Acetylcholine Inhibitors Research Articles

Peripheral and central neurobiological effects of botulinum toxin A (BoNT/A) in neuropathic pain: a systematic review.

Botulinum toxin (BoNT), a presynaptic inhibitor of acetylcholine (Ach) release at the neuromuscular junction (NMJ), is a successful and safe drug for the treatment of several neurological disorders. However, a wide and recent literature review has demonstrated that BoNT exerts its effects not only at the "periphery" but also within the central nervous system (CNS). Studies from animal models, in fact, have shown a retrograde transport to the CNS, thus modulating synaptic function. The increasing number of articles reporting efficacy of BoNT on chronic neuropathic pain (CNP), a complex disease of the CNS, demonstrates that the central mechanisms of BoNT are far from being completely elucidated. In this new light, BoNT might interfere with the activity of spinal, brain stem, and cortical circuitry, modulating excitability and the functional organization of CNS in healthy conditions. Botulinum toxins efficacy on CNP is the result of a wide and complex action on many and diverse mechanisms at the basis of the maladaptive plasticity, the core of the pathogenesis of CNP. This systematic review aims to discuss in detail the BoNT's mechanisms and effects on peripheral and central neuroplasticity, at the basis for the clinical efficacy in CNP syndromes.

Vagus nerve stimulation-induced stromal cell-derived factor-l alpha participates in angiogenesis and repair of infarcted hearts.

We aim to explore the role and mechanism of vagus nerve stimulation (VNS) in coronary endothelial cells and angiogenesis in infarcted hearts. Seven days after rat myocardial infarction (MI) was prepared by ligation of the left anterior descending coronary artery, the left cervical vagus nerve was treated with electrical stimulation 1h after intraperitoneal administration of the α7-nicotinic acetylcholine inhibitor mecamylamine or the mAChR inhibitor atropine or 3days after local injection of Ad-shSDF-1α into the infarcted heart. Cardiac tissue acetylcholine (ACh) and serum ACh, tumour necrosis factor α (TNF-α), interleukin 1β (IL-1β) and interleukin 6 (IL-6) levels were detected by ELISA to determine whether VNS was successful. An inflammatory injury model in human coronary artery endothelial cells (HCAECs) was established by lipopolysaccharide and identified by evaluating TNF-α, IL-1β and IL-6 levels and tube formation. Immunohistochemistry staining was performed to evaluate CD31-positive vessel density and stromal cell-derived factor-l alpha (SDF-1α) expression in the MI heart in vivo and the expression and distribution of SDF-1α, C-X-C motif chemokine receptor 4 and CXCR7 in HCAECs in vitro. Western blotting was used to detect the levels of SDF-1α, V-akt murine thymoma viral oncogene homolog (AKT), phosphorylated AKT (pAKT), specificity protein 1 (Sp1) and phosphorylation of Sp1 in HCAECs. Left ventricular performance, including left ventricular systolic pressure, left ventricular end-diastolic pressure and rate of the rise and fall of ventricular pressure, should be evaluated 28days after VNS treatment. VNS was successfully established for MI therapy with decreases in serum TNF-α, IL-1β and IL-6 levels and increases in cardiac tissue and serum ACh levels, leading to increased SDF-1α expression in coronary endothelial cells of MI hearts, triggering angiogenesis of MI hearts with increased CD31-positive vessel density, which was abolished by the m/nAChR inhibitors mecamylamine and atropine or knockdown of SDF-1α by shRNA. ACh promoted SDF-1α expression and its distribution along with the branch of the formed tube in HCAECs, resulting in an increase in the number of tubes formed in HCAECs. ACh increased the levels of pAKT and phosphorylation of Sp1 in HCAECs, resulting in inducing SDF-1α expression, and the specific effects could be abolished by mecamylamine, atropine, the PI3K/AKT blocker wortmannin or the Sp1 blocker mithramycin. Functionally, VNS improved left ventricular performance, which could be abolished by Ad-shSDF-1α. VNS promoted angiogenesis to repair the infarcted heart by inducing SDF-1α expression and redistribution along new branches during angiogenesis, which was associated with the m/nAChR-AKT-Sp1 signalling pathway.

Pharmacological interventions to diminish cognitive side effects of electroconvulsive therapy: A systematic review and meta-analysis.

ObjectiveThe authors conducted a systematic review and meta‐analysis of pharmacological interventions to diminish cognitive side effects of ECT.MethodsElectronic databases of Pubmed, PsycInfo, Embase and Scopus were searched from inception through 1 April, 2021, using terms for ECT (e.g. electroconvulsive therapy), cognitive outcome (e.g. cogni*) and pharmacological intervention (e.g. calcium channel blocker and general terms, like protein). Original studies with humans receiving ECT were included, which applied pharmacological interventions in comparison with placebo or no additive intervention to diminish cognitive side effects. Data quality was assessed using Risk of Bias and GRADE. Random‐effects models were used. PROSPERO registration number was CRD42021212773.ResultsQualitative synthesis (systematic review) showed 52 studies reporting sixteen pharmacological intervention‐types. Quantitative synthesis (meta‐analysis) included 26 studies (1387 patients) describing twelve pharmacological intervention‐types. Low‐quality evidence of efficacy was established for memantine (large effect size) and liothyronine (medium effect size). Very low‐quality evidence shows effect of acetylcholine inhibitors, piracetam and melatonin in some cognitive domains. Evidence of no efficacy was revealed for ketamine (very low‐quality), herbal preparations with anti‐inflammatory properties (very low to low‐quality) and opioid receptor agonists (low‐quality).ConclusionMemantine and liothyronine are promising for further research and future application. Quality of evidence was low because of differences in ECT techniques, study populations and cognitive measurements. These findings provide a guide for rational choices of potential pharmacological intervention research targets to decrease the burden of cognitive side effects of ECT. Future research should be more uniform in design and attempt to clarify pathophysiological mechanisms of cognitive side effects of ECT.

An Update on the Routes for the Delivery of Donepezil.

Dementia is a significant public health problem in the 21st century. Alzheimer's disease (AD) is an essential factor in dementia. Currently, the drugs used for the treatment of AD are mainly acetylcholine inhibitors (AChEIs). As an AChEI, donepezil (DP) can improve patients' cognitive ability with low side effects and has been accepted by most patients and doctors. For AD patients, the dosage regimen is also crucial due to aging and diseases. Although there are DP oral tablets on the market, there are still many problems to be solved. At present, more and more research is conducted to optimize the route of administration of DP to improve the self-administration of patients. The research fields of DP administration include oral administration, injection administration, intranasal administration, and transdermal administration. This Review is to present the development of different DP administrations and evaluates the advantages and limitations of those works, hoping to optimize the DP dosage regimen for AD patients.

Acetylcholinesterase Inhibitory Potential of Various Sesquiterpene Analogues for Alzheimer's Disease Therapy.

Alzheimer’s disease (AD) is a gradually growing irreversible illness of the brain that almost affects every fifth person (aged > 80 years) in the world. World Health Organization (WHO) also revealed that the prevalence of this disease will enhance (upto double) significantly upto 2030. The poor cholinergic transmission at the synapse is considered to be one of the main reasons behind the progression and occurrence of this disorder. Natural inhibitors of acetylcholine (ACh) such as galanthamine and rivastigmine are used commercially in the treatmentof AD. The biomolecules such assesquiterpenes, possess a great structural diversity and are responsible for a plethora of pharmacological properties. The potential of various sesquiterpenes as anticholinesterase has been reviewed in this article. For this purpose, the various databases, mainly PubMed, Scopus, and Web of Science were investigatedwith different keywords such as “sesquiterpenes+acetylcholinesterase” and “sesquiterpenes+cholinesterase+inhibitors” in the surveyed time frame (2010–2020). A vast literature was evident in the last decade, which affirms the potential of various sesquiterpenes in the improvement of cholinergic transmission by inhibiting the AChE. After data analysis, it was found that 12 compounds out of a total of 58 sesquiterpenes were reported to possess IC50 < 9 μM and can be considered as potential candidates for the improvement of learning and memory. Sesquiterpene is an important category of terpenoids, found to possess a large spectrum of biological activities. The outcome of the review clearly states that sesquiterpenes (such as amberboin, lipidiol, etc.) from herbs could offer fresh, functional compounds for possible prevention and treatment of AD.

Improved tropane alkaloid production and changes in gene expression in hairy root cultures of two Hyoscyamus species elicited by silicon dioxide nanoparticles

Species of Hyoscyamus are rich sources of medicinally important tropane alkaloids, which have anticholinergic, antispasmodic and sedative effects and are competitive inhibitors of acetylcholine. The application of nanotechnology and nanomaterials for elicitation is rapidly expanding and recent research indicates that silicon dioxide nanoparticles (SiO2 NPs) can be used as an efficient elicitor to increase the production of hyoscyamine and scopolamine in Hyoscyamus species. Thus, in this work, the effect of SiO2 NPs (0, 25, 50, 100 and 200 mg L−1) with two treatment times (24 and 48 h) on the growth rate, total phenol and flavonoid content (TPC, TFC), antioxidant enzyme activity, tropane alkaloid yield and pmt (putrescine N-methyltransferase) and h6h (hyoscyamine 6<beta>-hydroxylase) gene expression levels in hairy roots of two Hyoscyamus species (H. reticulatus and H. pusillus) was investigated. The highest TPC and TFC accumulation was obtained in H. reticulatus elicited by SiO2 NPs (100 and 200 mg L−1), respectively, at 24 h of treatment. High-performance liquid chromatography (HPLC) revealed the highest amount of hyoscyamine (140.15 μg g−1 FW) and scopolamine (67.71 μg g−1 FW) accumulated in H. reticulatus transformed roots treated with 100 mg L−1 SiO2 NPs at 24 h, with a respective increase of 1212% and 272% compared to non-treated roots. In H. pusillus, the highest hyoscyamine (7.42 μg g−1 FW) and scopolamine (15.56 μg g−1 FW) production (about 82% and 241% higher, respectively, compared to the lowest amounts) was achieved with 25 and 100 mg L−1 SiO2 NPs, respectively, at 48 h of treatment. Semi-quantitative RT-PCR analysis determined the highest expression level of pmt and h6h genes in H. reticulatus transformed roots supplemented with 100 mg L−1 SiO2 NPs.

RETRACTED ARTICLE: Ornithine-A urea cycle metabolite enhances autophagy and controls Mycobacterium tuberculosis infection

Macrophages are professional phagocytes known to play a vital role in controlling Mycobacterium tuberculosis (Mtb) infection and disease progression. Here we compare Mtb growth in mouse alveolar (AMs), peritoneal (PMs), and liver (Kupffer cells; KCs) macrophages and in bone marrow-derived monocytes (BDMs). KCs restrict Mtb growth more efficiently than all other macrophages and monocytes despite equivalent infections through enhanced autophagy. A metabolomics comparison of Mtb-infected macrophages indicates that ornithine and imidazole are two top-scoring metabolites in Mtb-infected KCs and that acetylcholine is the top-scoring in Mtb-infected AMs. Ornithine, imidazole and atropine (acetylcholine inhibitor) inhibit Mtb growth in AMs. Ornithine enhances AMPK mediated autophagy whereas imidazole directly kills Mtb by reducing cytochrome P450 activity. Intranasal delivery of ornithine or imidazole or the two together restricts Mtb growth. Our study demonstrates that the metabolic differences between Mtb-infected AMs and KCs lead to differences in the restriction of Mtb growth.

Alzheimer’s disease: An overview of the current treatments

Alzheimer’s disease (AD) affects millions of people around the world and although there are treatments that help control symptoms and slow down the progress of the disease, there is still no cure. Current treatments include three acetylcholine inhibitors, a glutamate inhibitor and a combination of the two. Due to the failure of hundreds of clinical trials with monotherapies, multitarget treatments are currently being investigated that consider both brain and peripheral factors. Gene therapy is one of the most promising therapies to treat and prevent the development of AD. Nowadays, there is no available medical treatment based on gene therapy to treat AD; however, there are treatments in phase 1 and phase 2 clinical trials with promising results. In this review, we will focus on the most important gene therapy treatments, CERE-110 (adeno-associated virus AAV2-Nerve Growth Factor), Intracerebral AAV gene delivery of APOE2 and gene therapy using PPARγ-coactivator-1α(PGC-1α)

The Disease-modifying Drug Candidate, SAK3 Improves Cognitive Impairment and Inhibits Amyloid beta Deposition in App Knock-in Mice

Alzheimer’s disease (AD) is a progressive neurodegenerative disease and the most common form of elderly dementia in the world. At present, acetylcholine inhibitors, such as donepezil, galantamine and rivastigmine, are used for AD therapy, but the therapeutic efficacy is limited. We recently proposed T-type voltage-gated Ca2+ channels’ (T-VGCCs) enhancer as a new therapeutic candidate for AD. In the current study, we confirmed the pharmacokinetics of SAK3 in the plasma and brain of mice using ultra performance liquid chromatography-tandem mass spectrometry. We also investigated the effects of SAK3 on the major symptoms of AD, such as cognitive dysfunction and amyloid beta (Aβ) accumulation, in AppNL-F knock-in (NL-F) mice, which have been established as an AD model. Chronic SAK3 (0.5 mg/kg/day) oral administration for 3 months from 9 months of age improved cognitive function and inhibited Aβ deposition in 12-month-old NL-F mice. Using microarray and real-time PCR analysis, we discovered serum- and glucocorticoid-induced protein kinase 1 (SGK1) as one of possible genes involved in the inhibition of Aβ deposition and improvement of cognitive function by SAK3. These results support the idea that T-VGCC enhancer, SAK3 could be a novel candidate for disease-modifying therapeutics for AD.

Update on etiopathogenesis and treatment of Acne.

Acne, the most common skin disease, is a disorder of pilosebaceous units that affects adolescents mainly and adults occasionally. The pathogenesis is multifactorial. Besides genetic predisposition, other major factors include the action of androgens, pro-inflammatory lipids acting as ligands of peroxisome proliferator-activated receptors in the sebocytes, toll-like receptor-2 acting on keratinocytes, recognition of pathogen-associated molecular patterns, cytokines, chemokines, inflammasomes, neuroendocrine regulatory mechanisms, diet and other pro-inflammatory targets implicated in the activation of immune detection and response. Most of these factors converge on mammalian target of rapamycin complex1 (mTORC1) activation which is further enhanced by the nutrient signaling of Western diet. This multitude of pathogenic factors has led to a new armamentarium of drugs for the treatment of acne. Topical anti-androgens, insulin-like growth factor-1 inhibitors, peroxisome proliferator-activated receptor-modulators, acetylcholine inhibitors, topical retinoic acid metabolism-blocking agents, vitamin D analogues, antimicrobial peptides, interleukin-1α and interleukin-1β blockers and immunotherapy are some of the novel treatment options.

A Therapeutic Insight of Niacin and Coenzyme Q10 Against Diabetic Encephalopathy in Rats.

Diabetes mellitus (DM) is characterized by hyperglycemia due to insulin inactivity or insufficiency with increasing risk of developing specific complications, including retinopathy, nephropathy, neuropathy, and atherosclerosis. The aim of the present study is to evaluate the efficacy of coenzyme Q10 (CoQ10), niacin, as well as their combination in ameliorating brain disorders associated with streptozotocin (STZ)-induced diabetes in rats. Glibenclamide, a reference diabetic drug, and donepezil, an acetylcholine inhibitor drug, were also evaluated. Diabetes was induced by single intraperitoneal injection of STZ (60mg/kg body weight (b.wt)). One-month diabetic rats were treated with the selected drugs daily for another two consecutive weeks. The evaluation was done through the estimation of the levels of blood glucose, serum insulin, and oxidative stress markers: malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH); neurotransmitters: acetylcholinesterase (AchE) and dopamine (DA); vasoconstrictor indices: intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1(VCAM-1), and angiotensin II (Ang II); and apoptosis markers: tumor necrosis factor-α (TNF-α) and caspase-3 as well as the histopathological picture of the cerebellum region of the brain. The results revealed that the combination of niacin and CoQ10 improved most of the measured parameters with variable degrees. In conclusion, niacin and CoQ10 are promising dietary supplements in the management of diabetic encephalopathy.

The Ascaris suum nicotinic receptor, ACR-16, as a drug target: Four novel negative allosteric modulators from virtual screening

Soil-transmitted helminth infections in humans and livestock cause significant debility, reduced productivity and economic losses globally. There are a limited number of effective anthelmintic drugs available for treating helminths infections, and their frequent use has led to the development of resistance in many parasite species. There is an urgent need for novel therapeutic drugs for treating these parasites. We have chosen the ACR-16 nicotinic acetylcholine receptor of Ascaris suum (Asu-ACR-16), as a drug target and have developed three-dimensional models of this transmembrane protein receptor to facilitate the search for new bioactive compounds. Using the human α7 nAChR chimeras and Torpedo marmorata nAChR for homology modeling, we defined orthosteric and allosteric binding sites on the Asu-ACR-16 receptor for virtual screening. We identified four ligands that bind to sites on Asu-ACR-16 and tested their activity using electrophysiological recording from Asu-ACR-16 receptors expressed in Xenopus oocytes. The four ligands were acetylcholine inhibitors (SB-277011-A, IC50, 3.12 ± 1.29 μM; (+)-butaclamol Cl, IC50, 9.85 ± 2.37 μM; fmoc-1, IC50, 10.00 ± 1.38 μM; fmoc-2, IC50, 16.67 ± 1.95 μM) that behaved like negative allosteric modulators. Our work illustrates a structure-based in silico screening method for seeking anthelmintic hits, which can then be tested electrophysiologically for further characterization.

Phytochemical and Toxicological Studies of an Extract of the Seeds of Picralima Nitida (Stapf) (Apocynaceae) and Its Pharmacological Effects on the Blood Pressure of Rabbit

The phytochemical screening of the seeds extracts of Picralima nitida has highlighted the presence of alkaloids and terpenes poly sterols in chloroform solutions, methanol and in the aqueous. Unlike chloroform and methanol solutions, the aqueous revealed the presence of saponins. An acute toxicity study in mice showed that the aqueous extract of Picralima nitida would be slightly toxic with a lethal dose (LD) 50 % of 9120.11 mg/kg of body weight (bw). This extract, in rabbits induced a dose-dependent hypotension for the doses between 3.10 -6 g / kg bw and 2.10 -5 g/kg bw with an effective dose 50% (ED50) equal to 4.07×10 -6 g/kg bw. In the presence of atropine (6.10 -9 g/kg), a competitive inhibitor of acetylcholine, the hypotensive effect of aqueous extract of Picralima nitida is reduced, confirming in this extract the presence of cholinomimetics substances of muscarinic type. The results therefore suggest the presence of cholinomimetics substances in the aqueous extract of Picralima nitida seed. These substances could be responsible for the hypotensive effect of this extract. The same extract did not induce diuresis in rats.

Galanthamine, an acetylcholine inhibitor, prevents prepulse inhibition deficits induced by adolescent social isolation or MK-801 treatment

Adolescence is a critical period for neurodevelopment. MK-801 treatment and social isolation are important animal models for various neurodevelopmental disorders. Dysfunctions in the central cholinergic system are involved in creating the cognitive deficits observed in neurological diseases. In the present study, we aimed to investigate whether the acetylcholinesterase inhibitor galanthamine could reverse pre-cognitive prepulse inhibition (PPI) deficits and spatial learning deficits of adult rats in the Morris water maze. We induced these effects using either adolescent MK-801 treatment or social isolation from postnatal day (PND) 38–51. Our results showed that both adolescent social isolation and MK-801 treatment impaired PPI in adult rats, but neither had an effect on spatial learning. Furthermore, galanthamine injections over 7 days significantly enhanced PPI of normal rats and improved PPI disruption induced by adolescent pharmacological and rearing interventions. The results suggest that acetylcholinesterase inhibitors, such as galanthamine, might have the potential to improve pre-cognition in neurodevelopmental diseases by improving auditory sensory gating.

Glycopyrrolate does not influence the visual or motor-induced increase in regional cerebral perfusion

Acetylcholine may contribute to the increase in regional cerebral blood flow (rCBF) during cerebral activation since glycopyrrolate, a potent inhibitor of acetylcholine, abolishes the exercise-induced increase in middle cerebral artery mean flow velocity. We tested the hypothesis that cholinergic vasodilatation is important for the increase in rCBF during cerebral activation. The subjects were 11 young healthy males at an age of 24 ± 3 years (mean ± SD). We used arterial spin labeling and blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) to evaluate rCBF with and without intravenous glycopyrrolate during a handgrip motor task and visual stimulation. Glycopyrrolate increased heart rate from 56 ± 9 to 114 ± 14 beats/min (mean ± SD; p < 0.001), mean arterial pressure from 86 ± 8 to 92 ± 12 mmHg, and cardiac output from 5.6 ± 1.4 to 8.0 ± 1.7 l/min. Glycopyrrolate had, however, no effect on the arterial spin labeling or BOLD responses to the handgrip motor task or to visual stimulation. This study indicates that during a handgrip motor task and visual stimulation, the increase in rCBF is unaffected by blockade of acetylcholine receptors by glycopyrrolate. Further studies on the effect of glycopyrrolate on middle cerebral artery diameter are needed to evaluate the influence of glycopyrrolate on mean flow velocity during intense exercise.

Indentification of huperzine A-producing endophytic fungi isolated from Huperzia serrata

This present study was designed to investigate the production of huperzine A (HupA), an acetylcholine inhibitor, which was produced by an endophytic fungi isolated from Huperzia serrata. Screening of 94 endophytic fungal isolates obtained from plant H. serrata was carried out for the production of HupA. Their morphological characteristics were studied and rDNA sequence analysis was carried out. The cultures were grown in liquid culture medium and the extracted metabolites were analyzed by thin layer chromatography and high performance liquid chromatograph for the presence of HupA. The DPPH scavenging ratio and inhibition ratio of acetylcholinesterase (AchE) of the same were determined. 3 out of 94 strains i.e. S29, L44 and S94 showed significant AchE-inhibitory activity and antioxidant activity. Strain L44 which exhibited maximum yield of HupA (37.63μg/g on dry weight basis) was identified as Trichoderma species by ITS sequence analysis. In conclusion, endophytic fungi from H. serrata can be used as a new resource of HupA.

Anticholinesterase Activity of Phenolic Acids and their Derivatives

The ability of 36 phenolic acids and their derivatives to inhibit acetyl- and butyrylcholinesterase was studied. The most efficient acetylcholine inhibitors were: carnosic acid = gentisic acid > 3-hydroxy-4-methoxycinnamic acid = ethyl ferulate = ethyl vanillate = nordihydroguaiaretic acid > ethyl 4-hydroxybenzoate = methyl ferulate. The order of effectiveness towards butyrylcholinesterase was: carnosic acid > nordihydroguaiaretic acid = ethyl ferulate > salicylic acid > gentisic acid > rosmarinic acid = caftaric acid > homogentisic acid. The inhibitory activity was dependent on the number/position of OH or/and OCH3 groups attached to a phenol ring. It can be speculated that OCH3 substitution in the phenol ring can promote a higher antibutyrylcholinesterase activity (although not statistically confirmed at p < 0.05). The presence of a CH=CH-COOH group had a highly favourable effect on the antiacetylcholinesterase activity compared with a CH2-CH2-COOH or a COOH group. Methyl and ethyl esters were more potent inhibitors than the corresponding free acids. The molecular weight of the compounds (in the range of M = 154.12 - 474 g/mol) played a minor role in this context.

Another Suicide Using the Veterinary Drug T61 and Distribution of Drugs in the Body

The authors recently reported about the complex suicide of a former veterinarian who injected xylazine and levomethadone together with T61, which is normally used for the euthanasia of domestic and laboratory animals (1). Furthermore, various analgesics were detected in biological samples, probably taken as painkillers for an existing cancer disease. The quaternary ammonium compound mebezonium iodide, an acetylcholine inhibitor, is an active ingredient of T61, in addition to embutramide and tetracaine (2). Embutramide has narcotic properties and induces deep anesthesia and an inhibition of the respiratory center located in the brainstem. Tetracaine is a local anaesthetic substance and decreases painful reactions at injection sites. A recent report by the authors summarized cases of suicides or homicides involving the use of T61 (1). However, in most cases, embutramide, which is exclusively used in T61, was the only substance analyzed because of analytical difficulties when analyzing quarternary ammonium compounds like mebezonium. Before this report, mebezonium was only analyzed in two cases, once by thin-layer chromatography followed by ultraviolet spectrophotometry after elution from silica gel (3), and later by liquid-chromatography –mass spectrometry with quantification by a specific ion, m/z 294 (4). Because there are relatively few authentic cases reported in the literature, the distribution and concentration of all three ingredients of T61 in the body of a new case appears worthwhile to communicate. A 40-year-old male was found dead in the gateway of his home. In a garage 15 m away, opened bottles of wine, sherry and rum were found, as were a depleted 20 mL syringe, an opened pharmaceutical vial of T61 (50 mL with a rest of 5 mL) and a suicide note. Three years ago, T61 had been used for euthanasia of the Saint Bernard dog of the family and the veterinary surgeon had forgotten the rest of the drug, which was stored in the cellar. Autopsy findings The body weight was 84.1 kg and body height was 174.5 cm. No signs of external violence were observed. An injection mark was found over the back of the left hand with edema of the subcutaneous tissues. Another skin injection mark was noted on the palm of the left wrist, also with edema of the subcutaneous tissues. The subcutaneous tissues of both injection sites were dark black with discoloration. Edematous swelling of the subcutaneous tissues of the left forearm was observed, as were extreme congestion of internal organs, cerebral and pulmonary edema, acute pulmonary emphysema and advanced coronary atherosclerosis.

Acetylcholinesterase Liquid Crystal Biosensor Based on Modulated Growth of Gold Nanoparticles for Amplified Detection of Acetylcholine and Inhibitor

A novel acetylcholinesterase (AChE) liquid crystal (LC) biosensor based on enzymatic growth of gold nanoparticles (Au NPs) has been developed for amplified detection of acetylcholine (ACh) and AChE inhibitor. In this method, AChE mediates the hydrolysis of acetylthiocholine (ATCl) to form thiocholine, and the latter further reduces AuCl(4)(-) to Au NPs without Au nanoseeds. This process, termed biometallization, leads to a great enhancement in the optical signal of the LC biosensor due to the large size of Au NPs, which can greatly disrupt the orientational arrangement of LCs. On the other hand, the hydrolysis of ATCl is inhibited in the presence of ACh or organophosphate pesticides (OPs, a AChE inhibitor), which will decrease the catalytic growth of Au NPs and, as a result, reduce the orientational response of LCs. On the basis of such an inhibition mechanism, the AChE LC biosensor can be used as an effective way to realize the detection of ACh and AChE inhibitors. The results showed that the AChE LC biosensor was highly sensitive to ACh with a detection limit of 15 μmol/L and OPs with a detection limit of 0.3 nmol/L. This study provides a simple and sensitive AChE LC biosensing approach and offers effective signal enhanced strategies for the development of enzyme LC biosensors.

Receptor-dependent (RD) 3D-QSAR approach of a series of benzylpiperidine inhibitors of human acetylcholinesterase (HuAChE)

Acetylcholine inhibitors (AChEIs) are currently considered as potential drugs for treating Alzheimer disease. In this work, we developed a receptor-dependent 3D-QSAR (RD-3D-QSAR) models based on a series of 60 benzylpiperidine inhibitors of human acetylcholinesterase to support the design of new AChEIs. The best two models, A–F (N = 47, q2 = 0.736, r2 = 0.860) and C–F (N = 47, q2 = 0.753, r2 = =0.900) were developed and validated by a combined GA-PLS approach, available in WOLF. Residues of the aromatic gorge (Tyr341 and Trp439) and catalytic triad (His447) are related to both equations showing the consistency of these models with the SAR. Based on those models we have proposed four new benzylpiperidine derivatives and predicted the pIC50 for each molecule. The good predicted potency of benzylpiperidine derivative, IIa, indicates that it is a potential candidate as a new HuAChE inhibitor.