• 대한의생명과학회지
• /
• 제10권4호
• /
• pp.421-427
• /
• 2004

The possible mechanisms of decreased monoamine oxidase (MAO) A and B activities in cholestatic rat liver were studied. Hepatic and serum MAG activities were determined from the experimental rats with common bile duct ligation (CBDL). The Michaelis-Menten constants in these hepatic enzymes were also measured. The activities of mitochondrial MAO A and B, and mircosomal MAO B as well as their Vmax values were found to be decreased significantly in CBDL plus taurocholic acid (TCA) injected group than in the control group, such as CBDL alone groups. However, their Km values in the experimental groups did not vary. Serum MAO activity increased significantly in the CBDL plus TCA injected group than in the control group. The above results suggest that TCA represses biosynthesis of the MAO in the liver. The elevated activity of the serum MAO is believed to be caused by the increment of membrane permeability ofhepatocytes upon TCA mediated liver cell necrosis.

• Natural Product Sciences
• /
• 제5권4호
• /
• pp.159-161
• /
• 1999

The effects of bioactive fractions containing protoberberine alkaloids from Coptis japonica on monoamine oxidase (MAO) activity were investigated. The MAO was obtained from the mitochondrial fraction of mouse brain. The butanol fraction from Coptis japonica was fractionated into separate bioactive fraction (Fr I-IV) by silica gel column chromatography. MAO activity was strongly inhibited by Fr III and IV, which mainly contain protoberberine alkaloids such as berberine, palmatine and coptisine. These results indicated that the protoberberine alkaloids from Coptis japonica had an inhibitory effect on MAO activity.

• Archives of Pharmacal Research
• /
• 제18권4호
• /
• pp.271-276
• /
• 1995

Changes in the distribution of dopamine and its metabolites, activities of monoamine oxidase, and dopamine uptake were studied inhyperglycemic rat striatum. The hyperglycemia was induced by the administration of streptozotocin (STZ, 40 mg/kg, i.p. for 3 days.). The levels of dihydroxyphenylacetic acid (DOPAC) and homovanillic acid were significantly decreased without change in dopamine level in the synatic cleft 14 days after STZ treatment. In the synaptosome, the dopamine level, however, was significanly increased after the treatment. But the DOPAC level in the synaptosome was decreased 14 days after the treatment. The affinity of dopamine uptake was significantly decreased without changes in the velocity 14 days after the treatment. However the response to uptqke inhibitor was unchanged. The striatal monoamine oxidase activities were also decreased in the hyperglycemic state. These results indicate that various parameters of striatal dopamine activities were decreased in the hyperglycemic rats. Furthermore, it suggests that the increase in dopamine level of synaptosome might be due to the decrease in the release of dopaine in hyperglycemic state.

• 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
• /
• 제10권2호
• /
• pp.142-147
• /
• 1987

Fourteen kinds of medicinal plants were screened for determining inhibitory activities on monoamine oxidase B. The extracts of Artemisia Messer-Schmidtiana (herba), Chrysanthemum indicum(flos), Ericibe obtusifolia (radix et rhizoma) and Sophora japonica (flos) strongly inhibited the enzyme. Among them, Chrysanthemi flos was chosen for elucidating its active principles, and some flavonoids were isolated and identified as acasetin (I), 5, 7-dihydroxy chromone (II), diosmetin (III), apigenin (IV), eriodictyol (V) and luteolin (VI).$IC_{50} were determined as following: 1, 2.46;II, 0.19; III, 2. 11mM, and the others showed weak inhibition.

• Archives of Pharmacal Research
• /
• 제22권3호
• /
• pp.324-326
• /
• 1999

Four coumarins were isolated from chloroform extract of the root of Peucedanum japonicum and identified as praeruptorin A (1), xanthotoxin (2), psoralen (3) and bergapten (4) on the basis of spectroscopic methods. The inhibitory activities of these coumarins on monoamine oxidase prepared by mouse brian were tested. The IC50 values of them were shown to be $27.4{\mu}M$ (1), $40.7{\mu}M$ (2), $35.8{\mu}M$ (3), and $13.8{\mu}M$ (4), in vitro.

• 약학회지
• /
• 제29권6호
• /
• pp.367-374
• /
• 1985

The age-related changes of monoamine contents and monoamine oxidase (MAO) activities in the whole brain and blood pressures were measured and compared every week during the ages of 5 weeks to 12 weeks in two types of animals; (1) spontaneously hypertensive rats (SHR) and (2) normotensive Sprague-Dawley rats (NR). Blood pressures in SHR began to rise at the ages of 7 or 8 weeks and were significantly higher thereafter than in NR. Abnormally low MAO activities in the brain of SHR were detected from the ages of 8 weeks. Comparisons were also made between brain monoamine-norepinephrine, dopamine and 5-hydroxytrytamine contents of SHR and those of NR at the same ages throughout the test period. In SHR, none of those monoamine values was consistently higher or lower than in NR during the test period. Protein contents of the brain between SHR and NR were not significantly different at any ages. These observations suggest that the abnormally low MAO activities in SHR brain may be one of the underlying neurological factors for the susceptibilities to hypertension and the deficit of MAO activities may be due to the changes in properties rather than in amount of this enzyme.

• 대한한방내과학회지
• /
• 제22권3호
• /
• pp.321-330
• /
• 2001

Objectives: This study was undertaken to investigate the action mechanism of Holotrichia (HT) at parameter related to dementia. Methods: HT was tested for the effects on acetylchonine esterase and monoamine oxidase activities, lipid peroxidation, antioxidation in brain of lead acetate-treated rats. Lead acetate were treated firstly into samples for 10 days, and then lead acetate and HT were set with them for 20 days. Results: The level of lipid peroxide, acetylcholine esterase and monoamine oxidase activities, enzyme activities and ratio of type conversion of xanthine oxidase increased in lead acetate-treated rats were decreased as highly as normal group by HT. Superoxide dismutase, catalase and glutathione peroxidase activities, the level of acetylcholine decreased in lead acetate-treated rats were increased as lowly as normal group by HT. Conclusions : These results suggest that HT might have an effect on treatment of dementia according to decreasing the activities of acetylcholine esterase, monoamine oxidase and level of lipid peroxide in brain.

• Archives of Pharmacal Research
• /
• 제7권1호
• /
• pp.65-68
• /
• 1984

Mechanism of the monoamine oxidase inhibition by tranylcypromine was studied in relation to its metabolism to reactive apecies. A metabolic study performed to collect general biotransformation pathway in rats provided GC/MS evidence for the detection of two new metabolites, N-acetyl and hydroxylated N-acetyltranylacypromine.

• 한국응용약물학회:학술대회논문집
• /
• 한국응용약물학회 2008년도 Proceedings of the Convention
• /
• pp.166-166
• /
• 2008