• Journal of the Society of Cosmetic Scientists of Korea
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• v.20 no.1
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• pp.25-36
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• 1994

It is weal known that bacterial lipopolysaccharide (LPS) stimulates prostaglandin synthesis in various experimental system via enhancing the expression of cylooxygenase-2 (COX-2). This study was designed to characterize U)5-induced prostaglandin synthesis in mouse peritoneal macrophages LPS-stimulated prostaglandin synthesis in macrophages with short term exposure was not so much prominent, but there was a burst in prostaglandin synthesis 8 hours after the LPS treatment and this u·as accompanied with the increase of cyclooxygenase activity, Dexamethasone markedly inhibited prostaglandin synthesis in this system. Metabolic label ins data supported above observations and thus, it could be concluded that LPS induces the do novo synthesis of COX-2 by which it stimulates the prostaglandin synthesis in mouse peritoneal macrophages, These data suggested that this experimental model system could be used for the screening procedure of COX-2 selective inhibitors. Ketoprofen, a non steroidal anti inflammatory agent, appeared to inhibit COX-1 relatively more selectively than COX-2.

• Clinical and Experimental Pediatrics
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• v.45 no.12
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• pp.1591-1595
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• 2002

Familial adenomatous polyposis(FAP) is an autosomal dominant disease characterized by numerous adenomas in the colorectum. Patients with FAP are always at risk of malignant transformation, so that colectomy is unavoidable. NSAID, such as sulindac, and selective COX-2 inhibitor, such as celecoxib, have shown a positive effect on FAP by causing polyp regression in some patients. We report a case of FAP in a 9-year-old female whose polyposis regressed markedly after six months-treatment with celecoxib.

• Radiation Oncology Journal
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• v.23 no.1
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• pp.51-60
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• 2005

Purpose : Selective inhibition of multiple molecular targets may improve the antitumor activity of radiation. Two specific inhibitors of selective cyclooxygenase-2 (COX-2) and epidermal growth factor receptor (EGFR) were combined with radiation on the HeLa cell line. To investigate cooperative mechanism with selective COX-2 inhibitor and EGFR blocker, in vitro experiments were done. Materials and Methods : Antitumor effect was obtained by growth inhibition and apoptosis analysis by annexin V-Flous method. Radiation modulation effects were determined by the clonogenic cell survival assay. Surviving fractions at 2 Gy ($SF_2$) and dose enhancement ratio at a surviving fraction of 0.25 were evaluated. To investigate the mechanism of the modulation of radiosensitivity, the cell cycle analyses were done by flow cytometry. The bcl-2 and bax expressions were analyzed by western blot. Results : A cooperative effect were observed on the apoptosis of the HeLa ceil line when combination of the two drugs, AG 1478 and NS 398 with radiation at the lowest doses, apoptosis of $22.70\%$ compare with combination of the one drug with radiation, apoptosis of $8.49\%$. In cell cycle analysis, accumulation of cell on $G_0/G_l$ phase and decrement of S phase fraction was observed from 24 hours to 72 hours after treatment with radiation, AG 1478 and NS 398. The combination of NS 398 and AG 1478 enhanced radiosensitivity on a concentration-dependent manner in HeLa cells with dose enhancement ratios of 3.00 and $SF_2$ of 0.12 but the combination of one drug with radiation was not enhanced radlosensitivity with dose enhancement ratios of 1.12 and SF2 of 0.68 (p=0.005). The expression levels of bcl-2 and bax were reduced when combined with AG 1478 and NS 398. Conclusion : Our results indicate that the selective COX-2 inhibitor and EGFR blocker combined with radiation have potential additive or cooperative effects on radiation treatment and may act through various mechanisms including direct inhibition of tumor cell proliferation, suppression of tumor cell cycle progression and inhibition of anti-apoptotic proteins.

• Journal of Chest Surgery
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• v.38 no.4 s.249
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• pp.263-270
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• 2005

In recent years, a combination of two demographic phenomena, an increased number of older people in the population and an increase in the incidence of lung cancer with age, has made it mandatory to develop therapeutic modalities with less toxicity for the treatment of inoperable elderly patients with lung cancer. Therefore, we investigated the correlation between COX-2 expression and cytotoxicity of Nimesulide, a specific COX-2 inhibitor. Material and Method: Immunohistochemical staining of COX-2 was performed. After exposure of Nimesulide, XTT analysis, FACS analysis and Hoechst staining were carried out. Result: COX-2 protein was expressed in non-treated A549 cells strongly, but not in H1299. Cytotoxicity of Nimesulide against A549 cell and H1299 cell were similar and $IC_{50}$ of Nimesulide in both cell lines were $70.9{\mu}M$ in A549 cell line and $56.5{\mu}M$ in H1299 cell line respectively. FACS analysis showed $G_0/G_1$ arrest in both cell lines and the S phase cell fraction was decreased. Morphologic assessment of apoptosis by Hoechst 33258 staining, many apoptotic cells were detected in both cell lines. Conclusion: Selective COX-2 inhibitor, Nimesulide, can inhibit the proliferation of non-small cell lung cancer cell lines in vitro. Inhibitory effect of Nimesulide are induction of apoptosis and $G_0/G_1$ arrest. There is no correlation between COX-2 expression and cytotoxicity of Nimesulide, a specific COX-2 inhibitor. Therefore, highly selective COX-2 inhibitors such as Nimesulide can be expected to lead to even greater efficacy of their use as adjuncts to various anticancer angents and radiation therapy for the treatment of high-risk patients.

• Journal of Yeungnam Medical Science
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• v.23 no.1
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• pp.36-44
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• 2006

Background: There is controversy regarding whether COX-2 specific inhibitors are associated with elevation of blood pressure. We compared the effects of aspirin, indomethacin, and celecoxib for vascular reactivity induced by phenylephrine. We also tested the effects of indomethacin and NO donor on COX-1 and COX-2 protein expression, as well as nitrite production in culture medium of vascular smooth muscle cells. Materials and Methods: In this experiment, we used the isometric tension study for vascular reactivity. After 45 minutes of pretreatment with aspirin, indomethacin, celecoxib, and phenylephrine induced contractions were tested. COX-1 and COX-2 protein expressions were analyzed by Western blot and nitrite production by the Griess reaction. Results: Although celecoxib pretreatment caused enhanced arterial contraction, aspirin pretreatment induced more potent arterial contraction than celecoxib in the isometric tension study of rabbit femoral artery. COX-1 protein expression was unchanged by indomethacin, SNP and NOR-3; COX-2 protein expression was increased by the addition of indomethacin, SNP, and NOR-3. Especially, NOR-3, a NO donor, significantly increased COX-2 protein expression with unstimulated conditions as well as LPS stimulation. Induction of nitrite production was higher with NOR-3 treatment than SNP treatment with LPS stimulation. Conclusion: These results suggest that aspirin caused more potent vascular contraction than celecoxib and indomethacin. COX-2 expression in VSMC depended on the types of NO donor and LPS stimulation.

• Journal of Life Science
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• v.23 no.11
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• pp.1342-1350
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• 2013

We examined the effect of hydrogen sulfide ($H_2S$) in chemical hypoxia-induced injury in mouse hepatocytes. Cell viability was significantly decreased by cobalt chloride ($CoCl_2$), a well-known hypoxia mimetic agent in a time- and dose- dependent manner. Sodium hydrosulfide (NaHS, a donor of $H_2S$) pretreatment before exposure to $CoCl_2$ significantly attenuated the $CoCl_2$-induced decrease of cell viability. $CoCl_2$ treatment resulted in an increase of intracellular ROS generation, which is inhibited by NaHS or N-acetyl-cysteine (NAC, a ROS scavenger), and p38 MAPK phosphorylation, which is also blocked by NaHS or NAC. The $CoCl_2$-induced increase of the Bax/Bcl-2 ratio was attenuated by NaHS, NAC, and SB 203580 (p38 MAPK inhibitor). The $CoCl_2$-induced decrease of cell viability was also attenuated by NaHS, NAC, and SB 203580 pretreatment. Additionally, NaHS inhibited the $CoCl_2$-induced COX-2. Similar to the effect of NaHS, NAC blocked $CoCl_2$-induced COX-2 expression. Furthermore, NS-398 (a selective COX-2 inhibitor) attenuated not only the $CoCl_2$-induced increase of the Bax/Bcl-2 ratio, it also decreased cell viability. Taken together, $H_2S$ protects primary cultured mouse hepatocytes against $CoCl_2$-induced cell injury through inhibition of the ROS-activated p38 MAPK cascade and the COX-2 pathway.

• Tuberculosis and Respiratory Diseases
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• v.48 no.2
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• pp.191-202
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• 2000

Background: Bronchial asthma is characterized by airway hyperresponsiveness(BHR) and inflammation. The cyclooxygenase(COX) is believed to be one of the important enzymes in these inflammatory reactions. Recently, the COX was divided into two isoforms, COX1 and COX2. COX2 is induced by lipopolysaccharide and some cytokines at the inflammation site. Prostaglandin E2(PGE2), produced from COX2, may affect airway inflammation. The purpose of this study is to evaluate the effect of COX2 inhibitor on COX2 expression, plasma PGE2, airway resistance and histologic finding in an animal asthma model. Methods : Sprague-Dawley rats were divided into 3 groups. The normal control group did not receive any treatment, but the asthma control group was sensitized by ovalbumin but not treated with the COX2 inhibitor(nimesulide, Mesulid$^{(R)}$). The treatment group was sensitized and treated with nimesulide. Specific airway resistance(sRaw) before and after nimesulide ingestion was investigated. The PGE2 level in the plasma was examined and COX2 immunogold-silver stain on lung tissue was performed. Results: sRaw and eosionophilic infiltration on airway, which increased in the asthma control group, was compared to normal control(p=0.014). However, there was no difference in eosinophilic infiltration between asthma control and treatment groups(p=0.408) and no difference in COX2 expression on bronchiolar epithelium among the three groups. Plasma PGE2 levels were not statically different among the three groups. Conclusion: The role of COX2 in the allergen-induced BHR was not significant The effect of nimesulide was not observed on BHR, COX2 expression, and plasma PGE2 level. Therefore, COX2 may not be a major substance of allergic asthma.

• Radiation Oncology Journal
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• v.21 no.3
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• pp.216-221
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• 2003

Purpose: To investigate the modulation of radiosensitivity by celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, on cancer cells over- and under-expressing COX-2. Materials and Methods: A clonogenic radiation survival analysis was performed on A549 human lung and MCF-7 human breast cancer cell lines incubated in both 1 and $10\%$ fetal bovine serum (FBS) containing media. The apoptosis in both cell lines was measured after treatment with radiation and/or celecoxib. Results: Celecoxib enhanced the radiation sensitivity of the A549 cells in the medium containing the $10\%$ FBS, with radiation enhancement ratios of 1.58 and 1.81 respectively, at surviving fractions of 0.1, with $30\muM\;and\;50\muM$ celecoxib. This enhanced radiosensitivity disappeared in the medium containing the $1\%$ FBS. Celecoxib did not change the radiation sensitivity of the MCF-7 cells in either media. The induction of apoptosis by celecoxib and radiation was not synergistic in either cell line. Conclwsion: Celecoxib, a selective COX-2 inhibitor, preferentially enhanced the effect of radiation on COX-2 over-expressing cancer cells compared to the cells with a low expression, and this effect disappeared on incubation of the cells during drug treatment in the medium with suboptimal serum concentration. Apoptosis did not appear to be the underlying mechanism of this radiation enhancement effect due to celecoxib on the A549 cells. These findings suggest radiosensitization by a selective COX-2 inhibitor is COX-2 dependent.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.114-121
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• 2023

Selective cyclooxygenase (COX)-2 inhibition is a novel strategy to reduce the risk of gastrointestinal side effects caused by conventional nonsteroidal anti-inflammatory drugs. However, some selective COX-2 inhibitors have become apparent to increase the risk of severe cardiovascular disease. The aim of this study was to examine the anti-inflammatory effect of rosemary extract (RE) and confirm the safety of cardiovascular side effects. Inhibition of COX enzyme activity was assessed, and the levels of COX-2 and prostaglandin E₂ (PGE₂) and COX-1 and thromboxane B₂ (TXB₂) were evaluated in lipopolysaccharide (LPS)-induced RAW 264.7 cells. The 40% RE group showed increased COX-2 inhibition activity in a dose-dependent manner, whereas the 50% RE group only exhibited at 100 ㎍/mL. In a cell-based study, COX-2 mRNA expression was similar in both RE groups and PGE₂ levels tended to decrease in the 40% RE group compared to the LPS group in the LPS pretreatment condition. In the LPS posttreatment condition, the COX-2 mRNA expression decreased in the 40% RE group, and PGE₂ levels were increased in the 40 and 50% RE groups. In both conditions, there was no significant difference in COX-1 and TXB₂ levels. In conclusion, 40 and 50% RE showed significant COX-2 inhibition, similar to the positive control group. It was confirmed that the inhibition of the COX-2 expression, but the effect did not affect the balance between prostacyclin and TXB₂. These results indicate that rosemary showed COX-2 inhibition activity with a low risk of cardiovascular diseases.

• Korean Journal of Food Science and Technology
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• v.39 no.3
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• pp.348-352
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• 2007

Inflammation is a complex process resulting from a variety of mechanisms. Combined inhibition of the activities of enzymes involved in the process may therefore be considered more important in anti-inflammatory property of plant extracts than any single contribution. In this study, the inhibitory effects of the ethanol extracts of thirty plant foods on the activities of secretory phospholipase $A_{2}$ ($sPLA_{2}$), cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), and 12-lipoxygenase (12-LOX) were examined. Several legumes, mungbean sprout and some leaf vegetables inhibited the activity of $sPLA_2$, upstream enzyme of inflammation pathway. Only soybean sprout and mungbean sprout significantly inhibited 12-LOX activity. Although most of extracts inhibited the activities of both COX-1 and COX-2, water dropwort and amaranth showed selectivity for the inhibition of COX-2 over COX-1. Especially, mungbean showed anti-inflammatory property at both upstream and downstream of inflammation pathway with relatively low $IC_{50}$ values for $sPLA_{2}$ and COX-2 enzymes. Mungbean sprout exhibited inhibitory effects on all enzymes related to early and late inflammation and soybean sprout suppressed 12-LOX and COX-2 simultaneously, although the activities of these plants were showed at relatively high concentration. Therefore, mungbean, mungbean sprout, and soybean sprout appear to exhibit anti-inflammatory effects by combined inhibition of inflammatory enzymes.