• The Korea Journal of Herbology
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• v.21 no.2
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• pp.135-142
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• 2006

Objectives : On-Bi-Tang(OB) has been prescribed Chinese traditional medicine for the treatment of inflammatory disease such as chronic renal failure. In this study, we investigated the anti-inflammatory effect of OB extract in the BV2 murine microglial cells. Methods : After the water extract of OB was treated in BV2 cells, murine microglial line, the cell viability was measured by MTT assay. The production of nitric oxide (NO) and $TNF-{\alpha}$ was determined based on Griess reagent and enzyme linked immunosorbant assay (ELISA). mRNA expression of inducible nitric oxide synthase (iNOS) and $TNF-{\alpha}$ was analyzed by RT-PCR. Results : OB extract significantly inhibited the LPS-induced production of NO and TNF-a in BV2 cells. OB extract also suppressed the mRNA expression of iNOS and $TNF-{\alpha}$ in BV2 cells activated with LPS. Conclusion : These data suggests that OB extract may have the anti-inflammatory effect through the modulation of NO production and inflammatory cytokine such as $TNF-{\alpha}$.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.1
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• pp.41-51
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• 2016

Adult hippocampal dentate granule neurons are generated from neural stem cells (NSCs) in the mammalian brain, and the fate specification of adult NSCs is precisely controlled by the local niches and environment, such as the subventricular zone (SVZ), dentate gyrus (DG), and Toll-like receptors (TLRs). Epigallocatechin-3-gallate (EGCG) is the main polyphenolic flavonoid in green tea that has neuroprotective activities, but there is no clear understanding of the role of EGCG in adult neurogenesis in the DG after neuroinflammation. Here, we investigate the effect and the mechanism of EGCG on adult neurogenesis impaired by lipopolysaccharides (LPS). LPS-induced neuroinflammation inhibited adult neurogenesis by suppressing the proliferation and differentiation of neural stem cells in the DG, which was indicated by the decreased number of Bromodeoxyuridine (BrdU)-, Doublecortin (DCX)- and Neuronal Nuclei (NeuN)-positive cells. In addition, microglia were recruited with activating TLR4-NF-${\kappa}B$ signaling in the adult hippocampus by LPS injection. Treating LPS-injured mice with EGCG restored the proliferation and differentiation of NSCs in the DG, which were decreased by LPS, and EGCG treatment also ameliorated the apoptosis of NSCs. Moreover, pro-inflammatory cytokine production induced by LPS was attenuated by EGCG treatment through modulating the TLR4-NF-${\kappa}B$ pathway. These results illustrate that EGCG has a beneficial effect on impaired adult neurogenesis caused by LPS-induced neuroinflammation, and it may be applicable as a therapeutic agent against neurodegenerative disorders caused by inflammation.

• Biomolecules & Therapeutics
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• v.21 no.1
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• pp.60-65
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• 2013

3,4,5-Trihydroxycinnamic acid (THC) is a derivative of hydroxycinnamic acids, which have been reported to possess a variety of biological properties such as anti-inflammatory, anti-tumor, and neuroprotective activities. However, biological activity of THC has not been extensively examined. Recently, we reported that THC possesses anti-inflammatory activity in LPS-stimulated BV2 microglial cells. However, its precise mechanism by which THC exerts anti-inflammatory action has not been clearly identified. Therefore, the present study was carried out to understand the anti-inflammatory mechanism of THC in BV2 microglial cells. THC effectively suppressed the LPS-induced induction of pro-inflammatory mediators such as NO, TNF-${\alpha}$, and IL-$1{\beta}$. THC also suppressed expression of MCP-1, which plays a key role in the migration of activated microglia. To understand the underlying mechanism by which THC exerts these anti-inflammatory properties, involvement of Nrf2, which is a cytoprotective transcription factor, was examined. THC resulted in increased phosphorylation of Nrf2 with consequent expression of HO-1 in a concentration-dependent manner. THC-induced phosphorylation of Nrf2 was blocked with SB203580, a p38 MAPK inhibitor, indicating that p38 MAPK is the responsible kinase for the phosphorylation of Nrf2. Taken together, the present study for the first time demonstrates that THC exerts anti-inflammatory properties through the activation of Nrf2 in BV2 microglial cells, suggesting that THC might be a valuable therapeutic adjuvant for the treatment of inflammation-related disorders in the CNS.

• The Korea Journal of Herbology
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• v.34 no.4
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• pp.9-18
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• 2019

Objectives : It has been known to be correlated between phlegm and dementia from the perspective of oriental medicine, but it is unexplored whether herbal medicines to treat phlegm have pharmacological actions on Alzheimer's disease (AD). The aim of this study was to evaluate and to compare effects of herbal medicines to treat phlegm against AD in vitro. Methods : We selected 11 herbal medicines which treat phlegm and obtained each extract by boiling in 10-fold distilled water for 2 h. And we performed the assay of acetylcholinesterase (AChE) inhibitory effects of 11 herbal extracts. Next, we evaluated neuroprotective effects of them against amyloid $beta_{25-35}$ ($A{\beta}_{25-35}$) plaque-induced toxicity in HT22 mouse hippocampal neuronal cells using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. To investigate whether they show the anti-inflammatory effects against lipopolysaccharide (LPS), we also measured the levels of nitric oxide (NO) in BV2 microglia cells using griess reagent assay. Results : We found that Gamiyeongsin-hwan (GYH) and Cheonghunhwadam-tang (CHT) exhibited remarkable AChE inhibitory effects. In HT22 cells, Arisaematis Rhizoma, Trichosanthis Semen and Fritillariae Thunbergii Bulbus suppressed $A{\beta}_{25-35}$ plaque-induced neuronal cell death. In BV2 cells, Cheongung-hwan significantly inhibited the increase of NO contents induced by LPS and GYH and CHT showed a tendency to inhibit LPS-induced NO generation. Conclusions : These results suggest that several herbal medicines to treat phlegm showed the significant effects on AChE inhibition, neuroprotection against $A{\beta}_{25-35}$ plaque-induced toxicity, and inhibition of NO generation. Therefore, we demonstrate the possibility that herbal medicines with treating phlegm has effects against AD.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.3
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• pp.253-260
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• 2020

Alzheimer's disease (AD) is a chronic and progressive neurodegenerative disease that can be described by the occurrence of dementia due to a decline in cognitive function. The disease is characterized by the formation of extracellular and intracellular amyloid plaques. Amyloid beta (Aβ) is a hallmark of AD, and microglia can be activated in the presence of Aβ. Activated microglia secrete pro-inflammatory cytokines. Furthermore, S100A9 is an important innate immunity pro-inflammatory contributor in inflammation and a potential contributor to AD. This study examined the effects of metformin and α-LA on the inflammatory response and NLRP3 inflammasome activation in Aβ- and S100A9-induced BV-2 microglial cells. Metformin and α-LA attenuated inflammatory cytokines, such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). In addition, metformin and α-LA inhibited the phosphorylation of JNK, ERK, and p38. They activated the nuclear factor kappa B (NF-κB) pathway and the NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome. Moreover, metformin and α-LA reduced the marker levels of the M1 phenotype, ICAM1, whereas the M2 phenotype, ARG1, was increased. These findings suggest that metformin and α-LA are therapeutic agents against the Aβ- and S100A9-induced neuroinflammatory responses.

• Biomolecules & Therapeutics
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• v.17 no.1
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• pp.47-56
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• 2009

Schizandra chinensis (S. chinensis) exhibits a harmless, 'adaptogen-type' effect leading to improvements in mental performance and learning efficacy in brain. Activated microglia contributes to neuronal injury by releasing neurotoxic products, which make it important to regulate microglial activation to prevent further cytological as well as functional brain damage. However, the effect of S. chinensis on microglial activation has not been examined yet. We have investigated the effects of four compounds (Gomisin A, Gomisin N, Schizandrin and Schizandrol A) from S. chinensis on lipopolysaccharide (LPS)-induced microglial activation. In this study, BV2 microglial cells were activated with LPS and the microglial activation was assessed by up-regulation of activation markers such as nitric oxide (NO), reactive oxygen species (ROS), and matrix metalloproteinase-9 (MMP-9). The results showed that all four compounds significantly reduced the intracellular level of ROS, the release of NO and MMP-9 as well as LPS-induced phosphorylation of ERK1/2. These results strongly suggested that S. chinensis may be useful to modulate inflammation-mediated brain damage by regulating microglial activation.

• Korean Journal of Acupuncture
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• v.30 no.1
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• pp.56-63
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• 2013

Objectives : Effects of repetitive electroacupuncture(EA) on the pain behavior and activation of spinal glial cells were examined in the rat model of neuropathic pain. Methods : Twenty one adult male Sprague-Dawley rats were randomly assigned into 3 groups(control group, SP6 group, ST36+GB34 group). Neuropathic pain was induced by tight ligation of L5 spinal nerve. Mechanical and thermal hypersensitivity of hind paw were tested. Immunohistochemistry was performed in spinal cord L5/6 of all groups. EA was treated once in a day from the $5^{th}$ day after surgery. Results : EA treatments applied to ST36 and GB34 reduced significantly both of mechanical and thermal hypersensitivity after 3 times of treatment throughout the experiments. In the SP6 group, the analgesic effect was also shown after 7 times of treatment. Immunohistochemistry demonstrated inhibition of microglia and astrocyte activation in the spinal cord L5/6 dorsal horn in the ST36+GB34 group. Conclusions : The present results suggest that repetitive EA exert strong analgesic effect on neuropathic pain. These analgesic effects in neuropathic pain are associated with suppressing the activation of microglia and astrocyte.

• 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.

• International Journal of Oral Biology
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• v.33 no.1
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• pp.1-5
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• 2008

Adenosine 5'-triphosphate (ATP) is an important extracellular signaling molecule which is involved in a variety of physiological responses in many different tissues and cell types, by acting at P2 receptors, either ionotropic (P2X) or G protein-coupled metabotropic receptors (P2Y). P2X receptors have seven isoforms designated as $P2X_{1^-}P2X_7$. In this study, we investigated the electrophysiological and pharmacological properties of rat $P2X_{1^-}P2X_4$ currents by using whole-cell patch clamp technique in a heterologous expression system. When ATP-induced currents were analyzed in human embryonic kidney (HEK293) cells following transient transfection of rat $P2X_{1^-}P2X_4$, the currents showed different pharmacological and electrophysiological properties. ATP evoked inward currents with fast activation and fast desensitization in $P2X_{^1-}$ or $P2X_{3^-}$ expressing HEK293 cells, but in $P2X_{2^-}$ or $P2X_{4^-}$ expressing HEK293 cells, ATP evoked inward currents with slow activation and slow desensitization. While PPADS and suramin inhibited $P2X_2$ or $P2X_3$ receptor-mediated currents, they had little effects on $P2X_4$ receptor-mediated currents. Ivermectin potentiated and prolonged $P2X_4$ receptor-mediated currents, but did not affect $P2X_2$ or $P2X_3$ receptor-mediated currents. We suggest that distinct pharmacological and electrophysiological properties among P2X receptor subtypes would be a useful tool to determine expression patterns of P2X receptors in the nervous system including trigeminal sensory neurons and microglia.

• Biomolecules & Therapeutics
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• v.23 no.6
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• pp.531-538
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• 2015

Preceding infection or inflammation such as bacterial meningitis has been associated with poor outcomes after stroke. Previously, we reported that intracorpus callosum microinjection of lipopolysaccharides (LPS) strongly accelerated the ischemia/reperfusionevoked brain tissue damage via recruiting inflammatory cells into the ischemic lesion. Simvastatin, 3-hydroxy-3-methylgultaryl (HMG)-CoA reductase inhibitor, has been shown to reduce inflammatory responses in vascular diseases. Thus, we investigated whether simvastatin could reduce the LPS-accelerated ischemic injury. Simvastatin (20 mg/kg) was orally administered to rats prior to cerebral ischemic insults (4 times at 72, 48, 25, and 1-h pre-ischemia). LPS was microinjected into rat corpus callosum 1 day before the ischemic injury. Treatment of simvastatin reduced the LPS-accelerated infarct size by 73%, and decreased the ischemia/reperfusion-induced expressions of pro-inflammatory mediators such as iNOS, COX-2 and IL-$1{\beta}$ in LPS-injected rat brains. However, simvastatin did not reduce the infiltration of microglial/macrophageal cells into the LPS-pretreated brain lesion. In vitro migration assay also showed that simvastatin did not inhibit the monocyte chemoattractant protein-1-evoked migration of microglial/macrophageal cells. Instead, simvastatin inhibited the nuclear translocation of NF-${\kappa}B$, a key signaling event in expressions of various proinflammatory mediators, by decreasing the degradation of $I{\kappa}B$. The present results indicate that simvastatin may be beneficial particularly to the accelerated cerebral ischemic injury under inflammatory or infectious conditions.