Monoamine Oxidase Inhibitors Research Articles

Differential modulation of amyloid‐beta levels by psychotropic medications in an in vitro model of Alzheimer’s disease

AbstractBackgroundPreclinical studies suggest that psychotropic drugs (e.g. antidepressants, benzodiazepines) can affect amyloid‐β (Aβ) levels, yet mechanisms remain unclear. We aimed to determine the effects of common psychiatric drugs on Aβ generation and clearance in an in vitro model of Alzheimer’s disease (AD).MethodThe effects of a range of psychotropic drugs on Aβ generation and clearance were assessed in N2a/APP695swe cells, a neuroblastoma cell line overexpressing APP with the Swedish mutation. Cells were incubated for 24h with either fluoxetine (selective serotonin reuptake inhibitor (SSRI); 1‐10μM), venlafaxine (serotonin‐norepinephrine reuptake inhibitor (SNRI); 0.1‐10μM), mirtazapine (α2‐adrenergic antagonist; 1‐25μM), phenelzine (monoamine oxidase inhibitor (MAOI); 10‐50μM) or nordiazepam (benzodiazepine (BNZ); 1‐25μM). Aβ42 levels were quantified in conditioned media using an enzyme‐linked immunosorbent assay (ELISA). Amyloid precursor protein (APP) processing was studied using western blots (WBs), including expression of different secretases, full‐length APP, C‐terminal fragments (CTFs) in membrane preps and APP soluble‐α in media. Neprilysin and insulin degrading enzyme (IDE) expression was quantified as major Aβ clearance factors.ResultsCertain drugs increased Aβ levels; in particular, Venlafaxine (SNRI) and nordiazepam (BNZ) elevated Aβ42 at 10 µM, due to increased amyloidogenic APP cleavage. Conversely, the anti‐depressant drug fluoxetine (SSRI; 10 µM) reduced Aβ42, concomitant with reduced β‐secretase (BACE1) and presenilin‐2 expressions. Mirtazapine (α2‐adrenergic antagonist) and phenelzine (MAOI), on the other hand, did not modulate Aβ levels.ConclusionCertain psychotropic medications, i.e. nordiazepam (BNZ) and venlafaxine (SNRI) can increase Aβ levels, while fluoxetine (SSRI) can reduce them. This results from the effects of these drugs on Aβ generation rather than clearance. This is important, as the administration of these drugs could affect AD‐risk.

Ishige foliacea ameliorates depressive-like behaviors in stress hormone treated mice

Chronic stress is an important factor to several physical and mental diseases. Ishige foliacea, an edible brown seaweed, has various biological properties; however, its role in alleviating stress-induced depression remains unclear. Thus, the antidepressant-like effects of I. foliacea ethanolic extract (IE) were investigated using corticosterone (CORT)-treated HT22 cells and CORT-induced depressive mice. IE significantly reduced the production of reactive oxygen species (ROS) and inhibited monoamine oxidase (MAO) activity and protein expression; furthermore, it up-regulated the extracellular signal-regulated kinase (ERK)-cAMP response element-binding protein (CREB)-brain derived neurotrophic factor (BDNF) signaling pathway. In the CORT-induced depressive mice, IE administration (500 mg/kg, bodyweight) exerted antidepressant effects according to behavioral tests. In addition, IE activated the ERK-CREB-BDNF signaling pathway owing to CORT exposure in the hippocampus. Therefore, IE inhibited ROS production and MAO activity and improved depressive behaviors caused by stress hormones, which demonstrates the therapeutic potential of IE in the treatment of depression.

Should residents be taught how to prescribe monoamine oxidase inhibitors?

Should residents be taught how to prescribe monoamine oxidase inhibitors?

Monoamine oxidase inhibitors attenuate the vascular hyperglycemic memory in diabetic mice

Monoamine oxidase inhibitors attenuate the vascular hyperglycemic memory in diabetic mice

Monoamine oxidase inhibition improves cardiac dysfunction in dystrophic cardiomyopathy

Monoamine oxidase inhibition improves cardiac dysfunction in dystrophic cardiomyopathy

Nomogram for Prediction of Postoperative Delirium after Deep Brain Stimulation of Subthalamic Nucleus in Parkinson's Disease under General Anesthesia.

Postoperative delirium can increase cognitive impairment and mortality in patients with Parkinson's disease. The purpose of this study was to develop and internally validate a clinical prediction model of delirium after deep brain stimulation of the subthalamic nucleus in Parkinson's disease under general anesthesia. We conducted a retrospective observational cohort study on the data of 240 patients with Parkinson's disease who underwent deep brain stimulation of the subthalamic nucleus under general anesthesia. Demographic characteristics, clinical evaluation, imaging data, laboratory data, and surgical anesthesia information were collected. Multivariate logistic regression was used to develop the prediction model for postoperative delirium. A total of 159 patients were included in the cohort, of which 38 (23.90%) had postoperative delirium. Smoking (OR 4.51, 95% CI 1.56-13.02, p < 0.01) was the most important risk factor; other independent predictors were orthostatic hypotension (OR 3.42, 95% CI 0.90-13.06, p=0.07), inhibitors of type-B monoamine oxidase (OR 3.07, 95% CI 1.17-8.04, p=0.02), preoperative MRI with silent brain ischemia or infarction (OR 2.36, 95% CI 0.90-6.14, p=0.08), Hamilton anxiety scale score (OR 2.12, 95% CI 1.28-3.50, p < 0.01), and apolipoprotein E level in plasma (OR 1.48, 95% CI 0.95-2.29, p=0.08). The area under the receiver operating characteristic curve (AUC) was 0.76 (95% CI 0.66-0.86). A nomogram was established and showed good calibration and clinical predictive capacity. After bootstrap for internal verification, the AUC was 0.74 (95% CI 0.66-0.83). This study provides evidence for the independent inducing factors of delirium after deep brain stimulation of the subthalamic nucleus in Parkinson's disease under general anesthesia. By predicting the development of delirium, our model may identify high-risk groups that can benefit from early or preventive intervention.

Effect of a Vegan Diet on Alzheimer's Disease.

There is evidence indicating that a vegan diet could be beneficial in the prevention of neurodegenerative disorders, including Alzheimer's disease (AD). The purpose of this review is to summarize the current knowledge on the positive and negative aspects of a vegan diet regarding the risk of AD. Regarding AD prevention, a vegan diet includes low levels of saturated fats and cholesterol, contributing to a healthy blood lipid profile. Furthermore, it is rich in phytonutrients, such as vitamins, antioxidants, and dietary fiber, that may help prevent cognitive decline. Moreover, a vegan diet contributes to the assumption of quercetin, a natural inhibitor of monoamine oxidase (MAO), which can contribute to maintaining mental health and reducing AD risk. Nonetheless, the data available do not allow an assessment of whether strict veganism is beneficial for AD prevention compared with vegetarianism or other diets. A vegan diet lacks specific vitamins and micronutrients and may result in nutritional deficiencies. Vegans not supplementing micronutrients are more prone to vitamin B12, vitamin D, and DHA deficiencies, which have been linked to AD. Thus, an evaluation of the net effect of a vegan diet on AD prevention and/or progression should be ascertained by taking into account all the positive and negative effects described here.

Uptake and Metabolization of Serotonin by Granulosa Cells Form a Functional Barrier in the Mouse Ovary

Serotonin (5-HT) plays an essential role in regulating female reproductive function in many animals. 5-HT accumulates in the mammalian ovary with the involvement of membrane serotonin transporter SERT and is functionally active in the oocytes of growing follicles, but shows almost no activity in follicular cells. In this study, we clarified the interplay between 5-HT membrane transport and its degradation by monoamine oxidase (MAO) in the mammalian ovary. Using pharmacologic agents and immunohistochemical staining of the cryosections of ovaries after serotonin administration in vitro, we demonstrated the activity of transport and degradation systems in ovarian follicles. The MAO inhibitor pargyline increased serotonin accumulation in the granulosa cells of growing follicles, indicating the activity of both serotonin uptake and degradation by MAO in these cells. The activity of MAO and the specificity of the membrane transport of serotonin was confirmed in primary granulosa cell culture treated with pargyline and fluoxetine. Moreover, the accumulation of serotonin is more effective in the denuded oocytes and occurs at lower concentrations than in the oocytes within the follicles. This confirms that the activity of SERT and MAO in the granulosa cells surrounding the oocytes impedes the accumulation of serotonin in the oocytes and forms a functional barrier to serotonin.

Classic Monoamine Oxidase Inhibitors for Depression: Update on Nursing Care

Classic Monoamine Oxidase Inhibitors for Depression: Update on Nursing Care

Fullerene carbon nanostructures for the delivery of phenelzine derivatives as new drugs to inhibit monoamine oxidase enzyme: Molecular docking interactions and density functional theory calculations

In this study, a molecular docking technique was used to investigate the interactions of phenelzine (P) and its derivatives, namely N-Nitrosobenzylmethylamine (P4) and [2-(4-Isopropylphenyl) ethyl] hydrazine (P9), with the enzyme monoamine oxidase. The development of new MAO-A and MAO-B inhibitors was the main goal of this research. Moreover, carbon nanostructures, including C30, C60, and C90 fullerenes, were studied as carriers of P, P4, and P9 using density functional theory (DFT). The larger adsorption energy (Eads) in the water phase for adsorption of P onto the nanostructures than in the gas phase suggested that the water phase leads to a stronger interaction of P with the nanostructures. In contrast, P4 and P9 interacted more strongly with the nanostructures in the gas phase. The values of Eads also showed weak interaction of P, P4, and P9 with the nanostructure, confirming that they can be used as carriers for the molecules. The analysis of density of states (DOS) indicated that C60 can be used as a strong sensor for P. Furthermore, the quantum theory of atoms in molecules confirmed that the interactions are via Van der Waals, which are considered weak interactions. In conclusion, the fullerene nanostructures presented in this study can be used as carriers of phenelzine derivatives as new drugs to inhibit monoamine oxidase.

Resveratrol Analogues as Dual Inhibitors of Monoamine Oxidase B and Carbonic Anhydrase VII: A New Multi-Target Combination for Neurodegenerative Diseases?

Neurodegenerative diseases (NDs) are described as multifactorial and progressive syndromes with compromised cognitive and behavioral functions. The multi-target-directed ligand (MTDL) strategy is a promising paradigm in drug discovery, potentially leading to new opportunities to manage such complex diseases. Here, we studied the dual ability of a set of resveratrol (RSV) analogs to inhibit two important targets involved in neurodegeneration. The stilbenols 1-9 were tested as inhibitors of the human monoamine oxidases (MAOs) and carbonic anhydrases (CAs). The studied compounds displayed moderate to excellent in vitro enzyme inhibitory activity against both enzymes at micromolar/nanomolar concentrations. Among them, the best compound 4 displayed potent and selective inhibition against the MAO-B isoform (IC50 MAO-A 0.43 µM vs. IC50 MAO-B 0.01 µM) with respect to the parent compound resveratrol (IC50 MAO-A 13.5 µM vs. IC50 MAO-B &gt; 100 µM). It also demonstrated a selective inhibition activity against hCA VII (KI 0.7 µM vs. KI 4.3 µM for RSV). To evaluate the plausible binding mode of 1-9 within the two enzymes, molecular docking and dynamics studies were performed, revealing specific and significant interactions in the active sites of both targets. The new compounds are of pharmacological interest in view of their considerably reduced toxicity previously observed, their physicochemical and pharmacokinetic profiles, and their dual inhibitory ability. Compound 4 is noteworthy as a promising lead in the development of MAO and CA inhibitors with therapeutic potential in neuroprotection.

Effectiveness and safety of monoamine oxidase inhibitor treatment for bipolar depression versus unipolar depression: An exploratory case cohort study.

Patients with bipolar disorder spend most of their clinical lifetime in the depressive phase of their illness. However, antidepressants are discouraged in the treatment of bipolar depression due to concerns over manic induction and drug ineffectiveness. Some reports suggest that monoamine oxidase inhibitors (MAOIs) may be safe and effective compared to other antidepressants in treating bipolar depression. The present study compared the safety and effectiveness of MAOI therapy in patients with bipolar versus unipolar depression. Data were collected from approximately 2500 clinical research charts of patients treated with MAOI therapy at a university mood disorder clinic between 1983 and 2015. A mixed-effects model was created with patient entered as the random effect. The model included the primary diagnosis (i.e., either unipolar or bipolar depression) and other clinical covariates as fixed-effect predictors. Patients with bipolar depression demonstrated lower post-treatment clinical global impressions/severity scores versus patients with unipolar depression (p=0.04). Neither group demonstrated a full syndromal manic or hypomanic episode. A higher proportion of patients with bipolar depression reported myoclonic tics and tremors, which may have resulted from concomitant lithium use. Amongst the covariates, only the number of prior antidepressant trials predicted poorer outcomes from MAOI therapy. MAOIs may be more effective-and as safe-for patients with bipolar depression versus unipolar depression. Future studies should explore this possible advantage using a larger sample size.

Exploration of a library of piperonylic acid-derived hydrazones possessing variable aryl functionalities as potent dual cholinesterase and monoamine oxidase inhibitors.

A library of piperonylic acid-derived hydrazones possessing variable aryl moiety was synthesized and investigated for their multifunctional properties against cholinesterases (ChEs) and monoamine oxidases (MAOs). The in vitro enzymatic assay results revealed that the tested hydrazones have exhibited excellent cholinesterase inhibition profile. Compound 4i, (E)-N'-(2,3-dichlorobenzylidene)benzo[d][1,3]dioxole-5-carbohydrazide showed promising dual inhibitory profile against AChE (0.048 ± 0.007μM), BChE (0.89 ± 0.018μM), and MAO-B (0.95 ± 0.12μM) enzymes. SAR exploration revealed that the truncation of the linker connecting both the aryl binding sites of the semicarbazone scaffold, by one atom, has relatively suppressed the AChE inhibitory potential. Kinetic studies disclosed that the compound 4i reversibly inhibited AChE enzyme in a competitive manner (Ki = 8.0 ± 0.076nM), while it displayed a non-competitive and reversible inhibition profile against MAO-B (Ki = 9.6 ± 0.021µM). Moreover, molecular docking studies of synthesized compounds against ChEs and MAOs provided the crucial molecular features that enable their close association and interaction with the target enzymes. All atomistic simulation studies confirmed the stable association of compound 4i within the active sites of AChE and MAO-B. In addition, theoretical ADMET prediction studies demonstrated the acceptable pharmacokinetic profile of the dual inhibitors. In summary, the attempted lead simplification study afforded a potent dual ChE-MAO-B inhibitor compound that merits further investigation.

Mechanistic insights into the role of plant polyphenols and their nano-formulations in the management of depression.

Depression is a condition characterized by low mood and an aversion to activity, that causes behavioral problems, poor quality of life and limits daily life activities. It is considered as the fourth leading cause of disability worldwide. Selective Serotonin Reuptake Inhibitors (SSRIs) Monoamine Oxidase (MAO) inhibitors, Tricyclic Antidepressants (TCAs), and atypical antidepressants are some of the conventional medications used to treat depression. However, only about half of patients with major depressive disorder (MDD) respond effectively to first-line antidepressant therapy. Additionally, there are a number of drawbacks to standard antidepressants, such as anti-cholinergic side effects, drug-drug interactions, and food-drug interactions, which prompts researchers to look at alternative approaches to the treatment of depression. Medicinal plants and their metabolites are extensively tested for their efficacy against depression. Electronic databases such as Google scholar, Science Direct, SciFinder and PubMed were used to search relevant literature on the role of polyphenols in depression. Plants-derived Polyphenols represent a major class of compounds extensively distributed in plants. Number of polyphenols have demonstrated antidepressant activity, among which berberine, piperine, curcumin, naringenin, ascorbic acid and ginsenosides are extensively evaluated. The medicinal plants and their derived compounds mediated synthesized green nanoparticles have also exhibited considerable efficacy in the management of depression. The therapeutic effects of these phytochemicals is mediated via differentiation and inhibition of neuronal cell apoptosis, promotion of neuronal cell survival and modulation of key neurotransmitters. The aim of this study is to review compressively the chemical, pharmacological and neurological evidence showing the potential of polyphenols in depression.

Clinically Relevant Drug Interactions with Monoamine Oxidase Inhibitors.

Monoamine oxidase inhibitors (MAOI) are a class of drugs that were originally developed for the treatment of depression but have since been expanded to be used in management of affective and neurological disorders, as well as stroke and aging-related neurocognitive changes. Ranging from irreversible to reversible and selective to non-selective, these drugs target the monoamine oxidase (MAO) enzyme and prevent the oxidative deamination of various monoamines and catecholamines such as serotonin and dopamine, respectively. Tyramine is a potent releaser of norepinephrine (NE) and is found in high concentrations in foods such as aged cheeses and meats. Under normal conditions, NE is unable to accumulate to toxic levels due to the presence of MAO-A, an enzyme that degrades neurotransmitters, including NE. When MAO-A is inhibited, the capacity to handle tyramine intake from the diet is significantly reduced causing the brain to be vulnerable to overstimulation of postsynaptic adrenergic receptors with as little as 8-10 mg of tyramine ingested and can result in life-threatening blood pressure elevations. In addition to adverse reactions with certain foods, both older and newer MAOIs can negatively interact with both sympathomimetic and serotonergic drugs. In general, patients on a MAOI want to avoid two types of medications: those that can elevate blood pressure via sympathomimetic actions (e.g., phenylephrine and oxymetazoline) and those that can increase serotonin levels via 5-HT reuptake inhibition (e.g., dextromethorphan, chlorpheniramine, and brompheniramine). Illicit drugs that stimulate the central nervous system such as ecstasy (MDMA, 3,4-methylenedioxymethamphetamine) act as serotonin releasers. Patient involvement is also crucial to ensure any interaction within the healthcare setting includes making other providers aware of a MAOI prescription as well as avoiding certain OTC medications that can interact adversely with MAOIs.

Molecular Pathways of the Therapeutic Effects of Ayahuasca, a Botanical Psychedelic and Potential Rapid-Acting Antidepressant.

Ayahuasca is a psychoactive brew traditionally used in indigenous and religious rituals and ceremonies in South America for its therapeutic, psychedelic, and entheogenic effects. It is usually prepared by lengthy boiling of the leaves of the bush Psychotria viridis and the mashed stalks of the vine Banisteriopsis caapi in water. The former contains the classical psychedelic N,N-dimethyltryptamine (DMT), which is thought to be the main psychoactive alkaloid present in the brew. The latter serves as a source for β-carbolines, known for their monoamine oxidase-inhibiting (MAOI) properties. Recent preliminary research has provided encouraging results investigating ayahuasca's therapeutic potential, especially regarding its antidepressant effects. On a molecular level, pre-clinical and clinical evidence points to a complex pharmacological profile conveyed by the brew, including modulation of serotoninergic, glutamatergic, dopaminergic, and endocannabinoid systems. Its substances also interact with the vesicular monoamine transporter (VMAT), trace amine-associated receptor 1 (TAAR1), and sigma-1 receptors. Furthermore, ayahuasca's components also seem to modulate levels of inflammatory and neurotrophic factors beneficially. On a biological level, this translates into neuroprotective and neuroplastic effects. Here we review the current knowledge regarding these molecular interactions and how they relate to the possible antidepressant effects ayahuasca seems to produce.

Curcumin Reprograms TAMs from a Protumor Phenotype towards an Antitumor Phenotype via Inhibiting MAO-A/STAT6 Pathway.

M1 phenotype macrophages have anticancer characteristics, whereas M2 phenotype macrophages promote tumor growth and metastasis. A higher M1/M2 ratio, therefore, has a beneficial effect on the tumor immune microenvironment, thereby inhibiting tumor growth. The natural alkaloid curcumin is found to have anticancer properties. However, the mechanism remains unclear. In this study, a cell co-culture system and M2 macrophage model were used to evaluate the effects of curcumin on tumor-associated macrophage (TAM) phenotypes. Our results demonstrate that curcumin reprogrammed the M2 macrophages by reducing the level of anti-inflammatory cytokines (TGF-β, Arg-1, and IL-10) and an M2 surface marker (CD206) induced by Cal27 cells or IL-4, as well as upregulating proinflammatory cytokines (TNF-α, iNOS, and IL-6) and an M1 surface marker (CD86). The in vitro assays suggested that curcumin treatment suppressed the migration and invasion of the Cal27 cells induced by the M2-like macrophages. Mechanistically, the repolarization of TAMs may be attributed to the inhibition of monoamine oxidase A (MAO-A)/STAT6 signaling after curcumin treatment. Collectively, our results show that the anticancer effects of curcumin could be explained by reprogramming TAMs from a protumor phenotype towards an antitumor phenotype.

N-Hydroxy-N-Propargylamide Derivatives of Ferulic Acid: Inhibitors of Cholinesterases and Monoamine Oxidases.

Alzheimer's disease (AD) is a complex disorder characterized by impaired neurotransmission in cholinergic and monoaminergic neurons, which, in combination with the accumulation of misfolded proteins and increased oxidative stress, leads to the typical features of the disease at the biomolecular level. Given the limited therapeutic success of approved drugs, it is imperative to explore rationally supported therapeutic approaches to combat this disease. The search for novel scaffolds that bind to different receptors and inhibit AD disease-related enzymes could lead to new therapeutic solutions. Here, we describe N-hydroxy-N-propargylamide hybrids 1-6, which were designed by combining the structures of Contilisant-a multifunctional anti-AD ligand-and ferulic acid, a natural antioxidant with various other biological activities. Among the synthesized compounds, we identified compound 4 as a micromolar inhibitor of hAChE with a potent radical-scavenging capacity comparable to resveratrol and Trolox. In addition, compound 4 chelated copper(II) ions associated with amyloid β pathology, mitochondrial dysfunction, and oxidative stress. The promising in vitro activity combined with favorable drug-like properties and predicted blood-brain barrier permeability make compound 4 a multifunctional ligand that merits further studies at the biochemical and cellular levels.

Chromenes - A Novel Class of Heterocyclic Compounds: Recent Advancements and Future Directions.

Chromenes are an important class of oxygen-containing heterocyclic compounds with intriguing biological activity, a simple structure with mild adverse effects. Chromenes are abundantly found in nature in the form of alkaloids, tocopherols, flavone, and anthocyanins. The Chromene nucleus is an important moiety for the discovery of new drug candidates. Chromene derivatives have shown various pharmacological activities like antiviral, anticancer, anti-inflammatory, antitumour, antimicrobial, antiproliferative, anticholinesterase, EPR-1 (Effector cell Protease Receptor-1) antagonist and MAO (Mono-Amine Oxidase) inhibitors. In SAR (Structure Activity Relationship) studies with chromene nucleus, it was found that 4-aryl moiety, 3-cyano group, and 2-amino group are essential for the cytotoxic activity. Substitution at the 7th position with electron donating group enhances the pharmacological activity whereas the electron withdrawing group decreases the pharmacological activity. Structural modifications at the chromene ring, middle aliphatic portion, and terminal aromatic ring yielded more potential 5-HT1A (5-Hydroxytryptamine 1A) receptor affinity and antidiabetic activity. Chromenes with cyclic secondary amine and 4-hydroxy phenyl substituents yielded potent antimicrobial compounds. This review summarizes the importance of chromenes in rational drug design and the development of novel molecules with a variety of pharmacological activities.

Biological activity evaluation of novel monoamine oxidase inhibitory compounds targeting Parkinsondisease.

Aim: Design of 5-methoxy benzofuran hybrids with 2-carbohydrazide and 2-(1,3,4-oxadiazol-2-yl) as potential inhibitors of monoamine oxidase (MAO)-B targeting Parkinson disease. Materials and methods: 12compounds were synthesized and analyzed via high-resolution mass spectrometry, 1H nuclear magnetic resonance and 13C nuclear magnetic resonance techniques. In vitro fluorometric assay was used to investigate the activity of the synthesized compounds on both MAO-A and MAO-B isozymes. Results: Three compounds - 3a, 3c and 3e - displayed half maximal inhibitory concentration values of 0.051±0.002, 0.038±0.001 and 0.077±0.003μM in the inhibition of MAO-A and 0.048±0.002, 0.040±0.001 and 0.072±0.002μM for MAO-B, respectively. A molecular dynamics simulation study showed that compound 3c has poor stability as a complex with MAO-A. Conclusion: Compound 3c may be a potential candidate for the treatment of Parkinson disease.