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BMC Complementary Medicine and Therapies Nov 2023Myrtus communis L. (MC) has been used in Mesopotamian medicine. Here, the cholinesterase (ChE) inhibitory potential of its methyl alcohol extracts has been investigated...
BACKGROUND
Myrtus communis L. (MC) has been used in Mesopotamian medicine. Here, the cholinesterase (ChE) inhibitory potential of its methyl alcohol extracts has been investigated and computationally dissected.
METHOD
The ChE inhibition has been measured based on usual Ellman's colorimetric method compared to a canonical ChE inhibitor, eserine. Through a deep text mining, the structures of phytocompounds (= ligands) of MC were curated from ChemSpider, PubChem, and ZINC databases and docked into protein targets, AChE (PDB 1EVE) and BChE (PDB 1P0I) after initial in silico preparedness and binding affinity (BA; kcal/mol) reported as an endpoint. The calculation of ADMET (absorption, distribution, metabolism, excretion, and toxicity) features of phytocompounds were retrieved from SwissADME ( http://www.swissadme.ch/ ) and admetSAR software to predict the drug-likeness or lead-likeness fitness. The Toxtree v2.5.1, software platforms ( http://toxtree.sourceforge.net/ ) have been used to predict the class of toxicity of phytocompounds. The STITCH platform ( http://stitch.embl.de ) has been employed to predict ChE-chemicals interactions.
RESULTS
The possible inhibitory activities of AChE of extracts of leaves and berries were 37.33 and 70.00%, respectively as compared to that of eserine while inhibitory BChE activities of extracts of leaves and berries of MC were 19.00 and 50.67%, respectively as compared to that of eserine. Phytochemicals of MC had BA towards AChE ranging from -7.1 (carvacrol) to -9.9 (ellagic acid) kcal/mol. In this regard, alpha-bulnesene, (Z)-gamma-Bisabolene, and beta-bourbonene were top-listed low toxic binders of AChE, and (Z)-gamma-bisabolene was a more specific AChE binder. Alpha-cadinol, estragole, humulene epoxide II, (a)esculin, ellagic acid, patuletin, juniper camphor, linalyl anthranilate, and spathulenol were high class (Class III) toxic substances which among others, patuletin and alpha-cadinol were more specific AChE binders. Among intermediate class (Class II) toxic substances, beta-chamigrene was a more specific AChE binder while semimyrtucommulone and myrtucommulone A were more specific BChE binders.
CONCLUSION
In sum, the AChE binders derived from MC were categorized mostly as antiinsectants (e.g., patuletin and alpha-cardinal) due to their predicted toxic classes. It seems that structural amendment and stereoselective synthesis like adding sulphonate or sulphamate groups to these phytocompounds may make them more suitable candidates for considering in preclinical investigations of Alzheimer's disease.
Topics: Cholinesterase Inhibitors; Myrtus; Physostigmine; Myrtaceae; Fruit; Ellagic Acid; Cholinesterases
PubMed: 37990185
DOI: 10.1186/s12906-023-04241-z -
CNS Neuroscience & Therapeutics Sep 2023Deep brain stimulation (DBS) of the anterior nucleus of the thalamus, is an effective therapy for patients with drug-resistant epilepsy, yet, its mechanism of action...
AIMS
Deep brain stimulation (DBS) of the anterior nucleus of the thalamus, is an effective therapy for patients with drug-resistant epilepsy, yet, its mechanism of action remains elusive. Adenosine kinase (ADK), a key negative regulator of adenosine, is a potential modulator of epileptogenesis. DBS has been shown to increase adenosine levels, which may suppress seizures via A1 receptors (A Rs). We investigated whether DBS could halt disease progression and the potential involvement of adenosine mechanisms.
METHODS
Control group, SE (status epilepticus) group, SE-DBS group, and SE-sham-DBS group were included in this study. One week after a pilocarpine-induced status epilepticus, rats in the SE-DBS group were treated with DBS for 4 weeks. The rats were monitored by video-EEG. ADK and A Rs were tested with histochemistry and western blot, respectively.
RESULTS
Compared with the SE group and SE-sham-DBS group, DBS could reduce the frequency of spontaneous recurrent seizures (SRS) and the number of interictal epileptic discharges. The DPCPX, an A R antagonist, reversed the effect of DBS on interictal epileptic discharges. In addition, DBS inhibited the overexpression of ADK and the downregulation of A Rs.
CONCLUSION
The findings indicate that DBS can reduce SRS in epileptic rats via inhibition of ADK and activation of A Rs. A Rs might be a potential target of DBS for the treatment of epilepsy.
Topics: Animals; Rats; Receptor, Adenosine A1; Adenosine Kinase; Epilepsy; Seizures; Status Epilepticus; Pilocarpine; Male; Rats, Sprague-Dawley; Disease Progression
PubMed: 37017409
DOI: 10.1111/cns.14199 -
Chemical Biology & Drug Design Mar 2024Studies have shown that saikosaponin D (SSD) has favorable neurotherapeutic effects. Therefore, the objective of this study was to explore the efficacy and possible...
Studies have shown that saikosaponin D (SSD) has favorable neurotherapeutic effects. Therefore, the objective of this study was to explore the efficacy and possible molecular mechanisms of SSD on pilocarpine (PP)-induced astrocyte injury. Primary astrocytes were isolated from juvenile rats and identified using immunofluorescence. The cells were treated with PP and/or SSD for 6 h and 12 h, respectively, followed by measurement of their viability through 3-(4,5-dimethylthiazol)-2,5-diphenyl-tetrazolium bromide (MTT) assay. Next, quantitative real-time polymerase chain reaction (qRT-PCR) was used to measure the expression levels of Glial fibrillary acidic protein (GFAP), C3, S100 calcium binding protein A10 (S100a10), pentraxin 3 (Ptx3), toll-like receptor 4 (TLR4), and RAG in astrocytes after different treatments. Enzyme-linked immunosorbent assay and biochemical tests were utilized to evaluate the level of inflammatory factors [interleukin (IL)-1β, IL-6, and tumor necrosis factor alpha (TNF-α)] secreted by cells and the content of oxidative stress-related factors (malondialdehyde [MDA] and glutathione [GSH]) or enzyme activity (catalase [CAT] and glutathione peroxidase [GPX]) in cells. The JC-1 mitochondrial membrane potential (MMP) fluorescence probe was used to measure the MMP in astrocytes. Additionally, western blot was applied to test the expression of proteins related to the nod-like receptor protein 3 (NLRP3)/caspase-1 signaling pathway. PP treatment (1 mM) induced cell injury by significantly reducing the viability of astrocytes and expression of cellular markers. SSD treatment (4 μM) had no toxicity to astrocytes. Besides, SSD (4 μM) treatment could significantly up-regulate the cell viability and marker expression of PP-induced astrocytes. Furthermore, SSD could be employed to inhibit inflammation (reduce IL-1β, IL-6, and TNF-α levels) and oxidative stress (decrease MDA level, elevate GSH level, the activity of CAT and GPX), and ameliorate mitochondrial dysfunction (upregulate JC-1 ratio) in PP-induced astrocytes. Moreover, further mechanism exploration revealed that SSD treatment significantly reduced the activity of the NLRP3/caspase-1 signaling pathway activated by PP induction. SSD increased cell viability, inhibited inflammation and oxidative stress response, and ameliorated mitochondrial dysfunction in PP-induced astrocyte injury model, thus playing a neuroprotective role. The mechanism of SSD may be related to the inhibition of the NLRP3/caspase-1 inflammasome.
Topics: Rats; Animals; NLR Family, Pyrin Domain-Containing 3 Protein; Astrocytes; Pilocarpine; Tumor Necrosis Factor-alpha; Caspases; Interleukin-6; Signal Transduction; Inflammation; Mitochondrial Diseases; Benzimidazoles; Carbocyanines; Oleanolic Acid; Saponins
PubMed: 38458969
DOI: 10.1111/cbdd.14481 -
American Journal of Respiratory Cell... Aug 2023Asthma is a heterogeneous chronic airway disease with an unmet need for improved therapeutics in uncontrolled severe disease. The calcium-sensing receptor (CaSR) is a G...
Asthma is a heterogeneous chronic airway disease with an unmet need for improved therapeutics in uncontrolled severe disease. The calcium-sensing receptor (CaSR) is a G protein-coupled receptor upregulated in asthma. The CaSR agonist, spermine, is also increased in asthmatic airways and contributes to bronchoconstriction. CaSR negative allosteric modulators (NAMs) oppose chronic airway inflammation, remodeling, and hyperresponsiveness in murine and guinea pig asthma models, but whether CaSR NAMs are effective acute bronchodilators compared with standard of care has not yet been established. Furthermore, the ability of different classes of NAMs to inhibit spermine-induced CaSR signaling or methacholine (MCh)-induced airway contraction has not been quantified. Here, we show CaSR NAMs differentially inhibit spermine-induced intracellular calcium mobilization and inositol monophosphate accumulation in HEK293 cells stably expressing the CaSR. NAMs reverse MCh-mediated airway contraction in mouse precision-cut lung slices with similar maximal relaxation compared with the standard treatment, salbutamol. Of note, the bronchodilator effects of CaSR NAMs are maintained under conditions of β-adrenergic receptor desensitization when salbutamol efficacy is abolished. Furthermore, overnight treatment with some, but not all, CaSR NAMs prevents MCh-mediated bronchoconstriction. These findings further support the CaSR as a putative drug target and NAMs as alternative or adjunct bronchodilators in asthma.
Topics: Mice; Humans; Animals; Guinea Pigs; Bronchodilator Agents; Receptors, Calcium-Sensing; HEK293 Cells; Spermine; Asthma; Albuterol; Methacholine Chloride
PubMed: 37098022
DOI: 10.1165/rcmb.2021-0544OC -
Epilepsy Research Dec 2023Acquired temporal lobe epilepsy (TLE) characterized by spontaneous recurrent seizures (SRS) and hippocampal inhibitory neuron dysfunction is often refractory to current...
Acquired temporal lobe epilepsy (TLE) characterized by spontaneous recurrent seizures (SRS) and hippocampal inhibitory neuron dysfunction is often refractory to current therapies. Gap junctional or electrical coupling between inhibitory neurons has been proposed to facilitate network synchrony and intercellular molecular exchange suggesting a role in both seizures and neurodegeneration. While gap junction blockers can limit acute seizures, whether blocking neuronal gap junctions can modify development of chronic epilepsy has not been examined. This study examined whether mefloquine, a selective blocker of Connexin 36 gap junctions which are well characterized in inhibitory neurons, can limit epileptogenesis and related cellular and behavioral pathology in a model of acquired TLE. A single, systemic dose of mefloquine administered early after pilocarpine-induced status epilepticus (SE) in rat reduced both development of SRS and behavioral co-morbidities. Immunostaining for interneuron subtypes identified that mefloquine treatment likely reduced delayed inhibitory neuronal loss after SE. Uniquely, parvalbumin expressing neurons in the hippocampal dentate gyrus appeared relatively resistant to early cell loss after SE. Functionally, whole cell patch clamp recordings revealed that mefloquine treatment preserved inhibitory synaptic drive to projection neurons one week and one month after SE. These results demonstrate that mefloquine, a drug already approved for malaria prophylaxis, is potentially antiepileptogenic and can protect against progressive interneuron loss and behavioral co-morbidities of epilepsy.
Topics: Rats; Animals; Neuroprotective Agents; Mefloquine; Status Epilepticus; Seizures; Epilepsy, Temporal Lobe; Hippocampus; Epilepsy; Pilocarpine; Disease Models, Animal
PubMed: 37989006
DOI: 10.1016/j.eplepsyres.2023.107257 -
Biomedicine & Pharmacotherapy =... Dec 2023In intestinal smooth muscle cells, receptor-operated TRPC4 are responsible for the majority of muscarinic receptor cation current (mI), which initiates cholinergic...
In intestinal smooth muscle cells, receptor-operated TRPC4 are responsible for the majority of muscarinic receptor cation current (mI), which initiates cholinergic excitation-contraction coupling. Our aim was to examine the effects of the TRPC4 inhibitor Pico145 on mI and Ca signalling in mouse ileal myocytes, and on intestinal motility. Ileal myocytes freshly isolated from two month-old male BALB/c mice were used for patch-clamp recordings of whole-cell currents and for intracellular Ca imaging using Fura-2. Functional assessment of Pico145's effects was carried out by standard in vitro tensiometry, ex vivo video recordings and in vivo postprandial intestinal transit measurements using carmine red. Carbachol (50 µM)-induced mI was strongly inhibited by Pico145 starting from 1 pM. The IC value for the inhibitory effect of Pico145 on this current evoked by intracellularly applied GTPγS (200 µM), and thus lacking desensitisation, was found to be 3.1 pM, while carbachol-induced intracellular Ca rises were inhibited with IC of 2.7 pM. In contrast, the current activated by direct TRPC4 agonist (-)-englerin A was less sensitive to the action of Pico145 that caused only ∼43 % current inhibition at 100 pM. The inhibitory effect developed rather slowly and it was potentiated by membrane depolarisation. In functional assays, Pico145 produced concentration-dependent suppression of both spontaneous and carbachol-evoked intestinal smooth muscle contractions and delayed postprandial intestinal transit. Thus, Pico145 is a potent GI-active small-molecule which completely inhibits mI at picomolar concentrations and which is as effective as trpc4 gene deficiency in in vivo intestinal motility tests.
Topics: Animals; Male; Mice; Carbachol; Gastrointestinal Motility; Myocytes, Smooth Muscle; Receptors, Muscarinic; TRPC Cation Channels
PubMed: 37857250
DOI: 10.1016/j.biopha.2023.115672 -
Epilepsy Research May 2024The hyperpolarization-activated cyclic nucleotide-gated cation channel (HCN1) is predominantly located in key regions associated with epilepsy, such as the neocortex and...
BACKGROUND
The hyperpolarization-activated cyclic nucleotide-gated cation channel (HCN1) is predominantly located in key regions associated with epilepsy, such as the neocortex and hippocampus. Under normal physiological conditions, HCN1 plays a crucial role in the excitatory and inhibitory regulation of neuronal networks. In temporal lobe epilepsy, the expression of HCN1 is decreased in the hippocampi of both animal models and patients. However, whether HCN1 expression changes during epileptogenesis preceding spontaneous seizures remains unclear.
OBJECTIVE
The aim of this study was to determine whether the expression of HCN1 is altered during the epileptic prodromal phase, thereby providing evidence for its role in epileptogenesis.
METHODS
We utilized a cobalt wire-induced rat epilepsy model to observe changes in HCN1 during epileptogenesis and epilepsy. Additionally, we also compared HCN1 alterations in epileptogenic tissues between cobalt wire- and pilocarpine-induced epilepsy rat models. Long-term video EEG recordings were used to confirm seizures development. Transcriptional changes, translation, and distribution of HCN1 were assessed using high-throughput transcriptome sequencing, total protein extraction, membrane and cytoplasmic protein fractionation, western blotting, immunohistochemistry, and immunofluorescence techniques.
RESULTS
In the cobalt wire-induced rat epilepsy model during the epileptogenesis phase, total HCN1 mRNA and protein levels were downregulated. Specifically, the membrane expression of HCN1 was decreased, whereas cytoplasmic HCN1 expression showed no significant change. The distribution of HCN1 in the distal dendrites of neurons decreased. During the epilepsy period, similar HCN1 alterations were observed in the neocortex of rats with cobalt wire-induced epilepsy and hippocampus of rats with lithium pilocarpine-induced epilepsy, including downregulation of mRNA levels, decreased total protein expression, decreased membrane expression, and decreased distal dendrite expression.
CONCLUSIONS
Alterations in HCN1 expression and distribution are involved in epileptogenesis beyond their association with seizure occurrence. Similarities in HCN1 alterations observed in epileptogenesis-related tissues from different models suggest a shared pathophysiological pathway in epileptogenesis involving HCN1 dysregulation. Therefore, the upregulation of HCN1 expression in neurons, maintenance of the HCN1 membrane, and distal dendrite distribution in neurons may represent promising disease-modifying strategies in epilepsy.
Topics: Animals; Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels; Male; Epilepsy; Rats, Sprague-Dawley; Rats; Hippocampus; Disease Models, Animal; Potassium Channels; Pilocarpine; Cobalt; Electroencephalography; Neurons; Neocortex
PubMed: 38555654
DOI: 10.1016/j.eplepsyres.2024.107355 -
British Journal of Anaesthesia Jan 2024Opioid administration to patients with obstructive sleep apnoea (OSA) is controversial because they are believed to be more sensitive to opioids. However, objective data...
BACKGROUND
Opioid administration to patients with obstructive sleep apnoea (OSA) is controversial because they are believed to be more sensitive to opioids. However, objective data on opioid effects in OSA are lacking. We tested the hypothesis that subjects with untreated OSA have increased sensitivity to opioids compared with subjects without OSA, or with OSA treated with continuous positive airway pressure (CPAP) or bilevel positive airway pressure (BIPAP).
METHODS
This was a single-centre, prospective cohort study in subjects without OSA (n=20), with untreated OSA (n=33), or with treated OSA (n=21). OSA diagnosis was verified using type III (in-home) polysomnography. Subjects received a stepped-dose remifentanil infusion (target effect-site concentrations of 0.5, 1, 2, 3, 4 ng ml). Primary outcome was miosis (pupil area fractional change), the most sensitive opioid effect. Secondary outcomes were ventilatory rate, end-expired CO, sedation, and thermal analgesia.
RESULTS
There were no differences in miosis between untreated OSA subjects (mean=0.51, 95% confidence interval [CI] 0.41-0.61) and subjects without OSA (mean=0.49, 95% CI 0.36-0.62) (mean difference=0.02, 95% CI -0.18 to 0.22); between treated OSA subjects (mean=0.56, 95% CI 0.43-0.68) and subjects without OSA (difference=0.07, 95% CI -0.16 to 0.29); or between untreated OSA and treated OSA (difference=-0.05, 95% CI -0.25 to 0.16). There were no significant differences between subjects without OSA, untreated OSA, and treated OSA in ventilatory rate, end-expired CO, sedation, or thermal analgesia responses to remifentanil. There was no relationship between OSA severity and magnitude of opioid effects.
CONCLUSIONS
Neither obstructive sleep apnoea nor obstructive sleep apnoea treatment affected sensitivity to the miotic, sedative, analgesic, or respiratory depressant effects of the opioid remifentanil in awake adults. These results challenge conventional notions of opioid effects in obstructive sleep apnoea.
CLINICAL TRIAL REGISTRATION
NCT02898792 (clinicaltrials.gov).
Topics: Adult; Humans; Analgesics, Opioid; Remifentanil; Prospective Studies; Carbon Dioxide; Sleep Apnea, Obstructive; Pain; Miosis; Continuous Positive Airway Pressure
PubMed: 37945413
DOI: 10.1016/j.bja.2023.09.032 -
Scientific Reports Jul 2023Focal cortical dysplasias (FCDs) are malformations of cortical development that often result in medically refractory epilepsy, with a greater incidence in the pediatric...
Focal cortical dysplasias (FCDs) are malformations of cortical development that often result in medically refractory epilepsy, with a greater incidence in the pediatric population. The relationship between the disturbed cortical morphology and epileptogenic activity of FCDs remains unclear. We used the BCNU (carmustine 1-3-bis-chloroethyl-nitrosourea) animal model of cortical dysplasia to evaluate neuronal and laminar alterations and how these result in altered activity of intracortical networks in early life. We corroborated the previously reported morphological anomalies characteristic of the BCNU model, comprising slightly larger and rounder neurons and abnormal cortical lamination. Next, the neuronal activity of live cortical slices was evaluated through large field-of-view calcium imaging as well as the neuronal response to a stimulus that leads to cortical hyperexcitability (pilocarpine). Examination of the joint activity of neuronal calcium time series allowed us to identify intracortical communication patterns and their response to pilocarpine. The baseline power density distribution of neurons in the cortex of BCNU-treated animals was different from that of control animals, with the former showing no modulation after stimulus. Moreover, the intracortical communication pattern differed between the two groups, with cortexes from BCNU-treated animals displaying decreased inter-layer connectivity as compared to control animals. Our results indicate that the altered anatomical organization of the cortex of BCNU-treated rats translates into altered functional networks that respond abnormally to a hyperexcitable stimulus and highlight the role of network dysfunction in the pathophysiology of cortical dysplasia.
Topics: Rats; Animals; Child; Humans; Carmustine; Calcium; Pilocarpine; Malformations of Cortical Development; Neurons
PubMed: 37518675
DOI: 10.1038/s41598-023-38717-2 -
International Journal of Molecular... Jul 2023Radiotherapy and chemotherapy can impair salivary gland (SG) function, which causes xerostomia and exacerbate other side effects of chemotherapy and oral infection,...
Radiotherapy and chemotherapy can impair salivary gland (SG) function, which causes xerostomia and exacerbate other side effects of chemotherapy and oral infection, reducing patients' quality of life. This animal study aimed to assess the efficacy of electroacupuncture (EA) as a means of preventing xerostomia induced by 5-fluorouracil (5-FU). A xerostomia mouse model was induced via four tail vein injections of 5-FU (80 mg/kg/dose). EA was performed at LI4 and LI11 for 7 days. The pilocarpine-stimulated salivary flow rate (SFR) and salivary glands weight (SGW) were recorded. Salivary immunoglobulin A (SIgA) and lysozyme were determined via enzyme-linked immunosorbent assay (ELISA). SG was collected for hematoxylin and eosin staining to measure acini number and acinar cell size. --, --, and mRNA expressions in SG were quantified via RT-qPCR. 5-FU caused significant decreases in SFR, SGW, SIgA, lysozyme, expression, and acini number, while and expressions and acinar cell size were significantly increased. EA treatment can prevent 5-FU damage to the salivary gland, while pilocarpine treatment can only elevate SFR and AQP5 expression. These findings provide significant evidence to support the use of EA as an alternative treatment for chemotherapy-induced salivary gland hypofunction and xerostomia.
Topics: Mice; Animals; Muramidase; Pilocarpine; Electroacupuncture; Quality of Life; Tumor Necrosis Factor-alpha; Salivary Glands; Xerostomia; Fluorouracil; Antineoplastic Agents; Immunoglobulin A, Secretory
PubMed: 37511411
DOI: 10.3390/ijms241411654