• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2001.10b
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• pp.130-130
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• 2001

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.10b
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• pp.189-189
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• 2003

Recent studies suggest that inflammatory events are implicated in a variety of human diseases including cancer and neurodegenerative diseases. It has been reported that expression of inducible cyclooxygenase (COX) and nitric oxide (NO) synthase and subsequent production of prostaglandins (PG)s and NO, respectively are elevated in many inflammatory disorders.(omitted)

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.10b
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• pp.164-164
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• 2003

We show that PCSC, a polysaccharide isolated from the sclerotium of Poria cocos with one percent sodium carbonate, significantly induces nitric oxide (NO) production and inducible NO synthase (iNOS) transcription through the activation of nuclear factor-$\kappa$B/Rel (NF-$\kappa$B/Rel).(omitted)

• Proceedings of the PSK Conference
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• 2000.10a
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• pp.189.2-189.2
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• 2000

• Proceedings of the PSK Conference
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• 2000.10a
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• pp.192.1-192.1
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• 2000

• IMMUNE NETWORK
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• v.7 no.1
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• pp.31-38
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• 2007

Background: Mizoribine (MZR) is an imidazole nucleoside isolated from Eupenicillium brefeldianum. MZR is currendy in clinical use for patients who have undergone renal transplantation. Therapeutic efficacy of MZR has also been demonstrated in rheumatoid arthritis and lupus nephritis. MZR has been shown to inhibit the proliferation or lymphocytes by interfering with inosine monophosphate dehydrogenase. Since the exact mechanism by which MZR benefits rheumatoid arthritis (RA) is not clear, we investigated the ability of MZR to direct its immunosuppressive influences on other antigen presenting cells, such as macrophages. Methods: Mouse macrophage RAW264.7 cells were stimulated with lipopolysaccharide in the presence of MZR. To elucidate the mechanism of the therapeutic efficacy in chronic inflammatory diseases, we examined the effects of MZR on the production of pro-inflammatory cytokines, nitric oxide (NO) and prostaglandin $E_2\;(PGE_2)$ in macrophages. Results: MZR dose-dependendy decreased the production of nitric oxide and pro- inflammatory cytokines such as tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), interleukins $1{\beta}$ (IL-${\beta}$ and IL-6 $PGE_2$. Examination of gene expression levels showed that the anti-inflammatory effect correlated with the down-regulation of inducible nitiric oxide synthase expression, cycloxygenase-2 expression and TNF-${\alpha}$ gene expression. Conclusion: In this work, we resulted whether MZR $(1.25{\sim}10{\mu}g/ml)$ inhibited macrophage activation by inhibiting secretion of pro-inflammatory cytokines, NO and $PGE_2$. These findings provide an explanation for the therapeutic efficacy of MZR in chronic inflammation-associated diseases.

• Molecular & Cellular Toxicology
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• v.1 no.3
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• pp.196-202
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• 2005

Nitric oxide (NO) is a small, diffusible, and highly reactive molecule, which plays dichotomous regulatory roles under physiological and pathological conditions. NO promotes apoptosis in some cells, and inhibits apoptosis in other cells. In the present study, we attempted to characterize the NO signaling pathway and cellular response in PC12 cells treated with cytokines. $IFN{\gamma}\;and\;TNF{\alpha}$ treatment resulted in a synergistic increase of nitrite accumulation, with the induction of inducible nitric oxide synthase (iNOS) in the PC12 cells. Moreover, as nitrite concentration increased, cell viability decreased. In order to explore MAP kinase involvement in nitric oxide production resultant from $IFN{\gamma}\;and\;TNF{\alpha}$ stimulation, we measured the activation of MAP kinase using specific MAP kinase inhibitors. PC12 cells pretreated with SB203580, a p38 MAP kinase-specific inhibitor, resulted in the inhibition of iNOS expression and NO production. However, PD98059, an ERK/MAP kinase-specific inhibitor, was not observed to exert such an effect. In addition, Stat1 activated by $IFN{\gamma}\;and\;TNF{\alpha}$ was interacted with p38 MAPK. These data suggest that p38 MAP kinase mediates cytokine-mediated iNOS expression in the PC12 cells, and Jak/Stat pathway interferes with p38 MAPK signaling pathway.

• Archives of Pharmacal Research
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• v.26 no.7
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• pp.559-563
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• 2003

Cytokines produced by immune cells infiltrating pancreatic islets have been incriminated as important mediators of $\beta$-cell destruction in insulin-dependent diabetes mellitus. In non insulin-dependent diabetes, cytokines are also associated with impaired $\beta$-cell function in high glucose condition. By the screening of various natural products blocking $\beta$-cell destruction, we have recently found that epigallocatechin gallate (EGCG) can prevent the in vitro destruction of RINm5F cell, an insulinoma cell line, that is induced by cytokines. In that study we suggested that EGCG could prevent cytokine-induced $\beta$-cell destruction by down-regulation of nitric oxide synthase (NOS) through inhibition of NF-kB activation. Here, to verify the in vivo antidiabetogenic effect of EGCG, we examined the possibility that EGCG could also prevent the experimental autoimmune diabetes induced by the treatment of multiple low doses of streptozotocin (MLD-STZ), which is recognized as an inducer of type I autoimmune diabetes. Administration of EGCG (100 mg/day/kg for 10 days) during the MLD-STZ induction of diabetes reduced the increase of blood glucose levels caused by MLD-STZ. Ex vivo analysis of $\beta$-islets showed that EGCG downregulates the MLD-STZ-induced expression of inducible NOS (iNOS). In addition, morphological examination showed that EGCG treatment ameliorated the decrease of islet mass induced by MLD-STZ. In combination these results suggest that EGCG could prevent the onset of MLD-STZ-induced diabetes by protecting pancreatic islets. Our results therefore revealed the possible therapeutic value of EGCG for the prevention of diabetes mellitus progression.

• Journal of Haehwa Medicine
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• v.23 no.2
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• pp.5-13
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• 2015

Objectives : The anti-inflammatory and antioxidant effects of water extracts of Sasangja-tang(SSJ) and Gami-sasangja-tang(GSJ) were investigated. The effects of SSJ and GSJ were compared. Methods : We performed cell viability assay in HaCaT cells and RAW 264.7 cells using 3-(4,5-dimethylthiazol-2-yl)-2, 5 diphenyltetrazolium bromide(MTT) assay. We measured chemokines(regulated on activation normal T-cell expression and secreted ; RANTES/CCL5, interferon-inducible protein; IP-10/CXCL10, macrophage-derived chemokine; MDC/CCL22) in HaCat cells, also we measured cytokines (tumor necrosis factor-${\alpha}$; TNF-${\alpha}$, interleukin-6; IL-6) and nitric oxide(NO) production in RAW 264.7 cells using enzyme-linked immunosorbent assay(ELISA) and NO assay. Western blot assay was used to evaluate the expression for inducible nitric oxide synthase(iNOS) in RAW 264.7 cells. Results : SSJ and GSJ did not affect the cell viability at the concentrations treated ($0-800{\mu}g/ml$). As a result of SSJ and GSJ treatment in HaCat cells stimulated by TNF-${\alpha}$(10 ng/ml) and interferon(IFN)-${\gamma}$(10 ng/ml), the production of RANTES and IP-10 was inhibited significantly. However there was no significant difference in the secretion of MDC. And in RAW 264. 7 cells stimulated by lipopolysaccharide(LPS, $1{\mu}g/ml$), SSJ and GSJ treatment significantly inhibited the secretion of TNF-${\alpha}$ and IL-6 and the production of NO. The expression of iNOS was also decresed by SSJ and GSJ treatment in RAW 264. 7 cells. Compared with SSJ, GSJ was superior to SSJ in inhibition of RANTES, IP-10, TNF-${\alpha}$, IL-6 and NO production at the concentration of $200{\mu}g/ml$. Conclusion : Both SSJ and GSJ have anti-inflammatory and antioxidant effects. And GSJ has better effects than SSJ.

• Food Science and Biotechnology
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• v.16 no.5
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• pp.728-733
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• 2007

Bamboo grass, Sasa quelpaertensis, is a native plant to Jeju Island, Korea. The leaves of Sasa plants are widely used in traditional Korean medicine to treat inflammation-related diseases. We investigated the effect of hot water extract from Sasa quelpaertensis leaves (HWE-SQ) on nitric oxide (NO) production and nuclear $factor-{\kappa}B\;(NF-{\kappa}B)$ activation in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. HWE-SQ inhibited LPS-induced NO production and inducible NO synthase (iNOS) protein expression in a dose-dependent manner. Reporter gene assays indicated that HWE-SQ decreases LPS-induced $NF-{\kappa}B$ transcriptional activation. However, HWE-SQ did not affect the phosphorylation and degradation of inhibitory ${\kappa}B{\alpha}\;(1{\kappa}B{\alpha})$. HWE-SQ also directly inhibited iNOS enzyme activity in a dose-dependent manner. These results suggest that HWE-SQ suppresses NO synthesis in macrophages by attenuating $NF-{\kappa}B-mediated$ iNOS protein expression and inhibiting iNOS enzymatic activity, thereby implicating a mechanism by which HWE-SQ is able to ameliorate inflammation-related diseases by limiting excessive or prolonged NO production in pathological events.