• The Korean Journal of Physiology and Pharmacology
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• v.2 no.5
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• pp.565-572
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• 1998

The present study was to evaluate the protective effects of bromocriptine, which is known as $D_2$ dopamine receptor agonist and used for the treatment of patients with Parkinson's disease (PD), on 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in vitro and in vivo. Lipid peroxidation product (malondialdehyde; MDA) produced by the administration of 6-OHDA was profoundly reduced following the treatment of bromocriptine in a dose-dependent manner in rabbit brain homogenate. Quinone formation by 6-OHDA autoxidation was also attenuated, and its effect was as potent as other antioxidants. Pretreatment of bromocriptine reduced the cytotoxicity of 6-OHDA on SH-SY5Y neuroblastoma cell lines dose-dependently. The loss of striatal dopamine and its metabolite, DOPAC (dihydroxyphenylacetic acid) as well as increase of MDA production caused by intrastriatal injection of 6-OHDA was significantly recovered following the treatment of bromocriptine. The present study clearly showed that bromocriptine had a protective action against 6-OHDA-induced neurotoxicity. These results suggest that bromocriptine has the antioxidant properties, which could be another advantage for delaying the progress of Parkinson's disease.

• Herbal Formula Science
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• v.11 no.1
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• pp.99-114
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• 2003

This study aimed to investigate the effects of Chaihushugansan and Chaihuyigantang on the change of monoamine-contents in the hypothalamus of mice induced by the immobilization stress. Each formula(1.0g/kg) was injected intragastrically to mice 1 hour prior to the immobilzation stress(15 minutes) before measuring the change of monoamine-contents level in mice hypothalamus. The results were as follows: 1. DA content at control group showed significant change. CHSGS group and CHYGT group showed significant decrease.(P<0.05) 2. NE content of the control group was increased than normal group. NE content of the CHYGT group was shown a significant decrease than control group.(P<0.05) 3. DOPAC contents didn't show significant changes at any groups. 4. 5-HT contents didn't show significant changes at any groups. 5. 5-HIAA contents at CHSGS group and CHYGT group showed signifiant changes.(P<0.05, 0.01) These data revealed that chaihushugansan and chaihuyigantang might have the anti-stress effect through the control of DA and NE contents in the hypothalamus.

• Biomolecules & Therapeutics
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• v.20 no.5
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• pp.482-486
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• 2012

Cerebral monoamines play important roles as neurotransmitters that are associated with various stressful stimuli. Some components such as ginsenosides (triterpenoidal glycosides derived from the Ginseng Radix) may interact with monoamine systems. The aim of this study was to determine whether ginsenoside Rb1 can modulate levels of the monoamines such as dihydroxyphenylalanine (DOPA), dopamine (DA), norepinephrine (NE), epinephrine (EP), 3,4-dihydroxyphenylacetic acid (DOPAC), 5-hydorxytryptamine (5-HT), 5-hydroxindole-3-acetic acid (5-HIAA), and 5-hydroxytryptophan (5-HTP) in mice frontal cortex and cerebellum in response to immobilization stress. Mice were treated with ginsenoside Rb1 (10 mg/kg, oral) before a single 30 min immobilization stress. Acute immobilization stress resulted in elevation of monoamine levels in frontal cortex and cerebellum. Pretreatment with ginsenoside Rb1 attenuated the stress-induced changes in the levels of monoamines in each region. The present findings showed the anti-stress potential of ginsenoside Rb1 in relation to regulation effects on the cerebral monoaminergic systems. Therefore, the ginsenoside Rb1 may be a useful candidate for treating several brain symptoms related with stress.

• Biomolecules & Therapeutics
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• v.2 no.4
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• pp.316-321
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• 1994

This study was undertaken to estimate whether nalbuphine, a mixed agonist/antagonist opioid analgesic produced psychic dependence. Moreover, the physical dependence liability of nalbuphine was compared with that of morphine after 7 days administrations of the drugs in mice and rats, and the effects of ginseng total saponin (GTS) on the development of physical dependence on nalbuphine were also studied. Nalbuphine did not produce psychic dependence. However, various abstinence signs precipitated by naloxone were observed in nalbuphine-dependent mice and rats. As the nature of the dependence syndrome produced by nalbuphine 30 mg/kg under these conditions seems similar to that induced by morphine 10 mg/kg, it is clear that nalbuphine possesses the substantial abuse potential. Therefore, nalbuphine may be needed to initiate more stringent controls for the prevention of nalbuphine abuse. On the other hand, GTS inhibited the development of physical dependence on nalbuphine and reduced the contents of dopamine and its metabolite in the brains of mice. Accordingly, results of this study suggest that the inhibitory effects of GTS on the development of physical dependence on nalbuphine may involve dopaminergic mechanism. GTS may be useful for the therapy of physical dependence on nalbuphine.

• Natural Product Sciences
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• v.22 no.3
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• pp.187-192
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• 2016

The goal of this study was to determine whether gypenosides (GPS) exert protective effects against dopaminergic neuronal cell death in a 6-hydroxydopamine (OHDA)-lesioned rat model of Parkinson's disease (PD) with or without long-term 3,4-dihydroxyphenylalanine (L-DOPA) treatment. Rats were injected with 6-OHDA in the substantia nigra to induce PD-like symptoms; 14 days after injection, groups of 6-OHDA-lesioned animals were treated for 21 days with GPS (25 or 50 mg/kg) and/or L-DOPA (20 mg/kg). Dopaminergic neuronal cell death was assessed by counting tyrosine hydroxylase (TH)-immunopositive cells in the substantia nigra and measuring levels of dopamine, norepinephrine, 3,4-dihydroxyphenylacetic acid (DOPAC), and homovanillic acid (HVA) in the striatum. Dopaminergic neuronal cell death induced by 6-OHDA lesions was ameliorated by GPS treatment (50 mg/kg). L-DOPA treatment exacerbated 6-OHDA-induced dopaminergic neuronal cell death; however, these effects were partially reversed by GPS treatment (25 and 50 mg/kg). These results suggest that GPS treatment is protective against dopaminergic neuronal cell death in a 6-OHDA-lesioned rat model of PD with long-term L-DOPA treatment. Therefore, GPS may be useful as a phytotherapeutic agent for the treatment of PD.

• Korean Journal of Biological Psychiatry
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• v.3 no.1
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• pp.51-56
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• 1996

The effects of 3 week treatment with haloperidol(2mg/kg/day, i.p.) on dopamine(DA) D2 receptor and DA metabolism in rat striata were studied at various time points after withdrawal from the drug treatment. Striatal DA D2 receptors were characterized with the radioligand 0.5nM [$^3H$]Spiperone. Dopamine(DA), homovanillic acid(HVA), 3,4-dihydroxyphenyl acetic acid(DOPAC) in rat striatum were measured with the high performance liquid chromatography. Drug withdrawal for 1 week induced significant increase in the number of D2 receptor in striatum after withdrawal for 1 week(p<0.05), and then this change was restored to control level during the withdrawal time of 2 and 4 weeks. There was no difference in striatal concentrations of DA and its metabolites among the groups. In conclusion, one-week withdrawal from chronic haloperidol treatment induced DA D2 receptor supersensitivity in the striatum, and that was normalized rapidly. Though this adaptive change in DA receptors, it may not affect the metabolism of DA in striatum.