Selective inhibition of MAO-A but not MAO-B activity increases rat pineal melatonin

1985 ◽  
Vol 61 (3-4) ◽  
pp. 265-270 ◽  
Author(s):  
G. F. Oxenkrug ◽  
R. McCauley ◽  
I. M. McIntyre ◽  
C. Filipowicz
Keyword(s):  
Selective Inhibition ◽  
Mao B ◽  
Pineal Melatonin ◽  
Mao A

scholarly journals Selective Interactions of O-Methylated Flavonoid Natural Products with Human Monoamine Oxidase-A and -B

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5358
Author(s):  
Narayan D. Chaurasiya ◽  
Jacob Midiwo ◽  
Pankaj Pandey ◽  
Regina N. Bwire ◽  
Robert J. Doerksen ◽  
...  
Keyword(s):  
Natural Products ◽  
Enzyme Inhibition ◽  
Selective Inhibition ◽  
Monoamine Oxidase A ◽  
Inhibition Kinetics ◽  
Free Energies ◽  
Mao B ◽  
Mao A ◽  
Enzyme Inhibition Kinetics ◽  
Binding Free Energies

A set of structurally related O-methylated flavonoid natural products isolated from Senecio roseiflorus (1), Polygonum senegalense (2 and 3), Bhaphia macrocalyx (4), Gardenia ternifolia (5), and Psiadia punctulata (6) plant species were characterized for their interaction with human monoamine oxidases (MAO-A and -B) in vitro. Compounds 1, 2, and 5 showed selective inhibition of MAO-A, while 4 and 6 showed selective inhibition of MAO-B. Compound 3 showed ~2-fold selectivity towards inhibition of MAO-A. Binding of compounds 1–3 and 5 with MAO-A, and compounds 3 and 6 with MAO-B was reversible and not time-independent. The analysis of enzyme-inhibition kinetics suggested a reversible-competitive mechanism for inhibition of MAO-A by 1 and 3, while a partially-reversible mixed-type inhibition by 5. Similarly, enzyme inhibition-kinetics analysis with compounds 3, 4, and 6, suggested a competitive reversible inhibition of MAO-B. The molecular docking study suggested that 1 selectively interacts with the active-site of human MAO-A near N5 of FAD. The calculated binding free energies of the O-methylated flavonoids (1 and 4–6) and chalcones (2 and 3) to MAO-A matched closely with the trend in the experimental IC50′s. Analysis of the binding free-energies suggested better interaction of 4 and 6 with MAO-B than with MAO-A. The natural O-methylated flavonoid (1) with highly potent inhibition (IC50 33 nM; Ki 37.9 nM) and >292 fold selectivity against human MAO-A (vs. MAO-B) provides a new drug lead for the treatment of neurological disorders.

scholarly journals Studies on 5-fluoro-.ALPHA.-methyltryptamine and p-chloro-.BETA.-methylphenethylamine: Determination of the MAO-A or MAO-B selective inhibition in vitro.

1988 ◽  
Vol 46 (2) ◽  
pp. 197-199 ◽  
Author(s):  
Hiroyasu KINEMUCHI ◽  
Yuichiro ARAI ◽  
Yoshie TOYOSHIMA ◽  
Takeshi TADANO ◽  
Kensuke KISARA
Keyword(s):  
Selective Inhibition ◽  
Mao B ◽  
Mao A

scholarly journals Studies on 5-Fluoro-α-Methyltryptamine and p-Chloro-β-Methylphenethylamine: Determination of the MAO-A or MAO-B Selective Inhibition In Vitro

1988 ◽  
Vol 46 (2) ◽  
pp. 197-199
Author(s):  
Hiroyasu KINEMUCHI ◽  
Yuichiro ARAI ◽  
Yoshie TOYOSHIMA ◽  
Takeshi TADANO ◽  
Kensuke KISARA
Keyword(s):  
Selective Inhibition ◽  
Mao B ◽  
Mao A

scholarly journals Selective Inhibition of Human Monoamine Oxidase B by 5-hydroxy-2-methyl-chroman-4-one Isolated from an Endogenous Lichen Fungus Daldinia fissa

2021 ◽  
Vol 7 (2) ◽  
pp. 84
Author(s):  
Geum-Seok Jeong ◽  
Myung-Gyun Kang ◽  
Sang-Ah Han ◽  
Ji-In Noh ◽  
Jong-Eun Park ◽  
...  
Keyword(s):  
Docking Simulation ◽  
Selective Inhibition ◽  
Competitive Inhibitor ◽  
Selective Inhibitor ◽  
Hydrogen Bond Interaction ◽  
Mao B ◽  
Brain Barrier Permeability ◽  
Mao A ◽  
Inhibitory Activities ◽  
Lichen Fungus

Inhibitory activities against monoamine oxidases (MAOs) and cholinesterases (ChEs) and antioxidant activity were evaluated for 195 extracts from Ukraine-derived endogenous lichen fungi (ELF). Among them, an ELF13 (identified as Daldinia fissa) extract showed the highest inhibitory activity against MAO-B, and 5-hydroxy-2-methyl-chroman-4-one (HMC) was isolated as a ~ 4-fold selective inhibitor of MAO-B (IC50 = 3.23 µM) compared to MAO-A (IC50 = 13.97 µM). HMC is a reversible competitive inhibitor with a Ki value of 0.896 µM. No cytotoxicity was observed in normal and cancer cells at 50 µM of HMC. HMC showed blood–brain barrier permeability and high gastrointestinal absorption in silico pharmacokinetics. The docking simulation results showed that the binding affinity of HMC for MAO-B (−7.3 kcal/mol) was higher than that of MAO-A (−6.1 kcal/mol) and that HMC formed a hydrogen bond interaction with Cys172 of MAO-B (distance: 3.656 Å), whereas no hydrogen bonding was predicted with MAO-A. These results suggest that HMC can be considered a candidate for the treatment of neurodegenerative diseases, such as Alzheimer’s disease and Parkinson’s disease.

scholarly journals Demonstration of Isoleucine 199 as a Structural Determinant for the Selective Inhibition of Human Monoamine Oxidase B by Specific Reversible Inhibitors

2005 ◽  
Vol 280 (16) ◽  
pp. 15761-15766 ◽  
Author(s):  
Frantisek Hubálek ◽  
Claudia Binda ◽  
Ashraf Khalil ◽  
Min Li ◽  
Andrea Mattevi ◽  
...  
Keyword(s):  
Monoamine Oxidase ◽  
Selective Inhibition ◽  
Competitive Inhibitor ◽  
Side Chain ◽  
Monoamine Oxidase B ◽  
Sequence Alignments ◽  
Reversible Inhibitors ◽  
Mao B ◽  
Mao A ◽  
Structural Determinant

Several reversible inhibitors selective for human monoamine oxidase B (MAO B) that do not inhibit MAO A have been described in the literature. The following compounds: 8-(3-chlorostyryl)caffeine, 1,4-diphenyl-2-butene, andtrans,trans-farnesol are shown to inhibit competitively human, horse, rat, and mouse MAO B withKivalues in the low micromolar range but are without effect on either bovine or sheep MAO B or human MAO A. In contrast, the reversible competitive inhibitor isatin binds to all known MAO B and MAO A with similar affinities. Sequence alignments and the crystal structures of human MAO B in complex with 1,4-diphenyl-2-butene or withtrans,trans-farnesol provide molecular insights into these specificities. These inhibitors span the substrate and entrance cavities with the side chain of Ile-199 rotated out of its normal conformation suggesting that Ile-199 is gating the substrate cavity. Ile-199 is conserved in all known MAO B sequences except bovine MAO B, which has Phe in this position (the sequence of sheep MAO B is unknown). Phe is conserved in the analogous position in MAO A sequences. The human MAO B I199F mutant protein of MAO B binds to isatin (Ki= 3 μm) but not to the three inhibitors listed above. The crystal structure of this mutant demonstrates that the side chain of Phe-199 interferes with the binding of those compounds. This suggests that the Ile-199 “gate” is a determinant for the specificity of these MAO B inhibitors and provides a molecular basis for the development of MAO B-specific reversible inhibitors without interference with MAO A function in neurotransmitter metabolism.

scholarly journals Selective Inhibition of Human Monoamine Oxidase B by Acacetin 7-Methyl Ether Isolated from Turnera diffusa (Damiana)

Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 810 ◽  
Author(s):  
Narayan Chaurasiya ◽  
Jianping Zhao ◽  
Pankaj Pandey ◽  
Robert Doerksen ◽  
Ilias Muhammad ◽  
...  
Keyword(s):  
Methyl Ether ◽  
Enzyme Inhibitor ◽  
Equilibrium Dialysis ◽  
Selective Inhibition ◽  
Standard Drug ◽  
Mao B ◽  
Turnera Diffusa ◽  
Mechanism Of Inhibition ◽  
Mao A

The investigation of the constituents that were isolated from Turnera diffusa (damiana) for their inhibitory activities against recombinant human monoamine oxidases (MAO-A and MAO-B) in vitro identified acacetin 7-methyl ether as a potent selective inhibitor of MAO-B (IC50 = 198 nM). Acacetin 7-methyl ether (also known as 5-hydroxy-4′, 7-dimethoxyflavone) is a naturally occurring flavone that is present in many plants and vegetables. Acacetin 7-methyl ether was four-fold less potent as an inhibitor of MAO-B when compared to acacetin (IC50 = 50 nM). However, acacetin 7-methyl ether was >500-fold selective against MAO-B over MAO-A as compared to only two-fold selectivity shown by acacetin. Even though the IC50 for inhibition of MAO-B by acacetin 7-methyl ether was ~four-fold higher than that of the standard drug deprenyl (i.e., SelegilineTM or ZelaparTM, a selective MAO-B inhibitor), acacetin 7-methyl ether’s selectivity for MAO-B over MAO-A inhibition was greater than that of deprenyl (>500- vs. 450-fold). The binding of acacetin 7-methyl ether to MAO-B was reversible and time-independent, as revealed by enzyme-inhibitor complex equilibrium dialysis assays. The investigation on the enzyme inhibition-kinetics analysis with varying concentrations of acacetin 7-methyl ether and the substrate (kynuramine) suggested a competitive mechanism of inhibition of MAO-B by acacetin 7-methyl ether with Ki value of 45 nM. The docking scores and binding-free energies of acacetin 7-methyl ether to the X-ray crystal structures of MAO-A and MAO-B confirmed the selectivity of binding of this molecule to MAO-B over MAO-A. In addition, molecular dynamics results also revealed that acacetin 7-methyl ether formed a stable and strong complex with MAO-B. The selective inhibition of MAO-B suggests further investigations on acacetin 7-methyl as a potential new drug lead for the treatment of neurodegenerative disorders, including Parkinson’s disease.

scholarly journals Inhibition of Butyrylcholinesterase and Human Monoamine Oxidase-B by the Coumarin Glycyrol and Liquiritigenin Isolated from Glycyrrhiza uralensis

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 3896
Author(s):  
Geum Seok Jeong ◽  
Myung-Gyun Kang ◽  
Joon Yeop Lee ◽  
Sang Ryong Lee ◽  
Daeui Park ◽  
...  
Keyword(s):  
Monoamine Oxidase ◽  
Binding Affinity ◽  
Competitive Inhibitor ◽  
Glycyrrhiza Uralensis ◽  
Form Hydrogen Bond ◽  
Docking Simulations ◽  
Mao B ◽  
Mao A ◽  
Ic50 Values ◽  
Noncompetitive Inhibitor

Eight compounds were isolated from the roots of Glycyrrhiza uralensis and tested for cholinesterase (ChE) and monoamine oxidase (MAO) inhibitory activities. The coumarin glycyrol (GC) effectively inhibited butyrylcholinesterase (BChE) and acetylcholinesterase (AChE) with IC50 values of 7.22 and 14.77 µM, respectively, and also moderately inhibited MAO-B (29.48 µM). Six of the other seven compounds only weakly inhibited AChE and BChE, whereas liquiritin apioside moderately inhibited AChE (IC50 = 36.68 µM). Liquiritigenin (LG) potently inhibited MAO-B (IC50 = 0.098 µM) and MAO-A (IC50 = 0.27 µM), and liquiritin, a glycoside of LG, weakly inhibited MAO-B (>40 µM). GC was a reversible, noncompetitive inhibitor of BChE with a Ki value of 4.47 µM, and LG was a reversible competitive inhibitor of MAO-B with a Ki value of 0.024 µM. Docking simulations showed that the binding affinity of GC for BChE (−7.8 kcal/mol) was greater than its affinity for AChE (−7.1 kcal/mol), and suggested that GC interacted with BChE at Thr284 and Val288 by hydrogen bonds (distances: 2.42 and 1.92 Å, respectively) beyond the ligand binding site of BChE, but that GC did not form hydrogen bond with AChE. The binding affinity of LG for MAO-B (−8.8 kcal/mol) was greater than its affinity for MAO-A (−7.9 kcal/mol). These findings suggest GC and LG should be considered promising compounds for the treatment of Alzheimer’s disease with multi-targeting activities.

Development of Monoamine Oxidase and Aldehyde Dehydrogenase in Reaggregating Cultures of Fetal Rat Brain Cells

1989 ◽  
Vol 16 (3) ◽  
pp. 281-286
Author(s):  
Olof Tottmar ◽  
Maria Söderbäck ◽  
Anders Aspberg
Keyword(s):  
Monoamine Oxidase ◽  
Rat Brain ◽  
Aldehyde Dehydrogenase ◽  
Brain Cells ◽  
Mao B ◽  
Adult Rat ◽  
Fetal Rat ◽  
Adult Rat Brain ◽  
Mao A ◽  
Fetal Rat Brain

The development of monoamine oxidase (MAO) and aldehyde dehydrogenase (ALDH) in reaggregation cultures of fetal rat brain cells was compared with that of enzymatic markers for glial and neuronal cells. Only MAO-A was detected in the cultures during the first week, but, during the following three weeks, the activity of MAO-B increased more rapidly than that of MAO-A. The ratio MAO-A/MAO-B in four-week aggregates was close to that found in the adult rat brain. The activity of ALDH started to increase rapidly after 15 days, and the developmental pattern was intermediate to those of the glial and neuronal markers. The activity after four weeks was close to that found in the adult rat brain. Epidermal growth factor (EGF) caused a slight decrease in the activities of the low-Km ALDH (after four weeks) and the neuronal marker, choline acetyltransferase (after two weeks), whereas the other markers were not affected. By contrast, the activities of MAO-A and MAO-B were greatly increased during almost the entire culture period. It is suggested that this effect of EGF was the result of increased mitotic activity and/or biochemical differentiation of other cell types present in the cell aggregates, e.g. capillary endothelial cells.

scholarly journals In Vitro,In Vivo, and Clinical Studies of Tedizolid To Assess the Potential for Peripheral or Central Monoamine Oxidase Interactions

2013 ◽  
Vol 57 (7) ◽  
pp. 3060-3066 ◽  
Author(s):  
S. Flanagan ◽  
K. Bartizal ◽  
S. L. Minassian ◽  
E. Fang ◽  
P. Prokocimer
Keyword(s):  
Blood Pressure ◽  
Monoamine Oxidase ◽  
Clinical Research ◽  
Systolic Blood Pressure ◽  
Clinical Studies ◽  
Geometric Mean ◽  
Interaction Study ◽  
Mao B ◽  
Mao A

ABSTRACTTedizolid phosphate is a novel oxazolidinone prodrug whose active moiety, tedizolid, has improved potency against Gram-positive pathogens and pharmacokinetics, allowing once-daily administration. Given linezolid warnings for drug-drug and drug-food interactions mediated by monoamine oxidase (MAO) inhibition, including sporadic serotonergic toxicity, these studies evaluated tedizolid for potential MAO interactions.In vitro, tedizolid and linezolid were reversible inhibitors of human MAO-A and MAO-B; the 50% inhibitory concentration (IC50) for tedizolid was 8.7 μM for MAO-A and 5.7 μM for MAO-B and 46.0 and 2.1 μM, respectively, with linezolid. Tedizolid phosphate was negative in the mouse head twitch model of serotonergic activity. Two randomized placebo-controlled crossover clinical studies assessed the potential of 200 mg/day tedizolid phosphate (at steady state) to enhance pressor responses to coadministered oral tyramine or pseudoephedrine. Sensitivity to tyramine was determined by comparing the concentration of tyramine required to elicit a ≥30-mmHg increase in systolic blood pressure (TYR30) when administered with placebo versus tedizolid phosphate. The geometric mean tyramine sensitivity ratio (placebo TYR30/tedizolid phosphate TYR30) was 1.33; a ratio of ≥2 is considered clinically relevant. In the pseudoephedrine study, mean maximum systolic blood pressure was not significantly different when pseudoephedrine was coadministered with tedizolid phosphate versus placebo. In summary, tedizolid is a weak, reversible inhibitor of MAO-A and MAO-Bin vitro. Provocative testing in humans and animal models failed to uncover significant signals that would suggest potential for hypertensive or serotonergic adverse consequences at the therapeutic dose of tedizolid phosphate. Clinical studies are registered atwww.clinicaltrials.govas NCT01539473 (tyramine interaction study conducted at Covance Clinical Research Center, Evansville, IN) and NCT01577459 (pseudoephedrine interaction study conducted at Vince and Associates Clinical Research, Overland Park, KS).

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