Search Results (467)

Obesity resulting from melanocortin-4 receptor (MC4R) dysfunction is characterized by combined metabolic dysregulation and maladaptive reward-related behaviors that limit the durability of existing therapies. The endocannabinoid system is a central regulator of appetite, lipid metabolism, and reward processing; however, first-generation cannabinoid receptor 1 (CB1) antagonists were limited by adverse neuropsychiatric effects. SKNY-1 is an orally active tetrahydrocannabivarin (THCV) analog designed to engage pathway-biased CB1 signaling, modulate cannabinoid receptor 2 (CB2), and selectively inhibit monoamine oxidase B (MAO-B), with the objective of addressing both metabolic and behavioral components of obesity while minimizing central nervous system liability through biased CB1 signaling, CB2 modulation, and potential complementary MAO-B inhibition. Here, we integrated in vitro pharmacological profiling of SKNY-1 with in vivo evaluation in an adult mc4r(G894C) zebrafish model exhibiting obesity-associated metabolic and reward-related phenotypes. In vitro, SKNY-1 displayed low-potency modulation of CB1 cyclic AMP signaling (EC₅₀ ~30 µM) but more potent antagonism of the CB1 β-arrestin pathway (IC₅₀ ~6 µM), consistent with differential CB1 pathway modulation. SKNY-1 acted as a CB2 partial agonist (EC₅₀ ~0.1 µM), with antagonist activity emerging at higher concentrations, and selectively inhibited MAO-B at low affinity with no activity against MAO-A. In vivo, mc4r(G894C) zebrafish mutants exhibited dyslipidemia, hepatic triglyceride accumulation, altered appetite-regulatory gene expression, increased metabolic rate, and enhanced compulsive high-calorie feeding and nicotine-seeking behaviors. Oral administration of SKNY-1 for six days produced dose-dependent effects. Both doses normalized total cholesterol and low-density lipoprotein levels and reduced hepatic triglycerides toward wild-type values without affecting circulating triglycerides. The higher dose (200 ng per fish per day) induced significant body weight reduction while preserving body density and attenuated reward-associated feeding and nicotine-seeking behaviors. The lower dose (20 ng per fish per day) more effectively normalized the leptin a-to-ghrelin expression ratio. Collectively, these findings demonstrate that SKNY-1 engages integrated endocannabinoid and potential dopaminergic mechanisms to improve metabolic parameters and attenuate maladaptive reward-related behaviors in an MC4R-deficient vertebrate model, supporting its further translational investigation for obesity complicated by compulsive eating and substance-seeking behaviors. Full article

MAO-B-specific inhibition, either in knockout (KO) mice or pharmacologically, preserves left ventricular function and reduces cardiac fibrosis after myocardial infarction or pressure overload. We investigated whether stimulation of MAO-B in cardiac fibroblasts provokes ROS production and myofibroblast development. Fibroblast-specific MAO-B knockdown (KD) mice were created by crossing Col1a2CreERT mice with MAO-B^fl/fl mice. The KD was induced by tamoxifen injection. Fibroblasts of KD mice and wild types (WTs) were isolated and reduced MAO-B expression in KD fibroblasts was confirmed. In isolated mitochondria from the left ventricle of these mice, ROS production was reduced under stimulation with the specific MAO-B substrate β-phenylethylamine (PEA). Mitochondrial ROS production in fibroblasts, detected by MitoSox Red staining, increased under PEA (1000 µM) stimulation only in WT fibroblasts. mRNA of the marker genes for myofibroblast differentiation, Col1a1 and periostin, increased 2- or 3-fold, respectively, in WT but not in MAO-B KD fibroblasts. The enhanced migration potential under PEA was reduced in MAO-B KD fibroblasts. In conclusion, stimulation of MAO-B in cardiac fibroblasts leads to the formation of mitochondrial ROS, enhancement of myofibroblast marker gene expression and migration of the cells. Excessive fibrosis caused by elevated MAO-B activity in myocardial infarction can therefore contribute to cardiac dysfunction. Full article

Neurological disorders, particularly Parkinson’s disease (PD), represent a pressing global health challenge with limited disease-modifying therapies. While Achyranthes bidentata exhibits neuroprotective potential, its bioactive constituents against PD remain poorly characterized. This study integrated phytochemical isolation and in silico target prediction to identify eight compounds from A. bidentata, followed by neuroprotective evaluation in 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-challenged SH-SY5Y cells. Among these, 25R-inokosterone significantly downregulated Monoamine oxidase B (MAOB) and Glycogen synthase kinase-3β (GSK-3β) expression and showed superior neuroprotection compared to β-ecdysterone. It markedly restored mitochondrial membrane potential, suppressed Bcl-2-associated X protein (Bax)/Cysteinyl aspartate specific proteinase 3 (caspase-3) apoptotic signaling, and alleviated oxidative stress. Mechanistically, Nuclear factor erythroid 2-related factor 2 (Nrf2)/Heme oxygenase 1 (HO-1) activation was the dominant and indispensable mechanism for neuroprotection, while MAOB/GSK-3β expression downregulation served as an upstream synergistic regulatory event, as evidenced by the abolition of neuroprotection following Nrf2 knockdown in SH-SY5Y cells. These findings identify 25R-inokosterone as a promising multi-target natural lead for PD, which exerts antioxidant and anti-apoptotic effects predominantly by activating Nrf2, accompanied by the upstream modulation of MAOB/GSK-3β expression. Full article

Astragaloside IV (AS-IV), a principal bioactive constituent of the medicinal and edible herb Radix astragali, exerts protective effects against ulcerative colitis (UC). This study investigated its underlying mechanisms in dextran sulfate sodium (DSS)-induced colitis using 16S rRNA sequencing, untargeted fecal metabolomics, and label-free proteomics. AS-IV intervention remodeled intestinal microbiota composition by markedly increasing Akkermansia abundance. Fecal metabolomic analysis revealed enhanced tryptophan (Trp) metabolism and elevated levels of kynurenic acid, 5-hydroxyindoleacetic acid and indole-3-acetic acid, which were significantly positively correlated with Akkermansia abundance. Proteomic analysis further identified Trp metabolism as a key pathway. Indoleamine 2,3-dioxygenase 1 (IDO1) and dopa decarboxylase (DDC) were recognized as differentially expressed proteins in colonic tissues. AS-IV ameliorated colitis by downregulating IDO1 expression, while upregulating the expression of tryptophan hydroxylase 1 (TPH1), DDC, monoamine oxidase A (MAO-A), and the aryl hydrocarbon receptor (AhR), as well as inhibiting NF-κB p65 phosphorylation. Collectively, these findings indicate that AS-IV enhances intestinal barrier function and mitigates colonic inflammation in DSS-induced UC. These beneficial effects are associated with the regulation of host–gut Trp metabolism, altered AhR expression, and suppressed NF-κB p65 activation. This study underscores the potential of AS-IV as a candidate functional food ingredient for the management of UC. Full article

Dravet syndrome (DS) is a severe, catastrophic childhood epilepsy predominantly caused by loss-of-function mutations in the SCN1A gene, which encodes the voltage-gated sodium channel Na_v1.1. In this study, we evaluated the therapeutic potential of 5-(Benzofuran-2-yl)-3-(2-chloro-4-fluorobenzyl)-1,3,4-oxadiazol-2(3H)-one (GM-90663), a novel small molecule designed to address the complex pathophysiology of DS. Using scn1lab knockout (KO) zebrafish larvae—a robust vertebrate model for DS—we demonstrated that GM-90663 significantly alleviates seizure-like behavioral movements and rescues deficit in cognitive-like functions. Whole-cell patch-clamp recordings in hippocampal slices revealed that GM-90663 modulates voltage-gated Na⁺ channel kinetics; specifically, it suppresses slow ramp-induced currents, thereby effectively attenuating neuronal hyperexcitability. Furthermore, neurochemical profiling indicated that GM-90663 treatment leads to a marked increase in endogenous serotonin (5-HT) levels in both wild-type and KO larvae. Molecular docking simulations and subsequent in vitro enzymatic assays confirmed that this elevation in serotonin is mediated through the potent inhibition of monoamine oxidase (MAO) activity. Collectively, our findings suggest that GM-90663 exerts its anti-seizure effects through a synergistic dual mechanism—stabilizing sodium channel conductance and elevating serotonergic activity—positioning it as a promising multi-target candidate for the treatment of DS. Full article

Neurodegenerative diseases are a serious problem for modern society, and their treatment remains an important issue discussed by the scientific community. One of the promising potential directions for modulating neurodegenerative processes is the use of acylhydrazones, a class of compounds that combine different bioactive fragments linked by an acylhydrazone moiety. So far, the biological properties of these compounds have been proven. They show antibacterial, antiviral, antifungal, antiparasitic, anticancer, anti-inflammatory and antioxidant activity. Many research papers focus on designing acylhydrazones that will find use in the treatment of neurodegenerative diseases by inhibiting the enzymatic activity of acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), β-secretase 1 (BACE1) and monoamine oxidase (MAO), as well as inhibiting β-amyloid aggregation, exhibiting metal chelation and antioxidant properties. Recent studies have described the acylhydrazone-based dual (multi-target) inhibitors, which have demonstrated encouraging outcomes during in vitro evaluations. This review covers recent articles published in the years 2020–2025 and offers a comprehensive overview of the biological properties of the acylhydrazones and their multifunctional derivatives on neurodegenerative processes and/or neuroprotection, while emphasizing their universal nature, structural versatility and role as leading structures in the search for new drugs. Full article

Neurodegenerative disorders (NDs), such as Alzheimer’s and Parkinson’s diseases (AD and PD), despite having different main neuropathological hallmarks, share several interconnected aetiologic mechanisms and lack effective disease-modifying treatments. The multifactorial nature of these diseases has encouraged the development of new drugs such as multi-target-directed ligands (MTDLs). In this work, an anti-AD drug (rivastigmine, RIV) was fused and conjugated with a series of antioxidant scaffolds to obtain a small library of RIV–antiox hybrids. In addition to inhibitory activity towards both cholinesterases, these hybrids exhibited radical scavenging activity, inhibition of Aβ aggregation, and neuroprotection against cell death induced in AD models. The relevant anti-AD properties already found for these hybrids challenged us to also assess their capacity to modulate and interfere with ROS-associated harmful dysfunctions, namely in the dysregulation of biometal ions (Fe³⁺, Cu²⁺, and Zn²⁺) and upregulation of monoamine oxidases (MAOs). In particular, the capacity of the hybrids for metal chelation and inhibition of Cu-induced Aβ aggregation and MAO isoforms was evaluated, as well as their neuroprotection capacity in cell models of PD. Overall, some of these RIV hybrids appear as lead compounds for the development of novel multifunctional agents against NDs. Full article

Chronic social isolation (CSIS) is a form of psychosocial stressor strongly associated with the development of depression. Preclinical studies demonstrated that CSIS induces behavioral phenotypes resembling human depression, including anhedonia, behavioral despair and anxiety. This review summarizes proteomic-driven discoveries characterizing hippocampal non-synaptic mitochondria (NSM) and synaptosomal fractions containing synaptic mitochondria from adult male rats exposed to six weeks of CSIS, an animal model of depression, compared to controls. The compartment-specific proteomic alterations reveal mechanisms underlying mitochondrial dysregulation, providing molecular insights into the depression-like phenotype. Hippocampal NSM exhibit changes in energy metabolism-related proteins, including components of the tricarboxylic acid cycle and oxidative phosphorylation, as well as mitochondrial transport proteins and alterations in chaperones, structural and translational proteins, and monoamine oxidase, further elucidating how these proteomic changes contribute to mitochondrial dysregulation. In contrast, synaptosomal proteomics reveal predominantly increased protein abundance associated with energy metabolism, signaling, cytoskeletal organization, protein quality control, and vesicle trafficking, suggesting compensatory adaptations. Together, these findings highlight compartment-specific mitochondrial proteomic changes that may underlie depression-like behaviors and represent potential targets for therapeutic intervention. Full article

Serotonin is a critical morphogen in early development, yet the mechanisms regulating its homeostasis in the preimplantation embryo remain unclear, particularly under conditions of maternal antidepressant exposure. Here, we investigated embryonic serotonergic autonomy using mouse models of pharmacological transport blockade (maternal fluoxetine treatment) and in vitro treatment with the monoamine oxidase inhibitor pargyline. We employed immunofluorescence, RT-qPCR, and live-cell imaging to assess metabolic flux, gene expression, and physiological health. We demonstrate that monoamine oxidase functions as a metabolic firewall, progressively maturing from zygote to blastocyst to degrade excess amines. Paradoxically, maternal serotonin transporter blockade triggered significant intracellular serotonin hyper-accumulation in blastocysts, associated with a trend toward a compensatory upregulation of the biosynthetic gene Ddc. While this serotonin overload did not compromise morphology, mitochondrial function, or pluripotency marker expression, it induced a robust epigenetic response. Excess serotonin promoted elevated H3Q5ser immunoreactivity in both nuclear and cytoplasmic compartments via a transglutaminase-dependent mechanism. These findings reveal that the preimplantation embryo possesses a resilient, autonomous serotonergic system capable of compensatory synthesis. However, environmental fluctuations are chemically recorded via transglutaminase-mediated serotonylation, representing an epigenetic mark that warrants further long-term study within the Developmental Origins of Health and Disease (DOHaD) framework. Full article

Parkinson’s disease (PD) is a multifactorial neurodegenerative disorder characterized by progressive motor and non-motor manifestations, including early gastrointestinal dysfunction. Growing evidence implicates the gut microbiota as an active modulator of host immune tone and neurodegenerative vulnerability, extending beyond descriptive taxonomic associations toward functional and metabolic mechanisms. PD-associated dysbiosis is consistently characterized by altered microbial functional capacity, including reduced short-chain fatty acid (SCFA) production, enrichment of pro-inflammatory metabolic traits, and sustained immune stimulation at the intestinal interface. These shifts promote chronic low-grade inflammation and intestinal barrier perturbations, creating conditions that may facilitate abnormal α-synuclein aggregation within the enteric nervous system. Current management predominantly relies on dopaminergic replacement and related symptomatic strategies, such as levodopa combinations, dopamine agonists, monoamine oxidase-B and catechol-O-methyltransferase (COMT) inhibitors, and device-aided therapies, which alleviate symptoms but do not halt underlying neurodegeneration or modify long-term disease course. These therapeutic limitations have intensified interest in upstream mechanisms that might be amenable to disease-modifying interventions, particularly those arising at the level of the gut microbiota and gut–immune–brain axis. This narrative review integrates clinical, metagenomic, metabolomic, and mechanistic evidence to propose a unified model in which microbiota-driven immune and metabolic perturbations may act as upstream drivers converging on α-synuclein pathology, neuroinflammation, and neurovascular dysfunction. Full article

Background/Objectives: Citrus limon leaf essential oil (EO) is traditionally used for its calming and cognitive-enhancing properties. Although the chemical composition of C. limon leaf essential oils (EOs) obtained by means of hydrodistillation (HD) and solvent-free microwave extraction (SFME) has been previously characterized, the influence of the extraction method on their neuroprotective efficacy and dose–response effects remains insufficiently explored. In the present study, EOs obtained by means of HD (CEH) and SFME (CEM) were compared for their behavioral, biochemical, and in silico neuroprotective effects against scopolamine (SCOP)-induced cognitive and anxiety-like impairments in adult zebrafish. Methods: Adult Tübingen zebrafish were exposed to CEH or CEM via immersion at 10, 100, and 150 µL/L for 19 days prior to SCOP challenge (100 µM). Cognitive performance was evaluated using the Y-maze and novel object recognition (NOR) tests, while anxiety-like behavior was assessed using the novel tank test (NTT) and novel approach test (NAT). Brain acetylcholinesterase (AChE) activity and oxidative stress markers were quantified. Molecular docking analyses were conducted to investigate interactions between major EO constituents and AChE and monoamine oxidase A (MAO A). Results: Both CEH and CEM significantly attenuated SCOP-induced memory deficits, improved spontaneous alternation and NOR discrimination, and reduced anxiety-like behaviors. These effects were associated with AChE inhibition and restoration of redox balance. Notably, CEM generally exhibited stronger neurobehavioral and biochemical effects at comparable doses. In silico analyses supported these findings, revealing favorable binding affinities of key EO constituents toward cholinergic and monoaminergic targets. Conclusions: This study demonstrates that the extraction method influences the neuroprotective efficacy of C. limon leaf EOs. While both CEH and CEM exert antioxidant and cholinergic modulatory effects, CEM shows enhanced neuroprotective potential in a zebrafish model of SCOP-induced cognitive impairment, supporting the relevance of extraction-dependent biological profiling in EO-based neurotherapeutic research. Full article

Neurodegenerative disorders (NDs), such as Alzheimer’s disease and Parkinson’s disease (PD), represent a significant challenge for ageing populations, with their prevalence increasing worldwide. Elevated human Monoamine Oxidase B (hMAO-B) activity has been related to neurodegenerative progression, where it contributes, among others, to oxidative stress and neuroinflammation. The identification and optimization of selective hMAO-B inhibitors is therefore pivotal in addressing the progression of NDs. In this work we introduced 2-aroylbenzothiophene analogues as promising agents to mitigate neurodegeneration. The synthesized compounds were screened against hMAO-A and hMAO-B, identifying compounds 4, 11, and 12 as the most promising. In vitro studies in hGF and SH-SY5Y cells revealed distinct toxicity profiles, with compound 4 being the least tolerated at 100 µM. ROS generation was investigated as a possible mechanism underlying this toxicity. Compounds 4 (12.5 µM), 11, and 12 (100 µM) were further evaluated for neuroprotective effects against 6-hydroxydopamine (6-OHDA)-induced toxicity in SH-SY5Y cells, showing a modest neuroprotective effect after 72 h at a sub-toxic 6-OHDA concentration (250 µM), comparable to the clinically used hMAO-B inhibitor (R)-(−)-Deprenyl at 100 µM. Finally, molecular modelling studies revealed that compound 4 establishes key stabilizing interactions within hMAO-B, accounting for its high inhibitory potency and selectivity over hMAO-A. Full article

The pathogenesis of Parkinson’s disease (PD) is characterized by progressive degeneration of nigrostriatal dopaminergic signaling, resulting in motor dysfunction. Although monoamine oxidase (MAO) inhibitors are clinically used in PD, their long-term efficacy and safety remain limited. In the present study, three novel N-benzylpyrrolidine derivatives (3e, 3f, and 3i), previously identified as dual MAO-A/B inhibitors in silico and in vitro, were pharmacologically evaluated in an acute 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD. The compounds were administered intraperitoneally starting 2 days prior to MPTP exposure and continuing for 6 days thereafter. Repeated administration of the compounds did not alter striatal dopamine (DA) levels under basal conditions, indicating no detectable modulation of dopaminergic tone in vivo. All three derivatives ameliorated MPTP-induced motor deficits. Compounds 3f and 3i improved motor function without detectable changes in striatal DA levels, whereas compound 3e partially restored striatal DA levels, similar to the positive control. In addition, compound-specific alterations in hippocampal pro-inflammatory cytokines were observed, including increased levels of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) following 3e administration. Together, these findings provide in vivo pharmacological characterization of novel MAO-targeting derivatives and reveal differential behavioral, neurochemical, and cytokine profiles among the tested compounds, supporting further mechanistic investigation. Full article

In recent years, psychopharmacology has experienced a significant challenge, highlighting a renewed and strong scientific interest in psychedelics as breakthrough therapies for mental disorders. Psychedelics can influence cognitive and emotional processes, showing solid therapeutic potential, particularly in treatment-resistant psychiatric disorders. Amongst the most promising compounds, ayahuasca and its main psychoactive component, N,N-dimethyltryptamine (DMT), have received considerable attention. Ayahuasca is a psychoactive brew traditionally prepared from the liana Banisteriopsis caapi and the leaves of Psychotria viridis. Its psychoactive properties derive mainly from DMT, while β-carbolines, which act as monoamine oxidase-A (MAO-A) inhibitors, prevent the metabolic degradation of DMT, enhancing its bioavailability and allowing oral administration. In contrast, in monotherapy, DMT or its analog 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT) is generally administered via alternative routes, like inhalation, intranasal, or intravenous delivery. DMT is primarily a serotonin (5-HT)2A receptor partial agonist, whereas 5-MeO-DMT has a higher affinity for the 5-HT1A receptor compared to 5-HT2A, though other receptor targets are engaged, fostering neuroplasticity and a reorganization of brain networks involved in perception, cognition, and mood regulation. Despite limited clinical trials, current evidence offers an optimistic outlook on DMT and 5-MeO-DMT efficacy for treatment-resistant depression (TRD) and major depressive disorder (MDD), whereas evidence for other mental disorders studies is still preliminary. There are four phase II studies with 5-MeO-DMT and one with DMT for TRD, while there are two phase II studies with DMT fumarate for MDD. Beyond their therapeutic potential, psychedelics also represent powerful tools for exploring the human mind, offering valuable insights into brain function and mental health. Full article

Differentiated human neuroblastoma (SH-SY5Y) cells were exposed to either 0.2 μM nicotine, a tobacco smoke preparation (TPM) diluted to the same nicotine concentration, or a cocktail of seven tobacco smoke monoamine oxidase inhibitors (MAOIs) at the concentrations measured in the TPM. Treatment occurred for 3 days, such that the cellular monoamine oxidase (MAO) concentration was reduced by approximately 50% in both the TPM and MAOI cocktail exposure groups. Changes in MAO gene expression after exposure to the different treatments were determined using qPCR, and the effect of these exposure treatments on global gene expression was also examined using mRNA sequencing. No change in MAOA and MAOB gene expression levels was observed, after any treatment, either using qPCR or mRNA sequencing. The MAOI versus control treatment comparison revealed that four genes were >2-fold down-regulated (ZNF727, RP11-310E22.4, CRYM, SEMA3F), and 19 genes were up-regulated after 3 days’ exposure to the MAOI cocktail. Many of these differentially expressed genes were linked with disease conditions related to smoking and addiction. Exposure to nicotine and TPM each resulted in up- and down-regulation of different sets of genes. The results indicate that changes in MAO gene expression are unlikely to be responsible for the changes in MAO activity. The association between genes whose expression changes with tobacco MAO treatment and smoking-related diseases and addiction suggests the central role that MAO inhibition may play in mediating the effects of smoking on smokers. Full article