Intellectual disability (ID), formerly known as mental retardation, is characterized by significant limitations in intellectual functioning and adaptive behavior, manifesting before age 18. It affects approximately 2–3% of the population and has a complex etiology involving genetic, environmental, and developmental factors. Among the genetic causes, X-linked intellectual disability (XLID) accounts for a substantial proportion, particularly in male patients. The oligophrenin-1 (OPHN1) gene, located on chromosome Xq12, is one of several genes linked to XLID through Rho GTPase-dependent signaling pathways. Initially described as a cause of non-syndromic XLID, recent studies have revealed that OPHN1 mutations are associated with distinct neuroanatomical features, including cerebellar hypoplasia, ventriculomegaly, and facial dysmorphisms such as strabismus and deep-set eyes.

In this study, we report a three-generation Brazilian family with XLID segregating a novel intragenic deletion in OPHN1. The deletion, identified via high-resolution array CGH, results in an in-frame loss of exon 7 at the transcript level (c.781_891del; r.487_597del). This alteration leads to the removal of 37 conserved amino acids from the N-terminal BAR domain of OPHN1, a region critical for membrane curvature sensing and protein–protein interactions. Despite the structural change, cDNA analysis confirmed that the mutant transcript is stable and undergoes normal splicing, indicating that the mutation does not trigger nonsense-mediated decay or aberrant splicing.

Clinically, affected males exhibited neonatal hypotonia, hyperactivity, instability, intolerance to frustration, and distinctive facial features including prominent nasal root, deep-set eyes, and strabismus.Risdiplam Cancer All affected individuals showed large lateral ventricles, vermis hypoplasia, and cystic dilatation of the cisterna magna on cranial MRI. Notably, hippocampal alterations—including hypoplasia and verticalization—were observed in three affected males, a feature not previously reported in patients with complete loss-of-function OPHN1 mutations. These findings suggest a specific role for the BAR domain in hippocampal development and function, beyond its general involvement in synaptic plasticity.

Carrier females displayed variable phenotypes: the mother (II.2) had severe ID and epilepsy, while her daughter (II.7) was cognitively unaffected despite carrying the deletion.UiO-66-(COOH)2 Cancer EEG recordings in II.7 revealed frontal epileptiform discharges, suggesting subclinical seizure activity. Neuroimaging in carrier females showed periventricular cysts and white matter hyperintensities in the mother and grandmother, but not in the asymptomatic aunt. X-inactivation analysis revealed random patterns in both II.2 and II.7, indicating that phenotypic variability may stem from tissue-specific expression rather than skewed inactivation.

This case represents the first documented in-frame deletion within the BAR domain of OPHN1. The absence of a premature stop codon implies that the mutant protein retains partial functionality, yet its altered structure likely disrupts regulatory mechanisms involving membrane dynamics and Rho GTPase signaling.PMID:35127542 The presence of microhomology at the deletion junction suggests a mechanism of microhomology-mediated break-induced repair (MMBIR), consistent with replication-based genomic rearrangements.

These findings expand our understanding of OPHN1’s functional domains and highlight the importance of the BAR domain in brain development. They also underscore the need for comprehensive neuroimaging and molecular screening in XLID families, especially those presenting with cerebellar abnormalities, seizures, or facial dysmorphisms. Further research into the role of the BAR domain may provide insights into the pathogenesis of cognitive disorders and inform future therapeutic strategies targeting synaptic stability and neural circuitry.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com

Mitochondria play a central role in cellular metabolism and are vital to numerous biological processes. Among their key functions is the maintenance of mitochondrial membrane potential (MMP), which serves as a critical indicator of cellular health and metabolic activity. Dysregulation of MMP has been linked to various diseases, including cancer, diabetes, and neurodegenerative disorders such as Parkinson’s disease. Despite its importance, real-time and reversible monitoring of MMP remains challenging due to the lack of effective fluorescent probes. This study presents the rational design, synthesis, and application of a novel fluorescent probe, REP, capable of reversibly detecting changes in MMP within living cells.

REP is based on an organic cationic fluorophore structure featuring a positively charged oxonium ion and a strong electron-donating diethylamino group. The molecular design enables efficient accumulation in mitochondria with high MMP through the Nernst equation-driven electrochemical gradient. Upon entering mitochondria, REP exhibits intense fluorescence due to restricted intramolecular motion and reduced solvent quenching. When MMP decreases—such as during depolarization caused by protonophores like CCCP—the probe is released from mitochondria, leading to significant fluorescence quenching. This dynamic behavior allows REP to serve as a sensitive and reversible indicator of MMP fluctuations.

The optical properties of REP were evaluated in both buffer and biological environments. Absorption spectra revealed peak absorption between 470 nm and 550 nm, with emission centered at approximately 570 nm, making it compatible with standard confocal laser systems using 488 nm, 514 nm, or 543 nm excitation wavelengths. Notably, the probe showed minimal interference from common biological molecules, including reactive oxygen species, amino acids, ions, and metal cations. Only a slight reduction in fluorescence was observed upon addition of Na₂S, likely due to a minor side reaction. These results confirm the probe’s selectivity and stability in complex biological matrices.

Cellular studies demonstrated that REP effectively targets mitochondria in live HepG2 cells. Co-localization experiments with MitoTracker Deep Red confirmed a Pearson correlation coefficient of 0.89, indicating strong spatial overlap. Time-lapse imaging revealed rapid responses: after adding 10 μM CCCP, intracellular fluorescence dropped sharply within 5 minutes, reflecting MMP collapse. Upon removal of CCCP and replacement with fresh medium, fluorescence recovered within 4 minutes, demonstrating the probe’s ability to monitor reversible changes in MMP dynamics.

Furthermore, REP successfully detected oxidative damage induced by hydrogen peroxide (H₂O₂). In pre-loaded cells, H₂O₂ exposure led to a progressive decline in fluorescence intensity over 5 minutes, correlating with MMP loss due to oxidative stress. Pseudo-color images clearly illustrated this transition from red (high signal) to blue (low signal), confirming the probe’s utility in visualizing cell injury in real time.SLC40A1 ProteinFormulation

Cytotoxicity assays using MTT revealed no significant cell death even after 24 hours of incubation with up to 10 μM REP, with viability remaining above 83%.NASP ProteinStorage & Stability The probe also exhibited excellent stability in PBS buffer over two days and sufficient water solubility for biological applications.PMID:34951423

In conclusion, REP represents a powerful tool for non-invasive, real-time, and reversible imaging of MMP in living cells. Its fast response, high specificity, low cytotoxicity, and robust performance under physiological conditions make it ideal for studying mitochondrial function, cellular stress, and disease mechanisms related to bioenergetic dysfunction. This work opens new avenues for investigating mitochondrial dynamics and cellular health in both basic research and clinical diagnostics.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com

In recent years, the neurotoxic potential of inhalational anesthetics has drawn significant attention, particularly in vulnerable populations such as elderly patients and those with pre-existing neurodegenerative conditions. Among these agents, isoflurane has been implicated in inducing caspase-3 activation, a key mediator of apoptosis, which may contribute to cognitive dysfunction and the progression of Alzheimer’s disease (AD). Despite growing evidence linking isoflurane to neurotoxicity, the precise molecular mechanisms underlying its effects remain incompletely understood. This study investigates whether isoflurane induces endoplasmic reticulum (ER) stress via ryanodine receptors (RyRs), leading to caspase-3 activation in primary mouse neurons.

Primary neuronal cultures derived from wild-type C57BL/6J mice were exposed to 1% or 2% isoflurane for durations of 1, 3, or 6 hours under controlled atmospheric conditions. Levels of two well-established ER stress markers—C/EBP homologous protein (CHOP) and cleaved caspase-12—were assessed using immunocytochemistry and western blot analysis. The results demonstrated that treatment with 2% isoflurane for 6 hours significantly increased CHOP levels by 876% (P = 0.00009) and cleaved caspase-12 by 276% (P = 0.006) compared to control conditions.(1,5-Cyclooctadiene)dimethylplatinum(II) Formula Furthermore, this exposure induced robust activation of caspase-3, confirming apoptotic signaling. In contrast, a shorter 3-hour exposure to 2% isoflurane elevated CHOP and caspase-12 levels without triggering caspase-3 activation, suggesting that ER stress precedes caspase-3 activation.

To explore the role of RyRs in this process, the study utilized dantrolene, a specific antagonist of RyRs.1,4-Di(4H-1,2,4-triazol-4-yl)benzene site Pre-treatment with dantrolene (5 mM) significantly attenuated both isoflurane-induced ER stress and caspase-3 activation.PMID:35122910 Western blot quantification revealed that dantrolene reduced CHOP elevation (F = 16.64, P = 0.0022), cleaved caspase-12 levels (F = 6.13, P = 0.0383), and caspase-3 activation (F = 32.06, P = 0.0005), indicating that RyR-mediated calcium release plays a central role in mediating the downstream effects of isoflurane.

These findings suggest that isoflurane triggers ER stress through RyR-dependent pathways, ultimately leading to caspase-3 activation. The concentration- and time-dependent nature of these effects underscores the importance of exposure parameters in determining neurotoxic outcomes. Moreover, the protective effect of dantrolene highlights the therapeutic potential of targeting RyRs to mitigate anesthesia-related neurotoxicity. Given the rising number of older adults undergoing surgical procedures under general anesthesia, understanding and intervening in these pathways could have significant clinical implications. Future research should focus on validating these findings in vivo and exploring whether pharmacological modulation of RyRs can prevent postoperative cognitive decline in high-risk populations.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com

A 69-year-old cachectic man presented to the accident and emergency department with tachycardia, hypotension, and a 7-day history of persistent vomiting and constipation. Notably, he reported no significant abdominal pain. On examination, his respiratory rate was 20 breaths per minute with shallow breathing; lungs were clear on auscultation. His pulse was 140 beats per minute, blood pressure 110/80 mmHg, and pitting edema extended to his knees. He was afebrile, alert, and oriented. Abdominal examination revealed distension, firmness, and diminished bowel sounds. The patient was markedly cachectic but not jaundiced.

Initial laboratory findings showed a white cell count of 24.8 × 10⁹/L and lactate level of 2.2 mmol/L. A chest X-ray demonstrated free air under the diaphragm, raising strong suspicion of bowel perforation, possibly secondary to malignancy or ischemia.2,6-Diisopropylnaphthalene web Urgent investigations were initiated: full blood count, coagulation profile, serum electrolytes, liver function tests, and an abdominal CT scan. Blood cultures were drawn, and broad-spectrum antibiotics—including ceftriaxone, metronidazole, gentamicin, and paracetamol—were administered empirically.

The abdominal CT scan revealed a large, gas-containing abscess in the right lobe of the liver measuring 21×17×16 cm, with an air-fluid level. A smaller simple cyst (1.1 cm) was identified in segment VI. There was no evidence of cholecystitis, diverticulitis, or other intra-abdominal infection. The presence of gas within the liver lesion mimicked pneumoperitoneum on the chest X-ray, explaining the radiographic appearance of free air.

Given the imaging findings, a multidisciplinary approach was adopted. Interventional radiology performed percutaneous drainage of the abscess under ultrasound guidance. Purulent fluid was aspirated and sent for microbiology. Cultures grew *Streptococcus milleri*, a Gram-positive, microaerophilic bacterium commonly associated with abdominal infections and abscesses.Benzylmethyl ether manufacturer The patient was started on targeted β-lactam antibiotic therapy and made a steady recovery.PMID:35035614

After two weeks of treatment, including completion of a full course of antibiotics and resolution of systemic signs, the patient was discharged home with outpatient follow-up arranged. No further surgical intervention was required. The case highlights the importance of considering liver abscess in patients presenting with signs of acute abdomen, especially when imaging reveals unexpected findings such as free air on chest X-ray. This can be misleading and may lead to unnecessary exploratory surgery if not carefully evaluated.

This case underscores several key learning points: liver abscesses can mimic malignancy and intestinal perforation clinically and radiologically; gas within a hepatic abscess may simulate pneumoperitoneum; and prompt diagnosis via imaging and microbiological analysis enables accurate, life-saving management. Radiologically guided drainage combined with appropriate antibiotics is highly effective in most cases. Additionally, recent studies suggest a potential association between pyogenic liver abscess and underlying colorectal cancer, warranting thorough investigation in survivors to detect occult malignancies early.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com

Plasmodium vivax remains the predominant malaria parasite in China, particularly in regions like Yunnan Province, which experiences both vivax and falciparum malaria transmission. As part of national efforts to eliminate malaria by 2020, effective treatment strategies are crucial, especially for radical cure of P. vivax infections. This open-label randomized non-inferiority trial evaluated the efficacy and safety of artemisinin-naphthoquine (ANQ) compared to the standard chloroquine-primaquine (CQ-PQ) regimen in treating uncomplicated P. vivax monoinfections among patients in Yunnan Province.

A total of 260 eligible patients aged over five years with parasite densities ranging from 400 to 100,000 per microliter were enrolled between February 2009 and December 2010 at Tengchong County Center for Disease Control and Prevention and local hospitals along the China-Myanmar border.Isatuximab (anti-CD38) custom synthesis Participants were randomly assigned to receive either ANQ (naphthoquine 7 mg/kg + artemisinin 17.5 mg/kg) once daily for three days or CQ (24 mg base/kg/day) for three days plus primaquine (0.45 mg base/kg/day) for eight days. All patients were followed up for one year through monthly visits, including blood smear examinations and symptom monitoring.Rosmarinic acid manufacturer

Primary endpoints included the proportion of patients free of recurrence by day 42, while secondary endpoints included recurrence rates at day 28 and day 365, parasite and fever clearance times, and adverse events.PMID:35155577 By day 42, 125 patients (98.4%; 95% CI, 94.4–99.8%) in the ANQ group and 123 (96.1%; 95% CI, 91.1–98.7%) in the CQ-PQ group remained free of recurrence, with no statistically significant difference (P = 0.4496). At day 365, 101 patients (79.5%; 95% CI, 71.8–85.9%) in the ANQ group and 106 (82.8%; 95% CI, 75.1–88.9%) in the CQ-PQ group had no recurrence (P = 0.610), indicating comparable long-term efficacy.

Parasite clearance occurred rapidly in both groups, with all patients clearing parasitemia by day 3. ANQ demonstrated faster parasite and gametocyte clearance times compared to CQ-PQ (P < 0.0001). Fever clearance time was also significantly shorter in the ANQ group (mean 26.7 vs. 36.2 hours; P < 0.0001). Adverse events were reported in 49 patients (19.2%), with no significant difference between groups (RR 1.05; 95% CI, 0.63–1.74; P = 0.97). Nausea and anorexia were the most common side effects, occurring in 7.1% and 7.1% of the ANQ group versus 5.5% and 5.5% in the CQ-PQ group. Notably, two patients in the CQ-PQ arm withdrew due to severe hemoglobinuria after primaquine administration, suggesting potential G6PD deficiency, which is prevalent in this region (estimated 2.3%). The results demonstrate that a three-day ANQ regimen is non-inferior to the eight-day CQ-PQ regimen in preventing P. vivax recurrence, with superior tolerability and faster clinical response. Given its short course, high adherence, and favorable safety profile, ANQ presents a promising alternative for P. vivax treatment in endemic areas where primaquine use is limited by toxicity concerns. The study supports the integration of artemisinin-based combination therapies into routine management of vivax malaria, especially in co-endemic settings.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com

The accumulation of amyloid-β (Aβ) in the brain is a hallmark of Alzheimer’s disease, yet its distribution across brain regions is not uniform. Understanding why certain areas are more vulnerable than others before clinical symptoms appear remains a central question in neuroscience. This study investigates the regional patterns of Aβ, apolipoprotein E (apoE), synaptic markers, and other molecules involved in Aβ metabolism in non-demented individuals. Twelve brain regions—neocortical, limbic, and subcortical—were analyzed using a three-step sequential extraction method based on increasing insolubility. Levels of Aβ40, Aβ42, apoE, APP, APP-CTF, BACE1, presenilin-1, neprilysin, insulysin, LRP1, LDLR, synaptophysin, PSD95, GFAP, and lactate were quantified via ELISA or enzymatic assays.

Results revealed that the regional distribution of apoE showed a moderate-to-strong inverse correlation with Aβ levels, particularly insoluble Aβ40. In contrast, synaptic markers—especially PSD95—demonstrated a moderate-to-strong positive correlation with Aβ, particularly soluble Aβ40. These findings suggest that synapses may contribute to the initial accumulation of Aβ, while astrocyte-derived apoE may serve as a protective mechanism against such accumulation.Fluorescent brightener 71 Protocol Correlations between Aβ and LRP1, GFAP, or lactate were mild to moderate, indicating secondary roles in regional vulnerability. Notably, strong positive correlations were observed between apoE and GFAP or lactate, and between PSD95 and LRP1, supporting a functional link between synaptic integrity and clearance pathways.beta Amyloid 1-40 Antibody Epigenetics

Importantly, no significant regional correlations were found between Aβ and key Aβ-producing enzymes such as APP, APP-CTF, BACE1, or presenilin-1.PMID:34782242 Furthermore, no negative correlations emerged between Aβ and the major Aβ-degrading enzymes neprilysin or insulysin, suggesting these enzymes do not regulate regional Aβ levels under physiological conditions. These associations remained consistent regardless of the degree of Aβ accumulation or the presence of the APOE ε4 allele.

These findings support a model in which regional vulnerability to Aβ accumulation arises from a dynamic balance between two opposing processes: (1) synaptic activity promoting early Aβ deposition, and (2) astrocytic apoE limiting Aβ buildup. This dual mechanism may explain why neocortical and limbic regions—areas rich in synaptic connections—are preferentially affected early in the disease process. The data highlight the importance of both neuronal function and glial-mediated protection in determining where and when Aβ pathology begins, offering new insights into potential therapeutic targets aimed at modulating either synaptic activity or apoE function to delay or prevent Alzheimer’s disease onset.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com

Erlotinib, a tyrosine kinase inhibitor, is clinically approved for treating advanced non-small cell lung cancer (NSCLC). While it extends survival, its efficacy remains limited due to intrinsic or acquired resistance mechanisms, particularly in tumors with wild-type EGFR or secondary mutations such as T790M. To enhance erlotinib’s therapeutic potential, researchers explored combining it with quinacrine, a drug known to inhibit the FACT complex—a key regulator of chromatin transcription and NF-κB activity. The combination demonstrated strong synergistic effects across multiple NSCLC cell lines, including A549 (wild-type EGFR), H1975 (EGFR-L858R/T790M), and H1993 (MET amplified). Using the Chou-Talalay method, combination indices confirmed synergy at both 5:1 and 10:1 molar ratios of erlotinib to quinacrine. This synergy translated into significant inhibition of xenograft tumor growth in vivo.

At sub-IC50 concentrations of erlotinib—more reflective of achievable clinical levels—quinacrine alone or in combination significantly suppressed colony formation, induced G1/S and G2/M phase cell cycle arrest, and triggered apoptosis. Mechanistically, quinacrine reduced active SSRP1, a critical subunit of the FACT complex, and suppressed NF-κB-dependent luciferase reporter activity.1,4-bUtanedithiol Cancer Knockdown of SSRP1 mirrored these effects, reducing cell viability and sensitizing cells to erlotinib.Anti-LY6G6D Antibody Biological Activity Transcriptomic profiling revealed that the combination altered expression of cell cycle-related genes regulated by transcription factors linked to SSRP1 targets.PMID:34473330 Notably, genes more potently suppressed by the combination were associated with poor prognosis in lung adenocarcinoma patients, suggesting their utility as predictive biomarkers.

These findings demonstrate that quinacrine overcomes erlotinib resistance by simultaneously targeting FACT-mediated transcription, NF-κB signaling, and cell cycle progression. The results support ongoing clinical evaluation of this combination in advanced NSCLC, offering a promising strategy to improve outcomes in patients with limited treatment options.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com

RNA molecules play essential roles in numerous biological processes, with their functions often dependent on specific three-dimensional conformations. The secondary structure of RNA—formed by base pairing within a single strand and stacking of paired bases—is a critical determinant of its overall shape and function. Direct experimental determination of 3D structures is challenging and resource-intensive, making computational prediction a vital alternative. Among the most widely used approaches is energy-based prediction using thermodynamic models such as the Turner model, combined with dynamic programming algorithms like Zuker & Stiegler’s to identify minimum free energy (MFE) structures.Crovalimab Technical Information

Over recent years, significant advancements have been made in this domain, including improved parameter estimation from high-quality structural data, integration of probabilistic models, and the development of maximum expected accuracy (MEA) methods. Despite these improvements, evaluating the true performance differences between algorithms remains problematic due to inconsistent benchmarking practices and lack of robust statistical validation. Furthermore, no consistent winner has emerged across diverse RNA families, suggesting that individual methods possess complementary strengths.

To address these challenges, we present a comprehensive evaluation framework using state-of-the-art resampling techniques—bootstrap confidence intervals and permutation tests—applied to a large, high-confidence dataset of pseudoknot-free RNA structures. Our analysis reveals nuanced performance relationships among ten established MFE-based prediction tools, clarifying which methods outperform others under statistically significant conditions. We also introduce AveRNA, a novel ensemble-based method that combines predictions from multiple existing algorithms through weighted per-base-pair voting. By aggregating outputs from diverse sources, AveRNA leverages complementary prediction patterns to achieve superior accuracy.

Our results demonstrate that AveRNA achieves an average F-measure of 71.6% on the S-STRAND2 dataset—surpassing the previous best method, BL-FR, by 1.3 percentage points. This improvement is statistically significant and holds across different RNA classes, even when trained on subsets excluding specific types.Foscarbidopa GPCR/G Protein Moreover, AveRNA offers intuitive control over the trade-off between sensitivity and positive predictive value via a threshold parameter, enabling customization for applications requiring high recall or precision.PMID:35134800 The method is modular and extensible, allowing future integration of new algorithms and energy models without re-design.

The software, including MATLAB implementations and a web interface, is publicly available at http://www.cs.ubc.ca/labs/beta/Software/AveRNA, facilitating broad adoption and further research. In conclusion, AveRNA represents a major advance in RNA secondary structure prediction by systematically exploiting the collective intelligence of existing methods, thereby pushing the boundaries of accuracy while maintaining flexibility and adaptability for future innovations.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com

**Background**

Attention deficit hyperactivity disorder (ADHD) is a complex neurodevelopmental disorder characterized by persistent patterns of inattention, hyperactivity, and impulsivity. These symptoms are closely linked to dysregulation of key neurotransmitters in the prefrontal cortex and other brain regions, particularly norepinephrine (NE), dopamine (DA), and serotonin (5-HT). Modulating the levels of these monoamines in the synaptic cleft is a primary therapeutic strategy for managing ADHD symptoms and improving cognitive function. Consequently, the development of selective inhibitors and receptor modulators that can precisely tune these neurotransmitter systems is of significant research importance. In this context, we will introduce a selective norepinephrine transporter inhibitor and 5-HT receptor modulator – Viloxazine.

**Definition**

Viloxazine is a non-brain-penetrant, selective norepinephrine transporter (NET) inhibitor with an IC50 value of 0.26 μM, which also acts as a modulator of 5-HT receptors.

**In Vitro and In Vivo Studies**

According to the Viloxazine description, this compound functions by competitively inhibiting NET to increase NE and DA levels in the synaptic cleft. It further enhances 5-HT neurotransmission by acting as an antagonist at 5-HT2B receptors (Ki = 4.2 μM) and an agonist at 5-HT2C receptors (EC50 = 32 μM). Regarding Viloxazine in vitro activity, a kinase binding assay using 10 μM of the compound demonstrated significant inhibition of 7 out of 132 targets, including NET, 5-HT2B, 5-HT2C, 5-HT1B, 5-HT7, ADR α1A, and ADR α1B receptors, showing the highest selectivity for NET with an inhibition rate exceeding 50%.

The Viloxazine biological activity has been further validated through extensive animal studies. In vivo studies using male Sprague-Dawley rats (300-400 g, 7-8 weeks) showed that a single intraperitoneal injection of 50 mg/kg significantly increased extracellular NE, DA, and 5-HT levels in the prefrontal cortex (PFC), nucleus accumbens (Acb), and amygdala (Amg), with peak responses occurring at 60 minutes post-injection (NE: 649%, DA: 670%, and 5-HT: 506% of baseline). Additionally, doses ranging from 1 to 30 mg/kg (i.p.) dose-dependently increased NE and 5-HT levels in the PFC, while significantly decreasing the NE metabolite DHPG at 10 and 30 mg/kg, without significantly affecting DA levels. The median lethal dose (LD50) was reported as 500-1000 mg/kg (p.o., mouse), 2000 mg/kg (p.o., rat), and 60 mg/kg (i.v., mouse). In conclusion, Viloxazine is a potent NET inhibitor and 5-HT receptor modulator that effectively increases monoamine levels in key brain regions, making it a valuable tool for ADHD research.

Keywords

Viloxazine, 35604-67-2, Viloxazin, Emovit, 5-HT Receptor, Serotonin Receptor, 5-hydroxytryptamine Receptor, Serotonergic, noradrenergic, 5-HT, depression, Inhibitor, inhibitor, inhibit

References

[1] Yu C, et al. New Insights into the Mechanism of Action of Viloxazine: Serotonin and Norepinephrine Modulating Properties. J Exp Pharmacol. 2020 Aug 25;12:285-300.
[2] Garcia-Olivares J, et al. Viloxazine Increases Extracellular Concentrations of Norepinephrine, Dopamine, and Serotonin in the Rat Prefrontal Cortex at Doses Relevant for the Treatment of Attention-Deficit/Hyperactivity Disorder. J Exp Pharmacol. 2024 Jan 16;16:13-24.
[3] Findling RL, et al. Viloxazine in the Management of CNS Disorders: A Historical Overview and Current Status. CNS Drugs. 2021 Jun;35(6):643-653.

In the nematode Caenorhabditis elegans, betaine functions as a key osmolyte and methyl donor, but its role in neurobiology has remained obscure. Recent findings reveal that betaine acts through a specific ligand-gated ion channel—ACR-23—to regulate locomotion and neuromuscular function. This study identifies ACR-23 as a betaine-activated cation channel belonging to the cys-loop receptor family. When activated by betaine, ACR-23 induces inward currents in neurons and body muscles, leading to sustained depolarization and hypercontraction of muscle cells. The activation threshold for ACR-23 is relatively low, with an EC50 of 1.4 mM, indicating high sensitivity to extracellular betaine levels.

The physiological impact of ACR-23 activation becomes evident when betaine clearance mechanisms fail. The SNF-3 transporter, a Na+/Cl−-dependent betaine uptake system, maintains low extracellular betaine concentrations. Loss-of-function mutations in snf-3 result in elevated extracellular betaine, which chronically activates ACR-23. In sensitized backgrounds such as egl-8 (phospholipase C) mutants, this leads to synthetic lethality characterized by severe uncoordination, dumpy morphology, and paralysis. These phenotypes are fully suppressed by mutations in acr-23, confirming that ACR-23 mediates betaine toxicity. Moreover, exogenous betaine exposure paralyzes snf-3 mutants but not snf-3 acr-23 double mutants, further supporting ACR-23’s central role.

Electrophysiological analysis of ACR-23 expressed in Xenopus oocytes confirms it forms a homomeric, non-selective monovalent cation channel permeable to Na+ and K+, with reversal potential near -9 mV. Notably, ACR-23 shows no permeability to divalent cations like Ba2+. The channel exhibits desensitization upon prolonged agonist exposure, but this process is blocked by the anthelmintic drug monepantel—a positive allosteric modulator that enhances betaine-induced currents without direct activation. This pharmacological profile suggests monepantel amplifies endogenous betaine signaling, leading to irreversible muscle contraction and death.2-Amino-4-chloropyrimidine supplier

ACR-23 expression is predominantly localized in mechanosensory neurons (ALM, PLM, AVM, PVM), interneurons, and body muscles.FITC-inulin Formula Functional rescue experiments show that neuronal expression of ACR-23 is sufficient to restore normal locomotion, while muscle-specific expression recapitulates hypercontracted phenotypes.PMID:34939989 Gain-of-function ACR-23(I301N) variants, engineered for increased ligand sensitivity, produce developmental arrest and adult paralysis indistinguishable from snf-3; egl-8 double mutants, demonstrating that excessive ACR-23 activity alone can drive lethal neuromuscular dysfunction.

These findings establish a novel betaine signaling pathway in nematodes: betaine released into the extracellular space is cleared by SNF-3, preventing aberrant activation of ACR-23. Disruption of this balance leads to pathological overstimulation of the nervous system and muscle. Given that ACR-23 is absent in vertebrates, this pathway offers a highly selective target for next-generation anthelmintics. Monepantel’s mechanism—potentiating betaine signaling via ACR-23—provides a blueprint for developing new drugs that exploit endogenous neurotransmitter systems in parasitic nematodes, potentially overcoming resistance seen with current treatments.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com