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Inhibition of Monoamine Oxidases (MAOs) by Green Tea Extracts
Author(s) -
Topaz Gemma Rose,
Rodriguez Joyce,
Mahmood Farah,
Depeiza Damien,
Lorenzo Loren,
Destine Rodely,
Stieglitz Kimberly
Publication year - 2018
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2018.32.1_supplement.797.13
Subject(s) - clorgyline , monoamine oxidase , monoamine oxidase b , monoamine oxidase a , serotonin , pargyline , monoamine neurotransmitter , benzylamine , dopamine , chemistry , serotonergic , tyrosine hydroxylase , moclobemide , selegiline , pharmacology , biochemistry , medicine , enzyme , disease , parkinson's disease , medicinal chemistry , receptor , hippocampus , antidepressant
Monoamine oxidase (MAO) performs deamination of amines and is found bound to the outer mitochondrial membrane at high‐concentration in neuronal cells. There are two isoforms of MAO: MAO_A which oxidizes serotonin, noradrenaline and adrenaline, and MAO_B which oxidizes dopamine, b‐phenylethylamine (PEA), and benzylamine. Alterations in MAO activity can occur in some central and peripheral nervous system diseases. More specifically, heightened MAO_B activity in the brain occurs in Alzheimer's disease, Huntington's disease, Parkinson's disease and normal aging. Abnormal MAO_A activity has found to be associated with depression, anxiety and psychiatric disorders. Drugs have been developed and continue to be developed for both MAO_A and MAO_B as targets. MAO_A is inhibited by clorgyline and MAO_B is potently inhibited by both deprenyl and pargyline. Using these inhibitors as controls, a fluorescent activity assay was performed with commercially available catechins (green tea extracts), serotonin, and benzylamine substrates for MAO_A and MAO_B respectively, to investigate and confirm recent studies suggesting that green tea catechins (polyphenols) may be preventative for certain degenerative diseases and emotional illnesses utilizing MAOs as a target. Using a fluorescent assay, the K m value of serotonin to MAO_A was 1.75 μM and the K m value of benzylamine to MAO_B was 0.75 μM. The IC 50 of clorgyline to MAO_A was 3.25 nM and that of deprenyl to MAO_B was 7.25 nM, in close agreement with the literature. The commercial catechins tested were found to have IC 50 s in the low‐to‐mid μM range (~50–750 μM). Efforts to purify catechins are underway to repeat these studies. Molecular docking of specific catechins into the MAO_A and MAO_B active sites resulted in binding constants in the low μM range (in agreement with experimentally determined K m values for natural substrates). Crystallization studies of MAO/catechin complexes are in progress. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .