• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.20 no.3
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• pp.98-106
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• 2007

포공영(蒲公英)은 예로부터 청열해독약(淸熱解毒藥)으로 사용되어 왔으며 NO가 염증의 한 요인이기 때문에 포공영의 항염증 작용기작을 밝히기 위하여 LPS로 자극된 대식세포주 RAW264.7 세포에서 포공영 열수 추출물 (AETM)의 NO 생성에 미치는 효과를 조사하였다. 포공영은 NO 생성 및 iNOS 단백질 발현, iNOS mRNA 발현을 저해하였으며, 전사인자인 $NF-kB$의 핵으로의 이동을 억제하였다. 또한 LPS에 의해서 활성화되는 ERK/MAPK 효소의 활성을 현저히 억제하였다. 이 결과들로 보아 포공영의 항염증 작용이 ERK/MAPK 활성 저해 및 $NF-kB$ 활성 저해로 인한 iNOS 발현의 억제 때문인 것으로 사료된다.

• BMB Reports
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• v.53 no.7
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• pp.373-378
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• 2020

Phosphorylation of the signaling component by protein kinase often leads to a kinase cascade or feedback loop. 3-Phosphoinositide-dependent kinase 1 (PDK1) signaling pathway diverges into various kinases including Akt and p70 S6 kinase (p70S6k). However, the PDK1 feedback mechanism remains elusive. Here, we demonstrated that UNC-51-like kinase (ULK1), an autophagy initiator kinase downstream of mechanistic target of rapamycin (mTOR), directly phosphorylated PDK1 on serine 389 at the linker region. Furthermore, our data showed that this phosphorylation affected the kinase activity of PDK1 toward downstream substrates. These results suggest a possible negative feedback loop between PDK1 and ULK1.

• International Journal of Oral Biology
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• v.39 no.4
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• pp.221-228
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• 2014

Glucosamine is commonly taken by the elderly without prescription as a nutritional supplement to attenuate the progression or symptoms of osteoarthritis. Previous studies demonstrated that glucosamine shows anti-inflammatory effects in tissues such as blood vessels and the heart. However, there have been few reports about the effects of glucosamine on oral inflammatory diseases. Therefore, in this study, the effects of glucosamine on lipopolysaccharide (LPS)-induced inflammatory responses were investigated using human periodontal ligament fibroblasts (HPDLFs). HPDLFs were incubated in the presence and absence of glucosamine (10 mM) for 24 h, followed by treatment with E. coli LPS (100 ng/ml) or vehicle. Quantitative RT-PCR and ELISA results showed that LPS exposure significantly increased the levels of IL-6 and IL-8 mRNA and protein, while the effect was significantly suppressed by glucosamine treatment. Glucosamine did not attenuate, but slightly increased, the LPS-induced activation of mitogen activated kinases (ERK, p38, JNK). However, it suppressed the LPS-induced increase in the DNA binding affinity and transcriptional activity of NF-${\kappa}B$. These results suggest that glucosamine exerts anti-inflammatory effects on HPDLFs exposed to LPS via inhibition of NF-${\kappa}B$ activity, necessitating further studies using animal periodontitis models.

• Journal of Physiology & Pathology in Korean Medicine
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• v.24 no.3
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• pp.410-415
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• 2010

The purpose of this study was to investigate the anti-inflammatory effects of aqueous extract from Belamcanda chinensis (BC) on the RAW 264.7 cells. To evaluate the anti-inflammatory effects of BC, we examined the cytokine productions including nitric oxide (NO), interleukin (IL)-1b, IL-6 and tumor necrosis factor-a (TNF-a) in lipopolysaccharide (LPS)-induced RAW 264.7 cells and also inhibitory mechanisms such as mitogen-activated protein kinases (MAPKs) and nuclear factor kappa B (NF-kB) using Western blot. BC inhibited LPS-induced production of NO, IL-6 and TNF-a but not of IL-1b in RAW 264.7 cells. BC respectively inhibited the activation of MAPKs such as c-Jun NH2-terminal kinase (JNK) and p38 but not of extracelluar signal-regulated kinase (ERK 1/2) and NF-kB in the LPS-stimulated RAW 264.7 cells. Taken together, Our results showed that BC down-regulated LPS-induced NO, IL-6 and TNF-a productions mainly through JNK and p38 MAPK pathway.

• Animal cells and systems
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• v.7 no.3
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• pp.173-186
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• 2003

The transition metal cadmium is a serious occupational and environmental toxin. To inhibit cadmium-induced damage, cells respond by increasing the expression of genes that encode stress-responsive proteins. The metal-regulatory transcription factor 1 (MTF-1) is a key regulator of heavy-metal induced transcription of metallothionein-I and II and other genes in mammals and other metazoans. Transcriptional activation of genes by MTF-1 is mediated through binding to metal-responsive elements in the target gene promoters. Phosphorylation of MTF-1 plays a critical role in the cadmium-inducible transcriptional activation of metallothionein and other responses. Studies using inhibitors indicate that multiple kinases and signal transduction cascades, including those mediated by protein kinase C, tyrosine kinase and casein kinase II, are essential for cadmium-mediated transcriptional activation. In addition, calcium signaling is also involved in regulating metal-activated transcription. In several species, cadmium induces heat shock genes. Recently much progress has been made in elucidating the cellular machinery that regulates this metal-inducible gene expression. This review summarizes these recent advances in understanding the role of some known cadmium-responsive genes and the molecular mechanisms that activate metal-responsive transcription factor, MTF-1.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.3
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• pp.211-218
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• 2015

The present study showed that silymarin, a polyphenolic flavonoid isolated from milk thistle (Silybum marianum), inhibited lipopolysaccharide (LPS)-induced morphological changes in the mouse RAW264.7 macrophage cell line. We also showed that silymarin inhibited the nuclear translocation and transactivation activities of nuclear factor-kappa B (NF-${\kappa}B$), which is important for macrophage activation-associated changes in cell morphology and gene expression of inflammatory cytokines. BAY-11-7085, an NF-${\kappa}B$ inhibitor, abrogated LPS-induced morphological changes and NO production, similar to silymarin. Treatment of RAW264.7 cells with silymarin also inhibited LPS-stimulated activation of mitogen-activated protein kinases (MAPKs). Collectively, these experiments demonstrated that silymarin inhibited LPS-induced morphological changes in the RAW264.7 mouse macrophage cell line. Our findings indicated that the most likely mechanism underlying this biological effect involved inhibition of the MAPK pathway and NF-${\kappa}B$ activity. Inhibition of these activities by silymarin is a potentially useful strategy for the treatment of inflammation because of the critical roles played by MAPK and NF-${\kappa}B$ in mediating inflammatory responses in macrophages.

• Journal of Microbiology and Biotechnology
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• v.27 no.2
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• pp.242-250
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• 2017

Anti-photoaging effects of standardized Siegesbeckia glabrescens extract (SGE) and its major active compound kirenol were investigated using Hs68 human dermal fibroblasts and hairless mice, respectively. UVB-irradiated hairless mice that received oral SGE (600 mg/kg/day) showed reduced wrinkle formation and skinfold thickness compared with the UVB-irradiated control. Furthermore, SGE treatment increased the mRNA levels of collagen synthesis genes (COL1A1, COL3A1, COL4A1, and COL7A1) and activated antioxidant enzyme (catalase), while suppressing matrix metalloproteinase (MMP-2, -3, -9, and -13) expression. In Hs68 fibroblasts, kirenol also significantly suppressed MMP expression while increasing the expression of COL1A1, COL3A1, and COL7A1. Collectively, our data demonstrate that both SGE and kirenol attenuated UVB-induced photoaging in hairless mice and fibroblasts through inhibition of the mitogen-activated protein kinases and nuclear factor kappa B pathways, suggesting that SGE has potential to serve as a natural anti-photoaging nutraceutical.

• Journal of Microbiology and Biotechnology
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• v.28 no.6
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• pp.839-848
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• 2018

Coptis chinensis (CC) is widely used in Asian countries to treat inflammatory diseases. We investigated the anti-inflammatory activity of the aqueous fraction separated from CC extract and of berberine, its key bioactive component, in human keratinocytes and the possible molecular mechanisms underlying this. Treating HaCaT keratinocytic cells with heat-killed Propionibacterium acnes induced nitric oxide and proinflammatory cytokine (e.g., tumor necrosis $factor-{\alpha}$, interleukin $(IL)-1{\beta}$, and IL-8) production and their mRNA expression; these effects were suppressed by pretreatment with the aqueous fraction or berberine, which also suppressed the phosphorylation of ERK, JNK, and p38 kinases and the nuclear expression of nuclear factor $(NF)-{\kappa}B$ p65 in P. acnes-stimulated cells. Thus, the aqueous fraction and berberine effectively exerted anti-inflammatory activities by suppressing mitogen-activated protein kinase and $NF-{\kappa}B$ signaling pathways in human keratinocytes and may be used for treating P. acnes-induced inflammatory skin diseases.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.106-106
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• 2018

Cyanidin 3 - rutinoside chloride (CRC) is major anthocyanin, found in Schisandra chinensis, is known to have antioxidant, anticancer, anti-inflammatory, tonic, and anti-aging effects in Korea, China and Japan. In the present study, the human mast cell line (HMC-1) was used to investigate the effects on the production of pro-inflammatory mediators. In this study, CRC showed no cytotoxicity in HMC-1. CRC significantly inhibited the secretion of inflammatory cytokines such as tumor necrosis factor $(TNF)-{\alpha}$ and interleukin (IL)-6 in PMA plus A23187 cacium ionophore (PMACI)-stimulated HMC-1 cells. In addition, CRC suppressed the serum levels of IgE. Furthermore, CRC decreased the PMACI- stimulated phosphorylation of mitogen activated protein kinases (MAPKs) such as p-ERK, p- JNK and p-P38. These results indicate that the pharmacological actions of CRC suggest their potential activity for treatment of allergic inflammation through the down-regulation of mast cell activation.

• Korean Journal of Clinical Pharmacy
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• v.29 no.4
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• pp.223-230
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• 2019

Background: Small-molecule tyrosine kinase inhibitors (TKIs) have had major impacts on anticancer therapy by targeting the catalytic activities of dysregulated tyrosine kinases. TKIs have not presented traditional toxicities; however, some serious adverse effects, including hepatotoxicity, have been documented in clinical trials and post-marketing surveillance. Although TKI-induced hepatotoxicity can cause severe clinical complications in patients, the underlying mechanism is still unclear. Methods: Studies on TKI-induced hepatotoxicity were identified by Pubmed search, and relevant articles were reviewed. Results: Immunoallergic reaction, cytochrome P (CYP) 450 polymorphisms, and formation of reactive metabolites are under consideration as mechanisms of TKI-induced hepatotoxicity. Host protein-drug metabolite conjugates are recognized as antigens by class II major histocompatibility complexes and are believed to cause liver injuries. Polymorphisms in CYP, which influences TKI metabolism, can slow TKI metabolism and may induce development of hepatotoxicity. The formation of reactive metabolites during drug metabolism can induce hepatotoxicity by directly causing cytotoxicity, leading to cell dysfunction, and indirect toxicity by mediating secondary immune reactions. Concurrent use of various medications with TKI can also cause hepatotoxicity by affecting drug transporter or enzyme activities. Conclusion: Periodic monitoring of patients taking TKIs and risk/benefit reassessments though post marketing surveillance are necessary to prevent hepatotoxicity.