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

• 대한약리학회지
• /
• 제20권2호
• /
• pp.73-80
• /
• 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.

• Journal of Microbiology and Biotechnology
• /
• 제25권9호
• /
• pp.1425-1428
• /
• 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.

• Natural Product Sciences
• /
• 제11권3호
• /
• pp.145-149
• /
• 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.

• Biomolecules & Therapeutics
• /
• 제20권2호
• /
• pp.214-219
• /
• 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.

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

• 보험의학회지
• /
• 제1권1호
• /
• pp.84-87
• /
• 1984

1. 전신가토(全身家兎) 및 척수가토(脊髓家兎)에서 MAO 억제하(抑制下)에서의 brethylium의 tyramine 승압효과(昇壓效果)에 미치는 영향(影響)을 관찰(觀察)하였다. 2. 전신가토(全身家兎) 및 척수가토(脊髓家兎)에서 bretylium 정주(靜注) 후(後)에는 tyramine의 승압효과(昇壓效果)는 강화(强化)되었으나 MAO 억제제(抑制劑)인 catron을 정주(靜注)하고 bretylium을 추가(追加) 주입(注入)한 후(後)에는 tyramine의 승압효과(昇壓效果)는 catron 투여전(投與前)의 그것보다 감약(減弱)되었다. 3. Bretylium에 의한 tyramine 승압효과(昇壓效果)의 강화(强化)는 MAO 억제작용(抑制作用)으로 설명(說明)되고, tyramine 승압효과(昇壓效果)의 감약(減弱)은 교감신경말단(交感神經末端)의 차단작용(遮斷作用)으로 설명(說明)된다.

• Archives of Pharmacal Research
• /
• 제28권4호
• /
• pp.400-404
• /
• 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
• /
• 제11권3호
• /
• pp.230-239
• /
• 1988

Thirty kinds of medicinal plants were screened to examine inhibitory activities on rat brain monoamine oxidase A, using serotonin as a substrate. As active principles, various kinds of stilbenes were isolated from Veratri Rhizoma, Reynoutriae Radix and Rhei undulati Rhizoma, and several kinds of flavonoids from Sophorae Flos, Chrisanthemi Flos and Glycine max. Among the compounds isolated, resveratrol(I) strongly inhibited MAO-A competitively, and its $IC_{50}$ and Ki values were 2 ${\mu}M$ and 2.5 ${\mu}M$, respectively. Inhibitory potencies towards MAO-A of some stilbenes and flavonoids were also compared.

• 생약학회지
• /
• 제38권2호통권149호
• /
• pp.108-112
• /
• 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.