of both enzyme analyzed in order to reduce the free ACh, a molecule which has an anti-inflammatory action. Therefore, our results lead to the hypothesis that cholinesterase plays an important role on the modulation of immune response against S. Gallinarum with an inflammatory effect, contributing to the response against this bacterium. This study should contribute to a better understanding on the pathogenic mechanisms involved in laying hens infected by S. Gallinarum.

Immunohistochemical analysis of hippocampal butyrylcholinesterase: Implications for regional vulnerability in Alzheimer's disease.

Studies of acetylcholine degrading enzymes acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) in Alzheimer's disease (AD) have suggested their potential role in the development of fibrillar amyloid-ß (Aß) plaques (amyloid plaques). A recent genome-wide association study analysis identified a novel association between genetic variations in the BCHE locus and amyloid burden. We studied BChE immunoreactivity in hippocampal tissue sections from AD and control cases, and examined its relationship with amyloid plaques, neurofibrillary tangles (NFT), dystrophic neurites (DN) and neuropil threads (NT). Compared to controls, AD cases had greater BChE immunoreactivity in hippocampal neurons and neuropils in CA2/3, but not in the CA1, CA4 and dentate gyrus. The majority of amyloid plaques (> 80%, using a pan-amyloid marker X-34) contained discrete neuritic clusters which were dual-labeled with antibodies against BChE and phosphorylated tau (clone AT8). There was no association between overall regional BChE immunoreaction intensity and amyloid plaque burden. In contrast to previous reports, BChE was localized in only a fraction (~10%) of classic NFT (positive for X-34). A similar proportion of BChE-immunoreactive pyramidal cells were AT8 immunoreactive. Greater NFT and DN loads were associated with greater BChE immunoreaction intensity in CA2/3, but not in CA1, CA4 and dentate gyrus. Our results demonstrate that in AD hippocampus, BChE accumulates in neurons and plaque-associated neuritic clusters, but only in a small proportion of NFT. The association between greater neurofibrillary pathology burden and markedly increased BChE immunoreactivity, observed selectively in CA2/3 region, could reflect a novel compensatory mechanism. Since CA2/3 is generally considered more resistant to AD pathology, BChE upregulation could impact the cholinergic modulation of glutamate neurotransmission to prevent/reduce neuronal excitotoxicity in AD hippocampus.

Enhanced stability of blood matrices using a dried sample spot assay to measure human butyrylcholinesterase activity and nerve agent adducts.

Dried matrix spots are safer to handle and easier to store than wet blood products, but factors such as intraspot variability and unknown sample volumes have limited their appeal as a sampling format for quantitative analyses. In this work, we introduce a dried spot activity assay for quantifying butyrylcholinesterase (BChE) specific activity which is BChE activity normalized to the total protein content in a sample spot. The method was demonstrated with blood, serum, and plasma spotted on specimen collection devices (cards) which were extracted to measure total protein and BChE activity using a modified Ellman assay. Activity recovered from dried spots was ∼80% of the initial spotted activity for blood and >90% for plasma and serum. Measuring total protein in the sample and calculating specific activity substantially improved quantification and reduced intraspot variability. Analyte stability of nerve agent adducts was also evaluated, and the results obtained via BChE-specific activity measurements were confirmed by quantification of BChE adducts using a previously established LC-MS/MS method. The spotted samples were up to 10 times more resistant to degradation compared to unspotted control samples when measuring BChE inhibition by the nerve agents sarin and VX. Using this method, both BChE activity and adducts can be accurately measured from a dried sample spot. This use of a dried sample spot with normalization to total protein is robust, demonstrates decreased intraspot variability without the need to control for initial sample volume, and enhances analyte stability.

Cholinesterase activity on Echinogammarus meridionalis (Pinkster) and Atyaephyra desmarestii (Millet): characterisation and in vivo effects of copper and zinc.

Metals are released into freshwater ecosystems from natural and anthropogenic sources, compromising their structural and functional equilibrium. As early warning tools, cholinesterases (ChEs) are usually used to assess the effects of organophosphate and carbamate pesticides, but are also known to be inhibited by metals. The objectives of this work were to characterise the activity of ChE present in the amphipod Echinogammarus meridionalis and the shrimp Atyaephyra desmarestii and to evaluate the in vivo effects of the metals copper and zinc in their ChE activity. To achieve this, firstly the activity of ChE forms were characterised using different in vitro assays with substrates and selective inhibitors. Then, the in vivo effects of 48 h exposures to increasing concentrations of copper and zinc on ChE activity were determined. The ChE form present in both species was acetylcholinesterase (AChE) since both revealed preference for the acetylthiocholine iodide substrate, total inhibition with eserine, the inhibitor of ChEs, and with 1,5-bis(4-allyldimethylammoniumphenyl)-pentan-3-one dibromide, the specific inhibitor of AChE, and presented insensitivity to iso-OMPA, a specific inhibitor of butyrylcholinesterase. The activity of ChEs was inhibited by zinc exposures in the amphipod species, but was not affected by copper. Exposure to copper and zinc did not affect ChEs activity in the shrimp at the concentrations tested. This work is a relevant contribution as foundation for the use of AChE in freshwater crustaceans in further studies including biomonitoring campaigns in different contamination scenarios.

Machine learning-assisted melamine-Cu nanozyme and cholinesterase integrated array for multi-category pesticide intelligent recognition.

Expanding target pesticide species and intelligent pesticide recognition were formidable challenges for existing cholinesterase inhibition methods. To improve this status, multi-active Mel-Cu nanozyme with mimetic Cu-N sites was prepared for the first time. It exhibited excellent laccase-like and peroxidase-like activities, and can respond to some pesticides beyond the detected range of enzyme inhibition methods, such as glyphosate, carbendazim, fumonisulfuron, etc., through coordination and hydrogen bonding. Inspired by the signal complementarity of Mel-Cu and cholinesterase, an integrated sensor array based on the Mel-Cu laccase-like activity, Mel-Cu peroxidase-like activity, acetylcholinesterase, and butyrylcholinesterase was creatively constructed. And it could successfully discriminate 12 pesticides at 0.5-50 µg/mL, which was significantly superior to traditional enzyme inhibition methods. Moreover, on the basis of above array, a unified stepwise prediction model was built using classification and regression algorithms in machine learning, which enabled concentration-independent qualitative identification as well as precise quantitative determination of multiple pesticide targets, simultaneously. The sensing accuracy was verified by blind sample analysis, in which the species was correctly identified and the concentration was predicted within 10% error, suggesting great intelligent recognition ability. Further, the proposed method also demonstrated significant immunity to interference and practical application feasibility, providing powerful means for pesticide residue analysis.

Near-infrared fluorescent probe for ultrasensitive detection of organophosphorus pesticides and visualization of their interaction with butyrylcholinesterase in living cells.

The toxicity of organophosphorus pesticides (OPs) can catastrophically cause liver cell damage and inhibit the catalytic activity of cholinesterase. We designed and synthesized a near-infrared fluorescent probe HP-LZB with large Stokes shift which can specifically identify and detect butyrylcholinesterase (BChE) and visually explore the interaction between OPs and endogenous BChE in living cells. Fluorescence was turned on when HP-LZB was hydrolyzed into HP-LZ in the presence of BChE, and OPs could inhibit BChE's activity resulting in a decrease of fluorescence. Six OPs including three oxon pesticides (paraoxon, chlorpyrifos oxon and diazoxon) and their corresponding thion pesticides (parathion, chlorpyrifos and diazinon) were investigated. Both in vitro and cell experiments indicated that only oxon pesticides could inhibit BChE's activity. The limits of detection (LODs) of paraoxon, chlorpyrifos oxon and diazoxon were as low as 0.295, 0.007 and 0.011 ng mL-1 respectively and the recovery of OPs residue in vegetable samples was satisfactory. Thion pesticides themselves could hardly inhibit the activity of BChE and are only toxic when they are converted to their corresponding oxon form in the metabolic process. However, in this work, thion pesticides were found not be oxidized into their oxon forms in living HepG2 cells due to the lack of cytochrome P450 in hepatoma HepG2 cell lines. Therefore, this probe has great application potential in effectively monitoring OPs in real plant samples and visually exploring the interaction between OPs and BChE in living cells.

Characterization of cholinesterases in the damselfish Sergeant major (Abudefduf saxatilis).

Cholinesterase (ChE) activity has been used for many years as a biomarker of exposure to organophosphate and carbamate pesticides. Recent studies have demonstrated that there could be biological factors that determine ChE type and levels; thus, juvenile Sergeant major (Abudefduf saxatilis) ChE enzymes were biochemically characterized. ChE enzymes found in the head and trunk were evaluated for their substrate preference and sensitivity to selective inhibitors. The use of the head and trunk was chosen as a strategy to reduce dissection time and to ensure sample uniformity between stations. The results indicated that there are two types of ChE enzymes in the head: acetylcholinesterase (AChE) and atypical butyrylcholinesterase (BChE) that exhibits intermediate characteristics of human AChE and BChE activities. Atypical BChE is predominantly found in the trunk. The results also indicated that the ChE activity found in A. saxatilis may be used as a biomarker in studies monitoring the Mexican Caribbean.

Effect of exposure to contaminated pond sediments on survival, development, and enzyme and blood biomarkers in veined treefrog (Trachycephalus typhonius) tadpoles.

Sediments are important elements of aquatic ecosystems and in general sediments accumulate diverse toxic substances. Amphibians potentially have a greater risk of exposure to contaminants in sediments, and the test of sediments provides first lines of evidences. Sediment outdoor microcosm experiments were conducted to analyze biological endpoints (survival, development, growth, and morphological and organ malformation), enzyme activity (butyrylcholinesterase, BChE; glutathione-S-transferase, GST; and catalase, CAT) and blood biomarkers in veined treefrog Trachycephalus typhonius tadpoles, a widespread neotropical species. Hatching (stage 23) of T. thyphonius was exposed until they reached metamorphosis (stage 46). Sediment tests were performed and four different treatments were used: three ponds (LTPA, ISP, and SSP) influenced by industrial and agricultural activities and a reference treatment from a forest (RFS). Physical and chemical variables and concentration of nutrients, pesticide residues, and metals were determined. One treatment was metal-rich (LPTA) and two were nutrient-rich (ISP and SSP). Sediment treatments had no significant effect on survival; in contrast they had significant sublethal effects on T. typhonius larval development and growth rates, and affected overall size and shape at stage 38. Principally, in LPTA animals were significantly larger than in RFS, exhibiting swollen bodies, tail muscles and tail fin. In addition, metamorphs from LPTA, ISP, and SSP were smaller and showed signs of emaciation by the end of the experiment. Statistical comparisons showed that the proportions of each type of morphological abnormalities (swollen bodies and diamond shape, gut uncoiling, diverted gut, stiff tails, polydactyly, and visceral and hindlimb hemorrhaging) were significantly greater in metal- and nutrient-rich sediment treatments. Moreover, activities of BChE, GST and CAT, as well as and presence of micronuclei, immature, mitotic, anucleated erythrocytes varied significantly among treatments. Our biological effects-based sediment study highlights the use of different biological endpoints and biomarkers on anuran larvae at sites where pond sediment is risky and sediment management should be considered. Finally, the information of those biological endpoints and biomarkers would be useful as a management tool to decide if there are sufficient exposures of tadpoles to suspected pollutants on sediment.

Cholinesterase enzymes inhibitors from the leaves of Rauvolfia reflexa and their molecular docking study.

Plants of the Apocynaceae family have been traditionally used in the treatment of age-related brain disorders. Rauvolfia reflexa, a member of the family, has been used as an antidote for poisons and to treat malaria. The dichloromethane, ethanol and methanol extracts from the leaves of Rauvolfia reflexa showed potential acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities, with IC50 values in the 8.49 to 52.23 g/mL range. Further cholinesterase inhibitory-guided isolation of these extracts afforded four bioactive compounds, namely: (E)-3-(3,4,5-trimethoxyphenyl)acrylic acid (1), (E)-methyl 3-(4-hydroxy-3,5-dimethoxyphenyl) acrylate (2), 17-methoxycarbonyl-14-heptadecaenyl-4-hydroxy-3-methoxycinnamate (3) and 1,2,3,4-tetrahydro-1-oxo-ß-carboline (4). The isolated compounds showed moderate cholinesterase inhibitory activity compared to the reference standard, physostigmine. Compounds 1 and 2 showed the highest inhibitory activity against AChE (IC50 = 60.17 µM) and BChE (IC50 = 61.72 µM), respectively. Despite having similar molecular weight, compounds 1 and 2 were structurally different according to their chemical substitution patterns, leading to their different enzyme inhibition selectivity. Compound 2 was more selective against BChE, whereas compound 1 was a selective inhibitor of AChE. Molecular docking revealed that both compounds 1 and 2 were inserted, but not deeply into the active site of the cholinesterase enzymes.

Compounds with Anti-Alzheimer Activity Isolated for the First Time from Melaleuca leucodendron (L.) Leaves.

OBJECTIVE: To discover a drug from natural triterpenes that has no side effects and is effective in treating Alzheimer's disease. We predict that the drug will be put on the market soon and achieve success. METHODS: The methanolic extract of M. leucodendron leaves was fractionated and subjected to different chromatographic techniques to isolate two new triterpene glycosides alongside five known compounds kaempferol 3, quercetin 4, quercetin3-O-ß-D-glucopyranoside 5, kaempferol3- O-ß-D-glucopyranoside 6 and kaempferol3-O-α-L-rhamnoside 7. The structures of compounds 1 and 2 were elucidated by spectroscopic analysis and chemical means. RESULTS: Two new triterpene glycosides, 21-O-α-L-rhamnopyranosyl-olean-12-ene-3-O-[α-Lrhamnopyranosyl (1-4) ß-D-galactopyranosyl (1-4) ß-D-glucouronopyranoside]1 and 21-O-α-Lrhamnopyranosyl- olean-12-ene-3-O-[α-L-rhamnopyranosyl (1→4) ß-D-galactopyra-nosyl (1→4) ß-D-galactopyranoside] 2, were isolated for the first time from 70% aqueous methanolic extract (AME) of M. leucodendron leaves. The inhibitory activities of the said compounds toward acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) were then assayed. Both compounds exhibited significant inhibitory activities toward the two enzymes, and evidence indicated that compound 2 was a more effective inhibitor than compound 1. CONCLUSION: Compounds 1 and 2 have a significant role in inhibiting the enzymes acetylcholinesterase and butyrylcholinesterase.

[Pseudocholinesterase activity in type 1 bipolar patients]. / Étude de l'activité pseudocholinestérasique chez des patients bipolaires de type 1.

This study aims to investigate the variation of pseudocholinesterase activity (BuChE) in bipolar patients and to explore its relation to the clinical and therapeutic characteristics of this disease. Our study included 105 patients with bipolar disorder and 100 control subjects aged 38.7 ±â€Š12.2 and 36.4 ±â€Š15.7 y, respectively. BuChE was determined by kinetic methods on Cobas Integra 400 plus™. Compared with controls, patients had a significantly higher pseudocholinesterase activity. Moreover, this increase was significantly associated (p = 0.001) with bipolar disorder with sensibility of 58% and specificity of 62% at threshold of 7392 IU/L. There was no significant change in pseudocholinesterase activity in relation to illness episodes and treatment, whereas the lowest values of this activity were seen in euthymic patients and those taking psychotics. Therefore, this activity is a real interest in the biological monitoring of patients as a risk factor for neurodegenerative diseases associated with bipolar disorder. But it would be most useful to evaluate their interest as a predictor of bipolar disorder in patients at risk.