• Korean Journal of Pharmacognosy
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• v.37 no.3
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• pp.157-161
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• 2006

We examined the inhibitory activities against monoamine oxidase (MAO) of Prunella vulgaris in vitro and in vivo methods. Methanolic extract of P. vulgaris showed significantly Inhibitorγ 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 P. vulgaris in vitro tests. It was observed that those activities in vivo tests have different tendency each other. MAO-A activity was increased by the oral administration of methanolic extract of P. vulgaris while MAO-B activity was decreased. Consequently, we suggest that P. vulgaris may have the effects on the inhibitory activities against MAO both in vitro and in vivo.

• Korean Journal of Pharmacognosy
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• v.30 no.2
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• pp.145-150
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• 1999

To explain the theory of KIMI which is the theory of therapeutics in oriental medicine, monoamine oxidase(MAO) activities were measured in the brain and liver of mice which were orally administered oriental medicinal herbs which were classified into cold and hot drugs. Rheum palmatum, Anemarrhena asphodeloides, Gardenia jasminoides, Scutellaria baicalensis and Coptis japonica were considered as the cold drugs and Zingiber officinale, Aconitum carmichaeli, Asiasarum sieboldi, Evodia officinalis and Cinnamomum cassia were included in the hot drugs. The effects of cold and hot drugs on in vitro enzyme activities were measured and compared with the in vivo effects. Serotonin is important neurotransmetter involved in the control of body temperature. The MAO plays a central role in the metabolism of many neurotransmetter monoamines including serotonin. 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, whereas MAO-B prefers phenylethylamine and benzylamine as substrates. Coptis japonica and Aconitum carmichaeli elevated the in vivo MAO activities and especialy, in vivo MAO-B activities were significantly increased. In vitro MAO-A activities were increased by hot drugs, whereas the in vitro MAO-B activities were inhibited. Cold drugs inhibited both enzyme activities in vitro.

• Korean Journal of Pharmacognosy
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• v.38 no.2 s.149
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• pp.108-112
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• 2007

We examined the inhibitory activities against monoamine oxidase (MAO) of Gardenia jasminoides in vitro and in vivo methods. Methanolic extract and ethylacetate fraction of Gardenia jasminoides fruit showed a significant inhibitory activity on MAO-A and MAO-B in vitro. The IC$_{50}$ values of each fraction on MAO-A and MAO-B are as fo11owed; total methanol extracts 1.23 and 1.34 mg/ml, EtOAc fraction 0.72 and 0.77 mg/ml. Water-soluble fraction also showed IC$_{50}$ values of 0.81 mg/ml on MAO-B. MAO-A activity was increased by the oral administration of ethanolic extract of G. jasminoides, while MAO-B activity was decreased. The concentration of serotonin of brain tissue administrated of ethanolic extract of G. jasminoides is slightly increased in rat. This tendency is not different from the activity of deprenyl which is a well known MAO inhibitor was used as a positive control. Consequently, we suggest that G. jasminoides may have the effects on the inhibitory activity against MAO This activity of G. jasminoides is considerable for development of functional materials for treatment and control of depression, dementia, Parkinson' disease, stress and promoting exercise, etc.

• Biomolecules & Therapeutics
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• v.20 no.2
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• pp.214-219
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• 2012

This research was designed to determine what components of Gardenia jasminoides play a major role in inhibiting the enzymes related antidepressant activity of this plant. In our previous research, the ethyl acetate fraction of G. jasminosides fruits inhibited the activities of both monoamine oxidase-A (MAO-A) and monoamine oxidase-B (MAO-B), and oral administration of the ethanolic extract slightly increased serotonin concentrations in the brain tissues of rats and decreased MAO-B activity. In addition, we found through in vitro screening test that the ethyl acetate fraction showed modest inhibitory activity on dopamine-${\beta}$ hydroxylase (DBH). The bioassay-guided fractionation led to the isolation of five bio-active compounds, protocatechuic acid (1), geniposide (2), 6'-O-trans-p-coumaroylgeniposide (3), 3,5-dihydroxy-1,7-bis(4-hydroxyphenyl) heptanes (4), and ursolic acid (5), from the ethyl acetate fraction of G. jasminoides fruits. The isolated compounds showed different inhibitory potentials against MAO-A, -B, and DBH. Protocatechuic acid showed potent inhibition against MAO-B ($IC_{50}$ $300{\mu}mol/L$) and DBH ($334{\mu}mol/L$), exhibiting weak MAO-A inhibition (2.41 mmol/L). Two iridoid glycosides, geniposide ($223{\mu}mol/L$) and 6'-O-trans-p-coumaroylgeniposide ($127{\mu}mol/L$), were selective MAO-B inhibitor. Especially, 6'-O-trans-p-coumaroylgeniposide exhibited more selective MAO-B inhibition than deprenyl, well-known MAO-B inhibitor for the treatment of early-stage Parkinson's disease. The inhibitory activity of 3,5-dihydroxy-1,7-bis (4-hydroxyphenyl) heptane was strong for MAO-B ($196{\mu}mol/L$), modest for MAO-A ($400{\mu}mol/L$), and weak for DBH ($941{\mu}mol/L$). Ursolic acid exhibited significant inhibition of DBH ($214{\mu}mol/L$), weak inhibition of MAO-B ($780{\mu}mol/L$), and no inhibition against MAO-A. Consequently, G. jasminoides fruits are considerable for development of biofunctional food materials for the combination treatment of depression and neurodegenerative disorders.

• 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.

• Biomedical Science Letters
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• v.10 no.4
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• pp.421-427
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• 2004

The possible mechanisms of decreased monoamine oxidase (MAO) A and B activities in cholestatic rat liver were studied. Hepatic and serum MAG activities were determined from the experimental rats with common bile duct ligation (CBDL). The Michaelis-Menten constants in these hepatic enzymes were also measured. The activities of mitochondrial MAO A and B, and mircosomal MAO B as well as their Vmax values were found to be decreased significantly in CBDL plus taurocholic acid (TCA) injected group than in the control group, such as CBDL alone groups. However, their Km values in the experimental groups did not vary. Serum MAO activity increased significantly in the CBDL plus TCA injected group than in the control group. The above results suggest that TCA represses biosynthesis of the MAO in the liver. The elevated activity of the serum MAO is believed to be caused by the increment of membrane permeability ofhepatocytes upon TCA mediated liver cell necrosis.

• Journal of Microbiology and Biotechnology
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• v.27 no.4
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• pp.785-790
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• 2017

Two piloquinone derivatives isolated from Streptomyces sp. CNQ-027 were tested for the inhibitory activities of two isoforms of monoamine oxidase (MAO), which catalyzes monoamine neurotransmitters. The piloquinone 4,7-dihydroxy-3-methyl-2-(4-methyl-1-oxopentyl)-6H-dibenzo[b,d]pyran-6-one (1) was found to be a highly potent inhibitor of human MAO-B, with an $IC_{50}$ value of $1.21{\mu}M$; in addition, it was found to be highly effective against MAO-A, with an $IC_{50}$ value of $6.47{\mu}M$. Compound 1 was selective, but not extremely so, for MAO-B compared with MAO-A, with a selectivity index value of 5.35. Compound 1,8-dihydroxy-2-methyl-3-(4-methyl-1-oxopentyl)-9,10-phenanthrenedione (2) was moderately effective for the inhibition of MAO-B ($IC_{50}=14.50{\mu}M$) but not for MAO-A ($IC_{50}$ > $80{\mu}M$). There was no time-dependency in inhibition of MAO-A or -B by compound 1, and the MAO-A and -B activities were almost completely recovered in the dilution experiments with an excess amount of compound 1. Compound 1 showed competitive inhibition for MAO-A and -B, with $K_i$ values of 0.573 and $0.248{\mu}M$, respectively. These results suggest that piloquinones from a microbial source could be potent reversible MAO inhibitors and may be useful lead compounds for developing MAO enzyme inhibitors to treat related disorders, such as depression, Parkinson's disease, and Alzheimer's disease.

• Journal of Microbiology and Biotechnology
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• v.25 no.9
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• pp.1425-1428
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• 2015

Monoamine oxidase (MAO) is found in most cell types and catalyzes the oxidation of monoamines. Three anithiactins (A-C, modified 2-phenylthiazoles) isolated from Streptomyces sp. were tested for inhibitory activity of two isoforms, MAO-A and MAO-B. Anithiactin A was effective and selective for the inhibition of MAO-A, with an IC₅₀ value of 13.0 μM; however, it was not effective for the inhibition of MAO-B. Anithiactins B and C were weaker inhibitors for MAO-A and MAO-B. Anithiactin A was a reversible and competitive inhibitor for MAO-A with a K_i value of 1.84 μM. The hydrophobic methyl substituent in anithiactin A may play an important role in the inhibition of MAO-A. It is suggested that anithiactin A is a selective reversible inhibitor for MAO-A, with moderate potency, and can be considered a new potential lead compound for further development of novel reversible inhibitors for MAO-A.

• Applied Biological Chemistry
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• v.42 no.2
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• pp.166-169
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• 1999

The repeated silica gel colum chromatographies of n-BuOH fraction obtained from MeOH extracts of Eucommia ulmoides leaves led to isolation of a flavonoid-glycoside inhibiting monoamine oxidase B activity. Its chemical structure was determined to be $3-O-[{\beta}-D-glucopyranosyl\;(1{\rightarrow}2)\;{\beta}-D-xylopyranosyl]$ quercetin through interpretation of spectral data and adaptation of acid hydrolysis. The $IC_{50}$ value of this compound in rat brain mitochondrial MAO-B inhibitory activity was evaluated to be $8.05\;{\mu}mol/l$.

• 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.