• Journal of Applied Biological Chemistry
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• 제61권2호
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• pp.187-190
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• 2018

Two curcumin derivatives, demethoxycurcumin (DMC) and bisdemethoxycurcumin (BDMC), isolated from Curcuma longa were analyzed for their inhibitory activities against two isoforms of monoamine oxidase (MAO), which is involved in the catalysis of neurotransmitting monoamines. In the study, DMC and BDMC potently inhibited human MAO-B, with $IC_{50}$ values of 2.45 and $2.59{\mu}M$, respectively, and both compounds showed effective inhibitory activities against human MAO-A, with $IC_{50}$ values of 3.24 and $3.09{\mu}M$, respectively. The inhibitory activities of the two compounds were higher than those of curcumin. The removal of the methoxy or dimethoxy groups in curcumin might increase the inhibitory activities against human MAO-A and MAO-B. The inhibited activities were recovered to almost the values of the reversible references in the dialysis experiments with DMC and BDMC. DMC and BDMC showed competitive inhibition for MAO-A and MAO-B, respectively, with $K_i$ values of 0.91 and $0.80{\mu}M$, respectively. These results suggest that the two curcumin derivatives may be useful or lead compounds in the treatment of related disorders as potent reversible MAO inhibitors.

• The Korean Journal of Physiology and Pharmacology
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• 제10권4호
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• pp.207-212
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• 2006

Mitochondrial permeability transition has been shown to be involved in neuronal cell death. Mitochondrial monoamine oxidase (MAO)-B is considered to play a part in the progress of nigrostriatal cell death. The present study examined the effect of MAO inhibitors against the toxicity of 1-methyl-4-phenylpyridinium $(MPP^+)$ in relation to the mitochondrial permeability transition. Chlorgyline (a selective inhibitor of MAO-A), deprenyl (a selective inhibitor of MAO-B) and tranylcypromine (nonselective inhibitor of MAO) all prevented cell viability loss, cytochrome c release, caspase-3 activation, formation of reactive oxygen species and depletion of GSH in differentiated PC12 cells treated with $500\;{\mu}M$$MPP^+$. The MAO inhibitors at $10\;{\mu}M$ revealed a maximal inhibitory effect and beyond this concentration the inhibitory effect declined. On the basis of concentration, the inhibitory potency was tranylcypromine, deprenyl and chlorgyline order. The results suggest that chlorgyline, deprenyl and tranylcypromine attenuate the toxicity of $MPP^+$ against PC12 cells by suppressing the mitochondrial permeability transition that seems to be mediated by oxidative stress.

• Archives of Pharmacal Research
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• 제28권4호
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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.

• Archives of Pharmacal Research
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• 제28권2호
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• pp.190-194
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• 2005

In our search for monoamine oxidase (MAO) inhibitors from natural resources, we found that the methanol extract of the roots of Sophora flavescens showed an inhibitory effect on mouse brain monoamine oxidase (MAO). Bioactivity-guided isolation of the extract yielded two known flavonoids, formononetin (1) and kushenol F (2), as active compounds along with three inactive compounds, oxymatrine (3), trifolirhizin (4), and ${\beta}$-sitosterol (5). Formononetin (1) and kushenol F (2) showed significant inhibitory effects on MAO in a dose-dependent manner with $IC_{50}$ values of 13.2 and $69.9\;{\mu}M$, respectively. Formononetin (1) showed a slightly more potent inhibitory effect against MAO-B ($IC_{50}:\;11.0\;{\mu}M$) than MAO-A ($IC_{50}:\;21.2\;{\mu}M$). Kushenol F (2) also preferentially inhibited the MAO-B activity than MAO-A activity with the $IC_{50}$ values of 63.1 and $103.7\;{\mu}M$, respectively.

• 대한의생명과학회지
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• 제12권2호
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• pp.91-97
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• 2006

The effects of intravenous administration of high concentration of taurocholic acid (TCA) on monoamine oxidase (MAO) A and B activities in rat liver mitochondria and microsomes were studied. These liver subcellular organelles and serum MAO activities were determined from the experimental rats with choledocho-caval shunt (CCS). The Michaelis-Menten constants in these hepatic enzymes were also measured. The activities of mitochondrial MAO A and B, and microsomal MAO B as well as their $V_{max}$ values were found to be decreased significantly in CCS plus TCA injected group then in the control group, such as CCS alone groups. However their $K_m$ values in the experimental groups did not vary. MAO of serum appeared in the CCS plus TCA injected groups only. The above results suggest that TCA represses biosynthesis of the MAO in the liver. The MAO of serum is believed to be caused by the increment of membrane permeability of hepatocytes upon TCA mediated liver cell necrosis.

• 한국식품과학회지
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• 제29권1호
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• pp.156-160
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• 1997

식용버섯류들의 MAO 저해활성을 검색할 목적으로 몇가지 유기용매를 이용하여 추출분획을 조제하고 이들의 MAO에 대한 저해활성을 검색하였다. 검색된 3종 버섯류의 유기용매 추출물들은 영지버섯 bud의 $CHCl_3$ 층을 제외하고는 모두 MAO-A에 대한 저해활성이 나타나지 않았으나 영지 bud의 경우 $CHCl_3$ 층에서 비교적 강력한 MAO-A 저해활성을 나타내어 영지 bud의 항암활성이 영지의 항암활성과 비교하여 더욱 강력하다는 기존의 보고와 관련하여 아주 흥미로운 결과로 영지의 성분연구에 아주 중요한 단서를 제공해 줄 것으로 생각된다. 또한 검색된 3종 버섯류의 유기용매 추출물들은 영지 bud, 표고버섯의 EtOAc 층에서 각각 51.3, 55.9%로 역한 정도의 저해활성이 관찰되었으며 그 외의 다른 버섯류들에서는 전혀 MAO-B에 대한 저해활성이 확인되지 않았다. 또한 영지버섯의 경우, $CHCl_3$ 층, EtOAc 층, $H_2O$ 층 모두에서 아주 미약하나마 MAO-B에 대한 저해활성을 나타냈으나 영지 bud의 경우 $CHCl_3$ 층에서 전혀 MAO-B에 대한 저해활성을 나타내지 않고 EtOAc 층에서 약한 MAO-B에 대한 저해활성이 확인되어 MAO-A와 MAO-B에 대한 영지버섯의 작용성분이 다른 성분일 것으로 추측된다.

• 한국식품과학회지
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• 제37권1호
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• pp.95-102
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• 2005

상심자 추출물이 운동에 의한 체내 monoamine oxidase (MAO) 활성 변화에 미치는 영향을 연구하여. 상심자 추출물을 경구투여(0.3g/kg body weight) 한 흰쥐의 뇌와 간에서 MAO-A와 MAO-B의 활성에 중요한 영향을 미치는 사실을 확인하였다. 각 효소활성은 serotonin과 benzylamine을 기질로 이용하여 측정하였다. 운동 전 후 운동의 유형에 따라 효소활성의 변화경향이 서로 다른 경향을 나타내었다. 뇌에서 측정한 MAO-A 활성은 운동에 의해 효소활성이 현저히 감소하였으며 반면, 간에서 측정한 MAO-B의 활성은 운동이 끝나고 60분이 경과할 때까지 증가된 상태를 유지하고 있었다. 운동 시 체내 변화의 지표효소인 혈중 LDH의 활성 변화와 혈중 lactate의 농도변화를 함께 관찰함으로서 MAO 활성과의 상관관계를 비교하였다. 상심자 추출물을 경구투여 하고 운동을 한 동물의 MAO-A 활성은 증가하였고 MAO-B, LDH 활성과 lactate level은 감소하는 것을 확인하였다. 결과적으로 모은 지표들이 운동 전의 정상상태로 회복되는 것으로 확인되었다. 이 연구의 결과들로부터 상심자 추출물이 운동 전후의 MAO 활성을 조절함으로써 운동능력을 향상시키고 피로를 회복하는 효능을 갖는 것으로 추정되며 이러한 기능성을 갖는 건강기능식품의 소재로 활용이 가능할 것으로 생각한다.

• Journal of Microbiology and Biotechnology
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• 제27권2호
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• pp.316-320
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• 2017

Alternariol monomethyl ether (AME), a dibenzopyrone derivative, was isolated from Alternaria brassicae along with altertoxin II (ATX-II). The compounds were tested for the inhibitory activity of monoamine oxidase (MAO), which catalyzes neurotransmitting monoamines. AME was found to be a highly potent and selective inhibitor of human MAO-A with an $IC_{50}$ value of $1.71{\mu}M$; however, it was found to be ineffective for MAO-B inhibition. ATX-II was not effective for the inhibition of either MAO-A or MAO-B. The inhibition of MAO-A using AME was apparently instantaneous. MAO-A activity was almost completely recovered after the dilution of the inhibited enzyme with an excess amount of AME, suggesting AME is a reversible inhibitor. AME showed mixed inhibition for MAO-A in Lineweaver-Burk plots with a $K_i$ value of $0.34{\mu}M$. The findings of this study suggest that microbial metabolites and dibenzopyrone could be potent MAO inhibitors. In addition, AME could be a useful lead compound for developing reversible MAO-A inhibitors to treat depression, Parkinson's disease, and Alzheimer's disease.

• 대한약리학회지
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• 제20권2호
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• pp.73-80
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• 1984

본 연구에서는 higenamine과 그 유도체들이 백서 뇌 미토콘드리아 Monoamine Oxidase(MAO) 의 활성에 미치는 영향에 관하여 관찰하였다. 시험한 화합물들 중에서 심장의 등장성 수축에는 효과를 나타내지 않는 methoxyhigenamine이 가장 5-hydroxytryptamine(5-HT)과 phenylethylamine(PEA)에 대한 MAO의 활성을 가역적으로 억제시켰으며, 그 억제 양상은 각각 pure competitive형과 hyperbolic mixed 형이었다. 이에 5-HT에 대한 $IC_{50}$ 는 PEA에 대한 것보다 10배 정도 낮아서 MAO-B 보다는 MAO-A에서 더 강한 억제 작용을 나타내었다. 이로써 methoxyhigenamine은 가역적이며 비교적 MAO-A에 대해 선택적인 MAO 억제제로 사료된다.

• 약학회지
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• 제46권6호
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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.