• Archives of Pharmacal Research
• /
• v.11 no.3
• /
• 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.

• The Korean Journal of Pharmacology
• /
• v.18 no.2
• /
• pp.27-32
• /
• 1982

To investigate the relationship between platelet monoamine oxidase activity and serum levels of testosterone and estradiol in schizophrenic patient, 78 chronic patients were compared with 135 normal controls. 1) The monoamine oxidase activity of chronic schizophrenic group was lower than normal group. 2) In normal group, there was no sex difference in monoamine oxidase activity. But in chronic schizophrenic group, the monoamine oxidase activity in male was lower than female. 3) In male schizophrenic group, the serum estradiol level was lower than normal group. 4) In female schizophrenic group, the serum testosterone level was lower than normal group. The significances of relationship between platelet monoamine oxidase activity and sex hormones are discussed.

• YAKHAK HOEJI
• /
• v.42 no.6
• /
• pp.634-638
• /
• 1998

The effects of MeOH extracts from 88 herbal medicines on monoamine oxidase (MAO) acitivity were investigated. MAO was purified from mouse brain and its activity was determined by fluorospectrophotometer using kynuramine as a substrate. The $K_m\;and\;V_{max}$ values (n=4) of MAO were $78.2{\pm}4.0\;{\mu}M$ and $0.65{\pm}0.05$ nmol/min/mg protein, respectively. Four MeOH extracts from Melilotus sauvelolens, Eupatorium lindleyanum Bupleurum longiradiatum and Sorbaria sirbiforia showed a strong inhibitory effect with less than $100{\mu}g/ml$ in their $IC_{50}$ values on MAO activity. Six MeOH extracts including Agastache rugosa showed a mild inhibitory effect with 100~200${\mu}$g/ml in their $IC_{50}$ values. Twenty-two MeOH extracts including Melandryum seoulense exhibited a week inhibition of MAO activity with 200~300${\mu}$g/ml in their $IC_{50}$ values.

• YAKHAK HOEJI
• /
• v.46 no.6
• /
• pp.433-440
• /
• 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.

• YAKHAK HOEJI
• /
• v.28 no.6
• /
• pp.305-311
• /
• 1984

Relationship between hypertension and monoamine oxidase (MAO) activity in rat brain and the change of this relationship by presynaptic ${\alpha}-receptor$ agonist were studied. Animals were divided into three groups. Group I was composed of normotensive Sprague-Dawley rats (NR), group II of spontaneously hypertensive rats (SHR) and group III of acquired hypertensive rats induced by deoxycorticosterone acetate (DOCA) and NaCl treatment. Clonidine, a presynaptic ${\alpha}-receptor$ agonist, was administered to groups II and III. Blood pressures and MAO activities were measured in each group. MAO activities in the brain of SHR were lower than those of NR. Animals in group II received clonidine which lowered blood pressures but did not change MAO activities in the brain. DOCA and NaCl induced hypertension 21 days after these treatments in group III and did not cause any changes in brain MAO activity. Clonidine lowered blood pressures of group III but did not change MAO activities. The data from the present study suggest that abnormaly low MAO activities in SHR brain may be one of the underlying factors for the susceptibility to hypertension and that the decrease in noradrenergic neuronal activities through presynaptic ${\alpha}-receptor$ activation by clonidine may not be related to the changes of brain MAO activities.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.16 no.3
• /
• pp.458-463
• /
• 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 Applied Pharmacology
• /
• 1998.11a
• /
• pp.132-132
• /
• 1998

It has been known that MAO (monoamine oxidase) catalyses the oxidation of endogenous neurotransmitter amines. From its key role in the regulation of some physiological amines, it has been the target of inhibitors used as antidepressive agents. In our continuing search for MAO inhibitors from Basidiomycete. sp., strain 8082 was selected. Two metabolites (8082-1 and 8082-2) were isolated by adsorption chromatography and HPLC from the culture broth of strain 8082. The structure of 8082-1 and 8082-2 were elucidated by $^1$H-, $\^$13/C-NMR and HMBC spectral data, and these products were identified as 5-methylmellein and nectriapyrone, respectively, which have significant inhibitory effect against mouse brain MAO.

• Biomolecules & Therapeutics
• /
• v.21 no.3
• /
• pp.234-240
• /
• 2013

Monoamine oxidase inhibitors (MAOI) have been widely used as antidepressants. Recently, there has been renewed interest in MAO inhibitors. The activity-guided fractionation of extracts from Angelica keiskei Koidzumi (A. keiskei K.) led to the isolation of two prenylated chalcones, xanthoangelol and 4-hydroxyderricin and a flavonoid, cynaroside. These three isolated compounds are the major active ingredients of A. keiskei K. to inhibit the MAOs and DBH activities. Xanthoangelol is a nonselective MAO inhibitor, and a potent dopamine ${\beta}$-hydroxylase (DBH) inhibitor. $IC_{50}$ values of xanthoangelol to MAO-A and MAO-B were calculated to be 43.4 ${\mu}M$, and 43.9 ${\mu}M$. These values were very similar to iproniazid, which is a nonselective MAO inhibitor used as a drug against depression. The $IC_{50}$ values of iproniazid were 37 ${\mu}M$, and 42.5 ${\mu}M$ in our parallel examination. Moreover, $IC_{50}$ value of xanthoangelol to DBH was calculated 0.52 ${\mu}M$. 4-Hydroxyderricin is a potent selective MAO-B inhibitor and also mildly inhibits DBH activity. The $IC_{50}$ value of 4-hydroxyderricin to MAO-B was calculated to be 3.43 ${\mu}M$ and this value was higher than that of deprenyl (0.046 ${\mu}M$) used as a positive control for selective MAO-B inhibitor in our test. Cynaroside is a most potent DBH inhibitor. The $IC_{50}$ value of cynaroside to DBH was calculated at 0.0410 ${\mu}M$. Results of this study suggest that the two prenylated chalcones, xanthoangelol and 4-hydroxyderricin isolated from A. keiskei K., are expected for potent candidates for development of combined antidepressant drug. A. keiskei K. will be an excellent new bio-functional food material that has the combined antidepressant effect.

• Toxicological Research
• /
• v.3 no.1
• /
• pp.9-14
• /
• 1987

The effects of monosodium glutamate (MSG) on the activities if tyrosine hydroxylase (TH), dopamine ${\beta}$-hydroxylase (DBH), tryptophan hydroxylase (TPH) and monoamine oxidase (MAO) in various regions (cerebral cortex, striatum, midbrain, pons and medulla of nat brain have been determined. It was observed that up to 1mM MSGhad no significant effects on the activities of brain tyrosine hydroxylase, dopamine ${\beta}$-hydroxylase, tryptophan hydroxylase and monoamine oxidase in all regions of rat brain. These results indicated that MSG itself exerted no direct effect on the important enzymes synthsizing and metabolizing the monoaminergic neuronal system.

• Bulletin of the Korean Chemical Society
• /
• v.35 no.5
• /
• pp.1269-1274
• /
• 2014

Monoamine oxidases catalyze the oxidative deamination of dietary amines and amine neurotransmitters, and assist in maintaining the homeostasis of the amine neurotransmitters in the brain. Dysfunctions of these enzymes can cause neurological and behavioral disorders including Parkinson's and Alzheimer's diseases. To understand their physiological roles, efficient assay methods for monoamine oxidases are essential. Reviewed in this Perspective are the recent progress in the development of fluorescent probes for monoamine oxidases and their applications to enzyme assays in cells and tissues. It is evident that still there is strong need for a fluorescent probe with desirable substrate selectivity and photophysical properties to challenge the much unsolved issues associated with the enzymes and the diseases.