• Journal of Life Science
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• v.30 no.5
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• pp.476-482
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• 2020

In rice agriculture, Eleocharis kuroguwai Ohwi (olbanggae) is a target for herbicidal intervention as a problem weed although it has also long been used clinically as a traditional medicine for jaundice, fever, and blood flow. E. kuroguwai has been evaluated in many clinical trials, but its molecular biological advantages are still unknown. Here, we investigate the anti-inflammatory effects of E. kuroguwai 80% ethanol extracts by screening NO production in LPS-induced macrophage activation. To find the most effective fractions, we partitioned five sub-fractions using HP20 column chromatography, namely 20%, 40%, 60%, 80%, and 100%. Of these, the 60% and 80% sub-fractions were found to significantly inhibit NO production; there were no toxicological effects at any concentration. In addition, the 80% sub-fraction inhibited significantly the iNOS and the mRNA of the pro-inflammatory mediators IL-6, TNF-α, and IL-1β by inhibiting the phosphorylation of JNK and ERK pathways associated with MAPKs signaling. Our results suggest that the 80% E. kuroguwai sub-fraction has the most significant anti-inflammatory effects of inhibiting iNOS and pro-inflammatory mediators and suppressing the phosphorylation of JNK and ERK. Therefore, the 80% sub-fraction of E. kuroguwai extract may be a therapeutic candidate for inflammatory diseases associated with the overexpression of MAPKs.

• IMMUNE NETWORK
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• v.10 no.6
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• pp.219-229
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• 2010

Background: N-myc downstream regulated gene 2 (NDRG2) is a member of the NDRG gene family. Our previous report indicated a possible role for NDRG2 in regulating the cytokine, interleukin-10 (IL-10), which is an important immunosuppressive cytokine. Several pathways, including p38-MAPK, NF-${\kappa}B$, and JAK/STAT, are used for IL-10 production, and the JAK/STAT pathway can be inhibited in a negative feedback loop by the inducible protein, SOCS3. In the present study, we investigated the effect of NDRG2 gene expression on IL-10 signaling pathway that is modulated via SOCS3 and STAT3. Methods: We generated NDRG2-overexpressing U937 cell line (U937-NDRG2) and treated the cells with PMA to investigate the role of NDRG2 in IL-10 production. U937 cells were also transfected with SOCS3- or NDRG2-specific siRNAs to examine whether the knockdown of SOCS3 or NDRG2 influenced IL-10 expression. Lastly, STAT3 and SOCS3 induction was measured to identify the signaling pathway that was associated with IL-10 production. Results: RT-PCR and ELISA assays showed that IL-10 was increased in U937-mock cells upon stimulation with PMA, but IL-10 was inhibited by overexpression NDRG2. After PMA treatment, STAT3 phosphorylation was decreased in a time-dependent manner in U937-mock cells, whereas it was maintained in U937-NDRG2 cells. SOCS3 was markedly reduced in U937-NDRG2 cells compared with U937-mock cells. IL-10 production after PMA stimulation was reduced in U937 cells when SOCS3 was inhibited, but this effect was less severe when NDRG2 was inhibited. Conclusion: NDRG2 expression modulates SOCS3 and STAT3 activity, eventually leading to the inhibition of IL-10 production.

• Journal of Applied Biological Chemistry
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• v.61 no.4
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• pp.417-421
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• 2018

Ultraviolet rays are electromagnetic waves with a shorter wavelength than visible light, and ultraviolet rays that pass through the ozone layer are the main cause of skin aging. Chronic exposure of skin tissue to ultraviolet light activates the Mitogen-activated Protein Kinases (MAPKs) signaling pathways in human keratinocytes, resulting in increased production of matrix metalloproteinases (MMPs). In this study, we investigated the herbal extracts from Jeju Island on the anti-aging effect in human keratinocytes (HaCaTs) by ultraviolet stimulation. We examined that herb extract from Jeju Island were decreased in anti-aging activity on measuring the level of MMP-1 gene and protein expression in ultraviolet-induced keratinocytes. As a result, it was confirmed that Thymus quinquecostatus extract (TQE) significantly reduced the expression of MMP-1 in a dose-dependent manner by UV irradiated HaCaTs. According to our data, TQE significantly attenuated UV-induced phosphorylation of the MAPKs signaling elements ERK1/2, JNK1/2 and p38 proteins. These results suggest that the MAPKs pathway may contribute to the inhibitory effect of TQE on UV-induced MMP-1 production in human keratinocytes. Our results suggest that TQE may be a protective agent against skin aging by preventing UV-induced MMP-1 production.

• Biomolecules & Therapeutics
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• v.20 no.1
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• pp.43-49
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• 2012

Stimulation of mast cells through the high affinity IgE receptor (Fc${\varepsilon}$RI) induces degranulation, lipid mediator release, and cytokine secretion leading to allergic reactions. Although various signaling pathways have been characterized to be involved in the Fc${\varepsilon}$RI-mediated responses, little is known about the precious mechanism for the expression of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) in mast cells. Here, we report that rapamycin, a specific inhibitor of mammalian target of rapamycin (mTOR), reduces the expression of TNF-${\alpha}$ in rat basophilic leukemia (RBL-2H3) cells. IgE or specific antigen stimulation of RBL-2H3 cells increases the expression of TNF-${\alpha}$ and activates various signaling molecules including S6K1, Akt and p38 MAPK. Rapamycin specifically inhibits antigeninduced TNF-${\alpha}$ mRNA level, while other kinase inhibitors have no effect on TNF-${\alpha}$ mRNA level. These data indicate that mTOR signaling pathway is the main regulation mechanism for antigen-induced TNF-${\alpha}$ expression. TNF-${\alpha}$ mRNA stability analysis using reporter construct containing TNF-${\alpha}$ adenylate/uridylate-rich elements (AREs) shows that rapamycin destabilizes TNF-${\alpha}$ mRNA via regulating the AU-rich element of TNF-${\alpha}$ mRNA. The antigen-induced activation of S6K1 is inhibited by specific kinase inhibitors including mTOR, PI3K, PKC and $Ca^{2+}$chelator inhibitor, while TNF-${\alpha}$ mRNA level is reduced only by rapamycin treatment. These data suggest that the effects of rapamycin on the expression of TNF-${\alpha}$ mRNA are not mediated by S6K1 but regulated by mTOR. Taken together, our results reveal that mTOR signaling pathway is a novel regulation mechanism for antigen-induced TNF-${\alpha}$ expression in RBL-2H3 cells.

• Journal of Life Science
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• v.24 no.6
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• pp.664-670
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• 2014

In the present study, we investigate the role of V. vulnificus in promoting the inflammation of mouse ileal ephitelium and its related signaling pathways. ICR mice were infected orally with V. vulnificus ($1{\times}10^9CFU$) for 16 h as a representative model of food-borne infection. To find the major portal of entry of V. vulnificus in mouse intestine, we have measured the levels of bacterial colonization in small intestine, colon, spleen, and liver. V. vulnificus appeared to colonize in intestine and colon in the order of ileum >> jejunum> colon, but lack in the duodenum, spleen, and liver. V. vulnificus in ileum caused severe necrotizing enteritis and showed shortened villi heights accompanied by an expanded width and inflammation, compared with the control mice. V. vulnificus induced ileal epithelium inflammation by activating phosphorylation of PKC and membrane translocation of $PKC{\alpha}$. V. vulnificus induced the phosphorylation of ERK and JNK, but did not affect p38 MAPK phosphorylation. Notably, V. vulnificus stimulated the I-${\kappa}B$-dependent phosphorylation of NF-${\kappa}B$ in mouse ileal epithelium. Finally, the ileal infection of V. vulnificus resulted in a significant increase in expression of proinflammatory cytokines and Toll-like receptors, respectively, compared to the control. Collectively, our results indicate that V. vulnificus induces ileal epithelium inflammation by increasing NF-${\kappa}B$ phosphorylation via activation of PKC, ERK, and JNK, which is critical for host defense mechanism in food-borne infection by V. vulnificus.

• Journal of Nutrition and Health
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• v.51 no.6
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• pp.507-514
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• 2018

Purpose: Sargassum horneri (S. horneri) is a species of brown macroalgae that is common along the coast of Japan and Korea. The present study investigated the immuno-modulatory effects of different types of S. horneri extracts in RAW264.7 macrophages. Methods: S. horneri was extracted by three different methods, hot water extraction, 50% ethanol extraction, and supercritical fluid extraction. Cell viability was then measured by MTT assay, while the production levels of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), interleukin-6 (IL-6), and nitric oxide (NO) were measured by enzyme-linked immunosorbent assay and Griess assay, respectively. The expression and activation levels of inducible NO synthase (iNOS), mitogen-activated protein kinase (MAPK) and nuclear factor ${\kappa}B$ ($NF-{\kappa}B$) were examined by western blot analysis. Results: The three different S. horneri extracts were nontoxic against RAW 264.7 cells up to $50{\mu}g/mL$, among which treatment with hot water extract (HWE) of S. horneri significantly enhanced the production of TNF-${\alpha}$, IL-6, and NO in a dose-dependent manner. Hot water extract of S. horneri also increased the expression level of iNOS, suggesting that up-regulation of iNOS expression by HWE of S. horneri was responsible for the induction of NO production. In addition, treatment of RAW 264.7 macrophages with HWE of S. horneri increased the phosphorylation levels of ERK, p38 and JNK. Furthermore, the activation and subsequent nuclear translocation of $NF-{\kappa}B$ was enhanced upon treatment with HWE of S. horneri, indicating that HWE of S. horneri activates macrophages to secrete TNF-${\alpha}$, IL-6 and NO and induces iNOS expression via activation of the $NF-{\kappa}B$ and MAPKs signaling pathways. Conclusion: Taken together, these findings suggest that HWE of S. horneri possesses potential as a functional food with immunomodulatory activity.

• Journal of Life Science
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• v.23 no.11
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• pp.1397-1403
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• 2013

Fructus Sophorae, the dried ripe fruit of Styphnolobium japonicum (L.), is an herbal ingredient used in traditional Oriental medicine. This study was carried out to investigate the effects of Fructus Sophorae extracts (FSE) on immune modulation in a murine RAW 264.7 macrophage model. As immune response parameters, the production of prostaglandin $E_2$ ($PGE_2$) and tumor necrotic $factor-{\alpha}$ ($TNF-{\alpha}$) were evaluated. Our data revealed that FSE increased the macrophage activation and the production of $PGE_2$ and $TNF-{\alpha}$, which was consistently correlated with upregulation of cyclooxygenase-2 (COX-2) and $TNF-{\alpha}$ expression at both transcriptional and translational levels. On comparative cytokine protein array, FSE significantly increased several cytokines, which was associated with phosphorylation of mitogen- activated protein kinases (MAPKs), including extracellular signal-regulated kinase (ERK), p38 MAPK and c-Jun N-terminal kinase (JNK), and Akt in RAW 264.7 cells. However, each inhibitor of these molecules attenuated the FSE-induced $PGE_2$ production. These results indicate that FSE activated macrophages through the activation of MAPKs and phosphatidylinositol-3-kinase (PI3K)/Akt signaling pathways in RAW 264.7 macrophages. These findings suggest that FSE may provide a promising source of an immunoenhancing agent.

• Journal of Yeungnam Medical Science
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• v.23 no.1
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• pp.26-35
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• 2006

Background: Luteolin, a flavone found in various Chinese herbal medicines is known to possess anti-inflammatory properties through its ability to inhibit various proinflammatory signaling pathways including NF-${\kappa}B$ and p38 MAPK. In this study, we investigated the potential therapeutic effect of luteolin on dextran sodium sulfate (DSS)-induced colitis. Materials and Methods: We used a transgenic mouse model expressing the enhanced green fluorescent protein (EGFP) under the transcriptional control of NF-${\kappa}B$ $cis$-elements. C57BL/6 NF-${\kappa}B^{EGFP}$ mice received 2.5% DSS in their drinking water for six days in combination with daily luteolin administration (1mg/kg body weight, 0.1ml vol, intragastric) or vehicle. NF-${\kappa}B$ activity was assessed macroscopically with a Charge-Coupled Device (CCD) camera and microscopically by confocal analysis. Results: A significant increase in the Disease Activity Index (DAI), histological score (p<0.05), IL-12 p40 secretion in colonic stripe culture (p<0.05) and EGFP expression was observed in luteolin and/or DSS-treated mice compared to water-treated mice. Interestingly, a trend toward a worse colitis (DAI, IL-12p40) was observed in luteolin-treated mice compared to non-treated DSS-exposed mice. In addition, EGFP expression (NF-${\kappa}B$ activity) strongly increased in the luteolin-treated mice compared to control mice. Confocal microscopy showed that EGFP positive cells were primarily lamina propria immune cells. Conclusions: These results suggest that luteolin is not a therapeutic alternative for intestinal inflammatory disorders derived for primary defects in barrier function. Thus, therapeutic intervention targeting these signaling pathways should be viewed with caution.

• ALGAE
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• v.29 no.4
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• pp.355-366
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• 2014

Fucoxanthin is known to be an effective cell proliferation inhibitor with anti-tumor and anti-angiogenic activities. However, there is a lack of data regarding the biological effects of cis isomers of fucoxanthin. To assess the potential therapeutic properties of 9'-cis-(6'R) fucoxanthin (FcA), and 13-cis and 13'-cis-(6'R) fucoxanthin complex (FcB) isolated from Sarggassum siliquastrum, we investigated their inhibitory effects on matrix metalloproteinases (MMPs) in phorbol 12-myristate 13-acetate (PMA)-induced human fibrosarcoma (HT1080) cells. FcA and FcB reduced MMP-2 and MMP-9 protein and mRNA levels, as well as the migration of these cells, in a dose-dependent manner. Additionally, FcA and FcB increased levels of MMPs inhibition factors such as tissue inhibitor of metalloproteinase-1. FcA and FcB significantly inhibited the transcriptional activity of nuclear factor ${\kappa}B$ (NF-${\kappa}B$) and by inhibiting c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinases. Our results demonstrate that suppression of the NF-${\kappa}B$, JNK, and p38 signaling pathways may inhibit PMA-induced MMP-2 and MMP-9 activity. Therefore, FcA and FcB may be useful in noninvasive therapeutic strategies against fibrosarcoma metastasis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.2
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• pp.181-187
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• 2016

Algae is a potential resource with various biological activities. In this study, the anti-inflammatory effect of Grateloupia imbricata Holmes ethanol extract (GIHEE) from red algae was investigated in LPS-induced RAW 264.7 cells. As a result, reduced secretion of pro-inflammatory cytokines [tumor necrosis factors-${\alpha}$, interleukin (IL)-$1{\beta}$, and IL-6] and nitric oxide (NO) was observed in a dose-dependent manner. Expression of nuclear factor-kappaB (NF-${\kappa}B$) as well as inducible NO synthase and cyclooxygenase-2 proteins was reduced by GIHEE, suggesting that the anti-inflammatory activity of GIHEE is related to suppression of NF-${\kappa}B$ signaling pathways. In addition, GIHEE reduced phosphorylation of mitogen-activated protein kinases. These results suggest that GIHEE can be used as a potential anti-inflammatory therapeutic.