• Title/Summary/Keyword: aromatic L-amino acid decarboxylase

Search Result 8, Processing Time 0.02 seconds

Inhibition of Aromatic L-Amino Acid Decarboxylase (AADC) by Some Phenolic Compounds from Medicinal Plants (천연 페놀성 화합물들의 방향족 아미노산 탈탄산효소 저해작용)

  • Ryu, Shi-Yong;Han, Yong-Nam;Han, Byung-Hoon
    • YAKHAK HOEJI
    • /
    • v.38 no.6
    • /
    • pp.791-794
    • /
    • 1994
  • Sixteen kinds of naturally occurring phenolic compounds including 5 stilbenes, 7 flavonoids and 4 anthraquinones were examined in the inhibitory activity against rat liver AADC(aromatic L-amino acid decarboxylase) in vitro, using 5-hydroxytryptophan as a substrate. Three hydroxystilbenes, resveratrol 1, rhapontigenin 3 and piceatanol 5, which were known to be monoamine oxidase A inhibitors, exhibited a significant inhibition against AADC($IC_{50}$=20, 8 and $5\;{\mu}M$, respectively). By the comparison of the activity of each phenolic compound, it was suggested that the 3',4'-dihydroxyphenyl group of stilbenes or flavones was the best pharmacophore for the AADC inhibitory activity.

  • PDF

Effects of Liriodenine on Dopamine Biosynthesis in PC12 Cells (Liriodenine이 PC12 세포중의 Dopamine 생합성에 미치는 영향)

  • Jin, Chun-Mei;Lee, Jae-Joon;Yin, Shou-Yu;Kim, Yu-Mi;Kim, Young-Kyoon;Rhu, Shi-Yong;Lee, Myung-Koo
    • Korean Journal of Pharmacognosy
    • /
    • v.34 no.1 s.132
    • /
    • pp.55-59
    • /
    • 2003
  • The effects of liriodenine, an aporphine isoquinoline alkaloid, on dopamine content in PCl2 cells were investigated. Treatment of PC12 cells with liriodenine decreased dopamine content in a dose-dependent manner (33.6% inhibition at $10\;{\mu}M$ for 12 h). The $IC_{50}$ in value of liriodenine was $8.4\;{\mu}M$. Dopamine content decreased at 3 h and reached a minimal level at 12 h after the exposure to liriodenine. Under these conditions, the activities of tyrosine hydroxylase and aromatic L-amino acid decarboxylase were also inhibited at $10\;{\mu}M$ of liriodenine by 10.1% and 20.2% relative to control, respectively. In addition, liriodenine inhibited the increase in dopamine content induced by L-DOPA Treatments $(50-100\;{\mu}M)$ in PC12 cells. These results suggest that liriodenine inhibited dopamine biosynthesis and L-DOPA-induced increase in dopamine content by reducing the activities of tyrosine hydroxylase and aromatic L- amino acid decarboxylase in PC12 cells.

Effects of Protoberberine Compounds on Serotonin Content in P815 Cells (Protoberberine 화합물이 P815 세포중의 serotonin 함량에 미치는 영향)

  • Lee, Myung-Koo;Kim, Eung-Il;Hur, Jae-Doo;Lee, Kyong-Soon;Ro, Jai-Seup
    • Korean Journal of Pharmacognosy
    • /
    • v.32 no.1 s.124
    • /
    • pp.49-54
    • /
    • 2001
  • The effects of protoberberine compounds on serotonin biosynthesis in P815 cells were investigated. Protoberberine compounds such as berberine, palmatine and coralyne decreased serotonin content dose-dependently, but coptisine did not. The $IC_{50}$ values of berberine, palmatine and coralyne were $3.0\;{\mu}M,\;16.5\;{\mu}M\;and\;14.5\;{\mu}M$, respectively. Protoberberine compounds at concentrations up to $20\;{\mu}M$ were not cytotoxic towards P815 cells. The activity of tryptophan hydroxylase, a ratelimiting enzyme in serotonin biosynthesis, was inhibited by the exposure of berberine, palmatine and coralyne in P815 cells (14.9-19.3% inhibition at $2-15\;{\mu}M$), but that of aromatic L-amino acid decarboxylase was not. These results suggest that the inhibition of tryptophan hydroxylase activity by berberine, palmatine and coralyne might partially contribute to the decrease in serotonin content in P815 cells.

  • PDF

Inhibition of L-DOPA-Induced Increase in Dopamine Content by $(1R,9S)-{\beta}-Hydrastine$ Hydrochloride in PC12 cells

  • Yin, Shou-Yu;Lee, Jae-Joon;Kim, Yu-Mi;Jin, Chun-Mei;Yang, Yoo-Jung;Kang, Min-Hee;Lee, Myung-Koo
    • Natural Product Sciences
    • /
    • v.10 no.3
    • /
    • pp.119-123
    • /
    • 2004
  • The effects of BHSH on L-DOPA-induced increase in dopamine content in PC12 cells were investigated. L-DOPA treatment at $20\;or\;50\;{\mu}M$ increased dopamine content after both 24 and 48 h of incubation in PC12 cells. However, the co-treatments of BHSH $(10-50\;{\mu}M)$ with L-DOPA $(20\;or\;50\;{\mu}M)$ significantly inhibited the increase of dopamine content induced by L-DOPA. BHSH treatment at $10-50\;{\mu}M$ significantly inhibited basal aromatic L-amino acid decarboxylase (AADC) activity in a concentration-dependent manner at 15 min, and then AADC activity was rapidly recovered to the control level at about 2 h. These results indicate that the inhibition of AADC activity by BHSH was, in part, contributed to the early-stage decrease of dopamine content induced by LDOPA in PC12 cells. Taken together, it is proposed that the short-term inhibition of dopamine biosynthesis by BHSH was mediated by the regulation of tyrosine hydroxylace (TH).

Inhibitory Effects of Ethaverine on Serotonin Content in Murine Mastocytoma P815 Cells (Ethaverine 화합물이 P815 세포중의 Serotonin 함량에 미치는 영향)

  • Kim, Eung-Il;Shin, Jung-Soo;Lim, Sung-Cil;Park, Seung-Kook;Lee, Myung-Koo
    • YAKHAK HOEJI
    • /
    • v.51 no.2
    • /
    • pp.83-87
    • /
    • 2007
  • The effects of ethaverine on serotonin biosynthesis in murine mastocytoma P815 cells were investigated. Ethaverine at 2.5${\sim}$10 ${\mu}$M decreased serotonin content in a concentration-dependent manner. The IC$_{50}$ value of ethaverine was 6.1 ${\mu}$M. Ethaverine at concentrations up to 20 ${\mu}$M was not cytotoxic towards P815 cells. Under these conditions, tryptophan hydroxylase (EC 1.14.16.4; TPH), a rate-limiting enzyme in serotonin biosynthesis, was inhibited by ethaverine in P815 cells (15.3% inhibition at 7.5 ${\mu}$M), however, aromatic L-amino acid decarboxylase (EC 4.1.1.28) was not. These results indicate that ethaverine leads to a decrease in serotonin content by reducing TPH activity in P815 cells.

Abuse Liability Assessment of l-Deprenyl by Testing Methamphetamine-like Discriminative Effects (메탐페타민 유사 분별능 시험을 통한 l-디프레닐의 약물남용가능성 평가)

  • Lee, Sun-Hee;Kim, Pu-Young
    • YAKHAK HOEJI
    • /
    • v.42 no.1
    • /
    • pp.101-107
    • /
    • 1998
  • The antiparkinsonian agent l-deprenyl, a selective monoamine oxidase (MAO)-B inhibitor, is metabolized in part to l-methamphetamine and l-amphetamine. l< /I>-Deprenyl was evaluated for amphetamine and methamphetamine-like discriminative stimulus effects in rats and its mechanism of action was investigated. Rats were trained under a 5-response, fixed ratio schedule of stimulus-shock termination or a 10-response. Fixed-ratio schedule of food-presentation which discriminate between d-amphetamine (1mg/kg, i.p.) and saline or d-methamphetamine (1mg/kg, i.p.) and saline in a two-lever, operant conditioning procedure. Full generalization was obtained to d-amphetamine (1~3mg/kg). d-methamphetamine (1~3mg/kg) and l-deprenyl (17~30mg/kg) under both the food presentation and stimulus shock termination schedule. l-Deprenyl has dose-dependent amphetamine-and methamphetamine-like discriminative stimulus properties in rats only at doses of 17 and 30mg/kg. Reversible MAO-B inhibitor, RO 16-6491 didn`t show any amphetamine-like discriminative properties. Aromatic amino acid decarboxylase inhibitor, NSD 1015 decreased % responding of l-deprenyl in the methamphetamine-trained rats under the stimulus-shock termination schedule. SKF-525A produced partial inhibition of methamphetamine-like discriminative effects of l-deprenyl under the food presentation schedule. These results suggest that l-deprenyl has no abuse liability at the therapeutic range but there needs some caution at high doses and furthermore, drug discrimination studies under the food presentation and shock termination schedule are useful for the assessment of abuse liability of psychostimulants.

  • PDF

Serotonin Synthesis and Metabolism in Dissociated Cultures of Fetal Rat Brainstem (흰쥐 태아 뇌간의 일차 세포배양에서 Serotonin의 합성 및 대사에 대한 연구)

  • Kim, Yung-Hi;Song, Dong-Keun;Wie, Myung-Bok;Song, Joon-Ho;Choi, Yeun-Sik
    • The Korean Journal of Pharmacology
    • /
    • v.26 no.1
    • /
    • pp.1-6
    • /
    • 1990
  • We established an in vitro system of central serotonergic neurons by culturing dissociated rat embryonic (El4) brainstem cells to 14 days in vitro and monitored the serotonergic neuronal growth by measuring 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) contents in the cells with hish performance liquid chromatography with electrochemical detection (HPLC-EC). We studied also tile effects of various drugs on the contents of 5-HT and 5-HIAA, confirming in vivo reports. The 5-HT content (13 ng/mg protein) and 5-HT turnover rate (17 pmol/mg protein/h) at 14 days in vitro were in good agreement with those reported in the adult rat brain. The 5-HT content was more easily depleted with p-chlorophenylalanine, a tryptophan hydroxylase inhibitor than with NSD 1015 (3-hydroxybenzylhydrazine), an aromatic L-amino acid decarboxylase (AADC) inhibitor. Incubation of the cultures with tryptophan or 5-hydroxytryptophan increased the rate of serotonin formation implying that neither tryptophan hydroxylase nor AADC is saturated with its amino acid substrate in this in vitro system . The 5-HT content was depleted by reserpine. The 5-HT and 5-HIAA contents were increased and decreased, respectively, by monoamine oxidase inhibitors. All the above results indicate that the biochemical properties of the central serotonergic neurons in this culture system reflect reliably those of central serotonergic neurons in vivo. We suggest that measuring 5-HT and 5-HIAA contents in the primary cultured dissociated brainstem-cells with HPLC-EC is useful in the study of pharmacology as well as toxicolgy of the central serotonergic neurons.

  • PDF

Induction of Midbrain Dopaminergic Phenotype in Nurr 1-Over expressing Human Neural Stem Cells (사람 신경 간세포에서 도파민 신경세포 분화유도에 대한 Nurr 1 유전자의 역할 규명)

  • Kim, Han-Jip;Lee, Haksup;Kim, Hyon-Chang;Min, Churl-Ki;Lee, Myung-Ae;Kim, Seung-Up;Han, Jin;Youm, Jae-Boum;Kim, Nari;Park, Won, Sun;Kim, Taeho;Kim, Euiyong;Han, Il-Yong
    • KSBB Journal
    • /
    • v.20 no.5 s.94
    • /
    • pp.363-370
    • /
    • 2005
  • Neural stem cells (NSCs) of the central nervous system (CNS) have raised a great interest not only for their importance in basic neural development but also for their therapeutic potentials in neurologically degenerative diseases such as Parkinson's, Alzheimer and stroke. During the CNS development, two molecular cascades determine specification of midbrain dopamine system. In one pathway, FGF-8, sonic hedgehog and transcription factor Nurr1 specify dopamine neurotransmitter phenotype. In the other, transcription factors $Lm{\times}lb\;and\;Pt{\times}3$ are required for induction of dopaminergic neurons. In Nurr1 knockout mouse, tyrosine hydroxylase (TH) positive cells fail to appear in substantia nigra, indicating that Nurr1 is essential in specification of dopaminergic cell phenotype. In this study, we used the immortalized human NSCs retrovirally transduced with Nurr1 gene to probe the Nurr1 mediated mechanism to induce dopamine phenotype. While Nurr1 over-expression alone did not generate dopamine phenotype in NSCs, applications of retinoid and forskolin induced expression of TH and AADC mRNAs. In addition, co-cultures of Nurr1 expressing NSCs with human astrocytes induced a marked increase of TH expression. In this co-culture system, the addition of retinoid and forskolin dramatically increased expression of TH. These results indicate that the immortalized human NSCs with Nurr1 gene could have a clinical utility for cell replacement for the Parkinson patients.