• Proceedings of the PSK Conference
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• 2003.10b
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• pp.113.2-113.2
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• 2003

Inducible cyclooxygenase-2 (COX-2) has been implicated in the processes of inflammation and carcinogenesis. Thus, the potential COX-2 inhibitors have been considered as anti-inflammatory or cancer chemopreventive agents. In this study, we investigated the effect of Caffeoyl-4-dihydrocaffeoyl quinic acid (CDCQ) isolated from Salicornia herbacea on the expression of cyclooxygenase (COX-2) in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. When CDCQ was treated with LPS, the prostaglandin $E_2$ production and COX-2 gene expression induced by LPS were markedly reduced in a dose-dependent manner. (omitted)

• The Korean Journal of Physiology and Pharmacology
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• v.10 no.1
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• pp.45-50
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• 2006

Melittin-induced pain model has been known to be very useful for the study of pain mechanism. Melittin-induced nociceptive responses are reported to be modulated by the changes in the activity of excitatory amino acid receptor, calcium channel, spinal serotonin receptor and extracellular signaling-regulated kinase. The present study was undertaken to investigate the role of cyclooxygenase (COX) in the melittin-induced nociception. Changes in mechanical threshold, flinchings and paw thickness were measured before and after intraplantar injection of melittin in the rat hind paw. Also studied were the effects of intraperitonealy administered diclofenac (25 mg & 50 mg/kg), piroxicam (10 mg & 20 mg/kg) and meloxicam (10 mg & 20 mg/kg) on the melittin-induced nociceptions. Intraplantar injection of melittin caused marked reduction of mechanical threshold that was dose-dependently attenuated by non-selective COX inhibitor (diclofenac) and selective COX-1 inhibitor (piroxicam), but not by COX-2 inhibitor (meloxicam). Melittin-induced flinchings were strongly suppressed by non-selective COX and COX-1 inhibitor, but not by COX-2 inhibitor. None of the COX inhibitors had inhibitory effects on melittin-induced increase of paw thickness (edema). These experimental findings suggest that COX-1 plays an important role in the melittin-induced nociceptive responses.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.2
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• pp.455-459
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• 2006

The inhibitors of prostaglandin $E_2\;(PGE_2)$ production and cyclooxygenase-2 (COX-2) activity have been considered as potential anti-inflammatory agents. In this study, we evaluated 9 compounds isolated from 5 Korean phytomedicinal plants (Spirea prunifolia, Paeonia suffruticosa, Salvia miltiorrhiza, Scutellaria baicalensis, and Artemisia capillaris) for the inhibition of $PGE_2$production and COX-2 expession in lipopolysaccharide (LPS)-stimulated human macrophages U937 cells. As a result, several compound such as prunioside A, penta-O-galloyl-beta-D-glucose, tanshinone IIA, baicalin, baicalein, wogonin, scopolatin, scoparone and decursinol showed potent inhibition of $PGE_2$production (50-70% inhibition at the test concentration of $10\;{\mu}M$). In addition, these compounds were also considered as potential inhibitors of COX-2 activity (45-73% inhibition at the test concentration of $10\;{\mu}M$). These active compound mediating COX-2 inhibitory activities are warranted for further elucidation of active principles for development of anti-inflammatory agents and these properties may contribute to the anti-atopic dermatitis activity.

• The Korean Journal of Physiology and Pharmacology
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• v.10 no.3
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• pp.161-165
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• 2006

NO and cyclooxygenase-2 (COX-2) are contributes to vascular inflammation induced by various stimulation. The mechanism, which explains a linkage between NO and COX-2, could be of importance in promoting pathophysiological conditions of vessel. We investigated the effects of NO donors on the COX-l and COX-2 mRNA/protein expression, as well as the nitrite production in culture medium of vascular smooth muscle cell (VSMC). VSMC was primarily cultured from thoracic aorta of rat. In this experiments, COX-l and COX-2 mRNA/protein expressions were analysed and nitrite productions were investigated using Griess reagent. VSMC did not express COX-2 protein in basal condition (Nonlipopolysaccharide (LPS) stimulated). In LPS-stimulated experiments, after 3 hours of NO donor pretreatment, LPS $10{\mu}g/ml$ was treated for 24 hours. COX-l protein expressions were unchanged by SNP and NOR-3. NOR-3 significantly increased COX-2 mRNA/protein expression under LPS stimulation. In contrast, SNP did not increase COX-2 mRNA/protein expression under LPS stimulation. Nitrite production was higher in NOR-3 treatment than SNP treatment under LPS stimulation. These results suggest that the expression of COX-2 in VSMC is regulated by NOR-3, COX-2 expressions were depending on the types of NO donor and LPS stimulation in VSMC.

• Clinical and Experimental Reproductive Medicine
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• v.25 no.1
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• pp.25-33
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• 1998

Cyclooxygenase (COX) is an enzyme involved in the conversion of arachidonic acid to prostaglandins (PGs), and exists in two forms, COX-1 and COX-2. COX has been reported to be involved in early implantation by secretion of PGs which causes permeability of vessels and reaction of decidual cells around the implantation site. Recently, in mice and sheep studies, COX-1 and COX-2 expression in the endometrium has been reported to be different according to implantation and stages of the estrous cycle, but expression of COX-1 and COX-2 in human endometrium during the menstrual cycle has not yet been established. The purpose of this study was to observe the variances of COX-1 and COX-2 expression by immunohistochemical staining in endometrial samples obtained from human hysterectomy specimens and biopsies of women of reproductive age according to different stages of the menstrual cycle. Also, we attempted to observe COX-1 and COX-2 expression in the epithelial and stromal cells of the endometrium obtained during the mid-secretory phase, which were cultured separately. COX-2 showed a cyclic pattern of expression according to the different stages of the menstrual cycle and was strongly expressed particularly at the mid-secretory phase which corresponds to the time of implantation. However, COX-1 tended to be increased in the early proliferative, and mid- and late secretory phases, but was also expressed in the whole menstrual cycle showing no particular pattern. In the separately cultured cells COX-1 was expressed in epithilial cells and COX-2 in the stromal cells. The above results suggest that since COX-2 is expressed at the same time as implantation and cultured cells display a specific secretory pattern, COX-2 has inductive endocrine enzyme properties and has an important effect on endometrial cells during implantation. Also, COX-2 expression in endometrial cells may be utilized as a useful marker of endometrial maturation.

• The Korean Journal of Physiology and Pharmacology
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• v.5 no.3
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• pp.253-258
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• 2001

The present study was aimed to examine whether the expression of renin is associated with that of cyclooxygenase-2 (COX-2) in the kidney. Male Sprague-Dawley rats were made two-kidney, one clip (2K1C) or deoxycorticosterone acetate (DOCA)-salt hypertensive, to stimulate or to inhibit the endogenous renin-angiotensin system, respectively. The expression of renin and COX-2 mRNA was determined in the cortex of the kidney by reverse transcription-polymerase chain reaction. 2K1C hypertensive rats showed an increased expression of renin as well as of COX-2 in the clipped kidney. The expression of renin was decreased in parallel with that of COX-2 in the contralateral non-clipped kidney. Removal of the renal arterial clip reversed the expression of both genes, along with the blood pressure, to the control level. On the other hand, DOCA-salt hypertension was associated with parallel decreases of renin and COX-2 expression. These results indicate that renin and COX-2 genes are coordinately expressed in the kidney.

• Environmental Mutagens and Carcinogens
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• v.25 no.4
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• pp.143-149
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• 2005

The identification of COX-2 (cyclooxygenase-2) has led to potential novel insights on disease pathogenesis (atherosclerosis, cancer, Alzheimer's disease) and the regulation of normal organ function. The present in vivo study with estrogen or soy-isoflavones has provided evidence for the association between COX-2 and ICAM-1 (Intercellular adhersion molecule-1). In the system of mature female rats, soy-isoflavones exerted more pronounced effect on ICAM-1 inhibitory and COX-2 stimulatory effect than estrogen. In the system of ovariectomized estrogen deficient rats, the down-regulatory properties of soy-isoflavones on ICAM-1 was less evident, whereas estrogen exerted the inhibitory activity. These results demonstrate that COX-2 limits adhersion molecule expression on rat aorta cells and suggest that COX-2 may play a protective role in cardiovascular system in mature female rats. Soy-isoflavones appear to have beneficial effect on vascular systems through modulation of ICAM-1 and COX-2, and these molecules appeared to be closely associated.

• The Journal of the Korean Society for Microbiology
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• v.34 no.5
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• pp.479-489
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• 1999

Invasion of enteric bacteria, such as Salmonella and invasive E. coli, into intestinal epithelial cells induces proinflammatory gene responses and finally epithelial cell apoptosis. In this study, we asked whether invasive bacterial infection of human intestinal epithelial cells could upregulate cyclooxygenase-2 (COX-2) gene expression and whether increased COX-2 expression could influence intestinal epithelial cell apoptosis. Expression of COX-2 mRNA and prostaglandin (PG) $E_2$ production were upregulated in HT-29 colon epithelial cells which were infected with S. dublin or invasive E. coli, as examined by quantitative RT-PCR and radioimmunoassay. Inhibition of COX-2 expression and $PGE_2$ production using NS-398, a specific COX-2 inhibitor, showed a significant increase of epithelial cell apoptosis and caspase-3 activation in HT-29 cells infected with invasive bacteria. However, the addition of valerylsalicylate, a specific COX-1 inhibitor, did not change apoptosis in S. dublin-infected HT-29 cells. These results suggest that up regulated COX-2 expression and $PGE_2$ production in response to invasive bacterial infection could contribute to host defense by inhibiting apoptosis of intestinal epithelial cells.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.3
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• pp.749-752
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• 2005

We investigated the effects of electroacupuncture (EA) on the expression of cyclooxygenase in the spinal cord of acute inflammatory pain model. Inflammation was induced by an intraplantar injection of 1% carrageenan into the right hind paw of Sprague-Dawley. Bilateral 2 Hz EA stimulation with 0.5 mA, 1 mA and 3 mA were delivered at those acupoints corresponding to Zusanli and Sanyinjiao in man via the needles in carrageenan-injected rats. Three hours after carrageenan injection, effects of EA on cyclooxygenase (COX) expression were observed in the dorsal horn of the spinal cord using immunohistochemical method. The immunoreaction of COX-1 tended to increase in the superficial laminae and the neck of the dorsal horn as compared with normal. The COX-2 immunoreaction in the carrageenan-injected rat was also significantly increased in the all regions of the dorsal horn as compared with normal one. However, COX-1 immunoreaction in carrageenan-injected rat were decreased in the superficial laminae and neck of the dorsal horn by low intensity of EA stimulation. Except high intensity of EA stimulation in the superficial laminae, COX-2 expression was attenuated in all regions of the dorsal horn by all types of EA treatment. It is concluded that EA treatment may attenuate inflammatory pain in carrageenan-injected rat through modulating expression of COX-2 in the dorsal horn of the spinal cord.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10a
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• pp.133-134
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• 2001

Abnormal regulation of the inducible form of cyclooxygenase (COX-2) has been often observed in various types of cancerous and transformed cells. Recently, targeted inhibition of COX-2 is recognized as one of the promising strategies for the prevention or treatment of cancer as well as inflammation, As part of a program to evaluate the cancer chemopreventive potential of anti-inflammatory phytochemicals, we initially determined the COX-2 inhibitory activity of some naturally occurring diarylheptanoids structurally related to curcumin.(omitted)