• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2004.10a
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• pp.74-79
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• 2004

Little is known about the effect of epigallocatechin-3 gallate (ESCG), a major constituent of green tea, on the expression of cyclooxygenase (COX)-2. Here, we studied the role of phospholipase D (PLD) isozymes in EGCG-induced COX-2 expression. Stimulation of human astrocytoma cells (U87) with EGCG induced formation of phosphatidylbutanol, a specific product of PLD activity, and synthesis of COX-2protein and its product, prostaglandin $E_2$ ($PGE_2$). Pretreatment of cells with 1-butanol, but not 3-butanol, suppressed EGCG-induced COX-2 expression and $PGE_2$ synthesis. Furthermore, evidence that PLD was involved in EGCG-induced COX-2 expression w3s provided by the observations that COX-2 expression was stimulated by over-expression of PLD1 or PLD2 isozymes and treatment with phosphatidic acid(PA), and that prevention of PA dephosphorylation by 1-propranolol significantly potentiated COX-2expression Induced by EGCG. EGCG induced activation of p38 mitogen-activated protein kinase (p38MAPK), and specific Inhibition of p38 MAPK dramatically abolished EGCG-Induced PLD activation, COX-2 expression, and $PGE_2$ formation. Moreover, protein kinase C (PKC) inhibition suppressed EGCG-induced p38 MAPK activation, COX-2 expression, and $PGE_2$ accumulation. The same pathways as those obtained in the astrocytoma cells were active in primary rat astrocytes, suggesting the relevance of the findings. Collectively, our results demonstrate for the first time that PLD isozymes mediate EGCG-induced COX-2 expression through PKC and p38 in immortalized astroglial line and normal astrocyte cells.

• Journal of Periodontal and Implant Science
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• v.34 no.2
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• pp.345-356
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• 2004

The triclosan was shown to have anti-microbial and anti-inflammatory effect with inhibition of inflammatory mediators such as prostaglandin $E_2(PGE_2)$. The purpose of this study was to elucidate whether and how $PGE_2$ could be inhibited by triclosan in human gingival fibroblast. Human gingival fibroblast-1 cells (ATCC CRL2014) were pre-treated for 1 hour with triclosan (0.001 ${\mu}/ml{\sim}10$ ${\mu}/ml$) and then stimulated with $TNF-{\alpha}$ (1.0 ng/ml). $PGE_2$ synthesis was evaluated by ELISA and gene expression of COX-1 and COX-2 was evaluated by RT-PCR after $TNF-{\alpha}$, triclosan, and NS-398 (COX-2 inhibitor, 5, ${\mu}M$) and/ or cycloheximide (protein synthesis inhibitor, 2 ${\mu}g/ml$). Triclosan was cytotoxic to human gingival fibroblasts in the concentration higher than 1.0 ${\mu}g/ml$ for longer than 24 hours in tissue culture. The $PGE_2$ synthesis was inhibited by triclosan in dose-dependent manner. Greater COX-2 mRNA suppression was observed with triclosan (0.1 ${\mu}g/ml$) than with $TNF-{\alpha}$ alone, without change in COX-1 gene expression. Inhibitory effects of triclosan on $PGE_2$ synthesis disappeared in presence of cycloheximide. This study suggests that triclosan inhibit prostaglandin $E_2$ at the level of COX-2 gene regulation and require de novo protein synthesis.

• Bulletin of the Korean Chemical Society
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• v.35 no.11
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• pp.3219-3223
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• 2014

Ochnaflavone, a naturally occurring biflavonoid composed of two units of apigenin (5,7,4'-trihydroxyflavone) joined via a C-O-C linkage, was first synthesized and evaluated its inhibitory activity on $PGE_2$ production. Total synthesis was accomplished through modified Ullmann diaryl ether formation as a key step. Coupling reactions of 4'-halogenoflavones and 3'-hydroxy-5,7,4'-trimethoxyflavone were explored in diverse reaction conditions. The reaction of 4'-fluoro-5,7-dimethoxyflavone (2c) and 3'-hydroxy-5,7,4'-trimethoxyflavone (2d) in N,N-dimethylacetamide gave the coupled compound 3 in 58% yield. Synthetic ochnaflavone strongly inhibited PGE2 production ($IC_{50}=1.08{\mu}M$) from LPS-activated RAW 264.7 cells, which was due to reduced expression of COX-2. On the contrary, the inhibition mechanism of wogonin was somewhat different from that of ochnaflavone although wogonin, a natural occurring anti-inflammatory flavonoid, showed strong inhibitory activity of $PGE_2$ production ($IC_{50}=0.52{\mu}M$), and seems to be COX-2 enzyme inhibition. Our concise total synthesis of ochnaflavone enable us to provide sufficient quantities of material for advanced biological studies as well as to efficiently prepare derivatives for structure-activity relationship study.

• Korean Journal of Oriental Medicine
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• v.14 no.3
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• pp.57-63
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• 2008

Glehnia littoralis (Umbelliferae) is the medicinal plant used traditionally for treatment of immune-related diseases. Prostaglandins and nitric oxide (NO) have been implicated as important mediators in the processes of inflammation and carcinogenesis. For understanding the mechanisms for pharmacological activities of Glehnia littoralis, we evaluated the inhibitory activity of Glehnia littoralis on lipopolysaccharide (LPS)-induced prostaglandin $E_2$ ($PGE_2$) and NO production in mouse macrophage RAW264.7 cells. The results showed that the extract of Glehnia littoralis inhibited LPS- induced $PGE_2$ production effectively, but not NO. Additional study revealed that the extract of Glehnia littoralis suppressed cyclooxygenase-2 (COX-2) expression in a dose-dependent manner. Present study suggests that Glehnia littoralis may have anti-inflammatory and/or cancer chemopreventive activity through the inhibition of $PGE_2$ production by the suppression of COX-2 activity.

• Food Science and Preservation
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• v.21 no.1
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• pp.114-120
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• 2014

Zizyphus jujube leaf fractions (ZLFs) showed no cytotoxic effects of up to $100{\mu}g/mL$, while the anti-inflammatory effects of ZLFs were analyzed by checking the productions of nitric oxide (NO), prostaglandin $E_2$ ($PGE_2$), cyclooxygenase-2 (COX-2), and inflammatory cytokines TNF-${\alpha}$, IL-$1{\beta}$, and IL-6 in the lipopolysaccharide (LPS)-stimulated Raw264.7 macrophage up to the concentration of $100{\mu}g/mL$. ZLFs ($100{\mu}g/mL$) demonstrated a strong anti-inflammatory activity that reduced 61~85% of NO and 71~100% of $PGE_2$ production in the LPS-stimulated Raw264.7 macrophage. Even the low ZLFs concentration of $1{\mu}g/mL$ have reduced NO and $PGE_2$ production by 34~64%. Expressions of COX-2 protein were also effectively inhibited by the ZLFs. Furthermore, the TNF-${\alpha}$, IL-$1{\beta}$, and IL-6 production were significantly suppressed through the treatment of ZLFs at concentrations of 1, 10, and $100{\mu}g/mL$. In the order of the Zizyphus jujube leaf water fraction (ZLWF) < buthanol fraction (ZLBF) < ethyl acetate fraction (ZLEF) showed anti-inflammatory activity. In particular, the ethyl acetate fraction ZLEF at $100{\mu}g/mL$ showed an excellent anti-inflammatory activity by reducing the production of NO, $PGE_2$, COX-2, and inflammatory cytokines (TNF-${\alpha}$, IL-$1{\beta}$, IL-6) in the level of Raw264.7 macrophage without LPS-stimulation or even better. The results of our study suggest the potential of ZLEF for use as an excellent ant-inflammatory inhibiting mediator and may be used as a therapeutic approach to various inflammatory diseases.

• Korean Journal of Medicinal Crop Science
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• v.22 no.6
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• pp.457-462
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• 2014

Prostaglandin (PG) $E_2$ is an important mediator of skin wound healing without excessive scarring and gastric ulcer healing. However, $PGE_2$ has a short lifetime in vivo because it is metabolized rapidly by 15-hydroxyprostaglandin dehydrogenase (15-PGDH). Ethanol extract of Eriobotryae folium (EFEE) elevated intracellular and extracellular $PGE_2$ levels in HaCaT cells and inhibited 15-PGDH ($ED_{50}$ : $168.4{\mu}g/mL$) with relatively low cytotoxicity ($IC_{50}$ : $250.0{\mu}g/mL$). Real-time PCR analysis showed that mRNA expression of cyclooxygenase (COX)-1 and COX-2 enzymes were increased and prostaglandin transporter (PGT) was decreased in HaCaT cells by EFEE. Moreover, wound healing effect of EFEE ($168.4{\mu}g/mL$) was comparable to that of TGF-${\beta}1$ (300 pg/mL) as a positive control. These results demonstrate that EFEE may be valuable therapeutic materials for the treatment of $PGE_2$ level dependent diseases.

• Biomolecules & Therapeutics
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• v.32 no.5
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• pp.635-639
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• 2024

Skin aging results from complex interactions of intrinsic and extrinsic factors, leading to structural and biochemical changes such as wrinkles and dryness. Ultraviolet (UV) irradiation leads to the degradation of hyaluronic acid (HA) in the skin, and the fragmented HA contributes to inflammation. This study revealed that the synergistic combination of carnosine and retinol (ROL) increases HA production in normal human epidermal keratinocytes (NHEKs) by upregulating hyaluronan synthase 2 (HAS2) gene transcription. Simultaneously, the combined treatment of carnosine and ROL significantly attenuates UVB-induced prostaglandin E₂ (PGE₂) synthesis in NHEKs. A significant correlation exists between the increase of HA synthesis and the inhibition of PGE₂ production. This study suggests that combined treatment of carnosine and ROL can improve skin aging phenotypes associated with UVB irradiation.

• Journal of Acupuncture Research
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• v.22 no.2
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• pp.147-154
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• 2005

Objective: In this study, the effects of Liriope Platyphylla against LPS-induced inflammation was investigated. Methods: Cell viability was determined using the MTT assay. To identify expressions of COX-2 and iNOS mRNA, RT-PCR was performed. Assessment of PGE2 synthesis was performed using the PGE2 immunoassay. Measurement of NO synthesis was performed using the NO detection. Result : The MTT assay revealed that Liriope Platyphylla exerted no significant cytotoxicity in the microglial BV2 cells. RT-PCR analysis revealed that the mRNA levels of COX-2 and iNOS were significantly decreased in the LPS- and 5 mg/ml Liriope Platyphylla treated group. From the PGE2 immunoassay and NO detection, PGE2 and NO synthesis was significantly suppressed in the LPS- and 5 mg/ml Liriope Platyphylla treated group. Conclusion : In these study, Liriope Platyphylla was shown to suppress PGE2 and NO production by inhibiting LPS-stimulated enhancement of COX-2 enzyme activity and iNOS expression. It is very possible that Liriope Platyphylla can offer a valuable mode of therapy for the treatment of brain inflammatory diseases.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.1
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• pp.41-47
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• 2017

Perhaps the most common type of reproductive dysfunction in captive fish is failure of females to undergo final oocyte maturation and thus to ovulate and spawn. The success of aquaculture could therefore be improved by developing techniques to enhance natural spawning, artificial maturation, and/or to induce ovulation in farmed fish. This study aimed to investigate the effects of prostaglandin $E_2$ ($PGE_2$) and prostaglandin $F_{2{\alpha}}$ ($PGF_{2{\alpha}}$) on in vitro oocyte maturation (germinal vesicle breakdown, GVBD) and ovulation in the marine fish Chasmichthys dolichognathus. Post-vitellogenic follicles (0.80-0.94 mm diameter oocytes) were incubated with $PGE_2$ or $PGF_{2{\alpha}}$ at concentrations of 5, 50, or 500 ng/mL for 24 hours. A significant increase in GVBD was seen in 0.84 mm and 0.94 mm oocytes incubated with 50 ng/mL $PGE_2$ compared with the control. There was no significant increase in GVBD in any of the other experimental conditions (5 or 500 ng/mL $PGE_2$ or 5, 50, or 500 ng/mL $PGF_{2{\alpha}}$). Neither of the prostaglandins induced ovulation at the concentrations tested.These results suggest that GVBD was induced by incubation with 50 ng/mL $PGE_2$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.9
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• pp.1115-1120
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• 2006

The effect of cinnamon ethanol extract (CN) on HT-29 cancer cell line has been examined. CN inhibited the growth of HT-29 colon cancer cells in a concentration and time dependent manner but not the growth of CCD-112CoN normal colon cells. And CN markedly inhibited the production of $PGE_2$ and cGMP as well as the mRNA expression of COX-2. These data suggest that non toxic concentration of CN has a significant inhibition effect on the growth of HT-29 cells, probably through the inhibition of $PGE_2$ production via COX-2 inhibition, and may have value as a safe chemopreventive agent for colon cancer.