Acetylcholinesterase Inhibition Test Research Articles

Phytochemical prospecting and biological activities of the floral extract from [Impatiens walleriana (Hook.)] (Balsaminaceae)

Impatiens walleriana is a plant species that presents diversity and variety of colors among flowers. This plant species has wide distribution and is easily cultivable throughout the world including natural gardens, greenhouses and parks. This study aims at evaluating the floral extracts of I. walleriana in terms of their qualitative phytochemical constitution and antifungal activities on Sclerotinia sclerotiorum, Colletotrichum gloeosporioides and Colletotrichum acutatum, as well as on the reduction of DPPH free radical and on the inhibition of acetylcholinesterase (AChE). Flowers were collected from two cultivars Pink and White of I. walleriana and the extract produced by maceration. The phytochemical qualitative assay was carried out using different reagents for determination by precipitation or colorimetric alteration. The antifungal test was carried out in Petri dishes with different concentrations of floral extract on S. sclerotiorum, C. gloeosporioides and C. acutatum. The DPPH reduction assay was performed by percentage and as standard antioxidant ascorbic acid. The acetylcholinesterase inhibition test was performed in percentage using Electrophorus electricus. Positive results were observed for phenolics, anthocyanins, organic acids, alkaloids, catechins, tannins, carboxylic acids, hemolytic saponins and sesquiterpene lactones. Fungal inhibition effect was better observed for cv. Pink with 10-26%, 6% and between 9-11% on S. sclerotiorum, C. gloeosporioides and C. acutatum, respectively. The DPPH reduction activity showed satisfactory results for cv. Pink 49% followed by cv. White 41%. And for inhibition of AChE cv. Pink with 30% and cv. White with 27%. The floral extracts of Impatiens walleriana show good results for the biological activities tested, especially for cv. Pink.

Removal of Sulfide Ions from Kraft Washing Effluents by Photocatalysis with N and Fe Codoped Carbon Dots.

N and Fe codoped carbon dots (N,Fe-CDs) were fabricated from citric acid, L-glutamic acid and ferric chloride via a hydrothermal method for the photocatalytic removal of S2- from kraft washing effluents (KWE). The N,Fe-CDs were fluorescent nanoparticles (average size of 3.18 nm) and catalyzed the oxidation of S2- following a first-order kinetic model with an activation energy of 33.77 kJ/mol. The N,Fe-CDs tolerated elevated temperatures as high as 80 °C without catalyst deactivation. The N,Fe-CDs catalysts were reusable for at least four cycles, preserving over 90% of the activity. In the treatment of KWE from the kraft pulping of eucalyptus, the concentration of S2- was decreased by the N,Fe-CDs from 1.19 to 0.41 mmol/L in 6 h. Consequently, near complete remediation was obtained in 24 h. In addition, half of the chemical oxygen demand was removed after treatment with 500 mg/L of the N,Fe-CDs. In addition, the present photocatalyst was safe within a concentration of 200 mg/L, as indicated by the acetylcholinesterase inhibition test. Our findings may help develop a cleaner production process for kraft brownstock washing.

Lithium Difluorophosphate: A Boon for High Voltage Li Ion Batteries and a Bane for High Thermal Stability/Low Toxicity: Towards Synergistic Dual Additives to Circumvent this Dilemma.

The specific energy/energy density of state-of-the-art (SOTA) Li-ion batteries can be increased by raising the upper charge voltage. However, instability of SOTA cathodes (i. e., LiNiy Cox Mny O2 ; x+y+z=1; NCM) triggers electrode crosstalk through enhanced transition metal (TM) dissolution and contributes to severe capacity fade; in the worst case, to a sudden death ("roll-over failure"). Lithium difluorophosphate (LiDFP) as electrolyte additive is able to boost high voltage performance by scavenging dissolved TMs. However, LiDFP is chemically unstable and rapidly decomposes to toxic (oligo)organofluorophosphates (OFPs) at elevated temperatures; a process that can be precisely analyzed by means of high-performance liquid chromatography-high resolution mass spectroscopy. The toxicity of LiDFP can be proven by the well-known acetylcholinesterase inhibition test. Interestingly, although fluoroethylene carbonate (FEC) is inappropriate for high voltage applications as a single electrolyte additive due to rollover failure, it is able to suppress formation of toxic OFPs. Based on this, a synergistic LiDFP/FEC dual-additive approach is suggested in this work, showing characteristic benefits of both individual additives (good capacity retention at high voltage in the presence of LiDFP and decreased OFP formation/toxicity induced by FEC).

Seleno-Analogs of Scaffolds Resembling Natural Products a Novel Warhead toward Dual Compounds.

Nowadays, oxidative cell damage is one of the common features of cancer and Alzheimer's disease (AD), and Se-containing molecules, such as ebselen, which has demonstrated strong antioxidant activity, have demonstrated well-established preventive effects against both diseases. In this study, a total of 39 Se-derivatives were synthesized, purified, and spectroscopically characterized by NMR. Antioxidant ability was tested using the DPPH assay, while antiproliferative activity was screened in breast, lung, prostate, and colorectal cancer cell lines. In addition, as a first approach to evaluate their potential anti-Alzheimer activity, the in vitro acetylcholinesterase inhibition (AChEI) was tested. Regarding antioxidant properties, compound 13a showed concentration- and time-dependent radical scavenging activity. Additionally, compounds 14a and 17a showed high activity in the melanoma and ovarian cancer cell lines, with LD50 values below 9.2 µM. Interestingly, in the AChEI test, compound 14a showed almost identical inhibitory activity to galantamine along with a 3-fold higher in vitro BBB permeation (Pe = 36.92 × 10-6 cm/s). Molecular dynamics simulations of the aspirin derivatives (14a and 14b) confirm the importance of the allylic group instead of the propargyl one. Altogether, it is concluded that some of these newly synthesized Se-derivatives, such as 14a, might become very promising candidates to treat both cancer and AD.

Effects of essential oils on native and recombinant acetylcholinesterases of Rhipicephalus microplus.

This study reports the action of essential oils (EO) from five plants on the activity of native and recombinant acetylcholinesterases (AChE) from Rhipicephalus microplus. Enzyme activity of native susceptible AChE extract (S.AChE), native resistant AChE extract (R.AChE), and recombinant enzyme (rBmAChE1) was determined. An acetylcholinesterase inhibition test was used to verify the effect of the EO on enzyme activity. EO from Eucalyptus globulus, Citrus aurantifolia, Citrus aurantium var.dulcis inhibited the activity of S.AChE and R.AChE. Oils from the two Citrus species inhibited S.AChE and R.AChE in a similar way while showing greater inhibition on R.AChE. The oil from E. globulus inhibited native AChE, but no difference was observed between the S.AChE and R.AChE; however, 71% inhibition for the rBmAChE1 was recorded. Mentha piperita oil also inhibited S.AChE and R.AChE, but there was significant inhibition at the highest concentration tested. Cymbopogon winterianus oil did not inhibit AChE. Further studies are warranted with the oils from the two Citrus species that inhibited R.AChE because of the problem with R. microplus resistant to organophosphates, which target AChE. C. winterianus oil can be used against R. microplus populations that are resistant to organophosphates because its acaricidal properties act by mechanism(s) other than AChE inhibition.

Coupling of In Vitro Bioassays with Planar Chromatography in Effect-Directed Analysis.

Modern analytical test methods increasingly detect anthropogenic organic substances and their transformation products in water samples and in the environment. The presence of these compounds might pose a risk to the aquatic environment. To determine a possible (eco)toxicological risk, aquatic samples are tested using various bioassays, including sub-organismic assays such as the luminescent bacteria inhibition test, the acetylcholinesterase inhibition test, and the umu-test. The effect-directed analysis (EDA) combines physicochemical separation methods with biological (in vitro) tests. High-performance thin-layer chromatography (HPTLC) has proved to be particularly well suited for the separation of organic compounds and the subsequent analysis of effects by the application of the biotests directly on the surface of the HPTLC plate. The advantage of using HPTLC in comparison to high-performance liquid chromatography (HPLC) for EDA is that the solvent which is used as a mobile phase during chromatography is completely evaporated after the separation and therefore can no longer influence the applied bioassays.A prioritization during the complex identification process can be achieved when observed effects are associated with the separated zones in HPTLC. This increases the probability of identifying the substance responsible for an adverse effect from the multitude of organic trace substances in environmental samples. Furthermore, by comparing the pattern of biological effects of a separated sample, it is possible to track and assess changes in biological activity over time, over space, or in the course of a process, even without identifying the substance. HPTLC has already been coupled with various bioassays.Because HPTLC is a very flexible system, various detection techniques can be used and combined. In addition to the UV/Vis absorption and fluorescence measurements, TLC can also be coupled with a mass spectrometer (MS) for compound identification. In addition, detection of functional groups by means of derivatization reagents can support this identification. It is also possible to combine derivatization and HPLC-MS.Two case studies are used to illustrate the significance of HPTLC-EDA in investigating water quality: Study on a wastewater treatment plant Possible influence of an artificial turf surface on ground water.

Screening for biological activities and toxicological effects of 63 phytoplankton species isolated from freshwater, marine and brackish water habitats

Several monitoring events in different freshwater, brackish water and marine habitats were conducted in the years 2004–2011. In some cases, mass occurrences of potential toxic species were accompanied by other species. While the antibacterial toxicity tests (LUMIStox) of samples showed the highest values, the producing taxa were not identified, although the bloom-forming species were in the majority. Under the acceptance that the accompanying taxa could be the source of the observed toxicity, we have tested 21 freshwater, 25 marine and 17 brackish water isolates for potential allelochemical production (e.g. alkaloids, flavonoids) and allelopathic activities (e.g. algicidal, antimicrobial). Most isolates accumulated potential phytochemical compounds in their biomass. Only polyunsaturated fatty acids, terpenes and sterols were found in supernatant extracts, but aldehydes, flavonoids, alkaloids and phenols were detected in biomass extracts. Of the bioassays employed in this study, the acetylcholinesterase inhibition test was the most responsive to the extracts, whereas the invertebrate lethality assay using Artemia salina was least sensitive. Standard tests for alkaloids, flavonoids, phenols including tannins and saponins indicate that bioactivities were not necessarily related to the presence of these compound classes. This indicates that other compound classes such as peptides/proteins or polysaccharides need also to be taken into consideration. These findings may have important consequences not only for ecological research but also for biotechnological applications.

Acetylcholinesterase inhibition activity of acetylated depsidones from Lobaria pulmonaria

As part of our ongoing project of new acetylcholinesterase inhibitors from lower marine and terrestrial species, a phytochemical investigation was conducted on a foliose lichen, Lobaria pulmonaria (L.) Hoffm. (Lobariaceae), from Bosnia and Herzegovina. The study led to the isolation of a mixture of acetylated depsidones which showed a moderate activity (0.5 µg) in the acetylcholinesterase inhibition test on Thin-layer chromatography plate. Our results indicate for the first time the significance of depsidones, highly specific metabolites from lichen species, in searching for these inhibitors which still represent the best drugs currently available for the management of Alzheimer's disease.

Bioassay-directed Fractionation of Organic Extracts of Marine Surface Sediments from the North and Baltic Sea - Part II: Results of the biotest battery and development of a biotest index (8 pp)

Part I: Determination and identification of organic pollutants Part II: Results of the biotest battery and development of a biotest index Preamble. This series of two papers presents the results of an interdisciplinary research project (ISIS) dealing with bioassay-directed fractionation of marine sediment extracts. Part I presents the extraction and fractionation procedure as well as the results of chemical analysis, including non-target analysis of sediments. Part II describes the results of the biotest battery in relation to chemicals possibly causing parts of the observed effects. A biotest index is used to compare the toxicities of the samples. AUTHORS / AFFILIATIONS Ninja Reineke (3), Werner Wosniok (4), Dirk Danischewski (1), Heinrich Huhnerfuss (3), Angelika Kinder (5), Arne Sierts-Herrmann (5), Norbert Theobald (2), Hans-Heinrich Vahl (6), Michael Vobach (1), Johannes Westendorf (6) and Hans Steinhart (5). (1) Federal Research Centre for Fisheries, Institute for Fishery Ecology, Palmaille 9, 22767 Hamburg, Germany (2) Federal Maritime and Hydrographic Agency, Bernhard-Nochtstr. 78, 20359 Hamburg, Germany (3) University of Hamburg, Institute for Organic Chemistry, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany (4) University of Bremen, Institute of Statistics, Bibliothekstr. 1, 28334 Bremen, Germany (5) University of Hamburg, Institute for Food Chemistry, Grindelallee 117, 20146 Hamburg, Germany (6) University of Hamburg, University Hospital Hamburg-Eppendorf, Department for Toxicology, Vogt-Kolln-Str. 30, 22527 Hamburg, Germany (7) Eurofins Wiertz-Eggert-Jorissen, Stenzelring 14b, 21107 Hamburg, Germany The ecological relevance of contaminants in mixtures is difficult to assess, because of possible interactions and due to lacking toxicity data for many substances present in environmental samples. Marine sediment extracts, which contain a mixture of environmental contaminants in low concentrations, were the object of this study. The extracts were investigated with a set of different biotests in order to identify the compound or the substance class responsible for the toxicity. For this goal, a combination of biotests, biotest-directed fractionation and chemical analysis has been applied. Further on, a strategy for the development of a biotest index to describe the toxicity of the fractions without a prior ranking of the test results is proposed. This article (Part II) focuses on the biological results of the approach. The toxicological potential of organic extracts of sediments from the North Sea and the Baltic Sea was analyzed in a bioassay-directed fractionation procedure with a set of biotests: luciferase reporter gene assays on hormone receptor and Ah receptor, arabinose resistance test, fish embryo test (Danio rerio), comet assay, acetylcholinesterase inhibition test, heat-shock protein 70 induction, oxidative stress and luminescence inhibition test (Vibrio fischeri). The test results provided the basis for the calculation of a biotest index by factor analysis to compare the toxicity of the samples and fractions. Results of 11 biotests on different fractionation levels of the samples were described and discussed with regard to the occurrence of contaminants and their toxic potentials. Polychlorinated biphenyls, polycyclic aromatic hydrocarbons, quinones, brominated indoles and brominated phenols were in the focus of interest. A biotest index was constructed to compare the toxic responses in the samples and to group the biotest results. The procedure presented in this study is well suited for bioassay-directed fractionation of marine sediment extracts. However, in relatively low contaminated samples, high enrichment factors and sufficient fractionation is necessary to allow identification of low concentrations of contaminants which is required to link effects and possible causes. In the present case, the relation between substances and effects was difficult to uncover due to relatively low concentrations of pollutants compared to the biogenic matrix and to the remaining complexity of the fractions. The results, with respect to the brominated phenols and indoles in the samples, highlight the successful use of bioassay directed fractionation in the case of high concentrations and high toxicity. In general, it has been shown that a marine risk assessment requires focusing on the input of diffuse sources and taking into account the fact of mixture toxicity. Effects resulting from biogenic substances will make the assessment of the influence of anthropogenic substances even more difficult.

Toxicity of Sodium Molybdate and Sodium Dichromate to Daphnia magna Straus Evaluated in Acute, Chronic, and Acetylcholinesterase Inhibition Tests

As a result of a widespread application in numerous industrial processes, chromium is a contaminant of many environmental systems. Chromium and their compounds are toxic to both invertebrates and vertebrates and, for this reason, there has been a search for suitable and less toxic alternatives. Molybdenum compounds have been studied as alternative to chromium compounds for some industrial applications. The toxicity of chromium is well known but the effects of molybdenum and molybdenum mining on natural populations and communities of freshwater invertebrates have not often been studied. However, chromium, and molybdenum (and their compounds) are included in the same list (List II) of European Union dangerous substances. In this study, the acute and chronic effects of sodium molybdate and sodium dichromate to Daphnia magna Straus were evaluated. Furthermore, in vitro and in vivo effects of these two metals on acetylcholinesterase (AChE) activity of D. magna Straus were investigated. LC50 values determined at 48 h were 0.29 and 2847.5 mg L−1 for chromium (as sodium dichromate) and molybdenum (as sodium molybdate), respectively. No significant in vitro effects of both metals on AChE were found. However, both toxicants inhibited AChE in vivo at concentrations under the respective 48-h LC50 values. Both sodium dichromate and sodium molybdate inhibited the reproduction and growth of D. magna, but the concentrations inducing significant effects were different for the two chemicals. Sodium molybdate had significant lower toxicity to D. magna Straus than sodium dichromate.

In vitro evaluation of the toxicity of several dithiocarbamates using anEscherichia coli growth inhibition bioassay and the acetylcholinesterase inhibition test

The industrial and sanitary use of dithiocarbamates (DTCs) is on the rise, and the synthesis of new derivatives has increased the field of their application. Both positive and negative pharmacological and toxicological effects have been documented for DTCs. The development and application of new DTCs must be accompanied by the study of their toxicity, beginning with the performance of simple and rapid biological screening tests. The objective of our study was to apply the IGEC biotest (inhibition of growth of Escherichia coli) and the acetylcholinesterase (AChE) inhibition test to a group of newly synthesized DTCs with possible applications in the area of public health. The substances studied were (−)-ephedrine-DTC, (+)-pseudoephedrine-DTC, N-ethylbenzyl-DTC, diethyl-DTC, and dimethyl-DTC, and the corresponding amines used in their synthesis: (−)-ephedrine, (+)-pseudoephedrine, N-ethylbenzylamine, diethylamine, and dimethylamine. The parameters for the minimal effective concentration tested (MEC), median effective concentration (EC50), and no observed effect concentration (NOEC) of each chemical were determined using the IGEC biotest. The AChE inhibition test was carried out for all the DTCs as well. Of the synthesized DTCs, (+)-pseudoephedrine-DTC showed the lowest toxicity (NOEC=30 μg mL−1 and EC50=301 μg mL−1) and N-ethylbenzyl-DTC showed the highest toxicity (EC50=26 μg mL−1). Although (−)-ephedrine-DTC exhibited a minimal inhibitory effect on AChE, the results obtained indicate a generalized absence of AChE inhibition for the DTCs. © 1998 John Wiley & Sons, Inc. Environ Toxicol Water Qual 13: 165–174, 1998

In vitro evaluation of the toxicity of several dithiocarbamates using an Escherichia coli growth inhibition bioassay and the acetylcholinesterase inhibition test

The industrial and sanitary use of dithiocarbamates (DTCs) is on the rise, and the synthesis of new derivatives has increased the field of their application. Both positive and negative pharmacological and toxicological effects have been documented for DTCs. The development and application of new DTCs must be accompanied by the study of their toxicity, beginning with the performance of simple and rapid biological screening tests. The objective of our study was to apply the IGEC biotest (inhibition of growth of Escherichia coli) and the acetylcholinesterase (AChE) inhibition test to a group of newly synthesized DTCs with possible applications in the area of public health. The substances studied were (−)-ephedrine-DTC, (+)-pseudoephedrine-DTC, N-ethylbenzyl-DTC, diethyl-DTC, and dimethyl-DTC, and the corresponding amines used in their synthesis: (−)-ephedrine, (+)-pseudoephedrine, N-ethylbenzylamine, diethylamine, and dimethylamine. The parameters for the minimal effective concentration tested (MEC), median effective concentration (EC50), and no observed effect concentration (NOEC) of each chemical were determined using the IGEC biotest. The AChE inhibition test was carried out for all the DTCs as well. Of the synthesized DTCs, (+)-pseudoephedrine-DTC showed the lowest toxicity (NOEC=30 μg mL−1 and EC50=301 μg mL−1) and N-ethylbenzyl-DTC showed the highest toxicity (EC50=26 μg mL−1). Although (−)-ephedrine-DTC exhibited a minimal inhibitory effect on AChE, the results obtained indicate a generalized absence of AChE inhibition for the DTCs. © 1998 John Wiley & Sons, Inc. Environ Toxicol Water Qual 13: 165–174, 1998

Toxicity of organophosphate insecticides and their metabolites to the water flea Daphnia magna, the Microtox test and an acetylcholinesterase inhibition test

The toxicity of the organophosphorous insecticides thiometon and disulfoton as well as some of their degradation products was determined using Daphnia magna, Photobacterium phosphoreum (Microtox ®) and an acetylcholinesterase (AChE) activity assay. For comparison, the toxicity of the organophosphorous insecticides dichlorvos, fenitrothion, parathion, etrimfos, propetamphos and quinalphos was measured. Although disulfoton and thiometon have a similar molecular structure they showed different inhibitory effects on D. magna and P. phosphoreum. Some of their degradation products (PO analogs) were stronger inhibitors of AChE than the parent compounds and showed also higher toxicity in the bioassay with D. magna. D. magna was less sensitive to the degradation products lacking the sulfur containing side-chain and to the low molecular weight sulfur compounds. A toxicological model was used to predict the toxicity of disulfoton and thiometon and their degradation products in soil leachates in the D. magna and P. phosphoreum bioassays. The predictions were based on the toxicity of the single compound and the concentration of each compound in the leachate. The predictions made showed good correlations with the determined toxicity for both bioassays.