• Molecules and Cells
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• v.25 no.3
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• pp.347-351
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• 2008

Several lines of evidence indicate that the oxidative modification of protein and the subsequent accumulation of the modified proteins have been found in cells during aging, oxidative stress, and in various pathological states including premature diseases, muscular dystrophy, rheumatoid arthritis, and atherosclerosis. The important agents that give rise to the modification of a protein may be represented by reactive aldehydic intermediates, such as ketoaldehydes, 2-alkenals and 4-hydroxy-2-alkenals. These reactive aldehydes are considered important mediators of cell damage due to their ability to covalently modify biomolecules, which can disrupt important cellular functions and can cause mutations. Furthermore, the adduction of aldehydes to apolipoprotein B in low-density lipoproteins (LDL) has been strongly implicated in the mechanism by which LDL is converted to an atherogenic form that is taken up by macrophages, leading to the formation of foam cells. During the search for an endogenous inducer of cyclooxygenase-2 (COX-2), an inducible isoform responsible for high levels of prostaglandin production during inflammation and immune responses, 4-hydroxy-2-noennal (HNE), one of the most representative lipid peroxidation product, has been identified as the potential inducer of COX-2. In addition, the following study on the molecular mechanism of the COX-2 induction by HNE has unequivocally established that a serum component, which is eventually identified to be denatured LDL, is essential for COX-2 induction. Here I review current understanding of the mechanisms by which HNE in cooperation with the serum component activates gene expression of COX-2.

• Korean Journal of Medicinal Crop Science
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• v.13 no.2
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• pp.75-79
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• 2005

Five coumarins, psoralen (1), scopoletin (2), isoimperatorin (4), (+)-marmesin (5) and xanthotoxin (6), three chromones, cimifugin (3), hamaudol (7) and sec-O-glucosylhamaudol (10), one sterol, daucosterol (8) and one aliphatic alcohol, galactitol (9) were isolated from the root of Peucedanum japonicum. Their chemical structures were identified by the physicochemical and spectroscopic data by comparing literature values. Among them, compounds 9 and 10 were isolated for the first time from this plant. The anti-inflammatory effects of isolated compounds were examined on cyclooxygenase (COX), compounds 1, 2 and 7 showed inhibitory activity on COX-1 with $IC_{50}$ values of 0.88, 0.27 and 0.30 mM, respectively. In the test for COX-2 activity, only compound 7 showed significant inhibitory activity with the $IC_{50}$ value of 0.57 mM. The other compounds exhibited weak inhibitory or no inhibitory activity.

• Genomics & Informatics
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• v.15 no.2
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• pp.56-64
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• 2017

We have previously reported that NS-398, a cyclooxygenase-2 (COX-2)-selective inhibitor, inhibited replicative cellular senescence in human dermal fibroblasts and skin aging in hairless mice. In contrast, celecoxib, another COX-2-selective inhibitor, and aspirin, a non-selective COX inhibitor, accelerated the senescence and aging. To figure out causal factors for the senescence-modulating effect of the inhibitors, we here performed cDNA microarray experiment and subsequent Gene Set Enrichment Analysis. The data showed that several senescence-related gene sets were regulated by the inhibitor treatment. NS-398 up-regulated gene sets involved in the tumor necrosis factor ${\beta}$ receptor pathway and the fructose and mannose metabolism, whereas it down-regulated a gene set involved in protein secretion. Celecoxib up-regulated gene sets involved in G2M checkpoint and E2F targets. Aspirin up-regulated the gene set involved in protein secretion, and down-regulated gene sets involved in RNA transcription. These results suggest that COX inhibitors modulate cellular senescence by different mechanisms and will provide useful information to understand senescence-modulating mechanisms of COX inhibitors.

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.05a
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• pp.88-88
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• 2002

Cyclooxygenase(COX) metabolizes arachidonic acid to prostaglandins and thromboxanes. It has been reported that there is 'cross-talk' between COX-2 and nitric oxide synthase(NOS). Stimulation of eNOS of estrogen fed animal heart was not accompanied by the increase in COX-2 expression.(omitted)

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.05a
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• pp.13-14
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• 2003

Ceramide, a potential cell death marker formed by sphingomyelinase, is involved in the expression of cyclooxygenase-2 (COX-2). This study examines the effect of C2-ceramide (C2), a cell-permeable ceramide analog, on the LPS-inducible COX-2 expression and signaling pathways. C2 did not induce COX-2, but potentiated LPS-inducible COX-2 expression in Raw264.7 cells, whereas dihydro-C2 was inactive.(omitted)

• Biomolecules & Therapeutics
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• v.9 no.2
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• pp.69-78
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• 2001

Cyclooxygenase (COX) is an enzyme, which catalyzes the production of prostaglandins from arachi-donic acid and exists in two isoforms (COX-1 and COX-2). COX-1 is involved in the maintenance of physiological functions such as platelet aggregation, cytoprotection in the stomach and maintenance of normal kidney function. COX-2 is induced significantly in vivo under inflammatory conditions. COX-1 and COX-2 serve different physiological and pathological functions. All commercially available nonsteroidal antiinflammatory drugs (NSAIDS) are inhibitors of both COX-1 and COX-2. Therefore, selective inhibitors of COX-2 may be effective antiinflammatory agents without the ulcerogenic effects associated with current NSAms. Since the mid 1990s, a number of reports have been appeared on the preparation and biological activity of selective COX-2 inhibitors. Recently celecoxib, and rofecoxib, the representative COX-2 inhibitors, are introduced in the drug market. In this paper the relationship of structure-activity for selective COX-2 inhibitors is reviewed.

• Food Science and Preservation
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• v.13 no.4
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• pp.513-518
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• 2006

Insect resources have been widely recognized that seven millions of insects exhibit it own biological activity by whole body or its metabolic intermediates. In order to investigate antioxidant activity and compare the cyclooxygenase-2 promoter activity from insect extract, we tested in vitro antioxidant assays and cyclooxygenase-2 promoter assay in Coccinella septempunctata Linne and Harmonia axyridis extracts have the anti-oxidant and cyclooxygenase-2 inhibition activities, we examined the anti-oxidant assays including DPPH, FRAP and linoleic acid, ana inhibition of cyclooxygenase-2 expression using a cyclooxygenase-2 promoter-inserted stable cell line. We found that Harmonia axyridis Pallas extract had potentials to anti-oxidant activity and inhibited about 25% of cyclooxygenase-2 transcription activity. These findings indicate that Coccinella septempunctata Linne and Harmonia axyridis Pallas extracts could be an useful insect resource for agrobiotechnological purposes.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.216.1-216.1
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• 2003

P. ginseng C.A. Meyer is one of the most widely used herbal medicine in Asia. It has been used for the treatment of many disorders. Its major constituent is known to be ginsenosides, and there are many documents about bioactivities of ginsenosides such as anti-oxidant, anti-tumorigenic, anti-fatigue, and anti-inflammatory activities. Some of these activities are supposed to have some correlation with inhibitory action of cyclooxygenase (COX). Ginsenosides from P. ginseng and sapogenins were evaluated for their inhibitory effects against both cyclooxygenase-1 and -2 (COX-1 and -2). Inhibitory activity was evaluated by measuring prostaglandin E$_2$ (PGE$_2$) production from arachidonic acid with an ELISA reader. (omitted)

• 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.

• The Korean Journal of Pain
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• v.35 no.3
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• pp.261-270
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• 2022

Background: The rostral ventromedial medulla (RVM) is a critical region for the management of nociception. The RVM is also involved in learning and memory processes due to its relationship with the hippocampus. The purpose of the present study was to investigate the molecular mechanisms behind orexin-A signaling in the RVM and hippocampus's effects on capsaicin-induced pulpal nociception and cognitive impairments in rats. Methods: Capsaicin (100 g) was applied intradentally to male Wistar rats to induce inflammatory pulpal nociception. Orexin-A and an orexin-1 receptor antagonist (SB-334867) were then microinjected into the RVM. Immunoblotting and immunofluorescence staining were used to check the levels of cyclooxygenase-2 (COX-2) and brain-derived neurotrophic factor (BDNF) in the RVM and hippocampus. Results: Interdental capsaicin treatment resulted in nociceptive responses as well as a reduction in spatial learning and memory. Additionally, it resulted in decreased BDNF and increased COX-2 expression levels. Orexin-A administration (50 pmol/1 µL/rat) could reverse such molecular changes. SB-334867 microinjection (80 nM/1 µL/rat) suppressed orexin's effects. Conclusions: Orexin-A signaling in the RVM and hippocampus modulates capsaicin-induced pulpal nociception in male rats by increasing BDNF expression and decreasing COX-2 expression.