• Natural Product Sciences
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• v.11 no.3
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• pp.145-149
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• 2005

A methanol soluble extract from the dried hooks and stems of Uncaria rhynchophylla showed a strong inhibitory activity against monoamine oxidase in mouse brain. Using a bioassay-guided purification of this extract, a known ${\beta}-carboline$ type alkaloid, harman (1), was obtained as an active constituent. In addition, five known indole alkaloids, isocorynoxeine (2), isorhynchophylline (3), corynoxeine (4), cadambine (5), and $3{\alpha}-dihydrocadambine$ (6), were isolated and found to be weakly active or inactive.

• Natural Product Sciences
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• v.6 no.1
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• pp.16-19
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• 2000

Four compounds were isolated from the dichloromethane fraction of Cinnamomi Cortex through bioassay-guided isolation. Their structures were identified as coumarin (1), 3,3-dimethoxy-1-propenyl benzene (2), cinnamic acid (3) and o-methoxy cinnamaldehyde (4) on the basis of spectroscopic data. All four compounds showed inhibitory activities in vitro against monoamine oxidase (MAO) prepared by mouse brain. The $IC_{50}$ values were $41.4\;{\mu}M\;(1),\;110.6\;{\mu}M\;(2),\;252.5\;{\mu}M\;(3)\;and\;83.1\;{\mu}M$ (4), respectively.

• Korean Journal of Pharmacognosy
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• v.34 no.2 s.133
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• pp.185-189
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• 2003

We examined the inhibitory activities against monoamine oxidase (MAO) of Morus alba in vitro and in vivo methods. Methanolic extract of M. alba showed significantly inhibitory activities on MAO-A and MAO-B that were prepared from rat brain and liver in vitro. The inhibitory activities were measured by serotonin and benzylamine as substrates, respectively. MAO-A and MAO-B activities were potently inhibited by ethylacetate extracts of M. alba in vitro tests. Those activities in vivo tests have different tendency each other. MAO-A activity was increased by the oral administration of methanolic extract of M. Alba, while, MAO-B activity was decreased. Consequently, we can suggest that M. alba may have the effects on the inhibitory activities against MAO both in vitro and in vivo.

• Natural Product Sciences
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• v.5 no.4
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• pp.159-161
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• 1999

The effects of bioactive fractions containing protoberberine alkaloids from Coptis japonica on monoamine oxidase (MAO) activity were investigated. The MAO was obtained from the mitochondrial fraction of mouse brain. The butanol fraction from Coptis japonica was fractionated into separate bioactive fraction (Fr I-IV) by silica gel column chromatography. MAO activity was strongly inhibited by Fr III and IV, which mainly contain protoberberine alkaloids such as berberine, palmatine and coptisine. These results indicated that the protoberberine alkaloids from Coptis japonica had an inhibitory effect on MAO activity.

• Archives of Pharmacal Research
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• v.28 no.4
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• pp.400-404
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• 2005

Activity-guided fractionation of a hexane-soluble extract of the roots of Lithospermum erythrorhizon, using a mouse brain monoamine oxidase (MAO) inhibition assay, led to the isolation of two known naphthoquinones, acetylshikonin and shikonin, and a furylhydroquinone, shikonofuran E. These compounds were shown to inhibit MAO with $IC_{50}$ values of 10.0, 13.3, and $59.1 {\mu}M$, respectively. Although no specificity for MAO-A and MAO-B was shown by acetylshikonin and shikonin, a Lineweaver-Burk plot analysis indicated that the inhibition was competitive for both MAO-A and MAO-B activity.

• YAKHAK HOEJI
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• v.46 no.6
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• pp.433-440
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• 2002

The protective efficacy of Rheum palmatum water extract on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced parkinsonism was studied in C57BL/6 mice. In order to demonstrate neuroprotective effect of R. palmatum extract, animals were administered intraperitoneally with the water extract (100 or 200 mg/kg/day) for 14 days, and MPTP (10 mg/kg/day) was injected subcutaneously into the mice for the first 6 consecutive days from the beginning 1 hr before R. palmatum extract treatment. All animals were measured the several neurobiochemical markers such as dopamine level and monoamine oxidase B (MAO-B) activity in various regions of brain. The treatment of mice with R. palmatum extract was confirmed recovery effect on MAO-B activity in the cerebellum and the cerebral cortex. R. palmatum extract was attenuated the MPTP-induced depletion of substantia nigra dopamine. The contents of MDA, a marker of lipid peroxidation, in brain tissues (cerebellum and cerebral cortex mitochondria) were decreased significantly by R. palmatum extract. These results suggest that R. palmatum water extract plays an effective role in attenuating MPTP-induced neurotoxicity in mice. This protective effect of R. palmatum might be estimated the result from the inhibitory activity on monoamine oxidase B and the enhancement of antioxidant activity.

• Korean Journal of Pharmacognosy
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• v.37 no.4 s.147
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• pp.229-234
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• 2006

We examined the inhibitory activities against monoamine oxidase (MAO) of Taraxacum mongolicum in vitro and in vivo methods. Methanol extract of T. mongolicum showed significantly inhibitory activities on MAO-A and MAOB that were prepared from rat brain and liver in vitro. MAO-A and MAO-B activities were potently inhibited by chloroform fraction of T. mongolicum in vitro tests. The $IC_{50}$ values of each fraction on MAO-A are as followed; methanol extracts (0.90 mg/ml), $CHCl_3$ fraction (0.10 mg/ml), EtOAc fraction (0.36 mg/ml). and those on MAO-B are methanol extracts $(0.39{\mu}g/ml)$, $CHCl_3$ fraction $(0.18{\mu}g/ml)$, BuOH fraction $(0.22{\mu}g/ml)$. Those MAO-A and MAO-B activities in vivo tests have different tendency each other. MAO-A activity was increased by the oral administration of ethanol extract of T mon golicum, while MAO-B activity was decreased. The concentration of serotonin of brain tissue after oral administration of ethanolic extract of T. mongolicum is slightly increased in rat. This tendency is not different from the activity of deprenyl which is the well known MAO inhibitor used as a positive control. Based on these results, we can suggest that T. mongolicum may have the effects on the inhibitory activities against MAO. Thess activities of T. mongolicum is considerable for development of functional materials for the purpose of treatment and control of depressant, dementia, Parkinson' disease, stress and promoting exercise.

• YAKHAK HOEJI
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• v.28 no.6
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• pp.305-311
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• 1984

Relationship between hypertension and monoamine oxidase (MAO) activity in rat brain and the change of this relationship by presynaptic ${\alpha}-receptor$ agonist were studied. Animals were divided into three groups. Group I was composed of normotensive Sprague-Dawley rats (NR), group II of spontaneously hypertensive rats (SHR) and group III of acquired hypertensive rats induced by deoxycorticosterone acetate (DOCA) and NaCl treatment. Clonidine, a presynaptic ${\alpha}-receptor$ agonist, was administered to groups II and III. Blood pressures and MAO activities were measured in each group. MAO activities in the brain of SHR were lower than those of NR. Animals in group II received clonidine which lowered blood pressures but did not change MAO activities in the brain. DOCA and NaCl induced hypertension 21 days after these treatments in group III and did not cause any changes in brain MAO activity. Clonidine lowered blood pressures of group III but did not change MAO activities. The data from the present study suggest that abnormaly low MAO activities in SHR brain may be one of the underlying factors for the susceptibility to hypertension and that the decrease in noradrenergic neuronal activities through presynaptic ${\alpha}-receptor$ activation by clonidine may not be related to the changes of brain MAO activities.

• 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.42 no.6
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• pp.634-638
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• 1998

The effects of MeOH extracts from 88 herbal medicines on monoamine oxidase (MAO) acitivity were investigated. MAO was purified from mouse brain and its activity was determined by fluorospectrophotometer using kynuramine as a substrate. The $K_m\;and\;V_{max}$ values (n=4) of MAO were $78.2{\pm}4.0\;{\mu}M$ and $0.65{\pm}0.05$ nmol/min/mg protein, respectively. Four MeOH extracts from Melilotus sauvelolens, Eupatorium lindleyanum Bupleurum longiradiatum and Sorbaria sirbiforia showed a strong inhibitory effect with less than $100{\mu}g/ml$ in their $IC_{50}$ values on MAO activity. Six MeOH extracts including Agastache rugosa showed a mild inhibitory effect with 100~200${\mu}$g/ml in their $IC_{50}$ values. Twenty-two MeOH extracts including Melandryum seoulense exhibited a week inhibition of MAO activity with 200~300${\mu}$g/ml in their $IC_{50}$ values.