• 대한의생명과학회지
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• 제19권2호
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• pp.168-172
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• 2013

Toll-like receptors (TLRs) play an important role for host defense against invading pathogens. TLR4 has been identified as the receptor for lipopolysaccharide (LPS), which is a cell wall component of gram-negative bacteria. The activation of TLR4 signaling by LPS leads to the activation of NF-${\kappa}B$ and the expression of pro-inflammatory gene products such as cytokines, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2). To evaluate the therapeutic potential of (E)-1-(2-(2-nitrovinyl)phenyl)pyrrolidine (NVPP), previously synthesized in our laboratory, NF-${\kappa}B$ activation and iNOS and COX-2 expression induced by LPS were examined. NVPP inhibited the activation of NF-${\kappa}B$ induced by LPS. NVPP also suppressed the iNOS expression induced by LPS but it did not suppress COX-2 expression induced by LPS. These results suggest that NVPP has the specific mechanism for anti-inflammatory responses.

• 약학회지
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• 제56권3호
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• pp.186-190
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• 2012

Nuclear factor-${\kappa}B$ (NF-${\kappa}B$) has been considered as one of the major targets for therapeutic agents of diverse human diseases. In the previous studies, 6-hydroxy-7-methoxychroman-2-carboxylic acid N-phenylamide (KL-1156) and chroman-2-carboxylic acid N-(4-chlorophenyl)amide were identified as good inhibitors of NF-${\kappa}B$ activation. In this continuous study, we describe the synthesis and NF-${\kappa}B$ inhibitory activities of chroman derivatives containing N-heteroaryl groups for exploration of SAR (structure-activity relationship). In addition, inhibitory effects of cell proliferation are evaluated against human cancer cell lines (NCI-H23 and PC-3).

• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book I
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• pp.780-803
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• 2003

Exposure of skin cells, particularly keratinocytes to various nuclear factor-kappaB ($\textrm{NF}_{-{\kappa}}\textrm{B}$) activators [e.g. tumor necrosis factor-$\alpha$, interleukin-1, lipopolysaccharides, and ultraviolet light] leads to phosphorylation and degradation of the inhibitory protein, $\textrm{I}_{{\kappa}}\textrm{B}$. Liberated $\textrm{NF}_{-{\kappa}}\textrm{B}$ is translocated into the nucleus where it can change or alter expression of target genes, resulting in the secretion of extracellular signaling molecules including melanotrophic factors affecting melanocyte. In order to demonstrate the possible role of $\textrm{NF}_{-{\kappa}}\textrm{B}$ activation on the synthesis of melanotrophic factors from the keratinocytes, the activities of $\textrm{NF}_{-{\kappa}}\textrm{B}$ induced by melanogenic inhibitors (MIs) were determined in human HaCaT keratinocytes transfected with $\textrm{pNF}_{-{\kappa}}\textrm{B}$-SEAP-NPT plasmid. Transfectant cells released the secretory alkaline phosphatase (SEAP) as a transcription reporter in response to the $\textrm{NF}_{-{\kappa}}\textrm{B}$ activity and contain the neomycin phosphotransferase (NPT) gene for the dominant selection marker for geneticin resistance. MIs such as niacinamide, kojic acid, hydroquinone, resorcinol, arbutin, and glycolic acid were preincubated with transfectant HaCaT cells for 3 h and then ultraviolet B (UVB) was irradiated. $\textrm{NF}_{-{\kappa}}\textrm{B}$ activation was measured with the SEAP reporter gene assay using a fluorescence detection method. Of the Mis tested, kojic acid ($IC_{50}$/ = 60 $\mu$M) was found to be the most potent inhibitor of UVB-upregulating $\textrm{NF}_{-{\kappa}}\textrm{B}$ activation in transfectant HaCaT cells, which is followed by niacinamide ($IC_{50}$/= 540 $\mu$M). Pretreatment of the transfectant HaCaT cells with the Mis, especially kojic acid and niacinamide, effectively lowered $\textrm{NF}_{-{\kappa}}\textrm{B}$ binding measured by electrophoretic mobility shift assay. Furthermore, these two inhibitors remarkably reduced the secretion level of IL-6, one of melanotrophic factors, triggered by UV-radiation of the HaCaT cells. These observations suggest that Mis working at the in vivo level might act partially through the modulation of the synthesis of melanotrophic factors in keratinocyte.

• IMMUNE NETWORK
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• 제11권6호
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• pp.420-423
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• 2011

Since CKD-712 has been developed as an anti-inflammatory agent, we examined the effect of CKD-712 during TLR4 signaling. Using HEK293 cells expressing TLR4, CKD-712 was pre-treated 1 hr before LPS stimulation. Activation of NF-${\kappa}B$ was assessed by promoter assay. The activation of ERK, JNK, p38, IRF3 and Akt was measured by western blotting. CKD-712 inhibited the NF-${\kappa}B$ signaling triggered by LPS. The activation of ERK, JNK, p38 or IRF3 was not inhibited by CKD-712. On the contrary the activation of these molecules was augmented slightly. The activation of Akt with stimulation of LPS was also enhanced with CKD-712 pre-treatment at lower concentration, but was inhibited at higher concentration. We suggest that during TLR4 signaling CKD-712 inhibits NF-${\kappa}B$ activation. However, CKD-712 augmented the activation of Akt as well as Map kinases. Therefore, we suggest that CKD-712 might have a role as an immunomodulator.

• BMB Reports
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• 제38권3호
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• pp.281-289
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• 2005

Tumor necrosis factor (TNF) signaling is mediated via two distinct receptors, TNFR2 and TNFR1, which shows partially overlapping signaling mechanisms and biological roles. In the present study, TNFR2 and TNFR1 signal transduction mechanisms involved in activation of $NF{\kappa}B$ and CMV promoter-enhancer were compared with respect to their susceptibility towards inhibitors of intracellular signaling. For this, we used SW480 cells, where we have shown that TNF-signaling can occur independently through each of the two receptors. The TNFR1 response was inhibited by D609, bromophenacyl bromide (BPB), nordihydroguararetic acid (NDGA), and by sodium salicylate, while TNFR2-mediated activation of $NF{\kappa}B$ and CMV promoter-enhancer was resistant to these compounds. The signaling mechanisms known to be affected by these inhibitors include phospholipases as well as redox- and pH-sensitive intracellular components. Our results imply that TNFR2 signaling involved in $NF{\kappa}B$ activation proceeds independently of these inhibitor-sensitive signaling components, indicating distinct signaling pathways not shared with TNFR1.

• 동의생리병리학회지
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• 제26권3호
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• pp.344-350
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• 2012

Previously, we showed that Dangguisoo-san (DGSS), an herbal formula that has been traditionally used for the treatment of blood stagnation, is also applicable for inflammatory lung diseases. Activation of Nrf2, an anti-inflammatory transcription factor, and suppression of NF-${\kappa}B$, a pro-inflammatory transcription factor, were suggested as an underlying mechanism. However, the constituents responsible for these activities remain unidentified. To this end, we prepared the water extracts of the 9 constituents of DGSS and tested for their effect on Nrf2 by using an Nrf2-Luciferase reporter cell line and western blot analysis. Results show that Carthamus tinctorius L.(CT), one of the 9 constituents of DGSS, strongly activated Nrf2. Similarly, when measured the effect of the 9 constituents on NF-${\kappa}B$ by using an NF-${\kappa}B$-Luciferase reporter cell line and western blotting for nuclear p65, indicative of activated NF-${\kappa}B$, most constituents were capable of suppressing NF-${\kappa}B$ in various degrees. However, CT and Cyperus rotundus L. (CR) strongly suppressed NF-${\kappa}B$ activity elicited by LPS. Of note, CT activated Nrf2 and suppressed NF-${\kappa}B$ strongly as well. Our results contributes to corroborating the anti-inflammatory effects of DGSS by identifying CT and CR as two major herbs responsible for activating Nrf2 and suppressing NF-${\kappa}B$. These results suggest that CT and CR represent some of the effects of DGSS in the regulation of inflammation.

• 한국자원식물학회지
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• 제33권3호
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• pp.183-193
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• 2020

Recently, as a natural substance has been emphasized interest in research to enhance the immune function. Green lettuce (Lactuca sativa L.) is a popular vegetable used fresh and it contains various phytochemicals and antioxidant compounds, and has been reported to have various physiological activities such as antibacterial, antioxidant, antitumor and anti-mutagenic. However, only a few studies have investigated on the mechanism of action of immune-enhancing activity of lettuce. Therefore, in this study, the immunomodulatory activities and potential mechanism of action of Green lettuce extracts (GLE) were evaluated in the murine macrophage cell line RAW264.7. GLE significantly increased NO levels by RAW264.7 cells, as well as expressions of immunomodulators such as iNOS, COX-2, IL-1β, IL-6, IL-12, TNF-α and MCP-1. Although GLE activated ERK1/2, p38, JNK and NF-κB, GLE-mediated expressions of immunomodulators was dependent on p38, JNK and NF-κB. In addition, TLR4 inhibition blocked GLE-mediated expressions of immunomodulators and activation of p38, JNK and NF-κB. Taken together, these results demonstrated that TLR4-MAPK/NF-κB signalling pathways participated in GLE-induced macrophage activation and GLE could be developed as a potential immunomodulating functional food.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2001년도 International Symposium on Signal transduction in Toxicology
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• pp.94-95
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• 2001

The purpose of these studies was to determine if hepatic tumor promoters could activate the transcription factor NF-kB, the mechanism of this activation, and whether activation of NF-kB is important in the carcinogenic process. We first demonstrated that the administration of the peroxisome proliferator ciprofibrate increases the hepatic DNA binding activity of NF-kB in rats and mice.(omitted)

• Journal of Acupuncture Research
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• 제22권2호
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• pp.133-139
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• 2005

Cobrotoxin, a venom of Vipera lebetina turanica, is a group of basic peptidescomposed of 233 amino acids with six disulfide bonds formed by twelve cysteins. NF-kB is activated by subsequent release of inhibitory IkB and translocation of p50. Since sulfhydryl group is present in kinase domain of p50 subunit of NF-kB, cobrotoxin could modify NF-kB activity by protein-protein interaction. We therefore examined effect of cobrotoxin on NF-kB activities in lipopolysaccharide (LPS) and sodium nitroprusside (SNP)-stimulated Raw 264.7 mouse macrophages. Cobrotoxin suppressed the LPS and SNP-induced release of IkB and p50 translocation resulted in inhibition of DNA binding activity of NF-kB. Inhibition of NF-kB resulted in reduction of the LPS and SNP-induced production of inflammatory mediators NO and PGE2 generation. The inhibitory effect of cobrotoxin on the NF-kB activity were blocked by addition of reducing agents dithiothreitol and glutathione. These results demonstrate that cobrotoxin inhibits activation of NF-kB, and suggest that pico to nanomolar range of cobrotoxin could inhibit the expression of genes in the NF-kB signal pathway.

• The Korean Journal of Physiology and Pharmacology
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• 제19권3호
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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.