Termination and beyond: acetylcholinesterase as a modulator of synaptic transmission

Dual-targeted NAMPT inhibitors as a progressive strategy for cancer therapy

In mammals, nicotinamide phosphoribosyltransferase (NAMPT) is a crucial enzyme in the nicotinamide adenine dinucleotide (NAD+) synthesis pathway catalyzing the condensation of nicotinamide (NAM) with 5-phosphoribosyl-1-pyrophosphate (PRPP) to produce nicotinamide mononucleotide (NMN). Given the pivotal role of NAD+ in a range of cellular functions, including DNA synthesis, redox reactions, cytokine generation, metabolism, and aging, NAMPT has become a promising target for many diseases, notably cancer. Therefore, various NAMPT inhibitors have been reported and classified as first and second-generation based on their chemical structures and design strategies, dual-targeted being one. However, most NAMPT inhibitors suffer from several limitations, such as dose-dependent toxicity and poor pharmacokinetic properties. Consequently, there is no clinically approved NAMPT inhibitor. Hence, research on discovering more effective and less toxic dual-targeted NAMPT inhibitors with desirable pharmacokinetic properties has drawn attention recently. This review summarizes the previously reported dual-targeted NAMPT inhibitors, focusing on their design strategies and advantages over the single-targeted therapies.

Intrinsic organization of the corpus callosum

The corpus callosum-the largest commissural fiber system connecting the two cerebral hemispheres-is considered essential for bilateral sensory integration and higher cognitive functions. Most studies exploring the corpus callosum have examined either the anatomical, physiological, and neurochemical organization of callosal projections or the functional and/or behavioral aspects of the callosal connections after complete/partial callosotomy or callosal lesion. There are no works that address the intrinsic organization of the corpus callosum. We review the existing information on the activities that take place in the commissure in three sections: I) the topographical and neurochemical organization of the intracallosal fibers, II) the role of glia in the corpus callosum, and III) the role of the intracallosal neurons.

Identification of a Novel Inhibitor of Cimex lectularius Acetylcholinesterase

Acetylcholinesterase (AChE) stands as a primary target of commercial insecticides, notably organophosphates and carbamates. Despite their widespread use in agricultural and indoor pest control, concerns over their high toxicity and the emergence of resistance have restricted their efficacy. In this study, we conducted high-throughput virtual screening against both wild-type (WT) and resistant Cimex lectularius AChE utilizing a library encompassing 1 270 000 compounds. From this screening, we identified 100 candidate compounds and subsequently assessed their inhibitory effects on purified AChE enzymes. Among these candidates, AE027 emerged as a potent inhibitor against both WT and resistant AChE, exhibiting IC50 values of 10 and 43 μM, respectively. Moreover, the binding of AE027 significantly stabilized AChE, elevating its melting temperature by approximately 7 °C. Through molecular docking and molecular dynamics simulation, we delineated the binding mode of AE027, revealing its interaction with a site adjacent to the catalytic center, which is distinct from known inhibitors, with differing poses observed between WT and resistant AChE. Notably, the resistance mutation F348Y, positioned at a site directly interfacing with AE027, impedes ligand binding through steric hindrance. Furthermore, we evaluated the toxicity and pharmacokinetic properties of AE027 utilizing bioinformatics tools. These findings lay a crucial foundation for the development of a novel generation of insecticides that can combat both WT and resistant pest populations effectively and safely.

Pulsed electromagnetic field-assisted reduced graphene oxide composite 3D printed nerve scaffold promotes sciatic nerve regeneration in rats

Peripheral nerve injuries can lead to sensory or motor deficits that have a serious impact on a patient's mental health and quality of life. Nevertheless, it remains a major clinical challenge to develop functional nerve conduits as an alternative to autologous grafts. We applied reduced graphene oxide (rGO) as a bioactive conductive material to impart electrophysiological properties to a 3D printed scaffold and the application of a pulsed magnetic field to excite the formation of microcurrents and induce nerve regeneration.In vitrostudies showed that the nerve scaffold and the pulsed magnetic field made no effect on cell survival, increased S-100βprotein expression, enhanced cell adhesion, and increased the expression level of nerve regeneration-related mRNAs.In vivoexperiments suggested that the protocol was effective in promoting nerve regeneration, resulting in functional recovery of sciatic nerves in rats, when they were damaged close to that of the autologous nerve graft, and increased expression of S-100β, NF200, and GAP43. These results indicate that rGO composite nerve scaffolds combined with pulsed magnetic field stimulation have great potential for peripheral nerve rehabilitation.

Toxicity assessment of polyethylene microplastics in combination with a mix of emerging pollutants on Physalaemus cuvieri tadpoles

Studies in recent years have shown that aquatic pollution by microplastics (MPs) can be considered to pose additional stress to amphibian populations. However, our knowledge of how MPs affect amphibians is very rudimentary, and even more limited is our understanding of their effects in combination with other emerging pollutants. Thus, we aimed to evaluate the possible toxicity of polyethylene MPs (PE-MPs) (alone or in combination with a mix of pollutants) on the health of Physalaemus cuvieri tadpoles. After 30 days of exposure, multiple biomarkers were measured, including morphological, biometric, and developmental indices, behavioral parameters, mutagenicity, cytotoxicity, antioxidant and cholinesterase responses, as well as the uptake and accumulation of PE-MPs in animals. Based on the results, there was no significant change in any of the parameters measured in tadpoles exposed to treatments, but induced stress was observed in tadpoles exposed to PE-MPs combined with the mixture of pollutants, reflecting significant changes in physiological and biochemical responses. Through principal component analysis (PCA) and integrated biomarker response (IBR) assessment, effects induced by pollutants in each test group were distinguished, confirming that the exposure of P. cuvieri tadpoles to the PE-MPs in combination with a mix of emerging pollutants induces an enhanced stress response, although the uptake and accumulation of PE-MPs in these animals was reduced. Thus, our study provides new insight into the danger to amphibians of MPs coexisting with other pollutants in aquatic environments.

In vitro and in silico analysis of the Anopheles anticholinesterase activity of terpenoids

Anopheles gambiae, An. coluzzii, An. arabiensis, and An. funestus are major vectors in high malaria endemic African regions. Various terpenoid classes form the main chemical constituent repository of essential oils, many of which have been shown to possess insecticidal effects against Anopheles species. The current study aimed to assess the bioactivity of terpenoids including four sesquiterpene alcohols, farnesol, (-)-α-bisabolol, cis-nerolidol, and trans-nerolidol; a phenylpropanoid, methyleugenol, and a monoterpene, (R)-(+)-limonene, using the larvicidal screening assay against the four Anopheles species. The mechanism of action was investigated through in vitro acetylcholinesterase inhibition assay and in silico molecular modelling. All six terpenoids showed potent larvicidal activity against the four Anopheles species. Insights into the mechanism of action revealed that the six terpenoids are strong AChE inhibitors against An. funestus and An. arabiensis, while there was a moderate inhibitory activity against An. gambiae AChE, but very weak activity against An. coluzzii. Interestingly, in the in silico study, farnesol established a favourable hydrogen bonding interaction with a conserved amino acid residue, Cys⁴⁴⁷, at the entrance to the active site gorge. While (-)-α-bisabolol and methyleugenol displayed a strong interaction with the catalytic Ser³⁶⁰ and adjacent amino acid residues; but sparing the mutable Gly²⁸⁰ residue that confers resistance to the current anticholinesterase insecticides. As a result, this study identified farnesol, (-)-α-bisabolol, and methyleugenol as selective bioinsecticidal agents with potent Anopheles AChE inhibition. These terpenoids present as natural compounds for further development as anticholinesterase bioinsecticides.

Exploring the neurogenic differentiation of human dental pulp stem cells

Human dental pulp stem cells (hDPSCs) have increasingly gained interest as a potential therapy for nerve regeneration in medicine and dentistry, however their neurogenic potential remains a matter of debate. This study aimed to characterize hDPSC neuronal differentiation in comparison with the human SH-SY5Y neuronal stem cell differentiation model. Both hDPSCs and SH-SY5Y could be differentiated to generate typical neuronal-like cells following sequential treatment with all-trans retinoic acid (ATRA) and brain-derived neurotrophic factor (BDNF), as evidenced by significant expression of neuronal proteins βIII-tubulin (TUBB3) and neurofilament medium (NF-M). Both cell types also expressed multiple neural gene markers including growth-associated protein 43 (GAP43), enolase 2/neuron-specific enolase (ENO2/NSE), synapsin I (SYN1), nestin (NES), and peripherin (PRPH), and exhibited measurable voltage-activated Na⁺ and K⁺ currents. In hDPSCs, upregulation of acetylcholinesterase (ACHE), choline O-acetyltransferase (CHAT), sodium channel alpha subunit 9 (SCN9A), POU class 4 homeobox 1 (POU4F1/BRN3A) along with a downregulation of motor neuron and pancreas homeobox 1 (MNX1) indicated that differentiation was more guided toward a cholinergic sensory neuronal lineage. Furthermore, the Extracellular signal-regulated kinase 1/2 (ERK1/2) inhibitor U0126 significantly impaired hDPSC neuronal differentiation and was associated with reduction of the ERK1/2 phosphorylation. In conclusion, this study demonstrates that extracellular signal-regulated kinase/Mitogen-activated protein kinase (ERK/MAPK) is necessary for sensory cholinergic neuronal differentiation of hDPSCs. hDPSC-derived cholinergic sensory neuronal-like cells represent a novel model and potential source for neuronal regeneration therapies.

Transcriptome profiling reveals toxicity mechanisms following sertraline exposure in the brain of juvenile zebrafish (Danio rerio)

Sertraline (SER) is one of the most commonly detected antidepressants in the aquatic environment that can negatively affect aquatic organisms at low concentrations. Despite some knowledge on its acute toxicity to fish, the effects of chronic SER exposure remain poorly understood along with any underlying mechanisms of SER-induced toxicity. To address this knowledge gap, the effects of chronic exposure to three SER concentrations from low to high were investigated in zebrafish. Juvenile zebrafish were exposed to three concentrations of 1, 10, or 100 μg/L of SER for 28 d, after which indicators of oxidative stress and neurotoxicity in the brain were measured. Superoxide dismutase (SOD) activity was significantly enhanced by SER at 1 up to 100 μg/L, and catalase (CAT) activity was significantly induced by SER at 1 or 10 μg/L. The activity of acetylcholinesterase (AChE) was significantly induced by 10 and 100 μg/L of SER, and the serotonin (5-HT) level was significantly increased by all three concentrations of SER. To ascertain mechanisms of SER-induced toxicity, transcriptomics was conducted in the brain of zebrafish following 100 μg/L SER exposure. The molecular signaling pathways connected with circadian system and the immune system were significantly altered in the zebrafish brain. Based on transcriptomic data, the expression levels of six circadian clock genes were measured, and three genes were significantly altered in relative abundance in fish from all experimental treatments with SER, including cryptochrome circadian regulator 2 (cry2), period circadian clock 2 (per2), and period circadian clock 3 (per3). We hypothesize that the circadian system may be related to SER-induced neurotoxicity and oxidative stress in the central nervous system. This study reveals potential mechanisms and key events (i.e., oxidative stress and neurotoxicity) associated with SER-induced toxicity, and improves understanding of the molecular and biochemical pathways putatively perturbed by SER.

Optimization of covalent docking for organophosphates interaction with Anopheles acetylcholinesterase

Organophosphates (OPs) used as potent insecticides for malaria vector control, covalently phosphorylate the catalytic serine residue of Anopheles gambiae AChE (AgAChE) in a reaction that liberates their leaving groups. In the recent 10-year insecticide use assessment, OPs were the most frequently used World Health Organization prequalified insecticides. Molecular modelling programs are best suited to display molecular interactions between ligands and the target proteins. The docking modes that generate ligand poses closer to the binding site show high accuracy in predicting the ligand binding mode. The implicit solvation approach such as molecular mechanics-generalized born surface area (MM-GBSA) is a more reliable method to predict ligand onformations and binding affinities. Apart from covalent docking studies being scarce, current molecular docking programs do not adequately possess the covalent docking reaction algorithm to display the molecular mechanism of OPs at the AgAChE catalytic site. This results into OP docking studies commonly being conducted through noncovalent pannels. The aim of this study was to establish the optimim covalent docking system for OPs through manual customization of Schrödinger's Glide covalent docking reaction algorithm. To achieve this, a newly customized covalent reaction algorithm was assessed on a set of ligands covering aromatic, non-aromatic and hydrophobic OPs and compared to the noncovalent docking results in terms of reliability based on the reported X-ray diffraction molecular interactions and crystal poses. The study established that by virtue of omitting the well-known OP hydrolysis, noncovalent mode suggested molecular interactions that were further from the catalytic triad and could not otherwise occur when the molecule is hydrolyzed as in the customized covalent docking mode. Moreover, the MM-GBSA concurred with the optimized covalent docking in eliminating such inaccurate molecular interactions. Additionally, the covalent docking mode confined the interactions and ligand poses to the catalytic site indicating relatively high accuracy and reliability. This study reports the optimized covalent docking panel that effectively confirmed the molecular mechanisms of OPs, as well as indentifying the corresponding amino acid residues required to stabilize the aromatic, non-aromatic and hydrophobic OPs at the AgAChE catalytic site in line with the reported X-ray diffraction studies. As such, the proposed manual customization of the Schrödinger's Glide covalent docking platform can be used to reliably predict molecular interactions between OPs and AgAChE target.

Radiological, Chemical, and Pharmacological Cholinergic System Parameters and Neurocognitive Disorders in Older Presurgical Adults

BACKGROUND

A pre-existing neurocognitive disorder (NCD) is a relevant factor for the outcome of surgical patients. To improve understanding of these conditions, we investigated the association between parameters of the cholinergic system and NCD.

METHOD

This investigation is part of the BioCog project (www.biocog.eu), which is a prospective multicenter observational study including patients aged 65 years and older scheduled for elective surgery. Patients with a Mini-Mental State Examination (MMSE) score ≤23 points were excluded. Neurocognitive disorder was assessed according to the fifth Diagnostic and Statistical Manual of Mental Disorders criteria. The basal forebrain cholinergic system volume (BFCSV) was assessed with magnetic resonance imaging, the peripheral cholinesterase (ChE) activities with point-of-care measurements, and anticholinergic load by analyzing the long-term medication with anticholinergic scales (Anticholinergic Drug Scale [ADS], Anticholinergic Risk Scale [ARS], Anticholinergic Cognitive Burden Scale [ACBS]). The associations of BFCSV, ChE activities, and anticholinergic scales with NCD were studied with logistic regression analysis, adjusting for confounding factors.

RESULTS

A total of 797 participants (mean age 72 years, 42% females) were included. One hundred and eleven patients (13.9%) fulfilled criteria for mild NCD and 82 patients (10.3%) for major NCD criteria. We found that AcetylChE activity was associated with major NCD (odds ratio [95% confidence interval]: [U/gHB] 1.061 [1.010, 1.115]), as well as ADS score ([points] 1.353 [1.063, 1.723]) or ARS score, respectively ([points] 1.623 [1.100, 2.397]) with major NCD. However, we found no association between BFCSV or ButyrylChE activity with mild or major NCD.

CONCLUSIONS

AcetylChE activity and anticholinergic load were associated with major NCD. Future research should focus on the association of the cholinergic system and the development of postoperative delirium and postoperative NCD.

Environmental enrichment applied with sensory components prevents age-related decline in synaptic dynamics: Evidence from the zebrafish model organism

Progression of cognitive decline with or without neurodegeneration varies among elderly subjects. The main aim of the current study was to illuminate the molecular mechanisms that promote and retain successful aging in the context of factors such as environment and gender, both of which alter the resilience of the aging brain. Environmental enrichment (EE) is one intervention that may lead to the maintenance of cognitive processing at older ages in both humans and animal subjects. EE is easily applied to different model organisms, including zebrafish, which show similar age-related molecular and behavioral changes as humans. Global changes in cellular and synaptic markers with respect to age, gender and 4-weeks of EE applied with sensory stimulation were investigated using the zebrafish model organism. Results indicated that EE increases brain weight in an age-dependent manner without affecting general body parameters like body mass index (BMI). Age-related declines in the presynaptic protein synaptophysin, AMPA-type glutamate receptor subunits and a post-mitotic neuronal marker were observed and short-term EE prevents these changes in aged animals, as well as elevates levels of the inhibitory scaffolding protein, gephyrin. Gender-driven alterations were observed in the levels of the glutamate receptor subunits. Oxidative stress markers were significantly increased in the old animals, while exposure to EE did not alter this pattern. These data suggest that EE with sensory stimulation exerts its effects mainly on age-related changes in synaptic dynamics, which likely increase brain resilience through specific cellular mechanisms.

Neuroprotective potential of hydroethanolic hull extract of Juglans regia L. on isoprenaline induced oxidative damage in brain of Wistar rats

The study was aimed at assessing isoprenaline (ISO) induced oxidative damage in brain of Wistar rats and its protection by hydroethanolic hull extract of Juglans regia. Administration of ISO significantly increases catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GR), malondialdehyde (MDA) and advanced oxidation protein product (AOPP) levels and significantly reduced activities of antioxidant status (TAS), total thiols (TTH), acetylcholinesterase (AChE), arylesterase (AE), and glutathione peroxidase (GPx) in rat brain. Histopathologically, neuronal degeneration, spongiosis and gliosis were seen in cerebral cortex after ISO administration. Pretreatment with hull extract restored TAS, TTH, AChE, CAT and SOD values. Additionally, significant reductions were noted in levels of MDA, AOPP, and severity of histomorphological changes in cerebral cortex following hull extract treatment. Altered antioxidant biomarkers along with histopathological changes indicate oxidative injury in rat brain following ISO administration. Repeated administration of J. regia hull extract demonstrating presence of neuroprotective properties against ISO induced oxidative damage in rat brain.

Muscarinic Regulation of Spike Timing Dependent Synaptic Plasticity in the Hippocampus

Long-term changes in synaptic transmission between neurons in the brain are considered the cellular basis of learning and memory. Over the last few decades, many studies have revealed that the precise order and timing of activity between pre- and post-synaptic cells ("spike-timing-dependent plasticity; STDP") is crucial for the sign and magnitude of long-term changes at many central synapses. Acetylcholine (ACh) via the recruitment of diverse muscarinic receptors is known to influence STDP in a variety of ways, enabling flexibility and adaptability in brain network activity during complex behaviors. In this review, we will summarize and discuss different mechanistic aspects of muscarinic modulation of timing-dependent plasticity at both excitatory and inhibitory synapses in the hippocampus to shape learning and memory.

Exposure during embryonic development to Roundup® Power 2.0 affects lateralization, level of activity and growth, but not defensive behaviour of marsh frog tadpoles

As glyphosate-based herbicides, sold under the commercial name Roundup®, represent the most used herbicides in the world, contamination of the freshwater environment by glyphosate has become a widespread issue. In Italy, glyphosate was detected in half of the surface waters monitoring sites and its concentrations were higher than environmental quality standards in 24.5% of them. It can last from days to months in water, leading to exposure for aquatic organisms and specifically to amphibians' larvae that develop in shallow water bodies with proven effects to development and behaviour. In this study, we tested the effects of a 96 h exposure during embryonic development of marsh frog's tadpoles to three ecologically relevant Roundup® Power 2.0 concentrations. As expected, given the low concentrations tested, no mortality was observed. Morphological measurements highlighted a reduction in the total length in tadpoles exposed to 7.6 mg a.e./L, while an increase was observed at lower concentrations of 0.7 and 3.1 mg a.e./L compared to control group. Tadpoles raised in 7.6 mg a.e./L also showed a smaller tail membrane than those raised in the control solution. Regarding behaviour, we tested tadpoles in two different sessions (Gosner stages 25 and 28/29) for lateralization, antipredator response and basal activity. Lower intensity of lateralization was detected in tadpoles raised at the highest Roundup® concentration in the first session of observation, while no significant difference among treatments was observed in the second one. In both sessions, effects of Roundup® Power 2.0 embryonic exposure on antipredator response, measured as the proportional change in activity after the injection of tadpole-fed predator (Anax imperator) cue, were not detected. Tadpoles exposed during embryonic development to Roundup® exhibited lower basal activity than the control group, with the strongest reduction for the 7.6 mg a.e./L treatment. Our results reinforce the concern of Roundup® contamination impact on amphibians.

Early-life stress affects behavioral and neurochemical parameters differently in male and female juvenile Wistar rats

Neonatal handling is an early life stressor that leads to behavioral and neurochemical changes in adult rats in a sex-specific manner and possibly affects earlier stages of development. Here, we investigated the effects of neonatal handling (days 1-10 after birth) on juvenile rats focusing on biochemical parameters and olfactory memory after weaning. Male neonatal handled rats performed more crossings on the hole-board task, increased Na⁺ /K⁺ -ATPase activity in the olfactory bulb, and decreased acetylcholinesterase activity in the hippocampus versus non-handled males. Female neonatal handled animals increased the number of rearing and nose-pokes on the hole-board task, decreased glutathione peroxidase activity, and total thiol content in the hippocampus versus non-handled females. This study reinforces that early life stress affects behavioral and neurochemical parameters in a sex-specific manner even before the puberty onset.

Theoretical studies and NMR assay of coumarins and neoflavanones derivatives as potential inhibitors of acetylcholinesterase

Currently Alzheimer's disease (AD) is a devastating neurological disorder that mainly affects the elderly. The treatment of AD has as main objective to increase the levels of ACh in the synaptic cleft by inhibiting the cholinesterase enzymes, which are responsible for the degradation of ACh. Twenty one synthesized coumarins and neoflavanones (4-arylcoumarins) and theoretical studies were used to select the most promising ligands for in vitro experimental studies by Nuclear Magnetic Resonance. The eight compounds selected for the experimental study only 12b (effectiveness 68.54 ± 3.22%) was promising AChE inhibitor. This compound (12b) presents substituents at positions 4, 5, 6, 7 and 8 in a coumarin nucleus, being the most significant characteristic in comparison to the other studied compounds. These results can be used for the design and synthesis of other possible derivatives with inhibitory potential of AChE.

Establishment of resveratrol and its derivatives as neuroprotectant against monocrotophos-induced alteration in NIPBL and POU4F1 protein through molecular docking studies

Monocrotophos (MCP) is a broad spectrum organophosphorus insecticide, which is widely used as foliar spray to the different important crops. MCP may reach the soil and the aquatic environment directly or indirectly during and after the application, which leads to the different environmental issues. MCP is found to be associated with neurotoxicity and its toxic effects have been monitored during different stages of neuronal development. Identification of gene expression in MCP-induced neurotoxicity during neuronal developmental stage is a major area of genomic research interest. In accordance with this identification, screening of potential neuroprotective, natural resources are also required as a preventive aspects by targeting the impaired genes. In this current course of work, microarray experiment has been used to identify genes that were expressed in monocrotophos (MCP)-induced mesenchymal stem cells (MSC) and also the neuroprotectant activity of RV on MCP-exposed MSCs. Microarray experiment data have been deposited in NCBI's Gene Expression Omnibus database and are accessible through GEO Series accession number GSE121261. In this paper, we have discussed two important genes NIPBL (nipped-B-like protein) and POU4F1 (POU domain, class 4, transcription factor 1). These genes were found to be significantly expressed in MCP-exposed MSC and show minimum expression in presence of RV. Homology modelling and docking study was done to identify the interaction and binding affinity of resveratrol and its derivatives with NIPBL and POU4F1 protein. Docking analysis shows that RV and its derivatives have strong interaction with NIPBL and POU4F1 protein hence proves the significance of resveratrol as potential neuroprotectant. This paper highlights the hazardous impact of MCP on neuronal development disorders and repairing potentiality of RV and its derivatives on altered genes involved in neuronal diseases. Graphical Abstract.

Experimental listeriosis: A study of purinergic and cholinergic inflammatory pathway

The cholinergic, purinergic and oxidative stress systems were related to nervous system damage in some pathologies, as well as being involved in pro-inflammatory and anti-inflammatory pathways. The objective was to investigate changes in purinergic, cholinergic systems and oxidative stress related to the neuropathology of listeriosis. Gerbils were used as experimental models. The animals were divided in two groups: control and infected. The animals were orally infected with 5 × 10⁸ CFU/animal of the pathogenic strain of Listeria monocytogenes. Collected of material was 6 and 12th days post-infection (PI). Infected animals showed moderate mixed inflammatory infiltrates in the liver. The spleen and brain was used for PCR analyses, confirming infection by L. monocytogenes. Increase in number of total leukocytes because of an increase in lymphocytes in infected (P < 0.001). ATP and ADP hydrolysis by NTPDase was lower at 6 and 12th days PI in infected animals than in the control group. ADA (adenosine deaminase) activity was higher on the 6th day PI (P < 0.05) and decreased on the 12th day PI (P < 0.05) in infected animals. AChE (acetylcholinesterase) activity did not differ between groups on the 6th day PI; however, activity decreased in infected group on the 12th day PI (P < 0.05). On the 12th day PI, an increase of oxygen-reactive species levels and lower catalase and superoxide dismutase activities in the infected group was observed, characterizing a situation of cerebral oxidative stress. The inflammatory and oxidative mechanisms are present in listeriosis in asymptomatic animals, and that ectonucleotidases and cholinesterase's are involved in immunomodulation.

Targeted acetylcholinesterase-responsive drug carriers with long duration of drug action and reduced hepatotoxicity

PURPOSE

Acetylcholinesterase (AChE) plays a critical role in the transmission of nerve impulse at the cholinergic synapses. Design and synthesis of AChE inhibitors that increase the cholinergic transmission by blocking the degradation of acetylcholine can serve as a strategy for the treatment of AChE-associated disease. Herein, an operational targeted drug delivery platform based on AChE-responsive system has been presented by combining the unique properties of enzyme-controlled mesoporous silica nanoparticles (MSN) with clinical-used AChE inhibitor.

METHODS

Functionalized MSNs were synthesized by liquid phase method and characterized by using different analytical methods. The biocompatibility and cytotoxicity of MSNs were determined by hemolysis experiment and MTT assay, respectively. Comparison of AChE activity between drug-loading system and inhibitor was developed with kits and by ELISA method. The efficacy of drug-loaded nanocarriers was investigated in a mouse model.

RESULTS

Compared with AChE inhibitor itself, the inhibition efficiency of this drug delivery system was strongly dependent on the concentration of AChE. Only AChE with high concentration could cause the opening of pores in the MSN, leading to the controlled release of AChE inhibitor in disease condition. Critically, the drug delivery system can not only exhibit long duration of drug action on AChE inhibition but also reduce the hepatotoxicity in vivo.

CONCLUSION

In summary, AChE-responsive drug release systems have been far less explored. Our results would shed lights on the design of enzyme controlled-release multifunctional system for enzyme-associated disease treatment.

Neurotransmitter signaling through heterotrimeric G proteins: insights from studies in C. elegans

Neurotransmitters signal via G protein coupled receptors (GPCRs) to modulate activity of neurons and muscles. C. elegans has ∼150 G protein coupled neuropeptide receptor homologs and 28 additional GPCRs for small-molecule neurotransmitters. Genetic studies in C. elegans demonstrate that neurotransmitters diffuse far from their release sites to activate GPCRs on distant cells. Individual receptor types are expressed on limited numbers of cells and thus can provide very specific regulation of an individual neural circuit and behavior. G protein coupled neurotransmitter receptors signal principally via the three types of heterotrimeric G proteins defined by the G alpha subunits Gαo, Gαq, and Gαs. Each of these G alpha proteins is found in all neurons plus some muscles. Gαo and Gαq signaling inhibit and activate neurotransmitter release, respectively. Gαs signaling, like Gαq signaling, promotes neurotransmitter release. Many details of the signaling mechanisms downstream of Gαq and Gαs have been delineated and are consistent with those of their mammalian orthologs. The details of the signaling mechanism downstream of Gαo remain a mystery. Forward genetic screens in C. elegans have identified new molecular components of neural G protein signaling mechanisms, including Regulators of G protein Signaling (RGS proteins) that inhibit signaling, a new Gαq effector (the Trio RhoGEF domain), and the RIC-8 protein that is required for neuronal Gα signaling. A model is presented in which G proteins sum up the variety of neuromodulator signals that impinge on a neuron to calculate its appropriate output level.

Arthropod venoms: Biochemistry, ecology and evolution

Comprising of over a million described species of highly diverse invertebrates, Arthropoda is amongst the most successful animal lineages to have colonized aerial, terrestrial, and aquatic domains. Venom, one of the many fascinating traits to have evolved in various members of this phylum, has underpinned their adaptation to diverse habitats. Over millions of years of evolution, arthropods have evolved ingenious ways of delivering venom in their targets for self-defence and predation. The morphological diversity of venom delivery apparatus in arthropods is astounding, and includes extensively modified pedipalps, tail (telson), mouth parts (hypostome), fangs, appendages (maxillulae), proboscis, ovipositor (stinger), and hair (urticating bristles). Recent investigations have also unravelled an astonishing venom biocomplexity with molecular scaffolds being recruited from a multitude of protein families. Venoms are a remarkable bioresource for discovering lead compounds in targeted therapeutics. Several components with prospective applications in the development of advanced lifesaving drugs and environment friendly bio-insecticides have been discovered from arthropod venoms. Despite these fascinating features, the composition, bioactivity, and molecular evolution of venom in several arthropod lineages remains largely understudied. This review highlights the prevalence of venom, its mode of toxic action, and the evolutionary dynamics of venom in Arthropoda, the most speciose phylum in the animal kingdom.

Thiazole-substituted benzoylpiperazine derivatives as acetylcholinesterase inhibitors

Hit, Lead & Candidate Discovery After acetylcholine is released into the synaptic cleft, it is reabsorbed or deactivated by acetylcholinesterase (AChE). Studies on Alzheimer's disease (AD) in the mid-20th century proved that cognitive dysfunctions are associated with cholinergic neurotransmission. Drugs, such as tacrine, rivastigmine, donepezil, and galantamine are known as acetylcholinesterase inhibitors. However, these drugs have limited use in advanced AD and dementia. Recently, the anticholinesterase activity of various heterocyclic-framed compounds, including piperazine derivatives, has been investigated, and compounds with similar effects to known drugs have been identified. The aim of this study was to design new donepezil analogs. In this study, 66 original piperazinyl thiazole derivatives were synthesized by the reaction of piperazine N'-benzoyl thioamides and bromoacetophenones to inhibit AChE. Biological activity was measured by the Ellman method. Compounds 35, 38, 40, 45, 57, and 61 showed a high inhibitory effect among the series (80.36%-83.94% inhibition), and donepezil had a 96.42% inhibitory effect. The IC₅₀ values of compounds 35, 38, and 40, were calculated as 0.9767 μM, 0.9493 μM, and 0.8023 μM, respectively. Compound 45 (IC₅₀ = 1.122), Compound 57 (IC₅₀ = 1.2130) and 61 (IC₅₀ = 0.9193) also exhibited good activity on AChE. Molecular modeling studies were in agreement with the predictions. Trp286, Arg296, and Tyr341 were the key amino acids at the active site. Both donepezil and synthesized compounds seemed to interact with these residues.

miRNA-Mediated Interactions in and between Plants and Insects

Our understanding of microRNA (miRNA) regulation of gene expression and protein translation, as a critical area of cellular regulation, has blossomed in the last two decades. Recently, it has become apparent that in plant-insect interactions, both plants and insects use miRNAs to regulate their biological processes, as well as co-opting each others' miRNA systems. In this review article, we discuss the current paradigms of miRNA-mediated cellular regulation and provide examples of plant-insect interactions that utilize this regulation. Lastly, we discuss the potential biotechnological applications of utilizing miRNAs in agriculture.

The differences in bioaccumulation and effects between Se(IV) and Se(VI) in the topmouth gudgeon Pseudorasbora parva

Selenium (Se) might be protective against oxidative stress at nutritional levels, but elevated Se concentrations in the diet has been revealed as the main culprit for the extinction of natural fish populations in Se-contaminated lakes. Though Se predominate as waterborne selenite (IV) and selenate (VI) in the water, the differences in bioaccumulation, effects (e.g., oxidative stress, antioxidants etc.) and molecular mechanisms between Se(IV) and Se(VI) have been relatively understudied in wild fish. In this study, the P. parva were exposed to waterborne Se (10, 200 and 1000 μg/L of Se(IV) or Se(VI)) and sampled at 4, 14 and 28 days. Bioaccumulation, tissue distributions of Se and following effects in different tissues were evaluated. The results showed that the levels of Se in the gills and intestine were significantly elevated with a seemingly concentration-dependent pattern in the Se(IV) treatment, with respectively 173.3% and 57.2% increase after 28 days of exposure, relative to that of Se(VI) treatment. Additionally, significant accumulation of Se was also observed in the muscle of Se(IV) treated fish. Se exposure increased the MDA levels in the brain and gills in the Se(IV) treatment, but less apparent in the Se(VI) treatment. Meanwhile, Se exposure lowered (at least 56%) the activity of GST in the gills, but increased the activity of AChE in the muscle (~69%) and brain (~50%) after 28 d. Most importantly, after 28 d of exposure, Se exposure caused significant decrease in GSH levels in the gills (at least 35%) and in all tissues examined at the highest test concentration. In general, the results showed that Se(IV) led to faster accumulation of Se than Se(VI) in P. parva, and the resulted lipid peroxidation was closely related to the levels of antioxidants, especially GSH. Our results suggest that the ecotoxicological effects of waterborne selenite and selenate differ in this freshwater species in the field.

Knockdown of Butyrylcholinesterase but Not Inhibition by Chlorpyrifos Alters Early Differentiation Mechanisms in Human Neural Stem Cells

Butyrylcholinesterase (BChE) is the evolutionary counterpart to acetylcholinesterase (AChE). Both are expressed early in nervous system development prior to cholinergic synapse formation. The organophosphate pesticide chlorpyrifos (CPF) primarily exerts toxicity through the inhibition of AChE, which results in excess cholinergic stimulation at the synapse. We hypothesized that the inhibition of AChE and BChE by CPF may impair early neurogenesis in neural stem cells (NSCs). To model neurodevelopment in vitro, we used human NSCs derived from induced pluripotent stem cells (iPSCs) with a focus on the initial differentiation mechanisms. Over the six days of NSC differentiation, the BChE activity and mRNA expression significantly increased, while the AChE activity and expression remained unchanged. The CPF treatment (10 μM) caused 82% and 92% inhibition of AChE and BChE, respectively. The CPF exposure had no effect on the cell viability or the expression of the differentiation markers HES5, DCX, or MAP2. However, the shRNA-knockdown of the BChE expression resulted in the decreased or delayed expression of the transcription factors HES5 and HES3. BChE may have a role in the differentiation of NSCs independent of, or in addition to, its enzymatic activity.

New 2-Aryl-9-methyl-β-carbolinium salts as Potential Acetylcholinesterase Inhibitor agents: Synthesis, Bioactivity and Structure-Activity Relationship

A series of 2-aryl-9-methyl-β-carbolinium bromides (B) were synthesized and explored for anti-acetylcholinesterase (AChE) activities in vitro, action mechanism and structure-activity relationship. All the compounds B along with their respective 3,4-dihydro intermediates (A) presented anti-AChE activity at 10 μM. Thirteen compounds B showed the excellent activity with IC₅₀ values of 0.11–0.76 μM and high selectivity toward AChE relative to butyrylcholinesterase (BChE), superior to galantamine (IC₅₀ = 0.79 μM), a selective AChE inhibitor drug. Kinetic analysis showed that the action mechanisms of both compounds B and A are a competitive inhibition model. Structure-activity relationship analyses showed that the C = N⁺ moiety is a determinant for the activity. Substituents at 6, 7 or 4′ site, the indole-N-alkyl and the aromatization of the C-ring can significantly improve the activity. Molecular docking studies showed that the compounds could combine with the active site of AChE by the π-π or cation-π action between the carboline ring and the phenyl rings of the residues, and the β-carboline moiety is embedded in a cavity surrounded by four aromatic residues of Trp86, Tyr337, Trp439 and Tyr449. The present results strongly suggest that the para-position of the D-ring should be a preferred modification site for further structural optimization design. Thus, 2-aryl-9-methyl-β-carboliniums emerged as novel and promising tool compounds for the development of new AChE inhibitor agents.

Assessment of Enzyme Inhibition: A Review with Examples from the Development of Monoamine Oxidase and Cholinesterase Inhibitory Drugs

The actions of many drugs involve enzyme inhibition. This is exemplified by the inhibitors of monoamine oxidases (MAO) and the cholinsterases (ChE) that have been used for several pharmacological purposes. This review describes key principles and approaches for the reliable determination of enzyme activities and inhibition as well as some of the methods that are in current use for such studies with these two enzymes. Their applicability and potential pitfalls arising from their inappropriate use are discussed. Since inhibitor potency is frequently assessed in terms of the quantity necessary to give 50% inhibition (the IC50 value), the relationships between this and the mode of inhibition is also considered, in terms of the misleading information that it may provide. Incorporation of more than one functionality into the same molecule to give a multi-target-directed ligands (MTDLs) requires careful assessment to ensure that the specific target effects are not significantly altered and that the kinetic behavior remains as favourable with the MTDL as it does with the individual components. Such factors will be considered in terms of recently developed MTDLs that combine MAO and ChE inhibitory functions.

Caffeic acid phenethyl ester protects the brain against hexavalent chromium toxicity by enhancing endogenous antioxidants and modulating the JAK/STAT signaling pathway

Hexavalent chromium [Cr(VI)] is commonly used in industry, and is a proven toxin and carcinogen. However, the information regarding its neurotoxic mechanism is not completely understood. The present study was designed to scrutinize the possible protective effects of caffeic acid phenethyl ester (CAPE), a bioactive phenolic of propolis extract, on Cr(VI)-induced brain injury in rats, with an emphasis on the JAK/STAT signaling pathway. Rats received 2mg/kgK₂CrO₄ and concurrently treated with 20mg/kg CAPE for 30 days. Cr(VI)-induced rats showed a significant increase in cerebral lipid peroxidation, nitric oxide and pro-inflammatory cytokines, with concomitantly declined antioxidants and acetylcholinesterase. CAPE attenuated oxidative stress and inflammation and enhanced antioxidant defenses in the cerebrum of rats. Cr(VI) significantly up-regulated JAK2, STAT3 and SOCS3, an effect that was reversed by CAPE. In conclusion, CAPE protects the brain against Cr(VI) toxicity through abrogation of oxidative stress, inflammation and down-regulation of JAK2/STAT3 signaling in a SOCS3-independent mechanism.

Highly sensitive GQDs-MnO2 based assay with turn-on fluorescence for monitoring cerebrospinal acetylcholinesterase fluctuation: A biomarker for organophosphorus pesticides poisoning and management

In this study, we demonstrated an assay with turn-on fluorescence for monitoring cerebrospinal acetylcholinesterase (AChE) fluctuation as a biomarker for organophosphorus pesticides (OPs) poisoning and management based on single layer MnO₂ nanosheets with graphene quantum dots (GQDs) as signal readout. Initially, the fluorescence of GQDs was quenched by MnO₂ nanosheets mainly due to the inner filter effect (IFE). However, with the presence of reductive thiocholine (TCh), the enzymatic product, hydrolyzed from acetylthiocholine (ATCh) by AChE, the redox reaction between MnO₂ and TCh occurred, leading to the destruction of the MnO₂ nanosheets, and thereby IFE was diminished gradually. As a consequence, the turn-on fluorescence of GQDs with the changes in the spectrum of the dispersion constituted a new mechanism for sensing of cerebrospinal AChE. With the method developed here, we could monitor cerebrospinal AChE fluctuation of rats exposed to OPs before and after therapy, and could thereby open up the pathway to a new sensing platform for better understanding the mechanism of brain dysfunctions associate with OPs poisoning.

Portable Agrichemical Detection System for Enhancing the Safety of Agricultural Products Using Aggregation of Gold Nanoparticles

Organophosphorus (OP) and triazole chemicals have been commonly used as insecticides and fungicides to protect agricultural foods from harmful insects and fungi. However, these agrichemicals sometimes remain after distribution and can cause serious health and environmental issues. Therefore, it is essential to detect OPs and triazole chemicals in agricultural products. Nowadays, many detection techniques for OPs and triazole chemicals are expensive and time-consuming and require highly trained technicians. Thus, particularly rapid, simple, and sensitive detection methods are in demand for on-site screening of agrichemicals. Gold nanoparticles (AuNPs) have been utilized for applications in analytical assays and real-time monitoring in the biosensor field because of their biocompatibility and outstanding size-dependent optical properties. In this study, we used AuNPs as a detection probe, which have a size of 17 nm in diameter, a red color, and the absorbance peak at 520 nm. When imidazole was added to AuNPs mixed with the agrichemicals, the AuNPs aggregated and their colors changed to purple, causing the appearance of a new peak at 660-670 nm, which could be measured within approximately 20 s. Moreover, we developed a novel device for multiple agrichemical detections using an AuNP-aggregation-based spectrometric detection system. This portable device is light, simple, fast, and highly sensitive as well as selective. With this system, agrichemical residues can be easily detected on the spot at a low cost and in a short reaction time.

Lipid rafts of mouse liver contain nonextended and extended acetylcholinesterase variants along with M3 muscarinic receptors

The observation of acetylcholinesterase (AChE) type H (AChE_H), which is the predominant AChE variant in visceral organs and immune cells, in lipid rafts of muscle supports functional reasons for the raft targeting of glypiated AChE_H The search for these reasons revealed that liver AChE activity is mostly confined to rafts and that the liver is able to make N-extended AChE variants and target them to rafts. These results prompted us to test whether AChE and muscarinic receptors existed in the same raft. Isolation of flotillin-2-rich raft fractions by their buoyancy in sucrose gradients, followed by immunoadsorption and matrix-assisted laser desorption ionization-time of flight-mass spectrometry application, gave the following results: 1) most hepatic AChE activity emanates from AChE-H mRNA, and its product, glypiated AChE_H, accumulates in rafts; 2) N-extended N-AChE readthrough variant, nonglypiated N-AChE_H, and N-AChE tailed variant were all identified in liver rafts; and 3) M3 AChRs were observed in rafts, and coprecipitation of raft-confined N-AChE and M3 receptors by using anti-M3 antibodies showed that enzyme and receptor reside in the same raft unit. A raft domain that harbors tightly packed muscarinic receptor and AChE may represent a molecular device that, by means of which, the intensity and duration of cholinergic inputs are regulated.-Montenegro, M. F., Cabezas-Herrera, J., Campoy, F. J., Muñoz-Delgado, E., Vidal, C. J. Lipid rafts of mouse liver contain nonextended and extended acetylcholinesterase variants along with M3 muscarinic receptors.

Effect of exposure to staphylococcus aureus, particulate matter, and their combination on the neurobehavioral function of mice

Neurotoxicity in Kunming mice caused by Staphylococcus aureus (S. aureus) and Particulate matter (PM) as individual matter and mixtures was studied in this paper. Male Kunming mice were instilled intratracheally with PM at doses of 0.2mg/mouse and S. aureus at doses of 5.08×10⁶ CFU/mouse as individual matter and mixtures two times at 5-day intervals. Morris water maze (MWM) test was performed during the exposure experiment. One day following the exposure experiment, the expression of neurotrophins, neurotransmitters, cholinergic system enzymes, oxidative damage levels, and pro-inflammatory cytokines (TNF-α, IL-1β) in the brain of mice were determined. Combined treatment of PM and S. aureus led to significant increment of escape latency at day 6, 8, and 10. Oxidative stress levels, and pro-inflammatory cytokines were affected significantly by S. aureus and PM as individual matter and mixtures. Meanwhile, Glu contents were increased significantly in S. aureus group, ChAT levels were decreased significantly in PM group, combined treatment of PM and S. aureus led to significant concentration reduction of AChE. Treatment of S. aureus or PM- S. aureus combination also led to significant concentration reduction of BDNF. Results showed that combined treatment of PM and S. aureus induced damage on physique and motor function, as well as impairment on learning and memory capacity of mice. Oxidative damage, abnormal metabolism of neurotransmitters and cholinergic system enzymes, and the alternation of neurotrophins and pro-inflammatory cytokines expression might be the possible mechanisms for PM - S. aureus -induced neurotoxicity.

The Impact of Plasma Cholinergic Enzyme Activity and Other Risk Factors for the Development of Delirium in Patients Receiving Palliative Care

CONTEXT

Delirium is an important complication in palliative care patients. One of the potential risk factors for cognitive disorders is deterioration in cholinergic neurotransmission. Anticholinergic medications are known to be important owing to the association of their metabolites with significant morbidity, which is often the result of cumulative effects of medications (anticholinergic burden). Additionally, cholinergic enzymes are possible candidates reflecting the cholinergic situation in patients. However, the role of cholinesterases (CHE) for delirium in palliative care patients is unknown.

OBJECTIVES

Following local Ethics Board approval and written informed consent, we recruited a cohort of patients who had been admitted to the Heidelberg University Palliative Care Unit related to CHE and other factors at risk for delirium.

METHODS

Delirium was assessed using the Nursing Delirium Screening Scale once daily in all cancer patients (N = 100) during their stay on the palliative care unit. In a subgroup of 69 probes, blood samples were analyzed for acetyl- and butyrylcholinesterase activity spectrophotometrically. Furthermore, patients' medications were recorded. Logistic regression analysis was used to evaluate potential predictors of delirium.

RESULTS

Delirium was identified in 29% of patients. Karnofsky Performance Status Scale score was significantly lower (P = 0.021) and mortality higher (P = 0.018) in patients with delirium. Plasma CHE activity was not associated with delirium. However, a significant effect of anticholinergic medication on plasma CHE activity was detected; so far midazolam (P = 0.01) seems to play an important role in that process.

CONCLUSION

Special care might be necessary with anticholinergic medication to minimize risk for delirium in palliative cancer patients.

Acute administration of fenproporex increased acetylcholinesterase activity in brain of young rats

Fenproporex is the second most commonly amphetamine-based anorectic consumed worldwide; this drug is rapidly converted into amphetamine, in vivo, and acts by increasing dopamine levels in the synaptic cleft. Considering that fenproporex effects on the central nervous system are still poorly known and that acetylcholinesterase is a regulatory enzyme which is involved in cholinergic synapses and may indirectly modulate the release of dopamine, the present study investigated the effects of acute administration of fenproporex on acetylcholinesterase activity in brain of young rats. Young male Wistar rats received a single injection of fenproporex (6.25, 12.5 or 25mg/kg i.p.) or vehicle (2% Tween 80). Two hours after the injection, the rats were killed by decapitation and the brain was removed for evaluation of acetylcholinesterase activity. Results showed that fenproporex administration increased acetylcholinesterase activity in the hippocampus and posterior cortex, whereas in the prefrontal cortex, striatum and cerebellum the enzyme activity was not altered. In conclusion, in the present study we demonstrated that acute administration of fenproporex exerts an effect in the cholinergic system causing an increase in the activity of acetylcholinesterase in a dose-dependent manner in the hippocampus and posterior cortex. Thus, we suggest that the imbalance in cholinergic homeostasis could be considered as an important pathophysiological mechanism underlying the brain damage observed in patients who use amphetamines such as fenproporex.

An investigation into the ameliorating effect of black soybean extract on learning and memory impairment with assessment of neuroprotective effects

BACKGROUND

The physiological effects of the non-anthocyanin fraction (NAF) in a black soybean seed coat extract on Aβ-induced oxidative stress were investigated to confirm neuroprotection. In addition, we examined the preventive effect of NAF on cognitive defects induced by the intracerebroventricular (ICV) injection of Aβ.

METHODS

Levels of cellular oxidative stress were measured using 2',7'-dichlorofluorescein diacetate (DCF-DA). Neuronal cell viability was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assay. To investigate in vivo anti-amnesic effects of NAF by using Y-maze and passive avoidance tests, the learning and memory impairment in mice was induced by Aβ. After in vivo assays, acetylcholinesterase (AChE) activity and level of malondialdehyde (MDA) in the mouse brain were determined to confirm the cognitive effect. Individual phenolics of NAF were qualitatively analyzed by using an ultra-performance liquid chromatography (UPLC) Accurate-Mass Quadrupole Time of-Flight (Q-TOF) UPLC/MS.

RESULTS

A NAF showed cell protective effects against oxidative stress-induced cytotoxicity. Intracellular ROS accumulated through Aβ1-40 treatment was significantly reduced in comparison to cells only treated with Aβ1-40. In MTT and LDH assay, the NAF also presented neuroprotective effects on Aβ1-40-treated cytotoxicity. Finally, the administration of this NAF in mice significantly reversed the Aβ1-40-induced cognitive defects in in vivo behavioral tests. After behavioral tests, the mice brains were collected in order to examine lipid peroxidation and AChE activity. AChE, preparation was inhibited by NAF in a dose-dependent manner. MDA generation in the brain homogenate of mice treated with the NAF was decreased. Q-TOF UPLC/MS analyses revealed three major phenolics from the non-anthocyanin fraction; epicatechin, procyanidin B1, and procyanidin B2.

CONCLUSIONS

The results suggest that the NAF in black soybean seed coat extracts may improve the cytotoxicity of Aβ in PC12 cells, possibly by reducing oxidative stress, and also have an anti-amnesic effect on the in vivo learning and memory deficits caused by Aβ. Q-TOF UPLC/MS analyses showed three major phenolics; (-)-epicatechin, procyanidin B1, and procyanidin B2. Above results suggest that (-)-epicatechins are the major components, and contributors to the anti-amnesic effect of the NAF from black soybean seed coat.

Neuroprotective effects of berry fruits on neurodegenerative diseases

Recent clinical research has demonstrated that berry fruits can prevent age-related neurodegenerative diseases and improve motor and cognitive functions. The berry fruits are also capable of modulating signaling pathways involved in inflammation, cell survival, neurotransmission and enhancing neuroplasticity. The neuroprotective effects of berry fruits on neurodegenerative diseases are related to phytochemicals such as anthocyanin, caffeic acid, catechin, quercetin, kaempferol and tannin. In this review, we made an attempt to clearly describe the beneficial effects of various types of berries as promising neuroprotective agents.

Mapping of the binding landscape for a picomolar protein-protein complex through computation and experiment

Our understanding of protein evolution would greatly benefit from mapping of binding landscapes, i.e., changes in protein-protein binding affinity due to all single mutations. However, experimental generation of such landscapes is a tedious task due to a large number of possible mutations. Here, we use a simple computational protocol to map the binding landscape for two homologous high-affinity complexes, involving a snake toxin fasciculin and acetylcholinesterase from two different species. To verify our computational predictions, we experimentally measure binding between 25 Fas mutants and the 2 enzymes. Both computational and experimental results demonstrate that the Fas sequence is close to the optimum when interacting with its targets, yet a few mutations could further improve Kd, kon, and koff. Our computational predictions agree well with experimental results and generate distributions similar to those observed in other high-affinity PPIs, demonstrating the potential of simple computational protocols in capturing realistic binding landscapes.