• 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.

• 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.

• 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.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.

• 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.

• 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.

• 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.

• 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.

• 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.

• Journal of Microbiology and Biotechnology
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• v.31 no.7
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• pp.1022-1027
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• 2021

Three compounds were isolated from marine-derived Streptomyces sp. CNQ-031, and their inhibitory activities against monoamine oxidases (MAOs), acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and β-secretase (BACE-1) were evaluated. Compound 1 (5,7-dihydroxy-2-isopropyl-4H-chromen-4-one) was a potent and selective inhibitor of MAO-A, with a 50% inhibitory concentration (IC₅₀) of 2.70 µM and a selectivity index (SI) of 10.0 versus MAO-B. Compound 2 [5,7-dihydroxy-2-(1-methylpropyl)-4H-chromen-4-one] was a potent and low-selective inhibitor of MAO-B, with an IC₅₀ of 3.42 µM and an SI value of 2.02 versus MAO-A. Compound 3 (1-methoxyphenazine) did not inhibit MAO-A or MAO-B. All three compounds showed little inhibitory activity against AChE, BChE, and BACE-1. The K_i value of compound 1 for MAO-A was 0.94 ± 0.28 µM, and the K_i values of compound 2 for MAO-A and MAO-B were 3.57 ± 0.60 and 1.89 ± 0.014 µM, respectively, with competitive inhibition. The 1-methylpropyl group in compound 2 increased the MAO-B inhibitory activity compared with the isopropyl group in compound 1. Inhibition of MAO-A and MAO-B by compounds 1 and 2 was recovered by dialysis experiments. These results suggest that compounds 1 and 2 are reversible, competitive inhibitors of MAOs and can be considered potential therapies for neurological disorders such as depression and Alzheimer's disease.