• YAKHAK HOEJI
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• v.34 no.5
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• pp.311-322
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• 1990

This study primarily attempted to investigate the effects of methamphetamine on stereotyped behavior. Furthermore, an extensive experiment was conducted to examine the cortex methamphetamine concentration and levels of dopamine, serotonin, and their metabolites in striatum, septum and hypothalamus. Following treatment with 10 mg/kg methamphetamine, stereotyped behavior was observed in 10 minutes. Consequently female rats displayed more intense and longer lasting activity than the male. The concentration of cortex methamphetamine was even higher in female than male. The administration of methamphetamine increased the rate of dopamine turnover-i.e. lower dopamine, higher homovanillic acid in the striatum, septum. The highest rate was found in the striatum. Methamphetamine decreased the levels of serotonin, and its metabolite of 5-indoleacetic acid in the striatum, septum. An intensity in behavioral response was accompanied by an increase in dopamine turnover, a decrease in serotonergic transmission. The reduction of 3,4-dihydroxyphenylacetic acid-i.e. the metabolite of dopamine was due not to the inhibition of monoamine oxidase but to the induction of monoamine oxidase but to the induction of catechol-O-methyltransferase. The phenomenon of biogenic amines by methamphetamine concurred upon the concentration of methamphetamine in the brain. This process preceded stereotyped behavior. After single injection of 10 mg/kg methamphetamine, the levels of biogenic amines recovered within 6 hours.

• 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.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.3
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• pp.458-463
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• 2002

This present study was designed to screen medicinal plants for the treatment of brain diseases such as Parkinson's disease or Alzheimer's disease. The inhibitory activity of monoamine oxidase B (MAO-B) was investigated in the water extracts of 56 species traditional medicines. Among the tested medicinal plants, E. lathyris, R. palmatum, F. rhynchonphylla, E. caryophyllata, E. pekinensis and H. syriacus were showed the strong inhibitory activity against MAO-B. Therefore, MAO-B inhibitory activity of 6 traditional medicine extracts in the different concentration (2.5, 6.5 and 12.5 ㎍/ml) was determined. The inhibitory effect of MAO-B was detected with dose dependently in 6 traditional plants extracts. E. caryophyllata and R. palmatum were showed the highest inhibitory activity, the MAO-B inhibitory activity at 2.5㎍ of herbal extract being 58% and 52%, respectively. The water extracts of 6 species were tested on antioxidant activity using radical scavenging effects against ABTS/sup +/. The water extracts of R. palmatum, E. caryphyllata, E. pekinensis and H. syriacus were showed strong antioxidant capacity at 20 ㎍ concentration. Among the 56 medicinal plants investigated, the water extracts of R. palmatum and E. caryphyllata were showed significant antioxidant capacity and MAO-B inhibiory activity. Therefore, R. palmatum and E. caryphyllata are expected to ameliorate the clinical symptoms in Parkinson's disease due to significant MAO-B inhibition and radical scavenging effect.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10a
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• pp.147-147
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• 2001

A previous study showed that sulfur amino acid deprivation (SAAD) potentiated cytotoxicity induced by arsenic (As) and that activation of ERKl/2, p38 kinase and JNK1 was responsible for the potentiation of As toxicity. In the present study, we found for the first time that deprenyl a selective monoamine oxidase B inhibitor prevented potentiation of As toxicity by SAAD in a dose-dependent manner.(omitted)

• Journal of Applied Biological Chemistry
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• v.66
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• pp.165-170
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• 2023

Isolation of the culture broth of a marine-derived Acremonium sp. CNQ-049 guided by HPLC-UV yielded compound 1 (3-phenethyl-2-phenylquinazolin-4(3H)-one), and its inhibitory activities against monoamine oxidases (MAOs), cholinesterases (ChEs), and β-secretase 1 (BACE1) were evaluated. Compound 1 was an effective selective MAO-B inhibitor with an IC₅₀ value of 9.39 µM and a selectivity index (SI) value of 4.26 versus MAO-A. In addition, compound 1 showed a potent selective butyrylcholinesterase (BChE) inhibition with an IC₅₀ value of 7.99 µM and an SI value of 5.01 versus acetylcholinesterase (AChE). However, compound 1 showed weak inhibitions against MAO-A, AChE, and BACE1. The Ki value of compound 1 for MAO-B was 5.22±1.73 µM with competitive inhibition, and the Ki value of compound 1 for BChE was 3.00±1.81 µM with mixed-type inhibition. Inhibitions of MAO-B and BChE by compound 1 were recovered by dialysis experiments. These results suggest that compound 1 is a dual-functional reversible inhibitor of MAO-B and BChE, that can be used as a treatment agent for neurological disorders.

• Journal of the Korean Society of Tobacco Science
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• v.19 no.2
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• pp.136-144
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• 1997

Cigarette smoking is known to suppress both 1-methy14-phenyl-155,Ltetrahydropy-ridine (MPTP)-induced parkinsonism and idiopathic Parkinson's disease (PD). However, the precise mechanism underlying its protective action against PD is not clearly elucidated yet. In order to find possible clue on the mechanism of protective action of smoking, we investigated the inhibitory effect of cigarette smoke components on rat brain mitochondria1 monoamine oxidase B (MAO-B), responsible enzyme for the activation of MPTP to its toxic metabolitesr and identified the components having an inhibitory potency on this enzyme from cigarette smoke. Total 31 eligible constituents including nicotine were selected from cigarette smoke condensates via solvents partitioning and silica gel chromatographic separation, and inhibitory potencies of 19 components on MAO-B were determined. Hydroquinone and methylcatechol, the phenolic components, showed the strongest inhibitory potencies on MAO-B activity in the components tested. 3,4-Dihydroxybenzylamino, myosmine and indole in basic fracton, eugenol in phenolic fraction, and farnesol in neutral fraction also inhibited the enzyme activity dose-dependently. Among tobacco alkaloids tested only myosmine was effective for the inhibition of this enzyme. These results suggest that the decrease in MAO-B activity by such components derived from cigarette smoke seems to be related to the suppression of MPTP-induced neurotoxicity and to the less incidence of Parkinson's disease in smokers than in nonsmokers.

• Natural Product Sciences
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• v.19 no.1
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• pp.8-14
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• 2013

The inhibitory effect and the structure-activity relationships of luteolin and its related derivatives isolated from Taraxacum mongolicum against MAO activities were investigated. The activity-guided isolation of extract from Taraxacum mongolicum led to the isolation of three flavonoids, luteolin, diosmetin, and luteolin-7-glucoside, a polyphenol, chlorogenic acid, a tyrosine and a uridine. The inhibitory activities of luteolin and its related derivatives against MAOs activities are dependent on their molecular structures. The presence of the phenolic hydroxy group at para-position is the active site for MAO-A inhibition as well as of MAO-B. The methoxy group has no potential on MAO-A inhibition. An additional phenolic hydroxy group at the ortho-position alleviates about 4-fold MAO-A inhibitory activity of phenolic hydroxy group at para-position. A carboxylic group seems to be critical for DBH inhibition and has no effects on MAO.

• Journal of Life Science
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• v.8 no.2
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• pp.167-172
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• 1998

To investigate the effect of pine needle extract (PNE) on membrane fluidirt and neurotransmiter-related enzymes in brain of Spragu-Dawley(SD), male SD rats were fed basic diets (control group), and experimantal diets (PNE group)with 0.5% and 0.1% fo PNE for 6 weeks. pine (pinus tabulaeformis C$_{ARR}$ is one of the popular plant drugs which has used as a medicine in Asia. Cholesterol levels in brain mitochondria of 0.5%-PNE and 0.1%-PNDE groups were significantly decreased in 15% and 25%, respectively, compared with control group, but cholesterol levels in brain microsomes of these PNE groups howed almost no change compared with control group. Lipofuscin accumulations in brain membranes of 0.5%-PNE and 0.1%-PNE groups were sgnificantly inhibited in 18% and 21%, respectively, compared with control group. Brain memberance fluidity was also activated in 50% and 100% by the administration of 0.5%-PNE and 0.1%-PNE. higher acetylcholinesterase(15% and25%) and lower monoamine oxidase B (25% and 15%0 activities were effectively modulated by the administration of 0.5%-PNE and 0.1%-PNDE. These results suggest that more beneficial effects such as inhibition of cholesterol and lipofuscin, increase of membrane fluidity, higher acetylcholinesterase and lower monoamone oxidase activities in brain membranes of SD rats may be effectively modulated by administration of pine needle extract (PNE).

• 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.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.6
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• pp.1666-1685
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• 2004

This present study was designed to screen medicinal plants for the treatment of brain diseases such as Parkinson's disease or aging. We tested the effects of the water extracts from 38 species medicinal plants on antioxidant capacity, monoamine oxidase B (MAO-B) inhibitory activity, acetylcholinesterase (AChE) inhibition and antiperoxidation activity in vitro. The water extracts from 38 species were tested on their antioxidant activity using radical scavenging effects against ABTS+. The water extract of C. sappan was showed the highest antioxidant capacity, the antioxidant activity at 1 Jig of herbal extract being 0.38mM TE. Lipid peroxidation in brain homogenates induced by NADPH and ADP-Fe/sup 2+/ was strong inhibited by C. sappan and R. palmatum extracts. Among the 38 medicinal plants investigated, R. palmatum showed significant biological activity (antioxidant capacity, MAO-B inhibiory activity, and AChE inhibitory activity). The protective efficacy of R. palmatum water extract on 1-methyl-4­phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced parkinsonism and its possible mechanism were studied in C57BL/6 mice. Treatment of R. palmatum water extract protected biomacromolecules such as lipids from oxidative damage induced by MPTP. The content of MDA in brain tissue was decreased significantly by R. palmatum extract. These results suggest that R. palmatum water extract plays on 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.