Concentrations Of Celecoxib Research Articles

A sensitive chemiluminescence method for the determination of celecoxib in pharmaceutical and biological samples

A simple and sensitive chemiluminometric method was developed for the determination of celecoxib, a nonsteroidal anti-inflammatory drug. It is based on the sensitization of Ce(IV)-Na2SO3 chemiluminescence reaction by celecoxib in the presence of Tb(III) ions. The mechanism of chemiluminescence reaction was studied by obtaining fluorescence and chemiluminescence spectra. The effects of various chemical parameters on chemiluminescence intensity were investigated and optimized. Under the optimum conditions, a linear relationship was obtained between the enhanced chemiluminescence intensity and the concentration of celecoxib in the range of 0.01–0.15 μg/mL, with a limit of detection of 2.5 ng/mL. Study of interferences confirmed the selectivity of the developed method for analysis of pharmaceutical and biological samples. The method was applied to the determination of celecoxib in pharmaceutical formulations and human plasma samples, and also to dissolution studies with satisfactory results.

Application of unfolded principal component analysis–radial basis function neural network for determination of celecoxib in human serum by three-dimensional excitation–emission matrix fluorescence spectroscopy

This study describes a simple and rapid approach of monitoring celecoxib (CLX). Unfolded principal component analysis–radial basis function neural network (UPCA–RBFNN) and excitation–emission spectra were combined to develop new model in the determination of CLX in human serum samples. Fluorescence landscapes with excitation wavelengths from 250 to 310nm and emission wavelengths in the range 280–450nm were obtained. The figures of merit for the developed model were evaluated. High performance liquid chromatography (HPLC) technique was also used as a standard method. Accuracy of the method was investigated by analysis of the serum samples spiked with various concentration of CLX and a recovery of 103.63% was obtained. The results indicated that the proposed method is an interesting alternative to the traditional techniques normally used for determining CLX such as HPLC.

Cyclooxygenase-2 inhibition as a strategy for treating gastric adenocarcinoma

Cyclooxygenase-2 (COX-2) has been proven to play critical roles in inflammation as well as in cancer. Some studies have shown that the anti-inflammatory, immunosuppressive and anti-arthritic effects of celecoxib are mainly attributed to the inhibition of COX-2 expression. The present study aimed to investigate the function of COX-2 in human gastric adenocarcinoma (GAC). Forty-five cases of human GAC tissues and corresponding adjacent non-cancerous tissues (ANCTs) were collected. The expression of COX-2 and proliferating cell nuclear antigen (PCNA) was assessed using immunohistochemical assay through a tissue microarray procedure. GAC cells (SGC-7901 and MKN-45) invitro were treated with COX-2 siRNA or different concentrations of celecoxib to observe their effects on cell proliferation, invasion and the underlying molecular mechanisms. As a consequence, the expression of COX-2 and PCNA was found in cancer tissues with a higher strong reactivity rate, compared with the ANCTs (80.0 vs. 53.3%, P=0.011; 68.9 vs. 48.9%, P=0.047), and COX-2 was positively associated with lymph node metastasis of GAC patients (P=0.011). Targeted knockdown of COX-2 inhibited the proliferation, migration and invasion of GAC cells with decreased expression of PCNA. COX-2 inhibitor celecoxib also suppressed the proliferative activities of GAC cells with decreased expression of COX-2 and PCNA. In addition, the tumor volume in the MKN-45 subcutaneous tumor model treated with siCOX-2 was significantly smaller than that of the negative control (NC) group (P<0.01). Taken together, our findings offer a strong preclinical rationale to target COX-2 signaling as a therapeutic strategy to improve the treatment of gastric adenocarcinoma.

Effect of lysine antifibrinolytics and cyclooxygenase inhibitors on the proteolytic profile of breast cancer cells interacting with macrophages or endothelial cells

Extracellular matrix (ECM) proteases play a key role in the regulation of tumour invasion, growth, and transendothelial migration. The expression of ECM proteases and their endogenous inhibitors by cancer cells is regulated by stromal cells. We investigated the effect of commonly used perioperative medications on this regulation. Breast cancer cells (4T1) were cultured alone or with endothelial cells (H5V) or macrophages (RAW264.7). Cell grown alone or in cocultures were treated with clinically relevant concentrations of cyclooxygenase (COX) inhibitors, aspirin (ASA), ketorolac, celecoxib, or lysine antifibrinolytics, ɛ-aminocaproic acid (EACA) and tranexamic acid (TXA). We determined the level of the ECM proteases urokinase-like plasminogen activator (uPA), matrix metalloproteinase (MMP)-2 and MMP-9, and endogenous MMP inhibitors, tissue inhibitors of metalloproteinase (TIMP)-1 and TIMP-2 in the conditioned media. Antifibrinolytics and COX inhibitors exerted a complex effect on cells grown alone and in cocultures. EACA increased the activity of MMP-9 and TIMP-1 in cocultures of 4T1 and RAW264.7. TXA increased TIMP-1 in the coculture without affecting MMP-9. EACA and TXA both attenuated MMP-2 detected in 4T1 and H5V cocultures. ASA and ketorolac both decreased the activity of MMP-2, MMP-9, and uPA. Celecoxib increased the activity of TIMP-1 in cocultures of 4T1 with both macrophages and endothelial cells. Antifibrinolytics and COX inhibitors can affect the proteolytic profile of the tumour microenvironment. Animal and clinical investigations are warranted to assess the effect of these proteolytic changes on the outcome of cancer surgery.

Effects of celecoxib on proliferation and tenocytic differentiation of tendon-derived stem cells

NSAIDs are often ingested to reduce the pain and improve regeneration of tendon after tendon injury. Although the effects of NSAIDs in tendon healing have been reported, the data and conclusions are not consistent. Recently, tendon-derived stem cells (TDSCs) have been isolated from tendon tissues and has been suggested involved in tendon repair. Our study aims to determine the effects of COX-2 inhibitor (celecoxib) on the proliferation and tenocytic differentiation of TDSCs. TDSCs were isolated from mice Achilles tendon and exposed to celecoxib. Cell proliferation rate was investigated at various concentrations (0.1, 1, 10 and 100μg/ml) of celecoxib by using hemocytometer. The mRNA expression of tendon associated transcription factors, tendon associated collagens and tendon associated molecules were determined by reverse transcription-polymerase chain reaction. The protein expression of Collagen I, Collagen III, Scleraxis and Tenomodulin were determined by Western blotting. The results showed that celecoxib has no effects on TDSCs cell proliferation in various concentrations (p>0.05). The levels of most tendon associated transcription factors, tendon associated collagens and tendon associated molecules genes expression were significantly decreased in celecoxib (10μg/ml) treated group (p<0.05). Collagen I, Collagen III, Scleraxis and Tenomodulin protein expression were also significantly decreased in celecoxib (10μg/ml) treated group (p<0.05). In conclusion, celecoxib inhibits tenocytic differentiation of tendon-derived stem cells but has no effects on cell proliferation.

Effect of COX-2 inhibitor celecoxib on proliferation, apoptosis of HL-60 cells and its mechanism

This study was aimed to investigate the effect of COX-2 inhibitor celecoxib on proliferation, apoptosis of human acute myeloid leukemia cell line HL-60 and its mechanism. HL-60 cells were cultured with different concentrations of celecoxib for 24 h. Cell proliferation was analyzed by CCK-8 assay, cell apoptosis and cell cycle distribution were detected by flow cytometry. Cyclin D1, cyclin E1 and COX-2 mRNA expressions were determined by RT-PCR. The results showed that after the HL-60 cells were treated with different concentrations of celecoxib for 24 h, the cell growth was significantly inhibited in a dose-dependent manner(r = 0.955), IC50 was 63.037 µmol/L of celecoxib. Celecoxib could effectively induce apoptosis in HL-60 cells also in dose-dependent manner(r = 0.988), blocked the HL-60 cells in the G0/G1 phase. The expression of cyclin D1, cyclin E1 and COX-2 mRNA were downregulated. It is concluded that celecoxib can inhibit the proliferation of HL-60 cells in dose-dependent manner, celecoxib causes cell G0/G1 arrest and induces cell apoptosis possibly through down-regulation of the cyclin D1 and cyclin E1 expression, and down-regulation of COX-2 expression respectively.

In-line solid state prediction during pharmaceutical hot-melt extrusion in a 12 mm twin screw extruder using Raman spectroscopy

The aim of this research was to use Raman spectroscopy for the in-line monitoring of the solid state of materials during pharmaceutical hot-melt extrusion in the die head of a 12mm (development scale) twin-screw extruder during formulation development.A full factorial (mixed) design was generated to determine the influence of variations in concentration of Celecoxib (CEL) in Eudragit® E PO, three different screw configurations and varying barrel temperature profiles on the solid state, ‘melt temperature’ and die pressure of continuously produced extrudates in real-time. Off-line XRD and DSC analysis were used to evaluate the suitability of Raman spectroscopy for solid state predictions. First, principal component analysis (PCA) was performed on all in-line collected Raman spectra from the experimental design. The resulting PC 1 versus PC 2 scores plot showed clustering according to solid state of the extrudates, and two classes, one class where crystalline CEL is still present and a second class where no crystalline CEL was detected, were found. Then, a soft independent modelling of class analogy (SIMCA) model was developed, by modelling these two classes separately by disjoint PCA models. These two separate PCA models were then used for the classification of new produced extrudates and allowed distinction between glassy solid solutions of CEL and crystalline dispersions of CEL. All extrudates were classified similarly by Raman spectroscopy, XRD and DSC measurements, with exception of the extrudates with a 30% CEL concentration extruded at 130°C. The Raman spectra of these experiments showed bands which were sharper than the amorphous spectra, but broader than the crystalline spectra, indicating the presence of CEL that has dissolved into the matrix and CEL in its crystalline state. XRD and DSC measurements did not detect this. Modifications in the screw configuration did not affect the solid state and did not have an effect on the solid state prediction of new produced extrudates.Secondly, the influence of variations in die pressure on the Raman spectra was examined. The applied drug concentration, processing temperature and feeder performance influence the die pressure, which is reflected in the Raman spectra as a change in spectral intensity. When applying PCA on the raw spectra from the experimental design, the first principal component describes the influence of die pressure on the spectra, which was seen as a decrease in Raman intensity of the whole spectrum when the pressure in the sample increased. Clustering according to processing temperature was found, although the temperature in the die remained constant, indicating that a difference in viscosity, resulting in a changed die pressure, was detected. When the feeder was stopped, the score values of the first principal component almost simultaneously decreased, and only stabilized once the die pressure became stable. Since Raman spectra collected in the extrusion die are influenced by changes in die pressure, disturbances upstream of the extrusion process can be observed and identified in the Raman measurements.

Colon-targeted celecoxib ameliorates TNBS-induced rat colitis: A potential pharmacologic mechanism and therapeutic advantages

The clinical usefulness of celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, for treatment of inflammatory bowel disease (IBD) is controversial in terms of efficacy and toxicity. To overcome these problems, colon-specific drug delivery was adopted, which generally confers therapeutic and toxicological advantages of drugs for treatment of colonic diseases. N-succinylaspart-1-yl celecoxib (SA1C), a colon-specific prodrug of celecoxib, was administered orally to rats with experimental colitis, and the anti-colitic effects and a molecular mechanism were investigated and compared to those of conventional celecoxib. SA1C, which delivered a much greater amount of celecoxib to the inflamed colon, alleviated the colonic injury, lowered myeloperoxidase activity in the inflamed colonic tissues and was much more effective than conventional celecoxib. SA1C but not conventional celecoxib significantly attenuated expression of NFκB target gene products in the inflamed tissues. Consistent with this, SA1C effectively prevented nuclear accumulation of p65 in the inflamed tissues. Moreover, while conventional celecoxib lowered the serum level of 6-keto-PGF1α, an inverse indicator of cardiovascular toxicity, SA1C did not change its serum level. Our data suggest that colonic delivery of celecoxib is a feasible strategy for treatment of IBD with improved therapeutic and toxicological properties.

The Effect of Helicobacter pylori on Epidermal Growth Factor Receptor-Induced Signal Transduction and the Preventive Effect of Celecoxib in Gastric Cancer Cells

Background/AimsHelicobacter pylori infection induces cyclooxygenase-2 (COX-2) and epidermal growth factor receptor (EGFR) overexpression, and these factors may engage in cross-talk. The aim of the present study was to evaluate the effect of H. pylori on EGFR signaling pathways and to determine whether celecoxib has an inhibitory effect on this pathway.MethodsThe AGS cell line was cocultured with H. pylori G27 and the isogenic cagE- mutant. The expression of COX-2, EGFR, heparin binding-epidermal growth factor (HB-EGF), and transforming growth factor-β (TGF-β) was measured by real time-polymerase chain reaction (RT-PCR). Next, Western blot analyses of COX-2, EGFR, total Akt, phosphorylated Akt (pAkt), and phosphorylated glycogen synthase kinase-3β (pGSK3β) were performed after incubating H. pylori-treated AGS cells for 24 hours with various concentrations of celecoxib (0, 10, 20, and 30 µmol/L).ResultsH. pylori infection upregulated the mRNA levels of COX-2, EGFR, HB-EGF, and TGF-β, as detected by RT-PCR. However, AGS cells treated with cagE- mutants, which have a defective type IV secretion system, did not exhibit EGFR upregulation. Celecoxib had inhibitory effects on the H. pylori-induced overexpression of COX-2 (p=0.015), EGFR (p=0.025), pAkt (p=0.025), and pGSK3β (p=0.029) by Western blot analysis.ConclusionsH. pylori with an intact type IV secretion system activated the COX-2 and EGFR-Akt pathways in the AGS cell line. As celecoxib exhibited inhibitory effects on the EGFR signaling pathway, the cross-talk of COX-2 and EGFR likely mediates H. pylori-induced gastric cancer.

Fluvoxamine and celecoxib may have caused adverse events in an elderly patient

FLUVOXAMINE, WHICH DOES not have anticholinergic activity, is suitable for elderly patients. Selective serotonin re-uptake inhibitors (SSRI), however, are metabolized by and inhibit isozymes of cytochrome P450 (CYP).1 Therefore, when SSRI are prescribed, drug interactions are a concern. Here we report the case of an elderly patient whose mental state had been controlled by fluvoxamine for several years, and who developed delirium following the additional prescription of celecoxib. Informed consent was obtained from her proxy. The patient was a 94-year-old woman at the time of the present episode. Six years previously she had become amnesic, and her daily life had been supported by her family. She was anxious because of the amnesia. At 4 years before the present episode she was referred to Showa University Fujigaoka Hospital. Her score on the Revised Hasegawa Dementia Scale was 25. We diagnosed her with Alzheimer's disease. Because her cognitive functions were relatively preserved, we decided to treat her anxiety first. Therefore, we prescribed fluvoxamine (25 mg) to be taken after dinner. Subsequently, her mental state was stable for 4 years. Just before the present episode she developed a swelling in her ankle due to arthritis for which celecoxib was prescribed by another physician, without knowledge of her fluvoxamine medication history. On the first night of taking both medications, she became restless and said ‘I should go to work,’ and tried to leave her home. Her family was upset and stopped both medications. However, because she became irritable and her ankle was swollen, they restarted fluvoxamine, and her physician changed her prescription from celecoxib to loxoprofen. Since then, her mental state and ankle swelling have improved. This episode was narrated to us by her proxy once she started recovering. Therefore, we cannot elucidate the true nature of the symptoms. We suggest, however, that this condition was caused by drug interaction. Because fluvoxamine is metabolized by1 and celecoxib inhibited the CYP2D6 enzyme,2 blood concentrations of fluvoxamine seem to be increased by celecoxib. The time at which maximum concentration occurs for fluvoxamine and celecoxib is approximately 5 h and 2 h after oral intake, respectively. The plasma half-life of celecoxib is 5 h. When the patient took this medication around 8 pm, the concentration of fluvoxamine may have reached a peak and the concentration of celecoxib may have reached half of its peak by midnight. Therefore, the blood concentration of fluvoxamine reached toxic levels because of inhibition of CYP2D6 by celecoxib. Moreover, loxoprofen does not inhibit the CYP2D6 enzyme and is not metabolized by the CYP1A2 enzyme. Therefore, loxoprofen and fluvoxamine do not interact. Although we have not found any reports on this issue, SSRI should be carefully prescribed when combined with other medicines, particularly in elderly patients.

Celecoxib induces apoptosis by the intrinsic pathway in HT‐29 colon carcinoma and A375 melanoma cells

Chronic use of non‐steroidal anti‐inflammatory drugs (NSAIDs) reduces the incidence of cancers of the colon, skin and other organs. The risk of adverse effects associated with NSAIDs precludes the use of many of these agents in a chemoprevention strategy. We and others have demonstrated direct cytotoxic effects of the COX‐2 selective NSAID, celecoxib, in human cancer cell lines. We sought to further elucidate the cellular mechanisms involved in celecoxib's cytotoxicity in HT‐29 colon carcinoma and A375 melanoma cells. HT‐29 and A375 cells were treated for 48 hours with increasing concentrations of celecoxib followed by the XTT assay to establish an IC50 value for each cell line. The IC50 values for celecoxib were 55 μM and 60 μM in the HT‐29 and A375 cell lines respectively. Western blotting was performed to assess induction of apoptotic markers subsequent to celecoxib treatment. HT‐29 and A375 cells were treated with celecoxib at IC50 and 2× IC50 doses respectively for 24 hours. Celecoxib at the 2× IC50 doses increased expression of cleaved caspases‐3 and ‐7 and poly ADP ribose polymerase (PARP) in both HT‐29 and A375 cells. Induction of intrinsic apoptosis by celecoxib was demonstrated in both cell lines indicated by increased expression of cleaved caspase‐9. These results demonstrate that celecoxib elicits a direct cytotoxic effect via induction of the intrinsic apoptosis pathway in HT‐29 and A375 cells.

Different Cell Cycle Modulation by Celecoxib at Different Concentrations

Abstract Different cyclooxygenase (COX)-2 inhibitors were known to cause different cell cycle changes. We investigated whether this different effect on cell cycle change was due to concentration-dependent effect. We investigated the effects of celecoxib, a COX-2 selective inhibitor, on cell cycle regulation in irradiated cancer cells that express high or low levels of COX-2. Four stably COX-2 knocked-down or overexpressed cell lines were treated with various concentrations of celecoxib with or without radiation. Celecoxib differentially modulated the cell cycle according to the concentrations applied. G1 arrest was induced at lower concentrations, whereas G2/M arrest was induced at higher concentrations in each cell line tested. Radiation-induced G2/M arrest was enhanced at lower concentrations but reduced at higher concentrations. The cutoff values to divide lower and higher concentrations were cell-type specific. Celecoxib treatment activated Cdc25C and inhibited p21 expression in both unirradiated and irradiated cells, regardless of COX-2 expression. Apoptosis was induced in irradiated cells 48 hours after treatment with celecoxib dependent of COX-2. These results imply that celecoxib deactivates the G2 checkpoint via both Cdc25C- and p21-dependent pathways in irradiated cells, which subsequently die by secondary apoptosis. Cell cycle modulating effects in irradiated cells resulting from treatment with celecoxib may have clinical importance with regard to the potential application of celecoxib in cancer patients undergoing radiotherapy.

Gene Expression Profile of Coronary Artery Cells Treated With Nonsteroidal Anti-inflammatory Drugs Reveals Off-target Effects

Nonsteroidal anti-inflammatory drugs (NSAIDs) have come under scrutiny because of the gastrointestinal, renal, and cardiovascular toxicity associated with prolonged use of these drugs. The purpose of this study was to identify molecular targets for NSAIDs related to cellular toxicity with a view to optimize drug efficacy in the clinic. Coronary artery smooth muscle cells and endothelial cells were treated with low (clinically achievable) and high (typically used in preclinical studies) concentrations of celecoxib, NS398, and ibuprofen for 24 hours. NSAIDs-induced gene expression changes were evaluated by microarray analysis and validated by real-time reverse-transcription polymerase chain reaction and western blotting. The functional significance of differentially expressed genes was evaluated by Ingenuity Pathway Analysis. At high concentrations, NSAIDs altered the expression of genes regulating cell proliferation and cell death. NSAIDs also altered genes associated with cardiovascular functions including inflammation, thrombosis, fibrinolysis, coronary artery disease, and hypertension. The gene expression was most impacted by ibuprofen, celecoxib, and NS398, in that order. This study revealed that NSAIDs altered expression of an array of genes associated with cardiovascular events and emphasizes the potential for fingerprinting drugs in preclinical studies to assess the potential drug toxicity and to optimize the drug efficacy in clinical settings.

Colon-specific delivery of celecoxib is a potential strategy to improve toxicological and pharmacological properties of the selective Cox-2 inhibitor: implication in treatment of familiar adenomatous polyposis

In general, colon-specific delivery of a drug decreases systemic absorption and increases therapeutic concentration of the drug at the target site. N-succinylglutam-1 or 5-yl celecoxib (SG1C and SG5C) were prepared as a colon-specific prodrug of celecoxib, a selective Cox-2 inhibitor, and investigated whether the celecoxib derivatives could deliver celecoxib to the target site and improve cardiovascular toxicity and therapeutic effectiveness for the treatment of familiar adenomatous polyposis. SG1C and SA5C were cleaved to release celecoxib in the cecal contents while stable in small intestinal contents. The cecal release of celecoxib was much greater for SG1C than SG5C. SG1C administered orally was barely detected in the blood and urine. SG1C delivered much greater amount of celecoxib to the large intestine while keeping the plasma concentration of celecoxib at much lower level compared with oral administration of free celecoxib. Consistent with these pharmacokinetic results, SG1C supplied a greater concentration of celecoxib for the entire colonic tissue and did not change the serum level of 6-keto-PGF1α whose decrease is associated with the cardiovascular toxicity of celecoxib. Taken together, colon-specific delivery of celecoxib using a prodrug approach may be a useful strategy to improve toxicological and pharmacological properties of celecoxib.

N-Succinylaspart-1-yl Celecoxib is a Potential Colon-Specific Prodrug of Celecoxib with Improved Therapeutic Properties

To develop a colon-specific prodrug of celecoxib, a cyclooxygenase-2 selective inhibitor, which could improve cardiovascular toxicity and therapeutic effectiveness for chemoprevention of colorectal cancer, aspart-1-yl celecoxib (A1C) or aspart-4-yl celecoxib (A4C), succinyl celecoxib (SC), and N-succinylaspart-1-yl celecoxib (SA1C) or N-succinylaspart-4-yl celecoxib (SA4C) were prepared and evaluated as a prodrug with such beneficial properties. On incubation with the small intestinal contents while SC, SA1C, and SA4C were stable, A1C and A4C were degraded to liberate celecoxib. In the cecal contents, the other conjugates except for SC and SA4C were cleaved to release celecoxib. These results suggest the colon-specific delivery and activation of SA1C. On oral administration of SA1C or celecoxib, no SA1C was detected in the blood and urine, indicating the limited absorption of SA1C. SA1C delivered a much greater amount of celecoxib to the large intestine while keeping the plasma concentration of celecoxib at much lower level, which is consistent with no change of the serum level of 6-ketoprostaglandin F(1α) whose decrease is associated with the cardiovascular toxicity of celecoxib. Moreover, SA1C administered orally supplied a greater concentration of celecoxib for the whole colonic tissue. Taken together, SA1C may be a colon-specific prodrug of celecoxib with improved therapeutic properties.

Celecoxib induces apoptosis and cell-cycle arrest in nasopharyngeal carcinoma cell lines via inhibition of STAT3 phosphorylation

To investigate the mechanisms underlying the anticancer effect of celecoxib on nasopharyngeal carcinoma (NPC). NPC cell lines, HNE1 and CNE1-LMP1, were treated with various concentrations of celecoxib for 48 h. The antiproliferative effect of celecoxib was assessed using MTT assay. Both cell cycle profiles and apoptosis were analyzed using flow cytometry. Western blot was used to measure the levels of signal transducer and activator of transcription 3 (STAT3), phosphorylated STAT3(Y705) (pSTAT3(Y705)), COX-2, Survivin, Mcl-1, Bcl-2 and Cyclin D1. Celecoxib (10-75 μmol/L) inhibited the proliferation of the NPC cell lines in a dose-dependent manner. Celecoxib (25 and 50 μmol/L) induced apoptosis and cell-cycle arrest at the G(0)/G(1) checkpoint in the NPC cell lines, which was associated with significantly reduced STAT3 phosphorylation. The genes downstream of STAT3 (ie, Survivin, Mcl-1, Bcl-2 and Cyclin D1) were significantly down-regulated after exposure to celecoxib (25 and 50 μmol/L). The anticancer effects of celecoxib on NPC cell lines results from inducing apoptosis and cell cycle arrest, which may be partly mediated through the STAT3 pathway.

Dual function of tributyrin emulsion: Solubilization and enhancement of anticancer effect of celecoxib

Tributyrin, a triglyceride analogue of butyrate, can act as a prodrug of an anticancer agent butyrate after being cleaved by intracellular enzymes. We recently demonstrated that the emulsion containing tributyrin as an inner oil phase possesses a potent anticancer activity. Herein we sought to develop tributyrin emulsion as a carrier of celecoxib, a poorly-water soluble drug with anticancer activity. Combined treatment of human HCT116 colon cancer cells with free celecoxib plus tributyrin emulsion inhibited the cellular proliferation more effectively than that of each drug alone, suggesting the possibility of tributyrin emulsion as a potential celecoxib carrier. The mean droplet size of emulsions tended to increase as the tributyrin content in emulsion increases and the concentration of celecoxib loaded in emulsions was affected by tributyrin content and the initial amount of celecoxib, but not by the total amount of surfactant mixture. The concentration of celecoxib required to inhibit the growth of HCT116 and B16-F10 cancer cells by 50% was 2.6- and 3.1-fold lowered by loading celecoxib in tributyrin emulsions, compared with free celecoxib. These data suggest that the anticancer activity of celecoxib was enhanced by loading in tributyrin emulsions, probably due to the solubilization capacity and anticancer activity of tributyrin emulsion.

Antitumor activity of the selective cyclooxygenase-2 inhibitor, celecoxib, on breast cancer in Vitro and in Vivo

BackgroundCyclooxygenase-2(COX-2) promotes carcinogenesis, tumor proliferation, angiogenesis, prevention of apoptosis, and immunosuppression. Meanwhile, COX-2 over-expression has been associated with tumor behavior and prognosis in several cancers. This study investigated the antitumor effects of the selective COX-2 inhibitor, Celecoxib, on breast cancer in vitro and in vivo.MethodsHuman breast cancer MCF-7 and MDA-MB-231 cells were cultured with different concentration (10, 20, 40 μmol/L) of celecoxib after 0-96 hours in vitro. MTT assay was used to determine the growth inhibition of breast cancer cells in vitro. The expression of COX-2 on mRNA was measured by real-time quantitive PCR analysis. Flow cytometry was performed to analyze the cell cycle of MCF-7 cells. Levels of PGE2 were measured by ELISA method. The in vivo therapeutic effects of celecoxib were determined using rat breast cancer chemically induced by 7,12-dimethylben anthracene (DMBA).ResultsThe inhibition of proliferation of both MCF-7 and MDA-MB-231 cells in vitro by celecoxib was observerd in time and dose dependent manner. Celecoxib effectively down-regulated the expression of COX-2. The cell cycle was arrested at G0/G1, and rate of cells in S phase was obviously decreased. Levels of PGE2 were inhibited by Celecoxib. The tumor incidence rate of the celecoxib group was lower than that of the control group. In addition, the tumor latency period of the celecoxib group was longer than that of the control group.ConclusionsCelecoxib inhibited the proliferation of breast cancer cell lines in vitro, and prevented the occurrence of rat breast cancer chemically induced by DMBA. Therefore, celecoxib exhibits an antitumor activity and seems to be effective in anti-tumor therapy.

Inhibition of hERG Potassium Channels by Celecoxib and Its Mechanism

BackgroundCelecoxib (Celebrex), a widely prescribed selective inhibitor of cyclooxygenase-2, can modulate ion channels independently of cyclooxygenase inhibition. Clinically relevant concentrations of celecoxib can affect ionic currents and alter functioning of neurons and myocytes. In particular, inhibition of Kv2.1 channels by celecoxib leads to arrhythmic beating of Drosophila heart and of rat heart cells in culture. However, the spectrum of ion channels involved in human cardiac excitability differs from that in animal models, including mammalian models, making it difficult to evaluate the relevance of these observations to humans. Our aim was to examine the effects of celecoxib on hERG and other human channels critically involved in regulating human cardiac rhythm, and to explore the mechanisms of any observed effect on the hERG channels.Methods and ResultsCelecoxib inhibited the hERG, SCN5A, KCNQ1 and KCNQ1/MinK channels expressed in HEK-293 cells with IC50s of 6.0 µM, 7.5 µM, 3.5 µM and 3.7 µM respectively, and the KCND3/KChiP2 channels expressed in CHO cells with an IC50 of 10.6 µM. Analysis of celecoxib's effects on hERG channels suggested gating modification as the mechanism of drug action.ConclusionsThe above channels play a significant role in drug-induced long QT syndrome (LQTS) and short QT syndrome (SQTS). Regulatory guidelines require that all new drugs under development be tested for effects on the hERG channel prior to first administration in humans. Our observations raise the question of celecoxib's potential to induce cardiac arrhythmias or other channel related adverse effects, and make a case for examining such possibilities.

The COX-2 inhibitor Celecoxib enhances the sensitivity of KB/VCR oral cancer cell lines to Vincristine by down-regulating P-glycoprotein expression and function

Previous studies have indicated that long-term chemotherapy decreases the sensitivity of oral cancer cells to chemotherapeutics while simultaneously increasing resistance to these drugs. COX-2 inhibitors are known to enhance the toxic action of anti-tumor drugs against cancer cells. Using the MTT method, we investigated the influence of the COX-2 selective inhibitor Celecoxib on the proliferation of KB/VCR oral cancer cell lines and analyzed the effect of Celecoxib on the regulation of P-glycoprotein (P-gp) expression and function. Western blot analysis was employed to detect the expression of P-gp, and flow cytometry was used to evaluate P-gp function by detecting the accumulation of the active P-gp functional fluorescence substrate within KB/VCR cells. The results revealed that a low dose of Celecoxib (10 μmol/L) showed no growth inhibitory effects on KB/VCR cell lines. When the concentration of Celecoxib was greater than or equal to 20 μmol/L, the inhibitory effect on KB/VCR cells was significantly enhanced in a time- and dose-dependent manner. The lower dose of Celecoxib (10 μmol/L) significantly enhanced the toxicity of Vincristine (VCR) against KB/VCR cell lines. After the application of Celecoxib plus VCR (10 μmol/L + 1.5 μmol/L, respectively) treatment for 24, 48 or 72 h, the growth inhibition rates of KB/KBV cells were 37.82 ± 1.60%, 47.84 ± 1.29% and 54.43 ± 2.35%, respectively, which were significantly higher than the rates in the cells treated only with Celecoxib (10 μmol/L) or VCR (1.5 μmol/L) (all P < 0.01). P-gp expression levels in KB/KBV cells treated with Celecoxib plus VCR (10 μmol/L + 1.5 μmol/L, respectively) were markedly lower than the levels in control cells and those treated with VCR (1.5 μmol/L) (all P < 0.01). In addition, the intensity of Rho123 fluorescence of KB/KBV cells in cells treated with Celecoxib plus VCR (10 μmol/L + 1.5 μmol/L, respectively) or Celecoxib alone (10 μmol/L) was significantly higher than the intensity observed in control cells and those treated with VCR alone (1.5 μmol/L) (all P < 0.01). The underlying mechanism of these phenomena is likely correlated with the down-regulation of the expression and function of P-gp due to Celecoxib, thereby increasing the amount of VCR accumulated in KB/VCR cells.