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Prostate cancer (PC) develops in a microenvironment where the stromal cells modulate adjacent tumor growth and progression. Here, we demonstrated elevated levels of monoamine oxidase B (MAOB), a mitochondrial enzyme that degrades biogenic and dietary monoamines, in human PC stroma, which was associated with poor clinical outcomes of PC patients. Knockdown or overexpression of MAOB in human prostate stromal fibroblasts indicated that MAOB promotes cocultured PC cell proliferation, migration, and invasion and co-inoculated prostate tumor growth in mice. Mechanistically, MAOB induces a reactive stroma with activated marker expression, increased extracellular matrix remodeling, and acquisition of a protumorigenic phenotype through enhanced production of reactive oxygen species. Moreover, MAOB transcriptionally activates CXCL12 through Twist1 synergizing with TGFβ1-dependent Smads in prostate stroma, which stimulates tumor-expressed CXCR4-Src/JNK signaling in a paracrine manner. Pharmacological inhibition of stromal MAOB restricted PC xenograft growth in mice. Collectively, these findings characterize the contribution of MAOB to PC and suggest MAOB as a potential stroma-based therapeutic target.

The inner mitochondrial membrane (IMM) generates power to drive cell function, and its dynamics control mitochondrial health and cellular homeostasis. Here, we describe the cell-permeant, lipid-like small molecule MAO-N3 and use it to assemble high-density environmentally sensitive (HIDE) probes that selectively label and image the IMM in live cells and multiple cell states. MAO-N3 pairs with strain-promoted azide-alkyne click chemistry-reactive fluorophores to support HIDE imaging using confocal, structured illumination, single-molecule localization and stimulated emission depletion microscopy, all with significantly improved resistance to photobleaching. These probes generate images with excellent spatial and temporal resolution, require no genetic manipulations, are non-toxic in model cell lines and primary cardiomyocytes (even under conditions that amplify the effects of mitochondrial toxins) and can visualize mitochondrial dynamics for 12.5 h. This probe will enable comprehensive studies of IMM dynamics with high temporal and spatial resolution.

[Display omitted] • Intermittent sucrose/fasting protocol led to overeating behavior. • Animals with loss-control eating also showed depressive-like behavior. • Fasting itself did not induce depressive-like or sucrose overeating behavior. • Activity of monoamine oxidases was disrupted in overeating mice. • Sucrose-exposed mice tend to exhibit increased risk behavior after 20 h-fasting. Binge eating disorder is the most prevalent eating disorder, affecting both sexes but more commonly found in women. Given the frequent co-occurrence of psychiatric disorders, this study aimed to establish a standardized experimental intermittent protocol to investigate overeating associated with depression. A 10-day protocol induced uncontrolled eating behavior in C57BL/6J female mice. The first experiment included the following groups: naive group (chow ad libitum), control group (chow and sucrose solution ad libitum), and fasting groups (16 and 20 h) exposed to an intermittent sucrose solution (10 %) and chow regimen. Subsequently, the feeding test, open field test, elevated plus maze test, tail suspension test, and light/dark conflict test were conducted. Furthermore, monoamine oxidase (MAO) A and B activities in brain structures and plasma corticosterone levels were assessed. Food overconsumption and depressive-like behavior were observed in both sucrose fasting groups, while risk-taking behaviors were specifically observed in the 20-hour fasting sucrose group. While both fasting sucrose groups caused reduced hippocampal MAO-A activity, only the F20 sucrose group inhibited MAO-B in the cortex and hypothalamus. Moreover, both fasting sucrose groups exhibited elevated corticosterone levels. In a separate design (Experiment 2), groups with 16 and 20 h of fasting alone (without sucrose) did not show the same behavioral results as the intermittent fasting sucrose groups, thus avoiding fasting bias. Based on these results, the 20-hour sucrose fasting group was chosen as the ideal protocol for mimicking overeating behavior associated with depression to investigate future therapeutic approaches for this comorbidity. [ABSTRACT FROM AUTHOR]

Depression and Parkinson's disease (PD) are devastating psychiatric and neurological disorders that require the development of novel therapeutic interventions. Drug repurposing targeting predefined pharmacological targets is a widely use approach in modern drug discovery. Monoamine oxidase B (MAOB) is a critical protein implicated in Depression and PD. In this study, we undertook a systematic exploration of repurposed drugs as potential inhibitors of MAO-B. Exploring a library of 3,648 commercially available drug molecules, we conducted virtual screening using a molecular docking approach to target the MAO-B binding pocket. Two promising drug molecules, Brexpiprazole and Trifluperidol, were identified based on their exceptional binding potential and drug profiling. Subsequently, all-atom molecular dynamics (MD) simulations were performed on the MAO-B-ligand complexes for a trajectory of 300 nanoseconds (ns). Simulation results demonstrated that the binding of Brexpiprazole and Trifluperidol induced only minor structural alterations in MAO-B and showed significant stabilization throughout the simulation trajectory. Overall, the finding suggests that Brexpiprazole and Trifluperidol exhibit strong potential as repurposed inhibitors of MAO-B that might be explored further in experimental investigations for the development of targeted therapies for depression and PD. [ABSTRACT FROM AUTHOR]

AbstractIntroductionMaterials and MethodsResultsConclusionOur investigation aims to appraise the neuroprotective impact of Bone Marrow-Mesenchymal Stem Cells (BM-MSCs) derived exosomes against Ag NPs-inducing neurotoxicity in rats.Twenty-four albino rats were divided into 3 groups. Group I (control negative), Group II (intraperitoneally injected with Ag NPs for 28 days, whereas Group III (intraperitoneally injected with Ag NP and BM-MSCs derived exosomes.There was a marked elevation of Malondialdehyde (MDA) along with a reduction of brain antioxidants, Gamma-aminobutyric acid (GABA) and Monoamine Oxidase (MAO) in the Ag NPs receiving group. Ag NPs upregulated c-Jun N-terminal Kinases (JNK) genes and c-Myc and downregulated the tissue inhibitors of metalloproteinases (TIMP-1) and Histone deacetylase 1 (HDAC1) genes. Otherwise, the co-treatment of BM-MSCs derived exosomes with Ag NPs could markedly increase the rat’s body weight, activity and learning while, decreasing anxiety, restoring all the toxicological parameters and improving the microscopic appearance of different brain areas.BM-MSCs-derived exosomes downregulated both apoptotic and inflammatory mediators and upregulated the antiapoptotic genes. BM-MSCs-derived exosomes exhibit a great therapeutic effect against the neurotoxic effects of Ag NPs. [ABSTRACT FROM AUTHOR]

Objective: To explore the effect and anxiolytic mechanism of a natural remedy called Fructus gardeniae (FG). Methods: The elevated-plus maze (EPM) test was used to confirm the anxiolytic effect of FG. The potential and anxiolytic components, targets, and route processes of FG were investigated using the network pharmacology method in conjunction with metabolomics and molecular docking technologies. Results: FG could greatly enhance the proportion of time and times of opening arms, according to the EPM data. As to the metabolomics findings, a total of 61 distinct metabolites were found, mainly involved in glycine, serine, and threonine metabolism as well as alanine, aspartate, and glutamate metabolism. The primary active ingredients of FG, nicotiflorin, jasminodiol, and crocetin, demonstrated substantial binding affinities with monoamine oxidase A (MAOA), monoamine oxidase A (ACHE), malate dehydrogenase 2 (MDH2), glutamate decarboxylase 2 (GAD2), glutamate decarboxylase 1 (GAD1), and nitric oxide synthase (NOS1), according to the findings of network pharmacology and molecular docking. Conclusion: FG exerts an anxiolytic action via targeting MAOA, ACHE, MDH2, GAD2, GAD1, and NOS1, and regulating the metabolism of glycine, serine, and threonine as well as alanine, aspartic acid, and glutamic acid. [ABSTRACT FROM AUTHOR]

Perry disease (PeD) is a rare, neurodegenerative, genetic disorder inherited in an autosomal dominant manner. The disease manifests as parkinsonism, with psychiatric symptoms on top, such as depression or sleep disorders, accompanied by unexpected weight loss, central hypoventilation, and aggregation of DNA-binding protein (TDP-43) in the brain. Due to the genetic cause, no causal treatment for PeD is currently available. The only way to improve the quality of life of patients is through symptomatic therapy. This work aims to review the latest data on potential PeD treatment, specifically from the medicinal chemistry and computer-aided drug design (CADD) points of view. We select proteins that might represent therapeutic targets for symptomatic treatment of the disease: monoamine oxidase B (MAO-B), serotonin transporter (SERT), dopamine D2 (D2R), and serotonin 5-HT1A (5-HT1AR) receptors. We report on compounds that may be potential hits to develop symptomatic therapies for PeD and related neurodegenerative diseases and relieve its symptoms. We use Phase pharmacophore modeling software (version 2023.08) implemented in Schrödinger Maestro as a ligand selection tool. For each of the chosen targets, based on the resolved protein–ligand structures deposited in the Protein Data Bank (PDB) database, pharmacophore models are proposed. We review novel, active compounds that might serve as either hits for further optimization or candidates for further phases of studies, leading to potential use in the treatment of PeD. [ABSTRACT FROM AUTHOR]

Cerebral dopamine neurotrophic factor (CDNF) is an unconventional neurotrophic factor because it does not bind to a known specific receptor on the plasma membrane and functions primarily as an unfolded protein response (UPR) regulator in the endoplasmic reticulum. Data on the effects of CDNF on nonmotor behavior and monoamine metabolism are limited. Here, we performed the intracerebroventricular injection of a recombinant CDNF protein at doses of 3, 10, and 30 μg in C57BL/6 mice. No adverse effects of the CDNF injection on feed and water consumption or locomotor activity were observed for 3 days afterwards. Decreases in body weight and sleep duration were transient. CDNF-treated animals demonstrated improved performance on the operant learning task and a substantial decrease in anxiety and behavioral despair. CDNF in all the doses enhanced serotonin (5-HT) turnover in the murine frontal cortex, hippocampus, and midbrain. This alteration was accompanied by changes in the mRNA levels of the 5-HT1A and 5-HT7 receptors and in monoamine oxidase A mRNA and protein levels. We found that CDNF dramatically increased c-Fos mRNA levels in all investigated brain areas but elevated the phosphorylated-c-Fos level only in the midbrain. Similarly, enhanced CREB phosphorylation was found in the midbrain in experimental animals. Additionally, the upregulation of a spliced transcript of XBP1 (UPR regulator) was detected in the midbrain and frontal cortex. Thus, we can hypothesize that exogenous CDNF modulates the UPR pathway and overall neuronal activation and enhances 5-HT turnover, thereby affecting learning and emotion-related behavior. [ABSTRACT FROM AUTHOR]

Monoamine oxidases (MAOs), mitochondrial enzymes that constantly produce hydrogen peroxide (H2O2) as a byproduct of their activity, have been recently acknowledged as contributors to oxidative stress in cardiometabolic pathologies. The present study aimed to assess whether MAOs are mediators of valvular oxidative stress and interact in vitro with angiotensin 2 (ANG2) to mimic the activation of the renin–angiotensin system. To this aim, valvular tissue samples were harvested from 30 patients diagnosed with severe primary mitral regurgitation and indication for surgical repair. Their reactive oxygen species (ROS) levels were assessed by means of a ferrous oxidation xylenol orange (FOX) assay, while MAO expression was assessed by immune fluorescence (protein) and qRT-PCR (mRNA). The experiments were performed using native valvular tissue acutely incubated or not with angiotensin 2 (ANG2), MAO inhibitors (MAOI) and the angiotensin receptor blocker, irbesartan (Irb). Correlations between oxidative stress and echocardiographic parameters were also analyzed. Ex vivo incubation with ANG2 increased MAO-A and -B expression and ROS generation. The level of valvular oxidative stress was negatively correlated with the left ventricular ejection fraction. MAOI and Irb reduced valvular H2O2. production. In conclusion, both MAO isoforms are expressed in pathological human mitral valves and contribute to local oxidative stress and ventricular functional impairment and can be modulated by the local renin–angiotensin system. [ABSTRACT FROM AUTHOR]

Background and Purpose: Demand for new antidepressants has resulted in a re‐evaluation of the therapeutic potential of psychedelic drugs. Several tryptamines found in psilocybin‐containing "magic" mushrooms share chemical similarities with psilocybin. Early work suggests they may share biological targets. However, few studies have explored their pharmacological and behavioural effects. Experimental Approach: We compared baeocystin, norbaeocystin and aeruginascin with psilocybin to determine if they are metabolized by the same enzymes, similarly penetrate the blood–brain barrier, serve as ligands for similar receptors and modulate behaviour in rodents similarly. We also assessed the stability and optimal storage and handling conditions for each compound. Key Results: In vitro enzyme kinetics assays found that all compounds had nearly identical rates of dephosphorylation via alkaline phosphatase and metabolism by monoamine oxidase. Further, we found that only the dephosphorylated products of baeocystin and norbaeocystin crossed a blood–brain barrier mimetic to a similar degree as the dephosphorylated form of psilocybin, psilocin. The dephosphorylated form of norbaeocystin was found to activate the 5‐HT2A receptor with similar efficacy to psilocin and norpsilocin in in vitro cell imaging assays. Behaviourally, only psilocybin induced head twitch responses in rats, a marker of 5‐HT2A‐mediated psychedelic effects and hallucinogenic potential. However, like psilocybin, norbaeocystin improved outcomes in the forced swim test. All compounds caused minimal changes to metrics of renal and hepatic health, suggesting innocuous safety profiles. Conclusions and Implications: Collectively, this work suggests that other naturally occurring tryptamines, especially norbaeocystin, may share overlapping therapeutic potential with psilocybin, but without causing hallucinations. [ABSTRACT FROM AUTHOR]

A set of sesamol-derived acetamides was designed, synthesized, and evaluated against monoamine oxidases (MAO-A and MAO-B) and cholinesterases (AChE and BChE) for targeting neurodegenerative diseases. Most of the tested compounds showed inhibition activity at micromolar to nanomolar ranges. The 3,4-dichoro derivative (compound 19) was the most potent MAO-A inhibitor (IC50 = 0.053 ± 0.001 µM) while the 4-methyl analog (compound 16) emerged as a lead MAO-B inhibitor (IC50 = 0.019 ± 0.001 µM) compared to the reference inhibitors clorgyline (MAO-A IC50 = 0.096 ± 0.003 µM) and selegyline (MAO B IC50 = 0.021 ± 0.002 µM). Further, the 2,4-dichloro analog (compound 20) emerged as a potent dual MAO (MAO-A IC50 = 0.160 ± 0.009 µM, MAO-B IC50 = 0.071 ± 0.002 µM) and ChE (AChE IC50 = 2.611 ± 0.086 µM and BChE IC50 = 4.22 ± 0.162 µM) inhibitor. Moreover, molecular simulation studies revealed that H-bonding and hydrophobic interactions stabilize the virtual lead inhibitor-protein complex. Selected MAO-ChE inhibitors showed significant antioxidant and iron-chelation properties, suggesting their potential in treating neurological disorders characterized by impaired iron homeostasis. In summary, the structural modification attempted in the present study yielded a few nanomolar MAO (MAO-B) inhibitors and, thus, provided new insights into the linker requirements for dual MAO/ChE inhibitory properties. [ABSTRACT FROM AUTHOR]

Neurodegenerative disorders are caused by the progressive death of neuronal cells in specific regions of the brain and spinal cord. The most common neurodegenerative disorders are Alzheimer's disease and Parkinson's disease. The inhibition of enzymes that metabolise neurotransmitter amines is an important approach in the treatment of these disorders and monoamine oxidase (MAO) B inhibitors have thus been used for the treatment of Parkinson's disease. Inhibitors of the MAO-A isoform, in turn, are used clinically for the treatment of affective (e.g., major depression) and anxiety disorders. Recent studies have shown that benzothiazole derivatives act as potent MAO inhibitors. Based on these findings, the present study group synthesised thirteen 2-methylbenzo[d]thiazole derivatives and evaluated their in vitro MAO inhibition properties. The results showed that the benzothiazole derivatives were potent and selective inhibitors of human MAO-B, with all compounds exhibiting IC50 values < 0.017 µM. The most potent MAO-B inhibitor (4d) had an IC50 value of 0.0046 µM, while the most potent MAO-A inhibitor (5e) had an IC50 value of 0.132 µM. It may be concluded that active benzothiazole derivatives may serve as potential leads for the development of MAO inhibitors for the treatment of neuropsychiatric and neurodegenerative disorders. [ABSTRACT FROM AUTHOR]

The Monoamine Oxidase-A (MAOA) EcoRV polymorphism (rs1137070) is a unique synonymous mutation (c.1409 T > C) within the MAOA gene, which plays a crucial role in Maoa gene expression and function. This study aimed to explore the relationship between the mouse Maoa rs1137070 genotype and differences in MAOA gene expression. Mice carrying the CC genotype of rs1137070 exhibited a significantly lower Maoa expression level, with an odds ratio of 2.44 compared to the T carriers. Moreover, the wild-type TT genotype of MAOA demonstrated elevated mRNA expression and a longer half-life. We also delved into the significant expression and structural disparities among genotypes. Furthermore, it was evident that different aspartic acid synonymous codons within Maoa influenced both MAOA expression and enzyme activity, highlighting the association between rs1137070 and MAOA. To substantiate these findings, a dual-luciferase reporter assay confirmed that GAC was more efficient than GAT binding. Conversely, the synonymous mutation altered Maoa gene expression in individual mice. An RNA pull-down assay suggested that this alteration could impact the interaction with RNA-binding proteins. In summary, our results illustrate that synonymous mutations can indeed regulate the downregulation of gene expression, leading to changes in MAOA function and their potential association with neurological-related diseases. [ABSTRACT FROM AUTHOR]

The potent hallucinogen N,N-dimethyltryptamine (DMT) has garnered significant interest in recent years due to its profound effects on consciousness and its therapeutic psychopotential. DMT is an integral (but not exclusive) psychoactive alkaloid in the Amazonian plant-based brew ayahuasca, in which admixture of several β-carboline monoamine oxidase A (MAO-A) inhibitors potentiate the activity of oral DMT, while possibly contributing in other respects to the complex psychopharmacology of ayahuasca. Irrespective of the route of administration, DMT alters perception, mood, and cognition, presumably through agonism at serotonin (5-HT) 1A/2A/2C receptors in brain, with additional actions at other receptor types possibly contributing to its overall psychoactive effects. Due to rapid first pass metabolism, DMT is nearly inactive orally, but co-administration with β-carbolines or synthetic MAO-A inhibitors (MAOIs) greatly increase its bioavailability and duration of action. The synergistic effects of DMT and MAOIs in ayahuasca or synthetic formulations may promote neuroplasticity, which presumably underlies their promising therapeutic efficacy in clinical trials for neuropsychiatric disorders, including depression, addiction, and post-traumatic stress disorder. Advances in neuroimaging techniques are elucidating the neural correlates of DMT-induced altered states of consciousness, revealing alterations in brain activity, functional connectivity, and network dynamics. In this comprehensive narrative review, we present a synthesis of current knowledge on the pharmacology and neuroscience of DMT, β-carbolines, and ayahuasca, which should inform future research aiming to harness their full therapeutic potential. [ABSTRACT FROM AUTHOR]

Nowadays, an efficient and robust virtual screening procedure is crucial in the drug discovery process, especially when performed on large and chemically diverse databases. Virtual screening methods, like molecular docking and classic QSAR models, are limited in their ability to handle vast numbers of compounds and to learn from scarce data, respectively. In this study, we introduce a universal methodology that uses a machine learning-based approach to predict docking scores without the need for time-consuming molecular docking procedures. The developed protocol yielded 1000 times faster binding energy predictions than classical docking-based screening. The proposed predictive model learns from docking results, allowing users to choose their preferred docking software without relying on insufficient and incoherent experimental activity data. The methodology described employs multiple types of molecular fingerprints and descriptors to construct an ensemble model that further reduces prediction errors and is capable of delivering highly precise docking score values for monoamine oxidase ligands, enabling faster identification of promising compounds. An extensive pharmacophore-constrained screening of the ZINC database resulted in a selection of 24 compounds that were synthesized and evaluated for their biological activity. A preliminary screen discovered weak inhibitors of MAO-A with a percentage efficiency index close to a known drug at the lowest tested concentration. The approach presented here can be successfully applied to other biological targets as target-specific knowledge is not incorporated at the screening phase. [ABSTRACT FROM AUTHOR]

Plants of the genus Tribulus have been used in folk medicine for wound healing, alleviating liver, stomach, and rheumatism pains, and as cognitive enhancers, sedatives, antiseptics, tonics, and stimulants. The present work aimed to evaluate whether Tribulus terrestris (Tt) administered for 15 days attenuated cognitive deficits and exhibited anxiolytic and antidepressant profiles in scopolamine-induced amnesia in zebrafish. Animals were randomly divided into six groups (eight animals per group): (1)–(3) Tt treatment groups (1, 3 and 6 mg/L), (4) control, (5) scopolamine (SCOP, 0.7 mg/kg), and (6) galantamine (Gal, 1 mg/L). Exposure to SCOP (100 µM) resulted in anxiety in zebrafish, as assessed by the novel tank diving test (NTT) and novel approach test (NAT). When zebrafish were given SCOP and simultaneously given Tt (1, 3, and 6 mg/L once daily for 10 days), the deficits were averted. Molecular interactions of chemical compounds from the Tt fractions with the monoamine oxidase A (MAO-A) were investigated via molecular docking experiments. Using behavioral experiments, we showed that administration of Tt induces significant anxiolytic-antidepressant-like effects in SCOP-treated zebrafish. Our result indicated that flavonoids of Tt, namely kaempferol, quercetin, luteolin, apigetrin, and epigallocatechin, could act as promising phytopharmaceuticals for improving anxiety-related disorders. [ABSTRACT FROM AUTHOR]

Parkinson's disease (PD) stands as the second most common neurological disorder after Alzheimer's disease, primarily affecting the elderly population and significantly compromising their quality of life. The precise etiology of PD remains elusive, but recent research has shed light on potential factors, including the formation of α‐synuclein aggregates, oxidative stress, neurotransmitter imbalances, and dopaminergic neurodegeneration in the substantia nigra pars compacta (SNpc) region of the brain, culminating in motor symptoms such as bradykinesia, akinesia, tremors, and rigidity. Monoamine oxidase (MAO) is an essential enzyme, comprising two isoforms, MAO‐A and MAO‐B, responsible for the oxidation of monoamines such as dopamine. Increased MAO‐B activity is responsible for decreased dopamine levels in the SNpc region of mid brain which is remarkably associated with the pathogenesis of PD‐like manifestations. Inhibitors of MAO‐B enhance striatal neuronal responses to dopamine, making them valuable in treating PD, which involves dopamine deficiency. Clinically approved MAO‐B inhibitors such as selegiline, L‐deprenyl, pargyline, and rasagiline are employed in the management of neurodegenerative conditions associated with PD. Current therapeutic interventions including MAO‐B inhibitors for PD predominantly aim to alleviate these motor symptoms but often come with a host of side effects that can be particularly challenging for the patients. While effective, they have limitations, prompting a search for alternative treatments, there is a growing interest in exploring natural products notably flavonoids as potential sources of novel MAO‐B inhibitors. In line with that, the present review focuses on natural flavonoids of plant origin that hold promise as potential candidates for the development of novel MAO‐B inhibitors. The discussion encompasses both in vitro and in vivo studies, shedding light on their potential therapeutic applications. Furthermore, this review underscores the significance of exploring natural products as valuable reservoirs of MAO‐B inhibitors, offering new avenues for drug development and addressing the pressing need for improved treatments in PD‐like pathological conditions. The authors of this review majorly explore the neuroprotective potential of natural flavonoids exhibiting notable MAO‐B inhibitory activity and additionally multi‐targeted approaches in the treatment of PD with clinical evidence and challenges faced in current therapeutic approaches. [ABSTRACT FROM AUTHOR]

Zebrafish (Danio rerio) are unusual in having two paralogues of the serotonin re-uptake transporter (Sert), slc6a4a (serta) and slc6a4b (sertb), the transporter that serves in serotonin re-uptake from a synapse into the pre-synaptic cell or in serotonin uptake from the extracellular milieu into cells in the peripheral tissues. To address a knowledge gap concerning the specific roles of these paralogues, we used CRISPR/Cas9 technology to generate zebrafish knockout lines predicted to lack functional expression of Serta or Sertb. The consequences of loss-of-function of Serta or Sertb were assessed at the gene expression level, focusing on the serotonergic signalling pathway, and at the behaviour level, focusing on aggression. Whereas serta mRNA was expressed in all tissues examined, with high expression in the heart, gill and brain, only the brain displayed substantial sertb mRNA expression. In both serta−/− and sertb−/− fish, changes in transcript abundances of multiple components of the serotonin signalling pathway were detected, including proteins involved in serotonin synthesis (tph1a, tph1b, tph2, ddc), packaging (vmat2) and degradation (mao), and serotonin receptors (htr1aa, htr1ab). Using a mirror aggression test, serta−/− male but not female fish exhibited greater aggression than wildtype fish. However, both male and female sertb−/− fish displayed less aggression than their wildtype counterparts. These differences in behaviour between serta−/− and sertb−/− individuals hold promise for increasing our understanding of the neurophysiological basis of aggression in zebrafish. [ABSTRACT FROM AUTHOR]

Levamisole is an anti-helminthic drug developed and introduced in veterinary medicine, and it has been used more frequently after the inclusion of its usage in human medicine regarding disorders with immunomodulatory properties. In recent years, it has started to attract attention since it has beneficial effects on the treatment of COVID-19 due to its immunomodulatory properties. To investigate the effects of levamisole on sexual behavior and the reproductive system in male rats, two groups were formed the vehicle (n = 10) and levamisole (n = 10) groups. The vehicle group was given purified water whereas the levamisole group was administered with levamisole (2 mg/kg) by oral gavage daily for 4 weeks. Levamisole treatment significantly increased the mount latency (ML, P < 0.001) as well as the intromission latency (IL, P < 0.01). It also significantly prolonged postejaculatory interval (PEI, P < 0.01), decreased copulatory rate (CR, P < 0.05), and sexual activity index (SAI, P < 0.05). It significantly decreased serum monoamine oxidase A (MAO-A) levels (P < 0.05). Additionally, levamisole induced disorganizations of germinal epithelial cells of seminiferous tubules, congestion, edema in the interstitial area, and metaphase arrest in some spermatocytes (P < 0.001), and it significantly increased the immunohistochemical expressions of apoptotic Bax and cytochrome c, which is crucial proapoptotic protein, in the testis (P < 0.001). Also, levamisole significantly upregulated the mRNA levels of the apoptosis-related key regulatory genes, including Bax (Bcl-2-associated X protein, P = 0.05) and Bax/Bcl-2 ratio (P < 0.01) in testis. The current research is the first to show that levamisole may decrease sexual performance, potency, sexual motivation, and libido and induce apoptosis in the testis. [ABSTRACT FROM AUTHOR]

Stress-related anxiety disorders and anxiety-like behavior in post-traumatic stress disorder (PTSD) are associated with altered neurocircuitry pathways, neurotransmitter systems, and the activities of monoamine and glucocorticoid-metabolizing enzymes. Resveratrol, a natural polyphenol, is recognized for its antioxidant, anti-inflammatory, and antipsychiatric properties. Previous studies suggest that resveratrol reduces anxiety-like behavior in animal PTSD models by downregulating key enzymes such as 11 β -hydroxysteroid dehydrogenase type 1 (11 β -HSD-1) and monoamine oxidases (MAOs). However, the underlying mechanisms remain unclear. In this study, we explored the efficacy of resveratrol in treating stress-induced anxiety using a chronic predator stress model in rats. Resveratrol was administered intraperitoneally at 100 mg/kg following a 10-day stress exposure, and anxiety behavior was assessed with an elevated plus maze. Our results indicated that stress-related anxiety correlated with increased activities of brain MAO-A, MAO-B, and hepatic 11 β -HSD-1, alongside elevated oxidative stress markers in the brain and liver. Resveratrol treatment improved anxiety behavior and decreased enzyme activities, oxidative stress, and hepatic damage. We demonstrate that resveratrol exerts antianxiogenic effects by modulating glucocorticoid and monoamine metabolism in the brain and liver. These findings suggest resveratrol's potential as a therapeutic agent for anxiety disorders, warranting further clinical investigation. [ABSTRACT FROM AUTHOR]

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The seeds of ginkgo biloba L (GB) have been widely used worldwide. This study investigated the bioefficacies of whole GB seed powder (WGP) retaining the full nutrients of ginkgo against aging, atherosclerosis, and fatigue. The experimental results indicated that WGP lowered brain monoamine oxidase and serum malondialdehyde levels, enhanced thymus/spleen indexes, and improved learning ability, and delayed aging in senescent mice. WGP regulated lipid levels and prevented atherosclerosis by reducing triglycerides, lowering low-density lipoprotein cholesterol, increasing high-density lipoprotein cholesterol, and decreasing the atherosclerosis index. WGP improved exercise performance by reducing blood lactate accumulation and extending exhaustive swimming and climbing times, improved energy storage by increasing muscle/liver glycogen levels, and relieved physical fatigue. Network pharmacology analysis revealed 270 potential targets of WGP that play roles in cellular pathways related to inflammation inhibition, metabolism regulation, and anti-cellular senescence, etc. Protein-protein interaction analysis identified 10 hub genes, including FOS, ESR1, MAPK8, and SP1 targets. Molecular docking and molecular dynamics simulations showed that the bioactive compounds of WGP bound well to the targets. This study suggests that WGP exerts prominent health-promoting effects through multiple components, targets, and pathways. [ABSTRACT FROM AUTHOR]

Background: Oral levodopa remains the mainstay of treatment for Parkinson's disease (PD). However, as PD progresses, response to treatment may fluctuate. Managing fluctuations can be demanding for clinicians and patients. There is a paucity of real-world studies reporting on PD management in patients with fluctuations in treatment response, especially in patients with advanced stages of PD. The multicentre, observational Parkinson's Disease Fluctuations treatment PAthway (PD-FPA) study describes the real-life management of response fluctuations in Italian patients with advanced PD. Patients and Methods: PD-FPA had a retrospective and prospective phase; herein, retrospective results are presented. Ten Italian centres enrolled patients with a PD diagnosis from 10-15 years prior to study entry (T0) and who had ≥2-year history of fluctuations. Data on patient demographics, medical history, PD stage, fluctuation characteristics, symptoms, and prescribed treatments were collected at T0 and retrospectively (2 years prior to T0) via patient chart review/interview. Results: Overall, 296 patients (60% male, mean age 68 years, 84% with Hoehn and Yahr scores 2-3) were enrolled. At T0, most patients (99.3%) were on oral levodopa therapy. All patients used dopaminergic medications; adjunctive medications included dopamine agonists (56%) and monoamine oxidase B (60%) and catechol-O-methyltransferase enzyme inhibitors (41%). At T0, 51% of patients had changed therapy, with response fluctuations being the most common reason (74%); wearing-off was the most common fluctuation (83%). Conclusion: This interim analysis of PD-FPA suggests that adequate levodopa dosing and adjunctive medications can stabilize advanced PD and provide patients with a good quality of life. [ABSTRACT FROM AUTHOR]

Genetic and environmental factors have been linked with neurodegeneration, especially in the elderly. Yet, efforts to impede neurodegenerative processes have at best addressed symptoms instead of underlying pathologies. The gap in the understanding of neuro-behavioral plasticity is consistent from insects to mammals, and cockroaches have been proven to be effective models for studying the toxicity mechanisms of various chemicals. We therefore used head injection of 74 and 740 nmol STZ in Nauphoeta cinerea to elucidate the mechanisms of chemical-induced neurotoxicity, as STZ is known to cross the blood-brain barrier. Neurolocomotor assessment was carried out in a new environment, while head homogenate was used to estimate metabolic, neurotransmitter and redox activities, followed by RT-qPCR validation of relevant cellular signaling. STZ treatment reduced the distance and maximum speed travelled by cockroaches, and increased glucose levels while reducing triglyceride levels in neural tissues. The activity of neurotransmitter regulators – AChE and MAO was exacerbated, with concurrent upregulation of glucose sensing and signaling, and increased mRNA levels of redox regulators and inflammation-related genes. Consequently, STZ neurotoxicity is conserved in insects, with possible implications for using N. cinerea to target the multi-faceted mechanisms of neurodegeneration and test potential anti-neurodegenerative agents. [ABSTRACT FROM AUTHOR]

Five dimethylamino-based chalcone derivatives (AC) were synthesized and evaluated for their inhibition degree against monoamine oxidase (MAO) enzymes. All AC compounds showed better inhibitory activity against MAO-B than that against MAO-A. AC4 showed the highest inhibitory ability with an IC50 value of 0.020 µM, similar to that of a reference drug safinamide (IC50 = 0.019 µM) against MAO-B, followed by AC1 (IC50 = 0.068 µM) and AC3 (IC50 = 0.083 µM). Substituent -F in ring A (AC4) increased the MAO-B inhibition, followed by -H (AC1), -Br (AC3), and -Cl (AC2). The selectivity index (SI) value of AC4 was high (SI = 82.00) as well as other compounds (44.41 to 98.15). AC4 was found to be a reversible inhibitor as confirmed through analysis using the dialysis method. Interestingly, AC4 was observed to be a noncompetitive MAO-B inhibitor with a rare case and with Ki values of 0.011 ± 0.0036 µM. These experiments confirmed that AC4 is a reversible and potent selective inhibitor of MAO-B. Molecular docking experiments revealed that AC4 showed the highest inhibitory activity with a docking score (-9.510 kcal/mol). A study using molecular dynamics modeling revealed that the protein–ligand complex was more stable. It was observed that AC4 was non-cytotoxic in the study using L929 cell line. In conclusion, compound AC4 shows promise as a MAO-B inhibitor. [ABSTRACT FROM AUTHOR]

The pharmacological effects of pomegranates have been described considering metabolic aspects such as hypoglycemic and hypolipidemic activities. The pomegranate extract has activity on the central nervous system (CNS) as a natural antidepressant and anxiolytic. The chemical composition of pomegranates is complex since the bioactive compounds are multiple secondary metabolites that have been identified in the extracts derived from the peel, seed, flowers, leaves, or in their combination; so, it has not been easy to identify an individual compound as responsible for its observed pharmacological properties. From this point of view, the present review analyzes the effects of crude extracts or fractions of pomegranates and their possible mechanisms of action concerning antidepressant- and anxiolytic-like effects in animal models. Serotonin receptors, estrogen receptors, the peroxisome proliferator-activated receptor gamma (PPARγ), or monoamine oxidase enzymes, as well as potent antioxidant and neuroplasticity properties, have been described as possible mediators involved in the antidepressant- and anxiolytic-like behaviors after pomegranate treatment. The pharmacological effects observed on the CNS in experimental models associated with a specific stress level suggest that pomegranates could simultaneously modulate the stress response by activating several targets. For the present review, scientific evidence was gathered to integrate it and suggest a possible pathway for mediators to be involved in the mechanisms of action of the pomegranate's antidepressant- and anxiolytic-like effects. Furthermore, the potential benefits are discussed on comorbid conditions with anxiety and depression, such as perimenopause transition and pain. [ABSTRACT FROM AUTHOR]

Black mulberry (Morus nigra L.) is a common edible fruit from the Moraceae family with a wide variety of nutritional and medicinal applications, mainly due to its antioxidant and anti-inflammatory properties. The purpose of this work was to investigate the cytoprotective and neuroprotective capacity of a hydrophilic black mulberry solvent-free extract rich in polyphenols, including the antioxidant, antiradical, and enzymatic mechanisms that would explain these effects. Its neuroprotective potential was evaluated in vitro using the Neuro-2a cell line and in vivo through the Caenorhabditis elegans organism model. Neuro-2a cells were treated at different concentrations of the extract (25–500 µg/mL) and hydrogen peroxide (300 µM) as an oxidant agent, simultaneously. From these treatments, redox status (intracellular ROS production) and cellular activity (MTT) were also quantified in Neuro-2a. Regarding the C. elegans assay, the protection of the extract against β-amyloid toxicity was measured against the CL4176 strain, which is a model of Alzheimer disease. As a complementary neuroprotective assay, its potential to inhibit the monoamine oxidase A (MAO-A) enzyme was measured. In addition, an Artemia salina bioassay was performed for preliminary toxicity screening. And its antioxidant properties were evaluated by means of the FRAP assay. The results confirm its neuroprotective potential and its ability to scavenge free radicals and decrease ROS production, also acting as a moderate MAO-A inhibitor. Moreover, the polyphenolic extract alleviates the toxicity induced by β-amyloid accumulation in C. elegans. Concluding, Morus nigra can be considered a functional food with bioactive compounds that may prevent the onset of neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

Ginkgo biloba extracts (GBE) have been shown to effectively improve cognitive function in patients with Alzheimer's disease (AD). One potential therapeutic strategy for AD is to prevent loss of adult hippocampal neurons. While recent studies have reported that GBE protects against oxidative stress in neurons, the underlying mechanisms remain unclear. In this study, an AD-like rat model was established via bidirectional injection of amyloid beta 25–35 (Aβ25–35; 20 μg) in the hippocampal CA1 region. Learning and memory abilities of experimental rats were AD assessed in response to oral administration of 7.5 g/L or 15 g/L Ginkgo biloba extract 50 (GBE50) solution and the peroxidation phenomenon of hippocampal mitochondria determined via analysis of mitochondrial H2O2 and several related enzymes. Levels of the oxidative stress-related signaling factor cytochrome C (Cyto C), apoptosis-related proteins (Bax, Bcl-2 and caspase-3) and caspase-activated DNase (CAD) were further detected via western blot. 8-Hydroxydeoxyguanosine (8-OHdG), the major product of DNA oxidative stress, was evaluated to analyze DNA status. Our results showed elevated H2O2 levels and monoamine oxidase (MAO) activity, and conversely, a decrease in the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the hippocampus of AD rats. Administration of GBE50 regulated the activities of these three enzymes and induced a decrease in H2O2. GBE50 exerted regulatory effects on abnormally expressed apoptotic proteins in the AD rat hippocampus, enhancing the expression of Bcl-2, inhibiting release of Cyto C from mitochondria, and suppressing the level of caspase-3 (excluding cleaved caspase-3). Furthermore, GBE50 inhibited DNA damage by lowering the generation of 8-OHdG rather than influencing expression of CAD. The collective findings support a protective role of GBE50 in hippocampal neurons of AD-like animals against mitochondrial oxidative stress. [ABSTRACT FROM AUTHOR]

Background: Alzheimer's disease (AD) is the most common neurodegenerative disease. Unfortunately, efficient and affordable treatments are still lacking for this neurodegenerative disorder, it is therefore urgent to identify new pharmacological targets. Astrocytes are playing a crucial role in the tuning of synaptic transmission and several studies have pointed out severe astrocyte reactivity in AD. Reactive astrocytes show altered physiology and function, suggesting they could have a role in the early pathophysiology of AD. Objective: We aimed to characterize early synaptic impairments in the AppNL-F knock-in mouse model of AD, especially to understand the contribution of astrocytes to early brain dysfunctions. Methods: The AppNL-F mouse model carries two disease-causing mutations inserted in the amyloid precursor protein gene. This strain does not start to develop amyloid-β plaques until 9 months of age. Thanks to electrophysiology, we investigated synaptic function, at both neuronal and astrocytic levels, in 6-month-old animals and correlate the synaptic activity with emotional behavior. Results: Electrophysiological recordings in the hippocampus revealed an overall synaptic mistuning at a pre-plaque stage of the pathology, associated to an intact social memory but a stronger depressive-like behavior. Astrocytes displayed a reactive-like morphology and a higher tonic GABA current compared to control mice. Interestingly, we here show that the synaptic impairments in hippocampal slices are partially corrected by a pre-treatment with the monoamine oxidase B blocker deprenyl or the fast-acting antidepressant ketamine (5 mg/kg). Conclusions: We propose that reactive astrocytes can induce synaptic mistuning early in AD, before plaques deposition, and that these changes are associated with emotional symptoms. [ABSTRACT FROM AUTHOR]

Monoamine oxidase (MAO) inhibitors are effective therapeutic agents for the treatment of neurodegenerative diseases, and natural flavonoids found in the species Agastache belong to them. In the present study, six new acylated flavone-O-glycosides were isolated from A. foeniculum and identified using UV, NMR spectroscopy, and mass spectrometry as agastoside A (acacetin 7-O-(2′′-O-malonyl)-β-D-glucopyranoside), B (acacetin 7-O-(4′′-O-malonyl)-β-D-glucopyranoside), C (acacetin 7-O-(2′′,6′′-di-O-malonyl)-β-D-glucopyranoside), D (acacetin 7-O-(4′′,6′′-di-O-malonyl)-β-D-glucopyranoside), E (acacetin 7-O-(2′′-O-malonyl-6′′-O-acetyl)-β-D-glucopyranoside), and F (acacetin 7-O-(4′′-O-acetyl-6′′-O-malonyl)-β-D-glucopyranoside). Using flash chromatography and liquid chromatography–mass spectrometry, an additional 34 known phenolic compounds were detected. A study of biological activity showed that A. foeniculum flavonoids had an inhibitory effect on MAO-A and MAO-B, with the greatest effect noted for acacetin 7-O-glucoside acetate and malonate esters, which may be promising compounds for the development new drugs. [ABSTRACT FROM AUTHOR]

Hypothyroidism has adverse effects on heart metabolism and functions including reduced heart rate, cardiac output and cardiac contractility. The therapeutic effects of alpha lipoic acid (LA) and metformin (MET) against hypothyroidism-induced myocardial complications were assessed in the current study. Rats were divided into control, propylthiouracil (PTU)-induced hypothyroidism model, hypothyroidism model treated with LA and/or MET. Serum thyroid hormones (T3, T4 and TSH) were measured. Lipid peroxidation (MDA), nitric oxide (NO), reduced glutathione (GSH), nuclear factor erythroid 2–related factor 2 (NrF2), B-cell lymphoma 2 (BCL2), nuclear factor kappa B (NF-κB), serotonin (5-HT), norepinephrine (NE) and dopamine (DA), acetylcholinesterase (AChE), monoamine oxidase (MAO) and Na+,K+,ATPase were measured in the cardiac tissue. The histopathological changes were also assessed. PTU significantly decreased T3 and T4 and significantly increased TSH. A significant increase in MDA, GSH, NrF2, BCL2, NF-κB, 5-HT, NE, DA, AChE, MAO and Na+,K+,ATPase and a significant decrease in NO were observed in the cardiac tissue of hypothyroidism model. This was associated with histopathological changes. LA alone or with MET restored T3 and TSH and improved almost all the biochemical changes except the decreased NO and the increased DA. MET restored T3, T4 and TSH and the biochemical changes induced in the cardiac tissue. MET ameliorated the histopathological changes that were still observed with LA alone or with MET. The present findings indicate that MET had cardioprotective effect against hypothyroidism and its myocardial complications. This effect was less prominent with LA alone or in combination with MET. [ABSTRACT FROM AUTHOR]

Resveratrol (3,5,4′-trihydroxy-trans-stilbene), a phenol commonly found in grapes and wine, has been associated as protective in experimental models involving alterations in different neurotransmitter systems. However, studies are reporting that resveratrol could have adverse effects. This study evaluated if the association of a low dose of ketamine and resveratrol could induce behavioral manifestations associated with biochemical alterations. Moreover, the effects of treatment with resveratrol and/or ketamine on monoamine oxidase (MAO) activity, oxidative stress markers, and IL-6 levels in the brain were also investigated. Male Swiss mice received a low dose of ketamine (20 mg/kg) for 14 consecutive days, and resveratrol (10, 30, or 100 mg/kg) from day 8 up to day 14 of the experimental period, intraperitoneally. Locomotor, stereotyped behavior, Y-maze, novel recognition object test (NORT), and social interaction were quantified as well as ex vivo analysis of MAO activity, IL-6 levels, and oxidative stress markers (TBARS and total thiol levels) in brain tissues. Ketamine per se reduced the number of bouts of stereotyped behavior on day 8 of the experimental period. Resveratrol per se reduced the locomotor and exploratory activity in the open field, the time of exploration of new objects in the NORT, MAO-A activity in the striatum and increased the IL-6 levels in the cortex. These effects were attenuated when the mice were co-treated with ketamine and resveratrol. There was a decrease in MAO-A activity in the cortex of mice treated with ketamine + resveratrol 100 mg/kg. No significant alterations were found in oxidative stress markers. Resveratrol does not appear to cause summative effects with ketamine on behavioral alterations. However, the effect of resveratrol per se, mainly on locomotor and exploratory activity, should be better investigated. [ABSTRACT FROM AUTHOR]

Introduction: Risk-allele carriers of a Monoamine oxidase A (MAOA) gene, shortallele (MAOA-S) in males and long-allele (MAOA-L) in females, in the presence of a negative environment, are associated with alcohol misuse. Whether MAOA-S/L alleles also present susceptibility to a positive environment to mitigate the risk of alcohol misuse is unknown. Thus, we assessed the association of the three-way interaction of MAOA, maltreatment, and positive parent-child relationship with alcohol consumption among adolescents. Methods: This prospective study included 1416 adolescents (females: 59.88%) aged 16-19 years from Sweden, enrolled in the "Survey of Adolescent Life in Västmanland" in 2012. Adolescents self-reported alcohol consumption, maltreatment by a family (FM) or non-family member (NFM), parent-child relationship, and left saliva for MAOA genotyping. Results and discussion: We observed sex-dependent results. Females carrying MAOA-L with FM or NFM and a good parent-child relationship reported lower alcohol consumption than those with an average or poor parent-child relationship. In males, the interactions were not significant. Results suggest MAOA-L in females, conventionally regarded as a "risk", is a "plasticity" allele as it is differentially susceptible to negative and positive environments. Results highlight the importance of a good parent-child relationship in mitigating the risk of alcohol misuse in maltreated individuals carrying genetic risk. However, the interactions were not significant after adjusting to several environmental and behavioural covariates, especially parent's alcohol use, negative parent-child relationship, and nicotine use (smoking and/or snus), suggesting predictor and outcome intersection. Future studies and frameworks for preventive strategies should consider these covariates together with alcohol consumption. More studies with larger sample sizes are needed to replicate the findings. [ABSTRACT FROM AUTHOR]

Background: Monoamine oxidase B (MAOB), a flavin monoamine oxidase, regulates biogenic and xenobiotic amine oxidative deaminization. We demonstrate MAOB expression in head and neck epithelium and its biological importance in head and neck squamous cell carcinoma (HNSCC) development. Methods: First, we found a possible MAOB downregulation in HNSCC using bioinformatic analysis. Second, we validated MAOB expression changes in vitro and assessed its tumorigenicity in HNSCC. Finally, preclinical xenograft models further confirmed our findings. Results: Results proved that MAOB was significantly reduced in HNSCC tissues and cell lines. By comparing MAOB localization in patient specimens, we found that epithelial basal cells express MAOB and that it changes throughout HNSCC development. We observed that MAOB overexpression inhibited HNSCC cell malignancy via lentiviral transfection. We additionally discovered that selegiline partly counter‐regulated MAOB overexpression‐induced phenotypes in HNSCC cells. Conclusions: We found that MAOB is a potent biomarker and a unique and essential indication of HNSCC carcinogenesis. [ABSTRACT FROM AUTHOR]

Molecular dynamics (MD) simulation is an in silico method used in the biomolecular level of research to study how the protein interacts with the target with time. It provides a detailed information of the protein dynamics and ligand structure with the crucial amino acid interactions. Monoamine oxidase B (MAO−B) is a crucial isoenzyme responsible for the catalyses of oxidative deamination of various biogenic amines in the brain and peripheral tissues. The selective inhibitors of MAO−B are considered as the management of symptoms of neurodegenerative disorders like Alzheimer's disease(AD) and Parkinson disease(PD). Recently the structural scaffolds containing chalcones, coumarins and chromones derived candidates shown potent, selective, competitive and reversible type of MAO−B inhibitors. The structural similarities between the above scaffolds can produce almost similar type of interactions in the inhibitor binding cavity of MAO−B. Numerous molecular simulation reports were supported by the above mentioned fact. The current review focus on the last ten year molecular dynamics report of chalcones, coumarins and chromones towards MAO−B inhibition. The review also focuses on the software details used in the MD dynamics simulation and the structural requirement from each class of compound for the recognition of MAO−B inhibitory activity. [ABSTRACT FROM AUTHOR]

Introduction: A 40-Hz white light emitting diode (WLED) has emerged as an alternative nonpharmacological and noninvasive approach to Alzheimer disease (AD). Here, we investigated the therapeutic effects of 40-Hz WLED on psychiatric symptoms (PS) and the contribution of mitochondrial factors in the early stages of sporadic AD (sAD) in rats. Methods: In male Wistar rats, the AD model was induced via intracerebroventricular (ICV) injection of streptozotocin (STZ). After recovering (7 days) from stereotaxic surgery, 40-Hz WLED exposure was performed for 7 consecutive days lasting 15 min/d. Behavioral (elevated plus maze (EPM), force swim test, and social interaction test), enzymatic, and molecular assays were conducted 24 hours after the last 40-Hz WLED exposure. Results: Behavioral tasks revealed that 40-Hz WLED exposure in STZ-induced toxicity rats lowered anxiety and depression and increased social interaction. Furthermore, the 40-Hz WLED therapy in STZ-induced toxicity rats increased catalase (CAT) activity in the amygdala, decreased the activity of monoamine oxidases A and B in the whole brain, and increased mitochondrial DNA in the hippocampus. Conclusion: The current study supports that 40-Hz WLED therapy improved PS and biomarkers in the early stages of sAD. Also, a potential relationship between PS and alterations in mitochondrial markers in certain brain regions seems to exist. [ABSTRACT FROM AUTHOR]

Numerous physiological processes happening in the human body, including cerebral development and function, require the participation of biometal ions such as iron, copper, and zinc. Their dyshomeostasis may, however, contribute to the onset of Alzheimer's disease (AD) and potentially other neurodegenerative diseases. Chelation of biometal ions is therefore a therapeutic strategy against AD. This review provides a survey of natural and synthetic chelating agents that are or could potentially be used to target the metal hypothesis of AD. Since metal dyshomeostasis is not the only pathological aspect of AD, and the nature of this disorder is very complex and multifactiorial, the most efficient therapeutics should target as many neurotoxic factors as possible. Various coumarin derivatives match this description and apart from being able to chelate metal ions, they exhibit the capacity to inhibit cholinesterases (ChEs) and monoamine oxidase B (MAO-B) while also possessing antioxidant, anti-inflammatory, and numerous other beneficial effects. Compounds based on the coumarin scaffold therefore represent a desirable class of anti-AD therapeutics. [ABSTRACT FROM AUTHOR]

Hyperbaric oxygen (HBO2) breathing induces generalized tonic and clonic seizures through poorly understood mechanisms. The purpose of the research was to evaluate the mechanisms of involvement of monoamine oxidase (MAO) in the development of hyperbaric oxygen seizures. In rats placed in a pressure chamber under an oxygen pressure of 5 ATA, convulsive reactions were analyzed after the administration of pyrazidol, an MAO-A inhibitor, and pargyline, an MAO-B inhibitor. Studies have shown a decrease in the activity of MAO isoforms in HBO2 as well as a delay in the development of seizures in animals with inhibition of MAO-A and MAO-B. The level of GABA in the brain decreased with HBO2, and inhibition of MAO-B with pargyline prevented the decrease in the inhibitory transmitter. The results indicate that MAO isoforms play an important role in regulating epileptogenesis in extreme hyperoxia. Hyperbaric oxygen, inhibiting the catalytic activity of MAO by transforming its molecular structure, leads to disruption of the regulation of the exchange of monoamine neurotransmitters and a decrease in the level of GABA in the brain, which together leads to an imbalance of excitation/inhibition processes in the central nervous system, which is the basis for the development of oxygen epilepsy. [ABSTRACT FROM AUTHOR]

The population of older people has been increasing rapidly worldwide. It was found that the neurons in the brains of the elderly were deteriorating, which has resulted in decreased learning and memory. The prevention of these conditions has therefore received more attention. The objective of this study was to evaluate the effects of germinated black rice extract (GBR) on learning and memory in middle-aged and elderly subjects. Twenty-four subjects aged 45 to 70 were randomized into 2 groups, a control and an experimental group who received placebo versus GBR (1,000 mg/day) for eight weeks. A computerized battery test was performed at weeks 4 and 8. One of the neurotransmitter biomarkers for learning and memory assessment is the inhibition of acetylcholinesterase (AChE) and monoamine oxidase (MAO) in plasma. The results showed that 4 weeks after GBR consumption, the working memory was improved by decreasing the response time, attentional control, and memory speed. Moreover, at week 8, there was a significant improvement in response time (speed of memory) and quality of memory compared to the placebo group. At the end of the study period, the findings revealed that AChE and MAO levels were statistically significantly lower in the intervention group than in the control group. Moreover, no alteration in biochemical parameters of the liver and renal function was observed, which could confirm the safety of this formula. Therefore, GBR could promote learning and memory. The possible mechanism might have occurred primarily via the suppression of AChE and MAO levels. [ABSTRACT FROM AUTHOR]

Retraining retired racehorses for various purposes can help correct behavioral issues. However, ensuring efficiency and preventing accidents present global challenges. Based on the hypothesis that a simple personality assessment could help address these challenges, the present study aimed to identify genetic markers associated with personality. Eight genes were selected from 18 personality-related candidate genes that are orthologs of human personality genes, and their association with personality was verified based on actual behavior. A total of 169 Thoroughbred horses were assessed for their tractability (questionnaire concerning tractability in 14 types of situations and 3 types of impressions) during the training process. Personality factors were extracted from the data using principal component analysis and analyzed for their association with single nucleotide variants as non-synonymous substitutions in the target genes. Three genes, CDH13, SLC6A4, and MAOA, demonstrated significant associations based on simple linear regression, marking the identification of these genes for the first time as contributors to temperament in Thoroughbred horses. All these genes, as well as the previously identified HTR1A, are involved in the serotonin neurotransmitter system, suggesting that the tractability of horses may be correlated with their social personality. Assessing the genotypes of these genes before retraining is expected to prevent problems in the development of a racehorse's second career and shorten the training period through individual customization of training methods, thereby improving racehorse welfare. [ABSTRACT FROM AUTHOR]

STUDY QUESTION Does abnormal serotonin homeostasis contribute to impaired endometrial decidualization in patients with recurrent implantation failure (RIF)? SUMMARY ANSWER Abnormal serotonin homeostasis in patients with RIF, which is accompanied by decreased monoamine oxidase (MAO) expression, affects the decidualization of endometrial stromal cells and leads to embryo implantation failure. WHAT IS KNOWN ALREADY Previous studies have indicated that the expression of MAO, which metabolizes serotonin, is reduced in the endometrium of patients with RIF, and serotonin can induce disruption of implantation in rats. However, whether abnormal serotonin homeostasis leads to impaired decidualization in patients with RIF and, if so, the mechanism involved, remains unclear. STUDY DESIGN, SIZE, DURATION Endometrial samples from 25 patients with RIF and 25 fertile patients were used to investigate the expression levels of monoamine oxidase A (MAOA), monoamine oxidase B (MAOB), and serotonin. We isolated human endometrial stromal cells to investigate the role of MAOA, MAOB, and serotonin in inducing decidualization in vitro and further explored the underlying mechanism using RNA-sequencing (RNA-seq) and liquid chromatography-mass spectrometry (LC/MS) analyses. PARTICIPANTS/MATERIALS, SETTING, METHODS The levels of serotonin in the endometrium of patients with RIF were detected by ELISA and immunohistofluorescence, and the key genes involved in abnormal serotonin metabolism were analyzed via combination with single-cell sequencing data. The effects of MAOA or MAOB on the decidualization of stromal cells were investigated using an in vitro human endometrial stromal cell-induced decidualization model and a mouse artificially induced decidualization model. The potential mechanisms by which MAOA and MAOB regulate decidualization were explored by RNA-seq and LC/MS analysis. MAIN RESULTS AND THE ROLE OF CHANCE We found that women with RIF have abnormal serotonin metabolism in the endometrium and attenuated MAO in endometrial stromal cells. Endometrial decidualization was accompanied by increased MAO in vivo and in vitro. However attenuated MAO caused an increased local serotonin content in the endometrium, impairing stromal cell decidualization. RNA-seq and LC/MS analyses showed that abnormal lipid metabolism, especially phosphatidylcholine metabolism, was involved in the defective decidualization caused by MAO deficiency. Furthermore, decidualization defects were rescued by phosphatidylcholine supplementation. LARGE SCALE DATA RNA-seq information and raw data can be found at NCBI Bioproject number PRJNA892255. LIMITATIONS, REASONS FOR CAUTION This study revealed that impaired serotonin metabolic homeostasis and abnormally reduced MAO expression were among the reasons for RIF. However, the source and other potential functions of serotonin in the endometrium remain to be further explored. WIDER IMPLICATIONS OF THE FINDINGS This study provides new insights into the mechanisms of serotonin homeostasis in human endometrial decidualization and new biomarkers or targets for the treatment of patients with RIF. STUDY FUNDING/COMPETING INTEREST(S) X. Sheng is supported by grants from the National Natural Science Foundation of China (82001629), the Wenzhou Basic Public Welfare Research Project (Y20240030), the Youth Program of Natural Science Foundation of Jiangsu Province (BK20200116), and Jiangsu Province Postdoctoral Research Funding (2021K277B). H.S. is supported by grants from the National Natural Science Foundation of China (82030040). G.Y. is supported by grants from the National Natural Science Foundation of China (82171653). The authors declare no conflicts of interest. [ABSTRACT FROM AUTHOR]

In this study, we collected seven prevalent Taiwanese Desmodium plants, including three species with synonymous characteristics, in order to assess their antioxidant phytoconstituents and radical scavenging capacities. Additionally, we compared their inhibitory activities on monoamine oxidase (MAO) and 6-hydroxydopamine (6-OHDA) auto-oxidation. Subsequently, we evaluated the neuroprotective potential of D. pulchellum on 6-OHDA-induced nerve damage in SH-SY5Y cells and delved into the underlying neuroprotective mechanisms. Among the seven Desmodium species, D. pulchellum exhibited the most robust ABTS radical scavenging capacity and relative reducing power; correspondingly, it had the highest total phenolic and phenylpropanoid contents. Meanwhile, D. motorium showcased the best hydrogen peroxide scavenging capacity and, notably, D. sequax demonstrated remarkable prowess in DPPH radical and superoxide scavenging capacity, along with selective inhibitory activity against MAO-B. Of the aforementioned species, D. pulchellum emerged as the frontrunner in inhibiting 6-OHDA auto-oxidation and conferring neuroprotection against 6-OHDA-induced neuronal damage in the SH-SY5Y cells. Furthermore, D. pulchellum effectively mitigated the increase in intracellular ROS and MDA levels through restoring the activities of the intracellular antioxidant defense system. Therefore, we suggest that D. pulchellum possesses neuroprotective effects against 6-OHDA-induced neurotoxicity due to the radical scavenging capacity of its antioxidant phytoconstituents and its ability to restore intracellular antioxidant activities. [ABSTRACT FROM AUTHOR]

Rasagiline (Azilect®) is a selective monoamine oxidase B (MAO-B) inhibitor that provides symptomatic benefits in Parkinson's disease (PD) treatment and has been found to exert preclinical neuroprotective effects. Here, we investigated the neuroprotective signaling pathways of acute rasagiline treatment for 22 h in PC12 neuronal cultures exposed to oxygen–glucose deprivation (OGD) for 4 h, followed by 18 h of reoxygenation (R), causing 40% aponecrotic cell death. In this study, 3–10 µM rasagiline induced dose-dependent neuroprotection of 20–80%, reduced the production of the neurotoxic reactive oxygen species by 15%, and reduced the nuclear translocation of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) by 75–90%. In addition, 10 µM rasagiline increased protein kinase B (Akt) phosphorylation by 50% and decreased the protein expression of the ischemia-induced α-synuclein protein by 50% in correlation with the neuroprotective effect. Treatment with 1–5 µM rasagiline induced nuclear shuttling of transcription factor Nrf2 by 40–90% and increased the mRNA levels of the antioxidant enzymes heme oxygenase-1, (NAD (P) H- quinone dehydrogenase, and catalase by 1.8–2.0-fold compared to OGD/R insult. These results indicate that rasagiline provides neuroprotection to the ischemic neuronal cultures through the inhibition of α-synuclein and GAPDH-mediated aponecrotic cell death, as well as via mitochondrial protection, by increasing mitochondria-specific antioxidant enzymes through a mechanism involving the Akt/Nrf2 redox-signaling pathway. These findings may be exploited for neuroprotective drug development in PD and stroke therapy. [ABSTRACT FROM AUTHOR]

Background: Computational mining of useful enzymes and biosynthesis pathways is a powerful strategy for metabolic engineering. Through systematic exploration of all conceivable combinations of enzyme reactions, including both known compounds and those inferred from the chemical structures of established reactions, we can uncover previously undiscovered enzymatic processes. The application of the novel alternative pathways enables us to improve microbial bioproduction by bypassing or reinforcing metabolic bottlenecks. Benzylisoquinoline alkaloids (BIAs) are a diverse group of plant-derived compounds with important pharmaceutical properties. BIA biosynthesis has developed into a prime example of metabolic engineering and microbial bioproduction. The early bottleneck of BIA production in Escherichia coli consists of 3,4-dihydroxyphenylacetaldehyde (DHPAA) production and conversion to tetrahydropapaveroline (THP). Previous studies have selected monoamine oxidase (MAO) and DHPAA synthase (DHPAAS) to produce DHPAA from dopamine and oxygen; however, both of these enzymes produce toxic hydrogen peroxide as a byproduct. Results: In the current study, in silico pathway design is applied to relieve the bottleneck of DHPAA production in the synthetic BIA pathway. Specifically, the cytochrome P450 enzyme, tyrosine N-monooxygenase (CYP79), is identified to bypass the established MAO- and DHPAAS-mediated pathways in an alternative arylacetaldoxime route to DHPAA with a peroxide-independent mechanism. The application of this pathway is proposed to result in less formation of toxic byproducts, leading to improved production of reticuline (up to 60 mg/L at the flask scale) when compared with that from the conventional MAO pathway. Conclusions: This study showed improved reticuline production using the bypass pathway predicted by the M-path computational platform. Reticuline production in E. coli exceeded that of the conventional MAO-mediated pathway. The study provides a clear example of the integration of pathway mining and enzyme design in creating artificial metabolic pathways and suggests further potential applications of this strategy in metabolic engineering. [ABSTRACT FROM AUTHOR]

Bee pollen is an apicultural product collected by honeybees from flower stamens and used as a functional food worldwide. In the present study, we aim to elucidate the functions of Australian bee pollen. Australian bee pollen extracts and their main components were tested for catechol- O -methyltransferase (COMT) and monoamine oxidase B (MAOB) inhibitory activities. These enzymes are key neurotransmitters involved in Parkinson's disease and depression. Myricetin (5), tricetin (6), and luteolin (7) exhibited high COMT inhibitory activities (half maximal inhibitory concentration [IC50] = 23.3, 13.8, and 47.4 µM, respectively). In contrast, 5, 7 , and annulatin (8) exhibited MAOB inhibitory activities (IC50 = 89.7, 32.8, and 153 µM, respectively). Quantitative analysis via high-performance liquid chromatography revealed that 5 was abundant in Australian bee pollen extracts. Our findings suggest that 5 contributes to the COMT and MAOB inhibitory activities of Australian bee pollen. [ABSTRACT FROM AUTHOR]

Considering the complex pathogenesis of Alzheimer's disease (AD), the multitarget ligand strategy is expected to provide superior effects for the treatment of the neurological disease compared to the classic single target approach. Thus, a series of 13 novel (5e-q) pyrrole-based Schiff bases were synthesized by conventional and microwave-assisted condensations, and the compounds were evaluated for MAO-A, MAO-B and AChE inhibitory activities. The chemical structures of the newly formed molecules were elucidated by a combination of spectral methods. The obtained results confirmed the theoretical data. The majority of the title Schiff bases demonstrated good potential towards AChE at 10 μM concentrations, with the most promising compound 5m (58%) exerting a comparative effect to that of the applied standard—Donepezil. 5j and 5o selectively inhibited MAO-B by 26% and 21% (at 1 μM concentration), respectively. The compound condensed with 5-nitro-2-furaldehyde (5j) achieved the best dual MAO-B and AChE inhibitory capacities. In addition to the in vitro analysis, docking simulations targeting the active sites of AChE (PDB ID: 4EY6) and MAO-B (PDB: 2V5Z) were employed to explore the possible interactions of the most prominent dual inhibitor (5j) with the enzymes. Furthermore, in silico ADME and PAMPA-blood–brain barrier (BBB) studies were conducted. [ABSTRACT FROM AUTHOR]

At the Institute of Cytology and Genetics (Novosibirsk, Russia) for over 85 generations, gray rats have been selected for high aggression toward humans (aggressive rats) or its complete absence (tame rats). Aggressive rats are an interesting model for studying fear-induced aggression. Benzopentathiepin TC-2153 exerts an antiaggressive effect on aggressive rats and affects the serotonergic system: an important regulator of aggression. The aim of this study was to investigate effects of TC-2153 on key serotonergic-system enzymes – tryptophan hydroxylase 2 (TPH2) and monoamine oxidase A (MAOA) – in the brain of aggressive and tame rats. Either TC-2153 (10 or 20 mg/kg) or vehicle was administered once intraperitoneally to aggressive and tame male rats. TPH2 and MAOA enzymatic activities and mRNA and protein levels were assessed. The selection for high aggression resulted in upregulation of Tph2 mRNA in the midbrain, of the TPH2 protein in the hippocampus, and of proteins TPH2 and MAOA in the hypothalamus, as compared to tame rats. MAO enzymatic activity was higher in the midbrain and hippocampus of aggressive rats while TPH2 activity did not differ between the strains. The single TC-2153 administration decreased TPH2 and MAO activity in the hypothalamus and midbrain, respectively. The drug affected MAOA protein levels in the hypothalamus: upregulated them in aggressive rats and downregulated them in tame ones. Thus, this study shows profound differences in the expression and activity of key serotonergic system enzymes in the brain of rats selectively bred for either highly aggressive behavior toward humans or its absence, and the effects of benzopentathiepin TC-2153 on these enzymes may point to mechanisms of its antiaggressive action. [ABSTRACT FROM AUTHOR]

Chalcones (trans-1,3-diphenyl-2-propen-1-ones) form simple chemical structures that act as precursors for the biogenesis of flavonoids. These are distributed in plants and have two aromatic or heteroaromatic rings connected by a three-carbon α, β-unsaturated carbonyl group. Considering the importance of chalcones as monoamine oxidase and acetylcholinesterase inhibitors, the study was designed as a comprehensive and systematic analysis to evaluate the pharmacological activities leading to the formation of drug molecules against Alzheimer's disease (AD). Based on our previous research, 11 indolyl chalcones (IC1–IC11) were synthesised and investigated for MAO-B inhibitory activity. The inhibitory potential was evaluated based on binding and reversibility studies using purified enzymes. The active and most promising molecule, (2E)-3-(4-bromophenyl)-1-(1H-indol-3-yl) prop-2-en-1-one (IC9), also found predominant acetylcholinesterase inhibition and hence it was found dual acting in vitro. Based on this, the molecule IC9 was further subjected to cell line studies to further explore its role as a neuroprotective agent against neuronal degeneration, one of the main contributing parameters related to AD. [ABSTRACT FROM AUTHOR]

The Mediterranean diet well known for its beneficial health effects, including mood enhancement, is characterised by the relatively high consumption of extra virgin olive oil (EVOO), which is rich in bioactive phenolic compounds. Over 200 phenolic compounds have been associated with Olea europaea, and of these, only a relatively small fraction have been characterised. Utilising the OliveNetTM library, phenolic compounds were investigated as potential inhibitors of the epigenetic modifier lysine-specific demethylase 1 (LSD1). Furthermore, the compounds were screened for inhibition of the structurally similar monoamine oxidases (MAOs) which are directly implicated in the pathophysiology of depression. Molecular docking highlighted that olive phenolics interact with the active site of LSD1 and MAOs. Protein–peptide docking was also performed to evaluate the interaction of the histone H3 peptide with LSD1, in the presence of ligands bound to the substrate-binding cavity. To validate the in silico studies, the inhibitory activity of phenolic compounds was compared to the clinically approved inhibitor tranylcypromine. Our findings indicate that olive phenolics inhibit LSD1 and the MAOs in vitro. Using a cell culture model system with corticosteroid-stimulated human BJ fibroblast cells, the results demonstrate the attenuation of dexamethasone- and hydrocortisone-induced MAO activity by phenolic compounds. The findings were further corroborated using human embryonic stem cell (hESC)-derived neurons stimulated with all-trans retinoic acid. Overall, the results indicate the inhibition of flavin adenine dinucleotide (FAD)-dependent amine oxidases by olive phenolics. More generally, our findings further support at least a partial mechanism accounting for the antidepressant effects associated with EVOO and the Mediterranean diet. [ABSTRACT FROM AUTHOR]

Monoamine oxidases (MAOs) are mitochondrial enzymes that catalyse the oxidative deamination of monoamine neurotransmitters and various xenobiotic amines in the central nervous system and peripheral tissues. They are of two types, MAO-A and MAO-B, which are different in terms of their substrates and tissue distributions. MAO-A oxidizes epinephrine, serotonin and norepinephrine, while MAO-B catalyzes the deamination of phenylethylamine and benzylamine. MAO-A inhibitors are used in the treatment of depression, while MAO-B inhibitors are used in the treatment of neurodegenerative diseases such as Parkinson's and Alzheimer diseases. MAO inhibitors are listed as the second choice in the treatment of major depression after selective serotonin reuptake inhibitors (SSRI) or tricyclic antidepressants. Various heterocyclic compounds with two or four nitrogen atoms have been used in the synthesis of selective and reversible MAO inhibitors for many years. In this study, the inhibitory effects of 2-(3-(4-methoxyphenyl)-5-aryl-4,5-dihydropyrazol-1-yl)benzo[d]thiazole compounds, having a 2-pyrazoline skeleton, on the MAO isoenzymes were investigated. Among the tested derivatives, compound 12 achieved IC50 values of 0.041 ± 0.001 mM. The nature of inhibition was also determined to be non-competitive based on the Lineweaver–Burk plot. Molecular docking studies were also performed for compound 12, which is the most potent agent in the MAO-Aand MAO-B catalytic sites. The evaluation and explanation of the biological results at the atomic level with the positive compounds selected for each target are provided. Studies can be developed based on compound 12 as a candidate lead compound for further research as a non-competitive MAO-A and MAO-B inhibitor. [ABSTRACT FROM AUTHOR]