• Biomolecules & Therapeutics
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• v.27 no.5
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• pp.442-449
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• 2019

This study sought to evaluate the effects of Asiatic acid in LPS-induced BV2 microglia cells and 1-methyl-4-phenyl-pyridine ($MPP^+$)-induced SH-SY5Y cells, to investigate the potential anti-inflammatory mechanisms of Asiatic acid in Parkinson's disease (PD). SH-SY5Y cells were induced using $MPP^+$ to establish as an in vitro model of PD, so that the effects of Asiatic acid on dopaminergic neurons could be examined. The NLRP3 inflammasome was activated in BV2 microglia cells to explore potential mechanisms for the neuroprotective effects of Asiatic acid. We showed that Asiatic acid reduced intracellular production of mitochondrial reactive oxygen species and altered the mitochondrial membrane potential to regulate mitochondrial dysfunction, and suppressed the NLRP3 inflammasome in microglia cells. We additionally found that treatment with Asiatic acid directly improved SH-SY5Y cell viability and mitochondrial dysfunction induced by $MPP^+$. These data demonstrate that Asiatic acid both inhibits the activation of the NLRP3 inflammasome by downregulating mitochondrial reactive oxygen species directly to protect dopaminergic neurons from, and improves mitochondrial dysfunction in SH-SY5Y cells, which were established as a model of Parkinson's disease. Our finding reveals that Asiatic acid protects dopaminergic neurons from neuroinflammation by suppressing NLRP3 inflammasome activation in microglia cells as well as protecting dopaminergic neurons directly. This suggests a promising clinical use of Asiatic acid for PD therapy.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.04a
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• pp.247-247
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• 1996

Previous work in our laboratory has shown that noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonists, MK-801, ketamine, dextrorphan and dextromethorphan cause a pronounced inhibition of apomorphine-induced cage climbing behavior in intact mice, suggesting the involvement of NMDA receptors in the glutamatergic modulation of dopaminergic function at the postsynaptic dopamine (DA) receptors: Therefore, in order to definitively establish the involvement of NMDA receptor in the apomorphine-induced dopaminergic response at the postsynaptic DA receptor, it is necessary to investigate whether or not the noncompetitive NMDA receptor antagonists would inhibit these phenomena not only in intact mice but also in the mice that are devoid of any involvement of indirect dopaminergic function. To minimize the risk of any indirect involvement of NMDA antagonists with DA neurons, vesicular DA stores were first depleted with reserpine.

• Environmental Analysis Health and Toxicology
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• v.7 no.1_2
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• pp.59-65
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• 1992

The role of central dopaminergic neural activity for the maintenance of hypertension was tested. Two groups of animals were prepared; 1) Spontaneously hypertensive rats (SHR) at 14 weeks of age which reveal hypertension and 2) age-matched normotensive Wistar Kyoto rats (WKY). Blood pressures and dopamine turnover rate were measured from animals in each group. Dopamine turnover rate was determined in four brain regions such as telence-phalon, hypothalamus/thalamus, midbrain and pons/medulla, from concentration of dopamine at time zero, 1 and 2 hours after alpha-methyl-para-tyrosine (AMPT) was injected into animals. In SHR dopamine turnover rate was greater than normotensive rats in only midbrain. The result from the present study implicates that dopaminergic neural activity in midbrain may be positively coupled to the manifestation of hypertension in SHR.

• Journal of Ginseng Research
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• v.16 no.1
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• pp.18-23
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• 1992

Central dopaminergic activity of standardized ginseng extract G115 was investigated in comparison with those induced by haloperidol in rats. The effects of G115 on the locomotor activity and, stereotyped behavior induced by apomorphine, which interacts directly with dopamine receptor were observed. Apomorphine(2 mg/kg) significantly decreased locomotor activity, whereas it showed a markdly increased incidence of stereotyped behavior. Standardized ginseng extract G115(100 mg/kg) and haloperidol(1 mg/kg) showed a significant decrease in locomotor activity but not induced stereotyped hehavior. Locomotor activity induced by apomorphine was markdly decreased by haloperidol(1 mg/kg), but that was significantly increased by standardized ginseng extract G115(50 mg/kg). Stereotyped behavior induced by apomorphine was completely supressed haloperidol(1 mg/kg), but was not changed by standardized ginseng extract G115. These results suggest that standardized ginseng extract G115 plays an important role in central dopaminergic activity, and haloperidol and standardized ginseng extract G115 seem to have a different action in behavior.

• The Korean Journal of Nuclear Medicine
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• v.37 no.1
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• pp.34-42
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• 2003

The dopamine transporter (DAT) is responsible for the re-uptake of dopamine from the synaptic cleft and is located on dopaminergic nerve terminals only. DAT single photon emission computed tomography (SPECT) and positron omission tomography (PET) imaging, therefore, offer the unique opportunity to study via striatal uptake the integrity of presynaptic dopaminergic nerve terminals in vivo. In recent years SPECT and PET using specific ligands binding to DAT have evolved as an useful tool for diagnosing and monitoring progression of neurodegenerative disorders affecting dopaminergic systems. This article briefly reviews the literature dealing with DAT SPECT and PET imaging in parkinsonism and other neurodegenerative disorders.

• Proceedings of the PSK Conference
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• 2003.10a
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• pp.108-111
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• 2003

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by a progressive loss of dopaminergic neurons in the substantia nigra. While its precise etiology is unknown, such factors as oxidative stress, impairment of mitochondrial respiration, excitotoxicity and inflammation may play roles in its pathogenesis. Although the role of apoptosis in the process of dopaminergic neuronal death has been highlighted in studies using postmortem brains and experimental models of PD, other evidence implicates both apoptosis and non-apoptotic death in PD. (omitted)

• Development and Reproduction
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• v.13 no.3
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• pp.173-181
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• 2009

One of the most extensively studied populations of multipotent adult stem cells are mesenchymal stem cells (MSCs). MSCs derived from the human umbilical cord vein (HUC-MSCs) are morphologically and immunophenotypically similar to MSCs isolated from bone marrow. HUC-MSCs are multipotent stem cells, differ from hematopoietic stem cells and can be differentiated into neural cells. Since neural tissue has limited intrinsic capacity of repair after injury, the identification of alternate sources of neural stem cells has broad clinical potential. We isolated mesenchymal-like stem cells from the human umbilical cord vein, and studied transdifferentiation-promoting conditions in neural cells. Dopaminergic neuronal differentiation of HUC-MSCs was also studied. Neural differentiation was induced by adding bFGF, EGF, dimethyl sulfoxide (DMSO) and butylated hydroxyanisole (BHA) in N2 medium and N2 supplement. The immunoreactive cells for $\beta$-tubulin III, a neuron-specific marker, GFAP, an astrocyte marker, or Gal-C, an oligodendrocyte marker, were found. HUC-MSCs treated with bFGF, SHH and FGF8 were differentiated into dopaminergic neurons that were immunopositive for tyrosine hydroxylase (TH) antibody. HUC-MSCs treated with DMSO and BHA rapidly showed the morphology of multipolar neurons. Both immunocytochemistry and RT-PCR analysis indicated that the expression of a number of neural markers including NeuroD1, $\beta$-tubulin III, GFAP and nestin was markedly elevated during this acute differentiation. While the stem cell markers such as SCF, C-kit, and Stat-3 were not expressed after neural differentiation, we confirmed the differentiation of dopaminergic neurons by TH/$\beta$-tubulin III positive cells. In conclusion, HUC-MSCs can be differentiated into dopaminergic neurons and these findings suggest that HUC-MSCs are alternative cell source of therapeutic treatment for neurodegenerative diseases.

• The Korea Journal of Herbology
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• v.29 no.3
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• pp.27-33
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• 2014

Objectives : The aim of this study was to investigate the protective effect of extract of Thuja orientalis leaves (TOFE) against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurotoxicity by inhibition of inflammation in in vitro and in vivo models of Parkinson's disease (PD). Methods : We evaluated the effect of TOFE against lipopolysaccharide (LPS)/1-methyl-4-phenylpyridinium ($MPP^+$) toxicity using nitric oxide (NO) assay, inducible NO synthase and cyclooxygenase 2 western blot, tyrosine hydroxylase and microglia activation immunohistochemistry (IHC) in BV2 cell, primary rat mesencephalic neurons, or C57BL/6 mice. We also evaluated the effect of TOFE in mice PD model induced by MPTP. C57BL/6 mice were treated with TOFE 50 mg/kg for 5 days and were injected intraperitoneally with four administrations of MPTP on the last day. We conducted behavioral tests and IHC analysis to see how TOFE affect MPTP-induced neuronal loss of dopaminergic neurons in substantia nigra pars compacta (SNpc) and striatum (ST) of mice. To assess the anti-inflammation effects, we carried out glial fibrillary acidic protein and macrophage-1 antigen integrin alpha M in IHC in SNpc and ST of mice. Results : In an in vitro system, TOFE decreasesd NO generations in BV2 cells. TOFE protected dopaminergic cells against LPS or $MPP^+$-induced toxicity in primary mesencephalic dopaminergic neurons. In vivo system, TOFE at 50 mg/kg treated group showed improved motor deteriorations than the MPTP only treated group and TOFE significantly protected striatal dopaminergic damage from MPTP-induced neurotoxicity in mice. Moreover, TOFE inhibited activation of astrocyte and microglia in SNpc and ST of the mice. Conclusions : We concluded that TOFE showed anti-parkinsonian effect by protection of dopaminergic neurons against MPTP toxicity through anti-inflammatory actions.

• The Journal of Korean Obstetrics and Gynecology
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• v.22 no.2
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• pp.119-131
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• 2009

Purpose: The depression accompanied with menopuase shows the relation with the dopamine secretion. These studies were undertaken to evaluate the anti- oxidative and neuroprotective effects of Bunsimgieum(BSGE) on dopaminergic neurons. Methods: To estimate the antioxidant effects, we carried out 1.1-diphenyl-2- picrylhydrazyl (DPPH) free radical scavenging assay, 2,2'-azinobis-(3-ethylbenzothiazoline -6-sulfonic acid (ABTS) radical cation decolorization assay, and measurement of total polyphenolic content. To evaluate neuroprotective effect of BSGE in vitro, We performed thiazolyl blue tetrazolium bromide (MTT) assay, reactive oxygen species (ROS) creation in SH-SY5Y. Tyrosine hydroxylase (TH) immunocytochemistry, nitric oxide (NO) assay, and TNF-${\alpha}$ assay in primary rat mesencephalic dopaminergic neurons. Results: The DPPH free radical and the ABTS radical cation inhibition activities were increased at a dose dependent manner. Total polyphenolic content was 0.83%. In SH-SY5Y culture, BSGE significantly increased the decreased cell viability by 6-OHDA at the concentrations of 10${\mu}$g/m${\ell}$ in pre-treatment group, 0.1-200${\mu}$g/m${\ell}$ in post-treatment group. The production of ROS induced by 6-OHDA was significantly inhibited in BSGE treated group. In mesencephalic dopaminergic cell culture, the BSGE group reduced the dopaminergic cell loss against 6-OHDA toxicity and the production of No and TNF-${\alpha}$ at the concentration of 5${\mu}$g/m${\ell}$. Conclusion: These results shows that BSGE has antioxidant and neuroprotective effects in the dopaminergic cells through decreasing the production of ROS, NO and TNF-${\alpha}$ which can cause many neurodegenerative changes in brain cell. We suggest that BSGE could be useful for the treatment of postmenopausal depression related with the decrease of dopamine.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.05a
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• pp.124-124
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• 2001

Tetrahydropapaveroline(THP), a dopamine-derived 6,7-dihydroxy-l-(3',4'-dihydroxybenzyl)-1,2,3,4-tetrahydrosioquinoline, has been suspected as a possible dopaminergic neurotoxin to elicit Parkinsonism. Autoxidation or monoamine oxidase-mediated oxidation of THP and subsequent generation of reactive oxygen species (ROS) may contribute to the degeneration of dopaminergic neurons induced by this isoquinoline alkaloid.(omitted)