• Biomolecules & Therapeutics
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• v.25 no.6
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• pp.641-647
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• 2017

Galangin (3,5,7-trihydroxyflavone) is a polyphenolic compound abundant in honey and medicinal herbs, such as Alpinia officinarum. In this study, we investigated the anti-inflammatory effects of galangin under in vitro and in vivo neuroinflammatory conditions caused by polyinosinic-polycytidylic acid (poly(I:C)), a viral mimic dsRNA analog. Galangin suppressed the production of nitric oxide, reactive oxygen species, and pro-inflammatory cytokines in poly(I:C)-stimulated BV2 microglia. On the other hand, galangin enhanced anti-inflammatory interleukin (IL)-10 production. Galangin also suppressed the expression of pro-inflammatory markers in poly(I:C)-injected mouse brains. Further mechanistic studies showed that galangin inhibited poly(I:C)-induced nuclear factor (NF)-${\kappa}B$ activity and phosphorylation of Akt without affecting MAP kinases. Interestingly, galangin increased the expression and transcriptional activity of peroxisome proliferator-activated receptor (PPAR)-${\gamma}$, known to play an anti-inflammatory role. To investigate whether PPAR-${\gamma}$ is involved in the anti-inflammatory function of galangin, BV2 cells were pre-treated with PPAR-${\gamma}$ antagonist before treatment of galangin. We found that PPAR-${\gamma}$ antagonist significantly blocked galangin-mediated upregulation of IL-10 and attenuated the inhibition of tumor necrosis factor (TNF)-${\alpha}$ and IL-6 in poly(I:C)-stimulated microglia. In conclusion, our data suggest that PI3K/Akt, NF-${\kappa}B$, and PPAR-${\gamma}$ play a pivotal role in mediating the anti-inflammatory effects of galangin in poly(I:C)-stimulated microglia.

• Biomolecules & Therapeutics
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• v.25 no.6
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• pp.618-624
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• 2017

Betulinic acid (BA), a natural pentacyclic triterpene found in many medicinal plants is known to have various biological activity including tumor suppression and anti-inflammatory effects. In this study, the cell-death induction effect of BA was investigated in BV-2 microglia cells. BA was cytotoxic to BV-2 cells with $IC_{50}$ of approximately $2.0{\mu}M$. Treatment of BA resulted in a dose-dependent chromosomal DNA degradation, suggesting that these cells underwent apoptosis. Flow cytometric analysis further confirmed that BA-treated BV-2 cells showed hypodiploid DNA content. BA treatment triggered apoptosis by decreasing Bcl-2 levels, activation of capase-3 protease and cleavage of PARP. In addition, BA treatment induced the accumulation of p62 and the increase in conversion of LC3-I to LC3-II, which are important autophagic flux monitoring markers. The increase in LC3-II indicates that BA treatment induced autophagosome formation, however, accumulation of p62 represents that the downstream autophagy pathway is blocked. It is demonstrated that BA induced cell death of BV-2 cells by inducing apoptosis and inhibiting autophagic flux. These data may provide important new information towards understanding the mechanisms by which BA induce cell death in microglia BV-2 cells.

• Journal of Physiology & Pathology in Korean Medicine
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• v.24 no.3
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• pp.463-469
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• 2010

This research is performed to obtain positive evidences of Mori cortex, a kind of oriental medicinal herbs, in the cellular levels. The extracts of M. cortex have shown anti-inflammatory effects against cutaneous inflammation and clinical effects on pulmonary asthma and congestion in oriental medicine. Thus BV2 cells were chosen because microglia are considered as the main immunocompetent cells in the central nervous system. Lipopolysaccharide (LPS)-induced microglial activation of cultured BV2 cells and subsequent release of nitric oxide (NO) and Prostaglandin E2 (PGE2) were effectively suppressed by methylene chloride extract of Morus alba L. (MEMA). From the inflammation-mediated mRNA and protein analyses, we showed that inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin-$1{\beta}$ (IL-$1{\beta}$) and tumor necrosis alpha (TNF-${\alpha}$) induced by LPS were markedly decreased by MEMA treatment. From the observation of nuclear factor-kB (NF-${\kappa}B$) which is controlling and mediating inflammation through COX-2 and iNOS, there showed that p65, a subunit of NF-${\kappa}B$, was increased in nuclear and $I{\kappa}B$, a competitor of NF-${\kappa}B$, was recovered in cytosol after MEMA treatment. These are corresponding with results of iNOS, COX-2, IL-$1{\kappa}$ and TNF-${\alpha}$, and confirm some suppressive effect against transcriptional activation of NF-${\kappa}B$. In conclusion, the anti-inflammatory action of M. cortex against BV2 microglia cells is expected to protect nerve tissues through suppression of neuronal inflammation in various neurodegenerative diseases.

• International Journal of Oral Biology
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• v.40 no.2
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• pp.71-77
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• 2015

The activation of glial cells in the spinal cord has been contribute to the initiation and maintenance of pain facilitation induced by peripheral inflammation and nerve injury. The present study investigated effects of botulinum toxin type A (BoNT-A), injected subcutaneously or intracisternally, on the expression of microglia and astrocytes in rats. Complete Freund's Adjuvant (CFA)-induced inflammation was employed as an orofacial chronic inflammatory pain model. A subcutaneous injection of $40{\mu}L$ CFA into the vibrissa pad was performed under 3% isoflurane anesthesia in SD rats. Immunohistochemical analysis for changes in Iba1 (a microglia marker) and GFAP (an astrocyte marker), were performed 5 days after CFA injection. Subcutaneous injection of CFA produced increases in Iba1 and GFAP expression, in the ipsilateral superficial lamia I and II in the medullary dorsal horn of rats. Subcutaneous treatment with BoNT-A attenuated the up-regulation of Iba1 and GFAP expressions induced by CFA injection. Moreover, intracisternal injection of BoNT-A also attenuated the up-regulated Iba1 and GFAP expressions. These results suggest that the anti-nociceptive action of BoNT-A is mediated by modulation activation of glial cells, including microglia and astrocyte.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.5
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• pp.1200-1210
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• 2006

This experiment was designed to investigate the effect of the CMT and MCMT hot water extract & ultra-fine powder on microglia and memory deficit model. The effects of the CMT and MCMT hot water extract on expression of IL-l${\beta}$, IL-6, TNF-${\alpha}$, NOS-II, COX-2, IL-10, TGF-${\beta}$1 mRNA and production of IL-lP, IL-6, TNF-a, NO, ROS in BV2 microglial cell line treated by lipopolysacchaide(LPS) ; serum glucose, uric acid, AChE activity of the memory deficit mice induced by scopolamine , behavior of the memory deficit mice induced by scopolamine and were investigated, respectively. The CMT and MCMT hot water extract suppressed the expression of IL-1${\beta}$, IL-6, TNF-${\alpha}$, NOS-II, COX-2 mRNA, production of IL-l${\beta}$, IL-6, TNF-${\alpha}$, NO, ROS and increased the expression of IL-10, TGF-${\beta}$l mRNA in BV2 microglial cell line treated by LPS. The MCMT hot water extract & ultra-fine powder increased glucose, decreased uric acid and AChE significantly in the serum of the memory deficit mice induced by scopolamine. The CMT and MCMT hotwater extract & ultra-fine powder groups showed significantly inhibitory effect on the scopolamine-induced impairment of memory in the experiment of Morris water maze. According to the above result, it is suggested that the CMT and MCMT hot water extract & ultra-fine powder might be usefully applied for prevention and treatment of dementia.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.4
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• pp.997-1008
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• 2006

This experiment was designed to investigate the effect of the CMT and PCMT hot water extract & ultra-fine powder on microglia and memory deficit model. The effects of the CMT and PCMT hot water extract on expression of $IL-l{\beta},\;IL-6,\;TNF-{\alpha}$, NOS-II, COX-2, IL-10, $TGF-{\beta}1$ mRNA and production of $IL-l{\beta},\;IL-6,\;TNF-{\alpha}$, NO, ROS in BV2 microglial cell line treated by lipopolysacchaide(LPS) , serum glucose, uric acid, AChE activity of the memory deficit mice induced by scopolamine , behavior of the memory deficit mice induced by scopolamine and were investigated, respectively. The CMT and PCMT hot water extract suppressed the expression of $IL-l{\beta},\;IL-6,\;TNF-{\alpha}$, NOS-11, COX-2 mRNA, production of $IL-l{\beta},\;IL-6,\;TNF-{\alpha}$, NO, ROS and increased the expression of IL-10, $TGF-{\beta}1$ mRNA in BV2 microglial cell line treated by LPS. The PCMT hot water extract & ultra-fine powder increased glucose, decreased uric acid and AChE significantly in the serum of the memory deficit mice induced by scopolamine. The CMT and PCMT hot water extract & ultra-fine powder groups showed significantly inhibitory effect on the scopolamine-induced impairment of memory in the experiment of Morris water maze. According to the above result, it is suggested that the CMT and PCMT hot water extract & ultra-fine powder might be usefully applied for prevention and treatment of dementia.

• 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.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.4
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• pp.389-397
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• 2020

Microglial cells function as major immune cells in the brain, playing an important role in the protection and damage of neurons. BV2 microglia, activated by drug stimulation, secrete inflammatory cytokines by activating the nuclear factor kappa-light-chain-enhancer of the activated B cells pathway and are involved in neuroinflammatory and immune responses. The overactivation of microglia by stimuli can cause neuronal damage, leading to brain disease. Noni, a natural product, reduces the activity of microglia to prevent neuronal damage and is a potential natural medicine because it exerts excellent regeneration and anti-inflammatory effects on damaged cells. In this study, when noni was used to treat BV2 cells stimulated by the anti-cancer drug doxorubicin, it reduced the release of pro-inflammatory cytokines from BV2. On the other hand, neuronal damage is a side effect of doxorubicin. Therefore, the cytokines released from doxorubicin-stimulated BV2 cells treated with noni had a positive effect on the neuronal viability compared to those released from doxorubicin-stimulated BV2 cells not treated with Noni. Thus, Noni increases neuronal viability. These results suggest that noni inhibits the release of cytokines by regulating the nuclear factor kappa-light-chain-enhancer of the activated B cells pathway of BV2, thereby inhibiting neuronal damage.

• BMB Reports
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• v.55 no.4
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• pp.181-186
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• 2022

Ventriculomegaly induced by the abnormal accumulation of cerebrospinal fluid (CSF) leads to hydrocephalus, which is accompanied by neuroinflammation and mitochondrial oxidative stress. The mitochondrial stress activates mitochondrial unfolded protein response (UPRmt), which is essential for mitochondrial protein homeostasis. However, the association of inflammatory response and UPRmt in the pathogenesis of hydrocephalus is still unclear. To assess their relevance in the pathogenesis of hydrocephalus, we established a kaolin-induced hydrocephalus model in 8-week-old male C57BL/6J mice and evaluated it over time. We found that kaolin-injected mice showed prominent ventricular dilation, motor behavior defects at the 3-day, followed by the activation of microglia and UPRmt in the motor cortex at the 5-day. In addition, PARP-1/NF-κB signaling and apoptotic cell death appeared at the 5-day. Taken together, our findings demonstrate that activation of microglia and UPRmt occurs after hydrocephalic ventricular expansion and behavioral abnormalities which could be lead to apoptotic neuronal cell death, providing a new perspective on the pathogenic mechanism of hydrocephalus.

• BMB Reports
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• v.55 no.9
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• pp.447-452
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• 2022

Neurogenic differentiation 1 (NeuroD1) is an essential transcription factor for neuronal differentiation, maturation, and survival, and is associated with inflammation in lipopolysaccharide (LPS)-induced glial cells; however, the concrete mechanisms are still ambiguous. Therefore, we investigated whether NeuroD1-targeting miRNAs affect inflammation and neuronal apoptosis, as well as the underlying mechanism. First, we confirmed that miR-30a-5p and miR-153-3p, which target NeuroD1, reduced NeuroD1 expression in microglia and astrocytes. In LPS-induced microglia, miR-30a-5p and miR-153-3p suppressed pro-inflammatory cytokines, reactive oxygen species, the phosphorylation of c-Jun N-terminal kinase, extracellular-signal-regulated kinase (ERK), and p38, and the expression of cyclooxygenase and inducible nitric oxide synthase (iNOS) via the NF-κB pathway. Moreover, miR-30a-5p and miR-153-3p inhibited the expression of NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasomes, NLRP3, cleaved caspase-1, and IL-1β, which are involved in the innate immune response. In LPS-induced astrocytes, miR-30a-5p and miR-153-3p reduced ERK phosphorylation and iNOS expression via the STAT-3 pathway. Notably, miR-30a-5p exerted greater anti-inflammatory effects than miR-153-3p. Together, these results indicate that miR-30a-5p and miR-153-3p inhibit MAPK/NF-κB pathway in microglia as well as ERK/STAT-3 pathway in astrocytes to reduce LPS-induced neuronal apoptosis. This study highlights the importance of NeuroD1 in microglia and astrocytes neuroinflammation and suggests that it can be regulated by miR-30a-5p and miR-153-3p.