• Natural Product Sciences
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• v.19 no.4
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• pp.281-285
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• 2013

This study was designed to investigate the nervous sedative effects of green tea. The sedative effect was evaluated by examination of Monoamine oxidases (MAOs) inhibitory activity in vitro in the brain and liver of rat fed on green tea cultivated and harvested from the different regions and periods. It showed that methanol extracts of green tea inhibited significantly the brain MAO-A activity. Especially late harvested green tea extracts showed potential inhibitory activity. The liver MAO-B activity was also inhibited by all of the green tea extracts with strong intensity. This study confirmed that major compounds of green tea such as catechin, epigallocatechin-3-gallate (EGCG) and L-theanine, which were well known for the main bioactive components in the tea plants, were not associated with the MAO inhibitory activities of green tea. These results suggested that a MAO inhibition activity comes from other minor tea components we have to search in the future.

• YAKHAK HOEJI
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• v.38 no.6
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• pp.791-794
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• 1994

Sixteen kinds of naturally occurring phenolic compounds including 5 stilbenes, 7 flavonoids and 4 anthraquinones were examined in the inhibitory activity against rat liver AADC(aromatic L-amino acid decarboxylase) in vitro, using 5-hydroxytryptophan as a substrate. Three hydroxystilbenes, resveratrol 1, rhapontigenin 3 and piceatanol 5, which were known to be monoamine oxidase A inhibitors, exhibited a significant inhibition against AADC($IC_{50}$=20, 8 and $5\;{\mu}M$, respectively). By the comparison of the activity of each phenolic compound, it was suggested that the 3',4'-dihydroxyphenyl group of stilbenes or flavones was the best pharmacophore for the AADC inhibitory activity.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.188-188
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• 1998

Extracts of 24 edible vegetables were tested concerning their action on in vitro inhibition on dopamine ${\beta}$-hydroxylase (DBH) and monoamine oxidase (MAO). All vegetables were purchased in Korean market and their common names were kept. Radish sprouts, ‘kkoch-na-mul’, ‘chong-gyong-chae’, ragwort, applemint showed strong DBH inhibitory effect when tyramine and crude bovine adrenal DBH were used as substrate and enzyme, respectively. ‘Cham-chwi’(Aster scaber), kale, ‘cham-na-mul’(Pimpinella brachycarpa), leek were found to have MAO-A inhibitory effect with serotonin and crude rat brain MAO-A. Lettuce, ‘chong-gyong-chae’, radish sprouts, beet leaves were found to have MAO-B inhibitory effect with benzyl amine and crude rat liver MAO-B.

• Bulletin of the Korean Chemical Society
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• v.33 no.11
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• pp.3841-3844
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• 2012

• Korean Journal of Food Science and Technology
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• v.37 no.1
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• pp.95-102
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• 2005

Effects of Morus alba fruit extracts on monoamine oxidase (MAO) activity were examined in rats during and after physical exercise. Oral administration of M. alba extract (0.3 g/kg body weight) significantly increased brain MAO-A activity but decreased liver MAO-B activity when they were measured using serotonin and benzylamine as substrates. Type of physical exercises had significant effect on MAO activity. Brain MAO-A activity markedly decreased with physical activity-related stress compared to normal group, whereas Liver MAO-B activity increased up to 60 min after exercise. Lactate dehydrogenase (LDH) activity and lactate concentration in blood, clinical indices of physical exercise activities, were also determined for correlation to MAO activities. MAO-A activity of rats subjected to oral administration of M. alba extract and physical exercise increased whereas MAO-B and LDH activities, and lactate level decreased, All indices eventually recovered normal levels, These results suggest M. alba may increase capability of physical activities by modulating MAO activities during exercise.

• BMB Reports
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• v.29 no.2
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• pp.142-145
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• 1996

To investigate the cause of increased plasma catecholamine levels in liver disease, catechol-O-methyltransferase (COMT), which provides a major route of catabolism for circulating catecholamines, was studied under the cholestasis induced by mechanical biliary obstruction in rats. Monoamine oxidase (MAO) activity and the $K_m$ and $V_{max}$ values for both enzymes were also measured. Cytosolic, microsomal, and mitochondrial COMT activities in the cholestatic liver were significantly decreased throughout the experiment. Microsomal, and mitochondrial MAO activity in the cholestatic liver were also significantly decreased. Vmax values of COMT and MAO were lower. Serum COMT and MAO activities were detected after CBD ligation. These results indicate that plasma catecholamine levels are increased in liver disease due to decreased hepatic degradation of catecholamines by decreased activities of COMT and MAO. The decreased activity of these enzymes is caused by decreased biosynthesis and by flowage into the blood from the damaged hepatocyte.

• Korean Journal of Pharmacognosy
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• v.33 no.4 s.131
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• pp.285-290
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• 2002

From the fruits of Crataegus pinnatifide BUNGE ursolic acid (1), $quercetin-3-O-{\alpha}-L-rhamnopyranosyl(1{\rightarrow}6)-{\beta}-D-glucopyranoside$ (2), (-)-epicatechin (3), $quercetin-3-O-{\beta}-D-galactopyranoside$ (4) and quercetin (5) have been isolated and identified on the basis of their physicochemical properties and spectroscopic evidences in comparison with authentic samples. Among isolated compounds, quercetin showed significant inhibitory effect against MAO.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.255.2-255.2
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• 2003

Monoamine oxidase (MAO) is flavin-containing enzyme that catalyzes the oxidation of variety of amine-containing neurotransmitters such as catecholamines and serotonin to yield the corresponding aldehyde. Thus, MAO activity might play important roles in some pathological states of central nervous system diseases such as depression, alcoholism, and schizophrenia. (omitted)

• Korean Journal of Food Science and Technology
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• v.29 no.1
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• pp.156-160
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• 1997

The monoamine oxidase (MAO, EC 1.4.3.4) plays a central role in the metabolism of many amines including the neurotransmitter monoamines. MAO is a flavoprotein found exclusively in the mitochondrial outer membrane, occuring in the MAO-A and MAO-B subtypes. MAO-A deaminates serotonin and noradrenaline much better than phenethylamine (PEA) or benzylamine (BA), and is preferentially inhibited by clorgyline, whereas MAO-B prefers PEA and BA as substrates and is preferentially inhibited by deprenyl. MAO inhibitors were among the first drugs used in the treatment of depression, and it is known to be the inhibition of MAO-A which is important for the antidepressant effect of MAO inhibitors. For the purpose of evaluating MAO inhibitory activities from natural resources, three kinds of edible mushrooms were screened by tracing the inhibitory activities against rat brain mitochondrial MAO-A, utilizing serotonin as a substrate and rat liver mitochondrial MAO-B utilizing benzylamine as a substrate. Among the tested mushrooms, Ganoderma lucidium and Lentinus edodes showed the weak inhibitory activities against MAO-B.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.256.1-256.1
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• 2003

As a part of our ongoing research to discover novel monamine oxidase (MAO) inhibitors of plant origin, we found that a MeOH extract from the whole plant of Cayratia japonica (Vitaceae) strongly inhibited the MAO activity in mouse brain. The EtOAc-soluble fraction was. therefore, subjected to the bioactivity-guided fractionations to isolate the active compounds. (omitted)