The cyclooxygenase (COX) is a key enzyme in the coversion of arachidonic acid to prostaglandins. COX-1 is constitutively expressed and is a critical housekeeping gene, whereas COX-2 is rapidly upregulated by growth factors and cytokines and thus responsible for inflammation. COX-2 is frequently overexpressed in colonic adenoma and carcinoma. Specific inhibitors of COX-2 have been shown to induce apoptosis in tumor cells and to inhibit tumor growth in animal models and in humans. Long-standing IBD patients have increased risk of developing colorectal cancer compared to general population. IBD-associated colorectal carcinogenesis is probably promoted by chronic inflammation and closely related to COX-2. In a recent study, powerful chemopreventive ability of selective COX-2 inhibitor was observed in colitis-related colon carcinogenesis in mouse model. But it was reported that even selective COX inhibitors aggravated the DSS-induced colonic inflammation. It is assumed that endogenous PGs are involved in the mucosal defense against DSS-induced colonic ulcerations which are produced by COX-1 at early phase and by COX-2 at late phase. Long-term use of COX-2 inhibitors for the chemoprevention of colitic cancer is needed to define their mechanism of action, that reduce side effects and have specific tumor target.
Animals ; Colitis, Ulcerative/*drug therapy ; Colonic Neoplasms/diagnosis ; Cyclooxygenase 1/metabolism ; Cyclooxygenase 2/metabolism ; Cyclooxygenase 2 Inhibitors/pharmacology/*therapeutic use ; Humans ; Mice ; Models, Animal

Cyclooxygenase (COX) is the obligate, rate-limiting enzyme for the conversion of arachidonic acid into prostaglandins, which mediate mitogenesis, apoptosis, angiogenesis, blood flow, secondary injury, and inflammation. COX is consist of 2 subtypes: COX-1 and COX-2. In recent years, there are a number of lines of evidence that COX-1 and COX-2 play a important in role brain injuries.
Animals ; Apoptosis/drug effects* ; Brain Injuries/pathology* ; Cyclooxygenase 1/metabolism* ; Cyclooxygenase 2/metabolism* ; Cyclooxygenase Inhibitors/therapeutic use* ; Humans ; Immunohistochemistry ; Neurons/drug effects* ; Rats ; Time Factors

OBJECTIVETo investigate the effects of the selective cyclooxygenase-2 (COX-2) inhibitor NS398 on the growth of human pancreatic tumor BxPC-3 cell strain and its possible mechanisms.

METHODSThe effect of NS398 on cell growth was assessed by 3- (4,5-dimethylthiazol-2-yl) -2, 5-diphenyl thiazolyl blue (MTT) assay. Apoptosis was determined by fluorescence-activated cell scanning (FACS) analysis and assessment of the floating cell/attached cell ratio. Caspase-3 activation was evaluated by Active Caspase-3 Apoptosis Kit with flow cytometry. Reverse transcriptase-polymerase chain reaction analysis (RT-PCR) and Western blot were used to demonstrate expression levels of COX-1, COX-2 mRNA, and protein, as well as Caspase-3 protein in pancreatic tumor BxPC-3 cell strain.

RESULTSSelective COX-2 inhibitor NS398 significantly decreased cell viability and induced apoptosis in pancreatic tumor BxPC-3 cell strain. The protein expression of Caspase-3 was induced by high-concentration NS398. Caspase-3 activity was strongly activated by NS398.

CONCLUSIONSSelective COX-2 inhibitor NS398 has antiproliferative and proapoptotic potential in pancreatic tumor BxPC-3 cells. Such effect is independent of COX-2, but correlates with Caspase-3 activation.

Apoptosis ; drug effects ; Caspase 3 ; drug effects ; metabolism ; Cyclooxygenase 1 ; metabolism ; Cyclooxygenase 2 ; metabolism ; Cyclooxygenase Inhibitors ; pharmacology ; Humans ; Nitrobenzenes ; pharmacology ; Pancreatic Neoplasms ; enzymology ; pathology ; Sulfonamides ; pharmacology ; Tumor Cells, Cultured

OBJECTIVETo evaluate the effect of peroxisome proliferator-activated receptor (PPAR)α agonist fenofibrate on the secretion of endothelium-derived contracting factors in hypertensive rats.

METHODSThe changes of vascular tension in SHR rats after having been incubated with 0.1, 1.0, or 10.0 μmol/L fenofibrate or 10.0 μmol/L fenofibrate and PPARα antagonist MK866 or PPARγ antagonist GW9662 for one hour were observed, and the findings were compared with those in WKY rats (control group). The serum levels of vascular endothelial contraction factor prostacyclin (PGF) 1α, 2α, and thromboxane B2 (TXB2) were determined by enzyme-linked immunosorbent assay (ELISA). The expression of COX-1 protein was determined by Western blot analysis.

RESULTSCompared with the control group, fenofibrate significantly reduced the vasoconstriction ability of the SHR rats(P=0.013). PPARα antagonist MK866 significantly improved the vascular contractility of SHR rats that had been incubated with 10.0 μmol/L fenofibrate (P=0.021). PPARγ antagonist GW9662 had no significant effect on the vascular contractility of SHR rats after having been incubated with 10.0 μmol/L fenofibrate (P=0.071). The serum levels of PGF1α(P=0.014), 2α(P=0.023), and TXB2 (P=0.017) in SHR rats incubated with 10.0 μmol/L fenofibrate were significantly lower than in the control group. With the presence of vascular endothelium, the expression of COX-1 in SHR rats incubated with fenofibrate was significantly lower than that in SHR rats incubated without fenofibrate (P=0.027).

CONCLUSIONFenofibrate reduces the secretion of endothelium-dependent contracting factors in SHR rats through lowering the expression of COX-1.

Animals ; Cyclooxygenase 1 ; metabolism ; Epoprostenol ; metabolism ; Fenofibrate ; pharmacology ; Hypertension ; metabolism ; Male ; Membrane Proteins ; metabolism ; Rats ; Rats, Inbred SHR ; Rats, Inbred WKY ; Thromboxane B2 ; metabolism

Syringa pinnatifolia Hemsl.( SP) is a representative Mongolian folk medicine with the effects of inhibiting Heyi related diseases,clearing heat and relieving pain. It has been used for the treatment of Heyi-induced heart tingling,heart palpitations,upset,insomnia and other symptoms. Total ethanol extract( T) and major fraction( M) of SP have been evaluated its anti-ischemic effects,and the mechanism was related to the regulation of cyclooxygenase( COX)-mediated inflammatory pathway and p53-mediated apoptosis pathway in our previous studies. This study reports the chemical fractionation on M by which to obtain subfractions( I and M_3),and the pharmacological evaluation of M,I,and M_3 against myocardial ischemia in mice. The result showed that I and M reduced the values of LVEDd and LVEDs,significantly increased EF and FS values,increased serum CK-MB and LDH levels in mice,and reduced in inflammatory cells infiltration and collagen deposition in the infarcted myocardial tissue,suggesting that M and I possess the same degree anti-myocardial is chemia equally whereas M_3 has no this effect. Related mechanism studies suggested that I can reduce the expression of COX-1,COX-2 and p53 protein in myocardial tissue in a dose-dependent manner. This study lays the foundation for further chemical segmentation and clarification of pharmacological substance groups,paving the way for the full use and benefits to be use of systematic biological methods to analyze the pharmacological basis of SP against myocardial ischemia.
Animals ; Cyclooxygenase 1/metabolism* ; Cyclooxygenase 2/metabolism* ; Heart/drug effects* ; Medicine, Mongolian Traditional ; Membrane Proteins/metabolism* ; Mice ; Myocardial Ischemia/drug therapy* ; Myocardium/metabolism* ; Plant Extracts/therapeutic use* ; Syringa/chemistry* ; Tumor Suppressor Protein p53/metabolism*

AIMTo observe protective effects of safflower injection (SI) on lung ischemia/reperfusion injury (LIRI) and investigate its potential mechanism.

METHODSRabbit lung model of ischemia/reperfusion injury was constituted in vivo. The rabbits were randomly divided into three groups: sham-operation group (S group), ischemia/reperfusion group (I/R group) and ischemia/reperfusion plus safflower injection group (SI group). Malondialdehyde (MDA) content, superoxide dismutase (SOD) and xanthine oxidase (XO) activities in serum were measured. The lung tissue sampled at the end of the experiment was assayed for wet/dry weight ratio (W/D), injured alveoli rate (IAR) and ultrastructural changes were observed under electron microscope. The expression of COX-1 and COX-2 were measured by immunohistochemistry (IHC). The expressions of COX-1mRNA and COX-2mRNA were observed by in situ hybridization (ISH).

RESULTSIn I/R group, XO and MDA increased and SOD decreased in serum, while the same changes happened in SI group but less severely(P<0.01). The value of W/D and IAR was much higher in I/R group than S group, but decreased in SI group. Electron microscope showed obvious ultrastructural injury brought by LIRI in I/R group, which was greatly attenuated in SI group. The IHC and ISH demonstrated that COX-2 and COX-2mRNA in pulmonary tissue of I/R group were significantly higher than those of SI group (P < 0.01). The difference of COX-1 and COX-1mRNA in pulmonary tissue among the three groups was not significant.

CONCLUSIONThe ischemia/reperfusion lung injury insults induced the regulation of COX-2 in lung. Safflower injection may attenuate lung ischemia/reperfusion injury through inhibiting cyclooxygenase-2 expression.

Animals ; Carthamus tinctorius ; Cyclooxygenase 1 ; metabolism ; Cyclooxygenase 2 ; metabolism ; Lung ; drug effects ; enzymology ; physiopathology ; Malondialdehyde ; blood ; Rabbits ; Reactive Oxygen Species ; metabolism ; Reperfusion Injury ; metabolism ; Superoxide Dismutase ; blood ; Xanthine Oxidase ; blood

OBJECTIVETo evaluate the effect of low salt (LS) on the expression of cyclooxygenase-2 (COX-2) and the activity of nuclear factor kappa B (NF-kappaB) and activator protein-1 (AP-1) in the mouse macula densa derived (MMDD1) cell line.

METHODSMMDD1 cells were transfected with luciferase reporter plasmid containing AP-1 or NF-kappaB. Luciferase reporter assay was used to evaluate the effect of normal salt (NS) and low salt (LS) on the activities of NF-kappaB and AP-1. The changes of COX-2 expression were examined by RT-PCR. The expression of p-p38 MAPK, p-p44/42, c-Jun, c-Fos, and COX-2 in MMDD1 cells were analyzed by Western blot.

RESULTSThe expressions of COX-2 mRNA and protein in MMDD1 cells were significantly increased by LS (P < 0.01). Phosphorylated p38 and p44/42 MAP kinase were significantly increased by treatment at 180 min (P < 0.01). The up-regulated COX-2 protein expression with LS were significantly reduced with SB 203580 (p38 inhibitors) and PD-98059 (p44/42 inhibitors) (P < 0.01). The expressions of c-Jun and c-Fos were increased by LS. The luciferase activities of AP-1 and NF-kappaB were stimulated in LS (P < 0.01), the up-regulated luciferase activities were attenuated by PDTC at 25 micromol/L (NF-kappaB inhibitor) and curcumin at 20 micromol/L (AP-1 inhibitor) (P < 0.01). LS altered COX-2 mRNA abundance and protein expression were decreased in treatment with PDTC at 25 micromol/L, curcumin at 20 micromol/L (P < 0.01).

CONCLUSIONLS can induce the expression of COX-2 in MMDD1 cells, which may be involved in the activation of p38 MAP kinase, p44/42 kinase, AP-1, and NF-kappaB pathways.

Animals ; Cell Line ; Cyclooxygenase 2 ; metabolism ; Kidney ; cytology ; metabolism ; Mice ; NF-kappa B ; metabolism ; Signal Transduction ; Transcription Factor AP-1 ; metabolism

OBJECTIVE: To determine the effect of indomethacin on high concentration glucose and lipopolysaccharide (LPS) induced fibronectin (FN) and plasminogen activator inhibitor-1 (PAI-1) secretion in cultured human peritoneal mesothelial cells. METHODS: Mesothelial cells were isolated from human omental specimens by trypsin disaggregation and incubated by 2.5% glucose or LPS together with different concentrations of indomethacin. Enzyme-linked immunosorbent assay determined the quantity of FN and PAI-1 in the cultured supernatants. RESULTS: Compared with the control group, the levels of FN and PAI-1 in the cultured supernatants were increased significantly exposuring to high concentration glucose and LPS (P <0.01). The different concentrations of indomethacin decreased FN and PAI-1 secretion in the 2.5% glucose or the LPS group within 24 h (P < 0.05). CONCLUSION Indomethacin can inhibit the synthesis and secretion of extracellular matrix in human peritoneal mesothelial cells, which may be effective in the gene therapy for peritoneal fibrosis.
Cells, Cultured ; Cyclooxygenase Inhibitors ; pharmacology ; Epithelial Cells ; metabolism ; Fibronectins ; metabolism ; Humans ; Indomethacin ; pharmacology ; Peritoneum ; cytology ; metabolism ; Plasminogen Activator Inhibitor 1 ; metabolism

Many studies have shown that chronic inflammation occurs in the brain of patients with Alzheimer's disease (AD). It is well known that long-term administration of non-steroidal anti-inflammatory drugs (NSAIDs) can alleviate the cognitive decline of AD patient and elderly. Several inflammatory cytokines produced in the metabolism of arachidonic acid (AA) are closely related to inflammatory diseases. Lipoxygenases (LOXs) and cyclooxygenases (COXs) play a crucial role in the AA network, the products eicosanoids have an important impact on the progression of AD. Although there are many arguments and conflicting evidence, currently LOXs and COXs are still the hot topics in the research on AD pathogenesis and drug development. Here, we review the progress in research on COXs and LOXs, including their actions on CNS and their association with AD, and explore the feasibility of LOXs and COXs as targets for the drugs to prevent and/or treat AD.
Alzheimer Disease ; drug therapy ; enzymology ; prevention & control ; Amyloid beta-Peptides ; metabolism ; Animals ; Anti-Inflammatory Agents, Non-Steroidal ; pharmacology ; therapeutic use ; Arachidonic Acid ; metabolism ; Brain ; metabolism ; Cyclooxygenase 1 ; metabolism ; Cyclooxygenase 2 ; metabolism ; Cyclooxygenase Inhibitors ; therapeutic use ; Humans ; Lipoxygenase Inhibitors ; therapeutic use ; Lipoxygenases ; metabolism ; Prostaglandin H2 ; metabolism ; Prostaglandin-Endoperoxide Synthases ; metabolism

AIM: In the present study, the anti-inflammatory and antioxidant activities of the methanol extract of Ruta graveolens leaves (RG-M) were evaluated using various in vivo and in vitro models. METHOD: For anti-inflammatory activity, RG-M was administered by the oral route (p.o.) in a carrageenan-induced paw edema model, and by the intraperitoneal route (i.p.) in an exudative inflammation model. In vitro inhibition of cyclooxygenase and lipoxygenase enzymes was evaluated. In vitro antioxidant activity was also examined. Endogenous antioxidant status was further evaluated by ferric reducing ability of plasma model. RESULTS: RG-M showed maximum inhibition of carrageenan-induced edema (100 mg·kg⁻¹ - 33.36%; 200 mg·kg⁻¹ - 45.32% and 400 mg·kg⁻¹ - 56.28%). In the exudative inflammation model, a significant reduction in leukocyte migration (200 mg·kg⁻¹ - 54.75% and 400 mg·kg⁻¹ - 77.97%) and protein exudation (200 mg·kg⁻¹ - 31.14% and 400 mg·kg⁻¹ - 49.91%) were observed. RG-M also exhibited inhibition of COX-1 (IC50 182.27 μg·mL⁻¹) and COX-2 (IC50 190.16 μg·mL⁻¹) as well as 5-LOX (IC50 215.71 μg·mL⁻¹). Antioxidant activity was significant with improved endogenous antioxidant status. CONCLUSION The results demonstrated the anti-inflammatory and antioxidant activity of RG-M with potent inhibitory effects on the arachidonic acid pathways.
Animals ; Anti-Inflammatory Agents ; pharmacology ; therapeutic use ; Antioxidants ; pharmacology ; therapeutic use ; Arachidonic Acid ; metabolism ; Carrageenan ; Cyclooxygenase 1 ; metabolism ; Cyclooxygenase 2 ; metabolism ; Cyclooxygenase Inhibitors ; pharmacology ; therapeutic use ; Disease Models, Animal ; Edema ; drug therapy ; Exudates and Transudates ; Ferric Compounds ; metabolism ; Inflammation ; drug therapy ; metabolism ; Leukocytes ; metabolism ; Lipoxygenase Inhibitors ; pharmacology ; therapeutic use ; Lipoxygenases ; metabolism ; Male ; Phytotherapy ; Plant Extracts ; pharmacology ; therapeutic use ; Plant Leaves ; Rats, Wistar ; Ruta