Monoamine Oxidase Inhibitors Research Articles

Parkinson's Disease: A Progressive Neurodegenerative Disorder and Structure-Activity Relationship of MAO Inhibitor Scaffolds as an Important Therapeutic Regimen.

Parkinson's disease is considered an advancing neurodegenerative disorder with unknown causes, and its association with some risk factors, including aging, family history, and exposure to chemicals, makes it the second most common occurring neurodegenerative disorder throughout the world with increasing prevalence. Parkinson's disease is associated with slow movement, rigidity, tremors, imbalance, depression, anxiety, cognitive impairment, orthostasis, hyperhidrosis, sleep disorders, pain, and sensory disturbances. In recent decades, there has been a rise in research on the development of effective and potential therapies for the treatment of Parkinson's disease. An important target for neuroprotection is Monoamine Oxidases (MAO), which hydrolyze neurotransmitters like dopamine and produce very reactive free radicals as a by-product. Aging and neurodegenerative illnesses cause overexpression in the brain, which exacerbates neuronal loss. The treatment of Parkinson's disease with MAO inhibitors has shown promising outcomes. Herein, we reported characteristic features of Parkinson's disease, various treatment strategies, and the SAR of potential drugs that can be explored further as lead for the development of newer molecules with improved pharmacological profiles.

Design, Synthesis, Molecular Docking, Pharmacokinetic Properties, and Molecular Dynamics Simulation of Sulfonyl Derivatives of Benzimidazole against Parkinson's Disease.

The disability and mortality related to Parkinson's disease (PD), a neurodegenerative disease, are increasing globally at a faster rate than other neurological disorders. With no permanent cure for PD, there is an urgent need to develop novel and effective anti-PD drugs. Targeting monoamine oxidases (MAO), which catalyze the breakdown of neurotransmitters, is one way to treat neurodegenerative diseases. In this context, an initial molecular docking of twenty designed sulfonyl derivatives of benzimidazole against monoamine oxidase B (MAO-B) associated with PD was conducted using AutoDock Vina. The results were compared with those of the conventional inhibitors, selegiline and rasagiline. Based on the docking score, the in-silico pharmacokinetic properties (ADME), drug-likeness, and toxicity profiles of the newly synthesized molecules were examined using SwissADME, PreADMET, ProTox-3.0, vNN, and ADMETlab web tools. Then, twelve potential derivatives were synthesized and characterized by IR, 1H-NMR, 13C-NMR, 19F-NMR (for some compounds), and mass spectrometry. Derivatives 2cj and 1bj were the two molecules having the best binding affinity of -11.9 and -11.8 kcal/mol, respectively, against MAOB, exhibiting a higher binding affinity compared to that of some commercially available drugs. A 50 ns MD simulation run was performed to observe the stability of the top two docked complexes, MAO-B-2cj and MAO-B-1bj, in order to further validate the efficacy of those two substances. Moreover, the MM-PBSA method was used to calculate the final, binding free energy of the simulated (MAO-B-2cj) complex. This study indicates that the binding affinity of most of the hits was superior to that of known MAO inhibitors; therefore, these newly synthesized benzimidazole derivatives may be developed into essential drug candidates for the treatment of PD.

Target Fisher: a Consensus Structure-Based Target Prediction Tool, and its Application in the Discovery of Selective MAO-B Inhibitors.

In this work we introduce Target Fisher, a consensus structure-based target prediction tool that integrates molecular docking and machine learning with the aim to aid in the identification of potential biological targets and the optimization of the use of bioassays. Target Fisher uses per-residue energy decomposition profiles extracted from docking poses as fingerprints to train target-specific machine learning models. It provides predictions for a curated set of 37 protein targets, covering a diverse range of biological entities, and offers a user-friendly interface accessible via a web server (https://gqc.quimica.unlp.edu.ar/targetfisher/). In this sense, Target Fisher is a valuable tool to aid organic and medicinal chemistry groups in target identification, drug discovery and drug repurposing. As a case study, we demonstrate the efficacy of Target Fisher by screening a small library of assorted natural products for targets relevant to neurodegenerative diseases, which resulted in the identification and experimental validation of selective inhibitors of monoamine oxidase B (MAO-B).

Comments on "Expert Opinion on Anesthetic Considerations For Patients Receiving a Classic Monoamine Oxidase Inhibitor".

Comments on "Expert Opinion on Anesthetic Considerations For Patients Receiving a Classic Monoamine Oxidase Inhibitor".

Chemical Composition and Biological Activity of Hypericum Species-H. hirsutum, H. barbatum, H. rochelii.

St. John's wort (Hypericum perforatum, Hypericaceae) is the most well-known species in the genus Hypericum, which comprises several hundred species. This study investigates the biological and phytochemical potential of the under-researched Hypericum species, H. hirsutum, H. barbatum, and H. rochelii. A high level of similarity between the chemical profiles of H. hirsutum and H. barbatum and the official source of the herbal drug (H. perforatum) was shown, but a higher content of quercetin and rutin was also found in all three evaluated species (116-230 µg/g dry herb). The highest amount of phenolics (195 mg GAE/g) was recorded in H. hirsutum extract, while the highest amount of flavonoids (47 mg QE/g) was recorded in H. barbatum extract. The evaluated species were excellent scavengers of DPPH, OH, and NO radicals, as well as strong ferric ion reducers in the FRAP test. Prominent monoamine oxidase A and α-glucosidase inhibition was observed, compared to modest inhibition of monoamine oxidase B, α-amylase, and acetylcholinesterase. High activity against Gram-positive MRSA S. aureus was demonstrated for the tested species, with MIC/MBC values recorded at 12.5 µg/mL. Antifungal activity against Candida strains was not observed. The obtained results emphasize the need for further investigation of species of the genus Hypericum to discover potentially new sources of biologically active compounds.

Perception of the Capixaba population regarding the use and benefits of antidepressants and anxiolytics

Depression is a routine disorder characterized by at least two weeks of loss of pleasure, mood, and interest in basic daily activities. Treatment involves psychotherapy, lifestyle changes, and medication therapy with antidepressants. These medications increase the availability of neurotransmitters in the central nervous system through different mechanisms of action, such as Monoamine Oxidase Inhibitors, Tricyclic Antidepressants, Selective Serotonin Reuptake Inhibitors, and Atypicals. Studies indicate that, after the pandemic, mental health issues such as anxiety and depression became more frequent in society, leading to greater use of antidepressants, especially clonazepam, sertraline, and amitriptyline. This project aims to investigate this usage, focusing on the benefits and drawbacks from the user’s perspective. To this end, it was submitted to the Ethics and Human Research Council of UNESC, with a bibliographic review conducted in the PubMed, Lilacs, and Scielo databases during the approval period. After approval, the research was conducted through structured questionnaires, made available online to the Capixaba society. The study evaluated the rate of use of these psychotropic drugs in the region, the benefits, risks, and behaviors regarding the use of antidepressants and anxiolytics from the perspective of patients. The use of psychotropic drugs by the population can be satisfactory for treating mental disorders, but it is essential that these medications are used with caution and under the guidance of a healthcare professional. Regular monitoring helps to manage adverse effects, ensure the medication is working properly, and prevent long-term medication-related problems.

Tilianin obtained from Agastache mexicana inhibits monoamine oxidase and modifies depressive behavior in rats.

Agastache mexicana is used in traditional medicine to treat anxiety, insomnia, pain, among others. In a previous study, the methanolic extract exerted anxiolytic and sedative effects, as observed behaviorally, associated with one of its major components, tilianin. To assess the effect produced by the extracts and tilianin obtained from Agastache mexicana on depressive-induced behavior model and on the activity of monoamine oxidases (MAOs). The depression experimental model consisted of the forced swimming test in rats. MAOs activity was evaluated in cortex and hippocampus from the tilianin and Agastache extracts treated rats using specific inhibitors for each isoform. The quantification of monoamines was carried out using an High Performance Liquid Chromatography method. An increase in the swimming time was observed in rodents treated with doses of 16 (226.6±5.5 seconds) and 50mg/kg (237.8±5.7 seconds) of tilianin, methanolic (260.4±3 seconds), and hydroalcoholic extracts (249.6±2.6 seconds) at 100mg/kg. MAOs activity was significantly decreased in brain tissue from animals treated with 16 and 50mg/kg of tilianin, methanolic, and hydroalcoholic extracts at 100mg/kg. The tilianin effect on monoamine oxidases inhibition is confirmed, suggesting its potential use in the treatment of certain neurological disorders.

Molecular Mechanism and Structure-activity Relationship of the Inhibition Effect between Monoamine Oxidase and Selegiline Analogues.

To investigate the inhibition properties and structure-activity relationship between monoamine oxidase (MAO) and selected monoamine oxidase inhibitors (MAOIs, including selegiline, rasagiline and clorgiline). The inhibition effect and molecular mechanism between MAO and MAOIs were identified via the half maximal inhibitory concentration (IC50) and molecular docking technology. It was indicated that selegiline and rasagiline were MAO B inhibitors, but clorgiline was MAO-A inhibitor based on the selectivity index (SI) of MAOIs (0.000264, 0.0197 and 14607.143 for selegiline, rasagiline and clorgiline, respectively). The high-frequency amino acid residues of the MAOIs and MAO were Ser24, Arg51, Tyr69 and Tyr407 for MAO-A and Arg42 and Tyr435 for MAO B. The MAOIs and MAO A/B pharmacophores included the aromatic core, hydrogen bond acceptor, hydrogen bond donor-acceptor and hydrophobic core. This study shows the inhibition effect and molecular mechanism between MAO and MAOIs and provides valuable findings on the design and treatment of Alzheimer's and Parkinson's diseases.

Harnessing Pharmacogenomics in Clinical Research on Psychedelic-Assisted Therapy.

Psychedelics have recently re-emerged as potential treatments for various psychiatric conditions that impose major public health costs and for which current treatment options have limited efficacy. At the same time, personalized medicine is increasingly being implemented in psychiatry to provide individualized drug dosing recommendations based on genetics. This review brings together these topics to explore the utility of pharmacogenomics (a key component of personalized medicine) in psychedelic-assisted therapies. We summarized the literature and explored the potential implications of genetic variability on the pharmacodynamics and pharmacokinetics of psychedelic drugs including lysergic acid diethylamide (LSD), psilocybin, N,N-dimethyltryptamine (DMT), 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT), ibogaine and 3,4-methylenedioxymethamphetamine (MDMA). Although existing evidence is limited, particularly concerning pharmacodynamics, studies investigating pharmacokinetics indicate that genetic variants in drug-metabolizing enzymes, such as cytochrome P450, impact the intensity of acute psychedelic effects for LSD and ibogaine, and that a dose reduction for CYP2D6 poor metabolizers may be appropriate. Furthermore, based on the preclinical evidence, it can be hypothesized that CYP2D6 metabolizer status might contribute to altered acute psychedelic experiences with 5-MeO-DMT and psilocybin when combined with monoamine oxidase inhibitors. In conclusion, considering early evidence that genetic factors can influence the effects of certain psychedelics, we suggest that pharmacogenomic testing should be further investigated in clinical research. This is necessary to evaluate its utility in improving the safety and therapeutic profile of psychedelic therapies and a potential future role in personalizing psychedelic-assisted therapies, should these treatments become available.

Prominent Neuroprotective Potential of Indole-2-N-methylpropargylamine: High Affinity and Irreversible Inhibition Efficiency towards Monoamine Oxidase B Revealed by Computational Scaffold Analysis

Background: Monoamine oxidases (MAO) are flavoenzymes that metabolize a range of brain neurotransmitters, whose dysregulation is closely associated with the development of various neurological disorders. This is why MAOs have been the central target in pharmacological interventions for neurodegeneration for more than 60 years. Still, existing drugs only address symptoms and not the cause of the disease, which underlines the need to develop more efficient inhibitors without adverse effects. Methods: Our drug design strategy relied on docking 25 organic scaffolds to MAO-B, which were extracted from the ChEMBL20 database with the highest cumulative counts of unique member compounds and bioactivity assays. The most promising candidates were substituted with the inactivating propargylamine group, while further affinity adjustment was made by its N-methylation. A total of 46 propargylamines were submitted to the docking and molecular dynamics simulations, while the best binders underwent mechanistic DFT analysis that confirmed the hydride abstraction mechanism of the covalent inhibition reaction. Results: We identified indole-2-propargylamine 4fH and indole-2-N-methylpropargylamine 4fMe as superior MAO-B binders over the clinical drugs rasagiline and selegiline. DFT calculations highlighted 4fMe as more potent over selegiline, evident in a reduced kinetic requirement (ΔΔG‡ = −2.5 kcal mol−1) and an improved reaction exergonicity (ΔΔGR = −4.3 kcal mol−1), together with its higher binding affinity, consistently determined by docking (ΔΔGBIND = −0.1 kcal mol−1) and MM-PBSA analysis (ΔΔGBIND = −1.5 kcal mol−1). Conclusions: Our findings strongly advocate 4fMe as an excellent drug candidate, whose synthesis and biological evaluation are highly recommended. Also, our results reveal the structural determinants that influenced the affinity and inhibition rates that should cooperate when designing further MAO inhibitors, which are of utmost significance and urgency with the increasing prevalence of brain diseases.

Drug-Drug Interactions of Selective Serotonin Reuptake Inhibitors: A Pharmacovigilance Study on Real-World Evidence from the EudraVigilance Database.

As the most common psychiatric symptom, depression represents a subject of high interest for the medical community. Background/Objectives: International guidelines consider selective serotonin reuptake inhibitors (SSRIs) the first-line treatment of depression. Although having better efficacy and tolerability in comparison to tricyclic antidepressants or monoamine oxidase inhibitors, the diversity and potential severity of adverse effects and interactions manifested by SSRIs, combined with the frequency of prescriptions, lead to the necessity of evaluating real-world data. The aim of this study was to identify and evaluate the drug interactions reported in EudraVigilance (EV) for the six SSRIs representatives that are authorized in Europe: fluoxetine (FXT), fluvoxamine (FVM), citalopram (CIT), escitalopram (ESC), paroxetine (PAR) and sertraline (SER). The entire class of SSRIs was examined as a comparator to identify whether one of the representatives was more prone to reporting. Methods: Descriptive analysis and disproportionality analysis were conducted on data extracted from the EV database. Results: A total of 326,450 adverse reactions (ADRs) were reported for the SSRIs group. Approximately a quarter of these (n = 83,201; 25.46%) were reported for SER and 22.37% (n = 73,131) for PAR. Of the total ADRs reported, 2.12% (n = 6925) represent preferred terms related to drug-drug interactions (DDIs): SER (n = 1474; 22.37%), CIT (n = 1272, 19.86), and FXT (n = 1309, 19.83%). Specific ADRs related to inhibitory activity represent 0.98%, and for potentiating activity, 1.89%. Conclusions: Although representing a small value of the total ADRs, DDIs may be related to severe outcomes. Awareness should be raised for this category of ADRs that can be reduced by the joined efforts of physicians and pharmacists.

Monoamine Oxidase Contributes to Valvular Oxidative Stress: A Prospective Observational Pilot Study in Patients with Severe Mitral Regurgitation.

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.

Functional efficacy of the MAO-B inhibitor safinamide in murine substantia nigra pars compacta dopaminergic neurons in vitro: A comparative study with tranylcypromine

Safinamide (SAF) is currently used to treat Parkinson's disease (PD) symptoms based on its theoretical ability to potentiate the dopamine (DA) signal, blocking monoamine oxidase (MAO) B. The present work aims to highlight the functional relevance of SAF as an enhancer of the DA signal, by evaluating its ability to prolong recovery from DA-mediated firing inhibition of DAergic neurons of the substantia nigra pars compacta (SNpc), compared to another MAO antagonist, tranylcypromine (TCP). Using multielectrode array (MEA) and single electrode extracellular recordings of spontaneous spikes from presumed SNpc DAergic cells in vitro, we show that SAF (30 μM) mildly prolongs the DA-mediated firing inhibition, as opposed to the profound effect of TCP (10 μM). In patch-clamp recordings, we found that SAF (30 μM) significantly reduced the number of spikes evoked by depolarizing currents in SNpc DAergic neurons, in a sulpiride (1 μM) independent manner. According to our results, SAF marginally potentiates the DA signal in SNpc DAergic neurons, while exerting an inhibitory effect on the postsynaptic excitability acting on membrane conductances. Thus, we propose that the therapeutic effects of SAF in PD patients partially depends on MAO inhibition, while other MAO-independent sites of action could be more relevant.

Microdialysis perfusion of COA-Cl enhances dopamine metabolism in the dorsal striatum of freely moving mice.

We performed a microdialysis study to examine the effects of local perfusion of COA‑Cl on the extracellular levels of dopamine (DA) and its metabolites in the dorsal striatum of mice in vivo. The mice were perfused with Ringer's solution (control) and COA‑Cl (0.05, 0.1, or 0.5 mM) into the dorsal striatum. Dialysate samples were collected every 30 min and then analyzed using high‑performance liquid chromatography coupled with an electrochemical detector. We found that local perfusion of COA‑Cl (0.1 or 0.5 mM) into the dorsal striatum of living mice produced a significant and dose‑dependent increase in extracellular levels of DA, 3‑methoxytyramine (3‑MT), and homovanillic acid (HVA), where only 0.5 mM COA‑Cl increased dihydroxyphenylacetic acid (DOPAC) levels. However, 0.05 mM of COA‑Cl did not significantly affect either DA levels or its metabolites. Then, we administered the monoamine oxidase (MAO) inhibitor clorgyline alone or in combination with COA‑Cl (0.1 mM) to test whether COA‑Cl‑induced increases in DOPAC and HVA are mediated by increased MAO activity. Clorgyline alone increased 3‑MT levels and decreased DOPAC and HVA levels but not DA levels. When combined with COA‑Cl, clorgyline increased 3‑MT levels and reversed the decrease in DOPAC and HVA levels caused by clorgyline. The increase in DA metabolism induced by COA‑Cl suggests that some DA was further metabolized into DOPAC, 3‑MT, and HVA. This indicates that COA‑Cl plays a role in DA metabolism via increased DA release and/or activation of MAO, offering new insights into the effects of COA‑Cl on DA metabolism in the brain.

Design, synthesis and evaluation of sesamol-derived acetamides as dual inhibitors of monoamine oxidases and cholinesterases

Design, synthesis and evaluation of sesamol-derived acetamides as dual inhibitors of monoamine oxidases and cholinesterases

Exploring the correlation between cardiovascular adverse events and antidepressant use: A retrospective pharmacovigilance analysis based on the FDA Adverse Event Reporting System database

BackgroundThe high comorbidity and mutually reinforcing relation between depression and cardiovascular disease have raised concerns about the cardiovascular risk of antidepressants. To gain a better understanding of this correlation, we performed a comprehensive evaluation regarding the types and degrees of cardiovascular adverse events (AEs) associated with 37 commonly prescribed antidepressants. MethodsAE reports from January 2004 to December 2023 were retrieved from the FDA Adverse Event Reporting System (FAERS) database. Disproportionality analysis was performed to identify antidepressant-related cardiovascular signals using the reporting odds ratio, proportional reporting ratio, and information component. Influencing factors of cardiovascular death, including age, sex, antidepressant choice, and concomitant medication, were explored. The underlying mechanisms of antidepressant-associated cardiovascular risk related to neurotransmitter transporters/receptors were further explored. ResultsThe use of antidepressants was associated with eight categories of Standardized MedDRA Queries of cardiovascular events. Different antidepressants exerted varying types and degrees of cardiovascular risks along with contributions to death in reports with cardiovascular AEs. Among them, monoamine oxidase inhibitors had the highest risk of developing six cardiovascular event categories: torsades de pointes (TdP)/QT prolongation, hypertension, cardiac arrhythmias, cardiomyopathy, pulmonary hypertension, and ischaemic heart disease. Age, male and the use of 24 types of antidepressants and concomitant medications were positively correlated with death in cardiovascular AEs. The highest risk associated with antidepressants was found in amoxapine (OR = 5.00 [2.13, 11.75], P < 0.001), followed by moclobemide (OR = 3.66 [1.85, 7.24], P < 0.001). Correlation analysis indicated the occurrence of antidepressant-related TdP/QT prolongation, hypertension and cardiomyopathy was associated with the binding and uptake inhibition of dopamine and norepinephrine transporters as well as their selectivity over serotonin transporters. ConclusionThe retrospective analysis revealed that cardiovascular AEs were connected with antidepressant use, and the binding/uptake inhibitory potency and selectivity of neurotransmitters of antidepressants played an important role, providing a preliminary basis for further in-depth study of antidepressant-related cardiovascular toxicity. However, as an exploratory study, prospective studies are needed to validate our findings in the future.

Exploring the Antidepressant-like Effects of Wogonin: Analysis of Behavioural, Neurochemical, and Biochemical Parameters

Background: Wogonin, a bioactive compound isolated from S. barbata D. Don, has been identified in the literature as a potential inhibitor of monoamine oxidase (MAO), a key enzyme involved in the degradation of neurotransmitters associated with mood regulation. This study aims to investigate the antidepressant-like activity of wogonin in vivo, utilizing a preclinical model. The rationale for selecting wogonin stems from its documented MAO inhibitory properties, suggesting a potential role in modulating neurotransmitter levels implicated in depressive disorder. Method: The study employs a multifaceted approach, incorporating behavioural, neurochemical, and biochemical assessments. The Chronic Unpredictable Mild Stress model is utilized to induce depression-like behavior in rodents for 21 days. Two doses of wogonin (20 and 40 mg/kg per orally) and standard (fluoxetine, 20 mg/kg, and imipramine, 15 mg/kg) were administered to albino mice. Behavioural paradigms, including the Tail Suspension Test, Forced Swim Test, and Open Field Test, are employed to assess the impact of wogonin on depressive-like symptoms on the 21st day. Neurochemical analyses focus on alterations in 5-HT, NE, and DA levels within relevant brain regions, and MAO activity is quantified to ascertain wogonin's potential as an MAO inhibitor on the 22nd day. Biochemical assessments emphasize wogonin's antioxidant properties and its ability to mitigate oxidative stress, a significant factor in depression pathophysiology. Plasma nitrite levels are measured to elucidate wogonin's impact on nitric oxide signalling. Plasma corticosteroid levels are also quantified to delineate wogonin's effect on the hypothalamicpituitary- adrenal (HPA) axis, a central regulator of stress response. Results: Wogonin demonstrates significant antidepressant effects in a dose-dependent manner in the behavioural assessments, showing a marked reduction in depressive-like behaviours across all paradigms. Neurochemical analyses revealed a significant (p ≤ 0.05) restoration of monoamine neurotransmitter levels in the relevant brain regions as compared to CUMS-induced stress group. Additionally, wogonin exhibits a potent (p ≤ 0.05) inhibitory effect on MAO activity. Biochemical assessments demonstrate a significant (p ≤ 0.05) increase in antioxidant capacity and a reduction in oxidative stress markers. Plasma nitrite levels indicate an enhancement of nitric oxide signalling. Corticosteroid levels showed a modulation of the HPA axis, suggesting a regulatory effect on stress response. Conclusion: This comprehensive study establishes wogonin as a promising MAO inhibitor with notable antidepressant potential. The findings provide crucial insights into its mechanisms of action, indicating a multifaceted approach to alleviating depression. Wogonin's demonstrated efficacy across behavioural, neurochemical, and biochemical parameters presents a strong foundation for further research and development of wogonin-based antidepressant interventions.

Mild/moderate phenotypes in AADC deficiency: Focus on the aromatic amino acid decarboxylase protein.

AADC deficiency is a severe neurometabolic inherited rare disorder due to the absence or decrease of dopamine and serotonin levels, causing deep motor and neurodevelopmental impairments. The disease is often fatal in the first decade of life, and pharmacological treatments (dopamine agonists, pyridoxine, and monoamine oxidase inhibitors as the first-line choices) can only alleviate the symptoms. Gene therapy surgery is now available for severe patients in the European Union and the United Kingdom, and follow-up data witness encouraging improvements. In the past few years, mostly due to the increased awareness and knowledge of AADC deficiency, together with newborn screening programs and advancements in methods for genetic diagnosis, the number of mild/moderate phenotypes of AADC deficiency patients has increased to 12% of the total. A review of the genotypes (homozygous/compound heterozygous) of AADC deficiency mild/moderate patients is presented here. The pathogenicity classification of each genetic variant is discussed. Then, we focused on the type of AADC protein possessed by patients and on the predictable structural score of the homodimeric/heterodimeric species of each protein variant. Since the terminology used for genetic and protein variants is the same, we highlighted how it could be misleading. We analyzed the loss-of-function as a fold-change decrease of activity of the recombinant purified AADC enzyme(s) theoretically synthesized by mild/moderate patients. A minimal residual kcat of 8% and/or kcat/Km of 1% seems necessary to avoid a severe disease manifestation. Overall, this cluster of mild/moderate patients needs consideration for a more appropriate and aimed therapeutic approach.

Adsorption of Nefazodone on single-wall carbon nanotube as an antidepressant drug delivery: A DFT study

Nefazodone, a derivative of triazolones, belongs to a group of heterocyclic aromatic compounds. It is used as an antidepressant for treating depression, including major depressive disorder. Unlike other antidepressant groups such as selective serotonin reuptake inhibitors, tricyclic antidepressants, or monoamine oxidase inhibitors, Nefazodone does not share chemical similarities. Recent research has focused on studying the reactivity and chemical structure influenced by Nefazodone's medicinal features in the drug's adsorption process on single-wall Carbon Nanotube (CNT) as an adsorbent in the gas phase using density functional theory (DFT), Becke, 3-parameter, Lee–Yang–Parr (B3LYP) 6-311+G(d,p) basis set (DFT/B3LYP/6-311+G(d,p)). The effect of electronegative atoms and phenyl groups on the adsorption of Nefazodone on CNT has been studied by calculating the adsorption energy for all active sites. On the other hand, thermodynamic values, such as Gibbs free energy (−4873.09 kJ), Enthalpy (−4872.83 kJ), and Entropy (903.09 J/mol.kelvin), as well as thermodynamic capacity (497.45 J/mol.kelvin), were calculated to show the reactivity of Nefazodone. The stability and reactivity were examined through the energies of the highest occupied molecular orbital (HOMO) (−5.53 eV) and lowest unoccupied molecular orbital (LUMO) (−0.58 eV) of Nefazodone, highlighting ten regions with chemical activity, all of which are thermodynamically stable. Some Electronic parameters such as chemical potential (µ), electronegativity (χ), softness (σ), hardness (η), and electrophilicity index (ω) were calculated. The comparison of chemical potential values between Nefazodone(−3.05 eV) and the more stable complex (−3.81 eV) illustrates the more reactivity for the complex. This suggests that Nefazodone can be transferred to biological systems through such an adsorption mechanism.

Monoamine oxidase and neurodegeneration: Mechanisms, inhibitors and natural compounds for therapeutic intervention

Mammalian flavoenzyme Monoamine oxidase (MAO) resides on the outer mitochondrial membrane (OMM) and it is involved in the metabolism of different monoamine neurotransmitters in brain. During MAO mediated oxidative deamination of relevant substrates, H2O2 is released as a catalytic by-product, thus serving as a major source of reactive oxygen species (ROS). Under normal conditions, MAO mediated ROS is reported to propel the functioning of mitochondrial electron transport chain and phasic dopamine release. However, due to its localization onto mitochondria, sudden elevation in its enzymatic activity could directly impact the form and function of the organelle. For instance, in the case of Parkinson's disease (PD) patients who are on l-dopa therapy, the enzyme could be a concurrent source of extensive ROS production in the presence of uncontrolled substrate (dopamine) availability, thus further impacting the health of surviving neurons. It is worth mentioning that the expression of the enzyme in different brain compartments increases with age. Moreover, the involvement of MAO in the progression of neurological disorders such as PD, Alzheimer's disease and depression has been extensively studied in recent times. Although the usage of available synthetic MAO inhibitors has been instrumental in managing these conditions, the associated complications have raised significant concerns lately. Natural products have served as a major source of lead molecules in modern-day drug discovery; however, there is still no FDA-approved MAO inhibitor which is derived from natural sources. In this review, we have provided a comprehensive overview of MAO and how the enzyme system is involved in the pathogenesis of different age-associated neuropathologic conditions. We further discussed the applications and drawbacks of the long-term usage of presently available synthetic MAO inhibitors. Additionally, we have highlighted the prospect and worth of natural product derived molecules in addressing MAO associated complications.