Celecoxib inhibits proliferation of retinal pigment epithelial and choroid-retinal endothelial cells by a cyclooxygenase-2-independent mechanism

Potential Therapeutic Candidates for Age-Related Macular Degeneration (AMD)

Aging contributes to the risk of development of ocular diseases including, but not limited to, Age-related Macular Degeneration (AMD) that is a leading cause of blindness in the United States as well as worldwide. Retinal aging, that contributes to AMD pathogenesis, is characterized by accumulation of drusen deposits, alteration in the composition of Bruch’s membrane and extracellular matrix, vascular inflammation and dysregulation, mitochondrial dysfunction, and accumulation of reactive oxygen species (ROS), and subsequent retinal pigment epithelium (RPE) cell senescence. Since there are limited options available for the prophylaxis and treatment of AMD, new therapeutic interventions are constantly being looked into to identify new therapeutic targets for AMD. This review article discusses the potential candidates for AMD therapy and their known mechanisms of cytoprotection in AMD. These target therapeutic candidates include APE/REF-1, MRZ-99030, Ciliary NeuroTrophic Factor (CNTF), RAP1 GTPase, Celecoxib, and SS-31/Elamipretide.

Cyclodextrin Multicomponent Complexes: Pharmaceutical Applications

Cyclodextrins (CDs) are naturally available water-soluble cyclic oligosaccharides widely used as carriers in the pharmaceutical industry for their ability to modulate several properties of drugs through the formation of drug-CD complexes. The addition of an auxiliary substance when forming multicomponent complexes is an adequate strategy to enhance complexation efficiency and to facilitate the therapeutic applicability of different drugs. This review discusses multicomponent complexation using amino acids; organic acids and bases; and water-soluble polymers as auxiliary excipients. Special attention is given to improved properties by including information on the solubility, dissolution, permeation, stability and bioavailability of several relevant drugs. In addition, the use of multicomponent CD complexes to enhance therapeutic drug effects is summarized.

Flurbiprofen suppresses the inflammation, proliferation, invasion and migration of colorectal cancer cells via COX2

Colorectal cancer is an aggressive disease with a poor prognosis and low survival rate at the advanced stage, therefore new innovative targets are urgently required. Flurbiprofen has been reported to exhibit therapeutic effects in other types of cancer, such as esophageal cancer, breast cancer and colorectal cancer. Therefore, the present study aimed to investigate the function of flurbiprofen in colorectal cancer. SW620 colorectal cancer cells were treated with different concentrations of flurbiprofen to determine the optimum concentration. Subsequently, COX2 expression affected by flurbiprofen was tested using western blotting, reverse transcription-quantitative PCR and immunofluorescence. Enzyme-linked immunosorbent assay was used to determine the levels of tumor necrosis factor-α, interleukin (IL)-6 and IL-1β. Cell Counting Kit-8, colony formation and flow cytometry assays were used to assess the proliferation and apoptosis of SW620 cells in various groups. Western blotting was performed to investigate the expression of proliferation-, apoptosis- and migration-related proteins after different treatments. Wound healing and Transwell assays were performed to measure the invasion and migration of colorectal cancer cells, respectively. The results demonstrated that flurbiprofen inhibited colorectal cancer cell proliferation. Furthermore, it was identified that flurbiprofen inhibited the expression of COX2. Notably, flurbiprofen suppressed the expression of inflammatory factors by inhibiting COX2. Moreover, flurbiprofen inhibited the proliferation, invasion and migration of colorectal cancer cells by inhibiting COX2. In conclusion, the present study revealed that flurbiprofen inhibited COX2 expression in colorectal cancer, and affected the proliferation, invasion, migration and apoptosis of colorectal cancer cells. These results expand the understanding of the function of COX2 in colorectal cancer and the effect of flurbiprofen on COX2 expression.

The Relationship between Neutrophil-to-lymphocyte Ratio and Age-related Macular Degeneration

PURPOSE

To investigate the possible associations of neutrophil-to-lymphocyte ratio (NLR) and high sensitivity C-reactive protein (hs-CRP) level with age-related macular degeneration (ARMD).

METHODS

Patients were divided to three groups of 40 patients with non-neovascular ARMD (group 1), 40 patients with neovascular ARMD (group 2), and 40 healthy control subjects (group 3). The neutrophil and lymphocyte counts were evaluated using an ABX Pentra DF120/USA biochemical analyzer, and hs-CRP levels were measured using a Beckman Coulter Immage 800. The NLR was measured by dividing neutrophil count by lymphocyte count.

RESULTS

The patients in group 2 were older and more often diabetic than the patients in groups 1 and 3 (p < 0.001 and p < 0.001, respectively). The NLR level was 1.65 ± 0.71 in group 1, 1.98 ± 0.84 in group 2, and 1.46 ± 0.44 in group 3. The hs-CRP value was 1.98 ± 0.251 mg/L in group 1, 3.242 ± 0.211 mg/L in group 2, and 1.145 ± 0.193 mg/L in group 3. Both NLR and hs-CRP values were significantly higher in group 2 compared to group 3 (p = 0.002 and p = 0.002, respectively). In multivariate analysis, NLR remained an independent predictor of neovascular ARMD (odds ratio, 3.882; 95% confidence interval, 1.574 to 9.576; p = 0.003) together with age (p < 0.001), diabetes mellitus (p = 0.041), and hs-CRP (p = 0.018).

CONCLUSIONS

Our study suggests that increased NLR value is independently associated with neovascular ARMD.

Bevacizumab inhibits proliferation of choroidal endothelial cells by regulation of the cell cycle

Background

The purpose of this study was to evaluate cell cycle changes in choroidal endothelial cells treated with varying doses of bevacizumab in the presence of a range of concentrations of vascular endothelial growth factor (VEGF). Bevacizumab, a drug widely used in the treatment of neovascular age-related macular degeneration, choroidal neovascularization, and proliferative diabetic retinopathy, neutralizes all isoforms of VEGF. However, the effect of intravitreal administration of bevacizumab on the choroidal endothelial cell cycle has not been established.

Methods

Monkey choroidal endothelial (RF/6A) cells were treated with VEGF 50 ng/mL and escalating doses of bevacizumab 0.1–2 mg/mL for 72 hours. Cell cycle changes in response to bevacizumab were analyzed by flow cytometry and propidium iodide staining. Cell proliferation was measured using the WST-1 assay. Morphological changes were recorded by bright field cell microscopy.

Results

Bevacizumab inhibited proliferation of choroidal endothelial cells by stabilization of the cell cycle in G0/G1 phase. Cell cycle analysis of VEGF-enriched choroidal endothelial cells revealed a predominant increase in the G2/M population (21.84%, P, 0.01) and a decrease in the G0/G1 phase population (55.08%, P, 0.01). Addition of escalating doses of bevacizumab stabilized VEGF-enriched cells in the G0/G1 phase (55.08%, 54.49%, 56.3%, and 64% [P, 0.01]) and arrested proliferation by inhibiting the G2/M phase (21.84%, 21.46%, 20.59%, 20.94%, and 16.1% [P, 0.01]). The increase in G0/G1 subpopulation in VEGF-enriched and bevacizumab-treated cells compared with VEGF-enriched cells alone was dose-dependent.

Conclusion

Bevacizumab arrests proliferation of VEGF-enriched choroidal endothelial cells by stabilizing the cell cycle in the G0/G1 phase and inhibiting the G2/M phase in a dose-dependent fashion.

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.

Hydrophilic prodrug approach for reduced pigment binding and enhanced transscleral retinal delivery of celecoxib

Transscleral retinal delivery of celecoxib, an anti-inflammatory and anti-VEGF agent, is restricted by its poor solubility and binding to the melanin pigment in choroid-RPE. The purpose of this study was to develop soluble prodrugs of celecoxib with reduced pigment binding and enhanced retinal delivery. Three hydrophilic amide prodrugs of celecoxib, celecoxib succinamidic acid (CSA), celecoxib maleamidic acid (CMA), and celecoxib acetamide (CAA) were synthesized and characterized for solubility and lipophilicity. In vitro melanin binding to natural melanin (Sepia officinalis) was estimated for all three prodrugs. In vitro transport studies across isolated bovine sclera and sclera-choroid-RPE (SCRPE) were performed. Prodrug with the highest permeability across SCRPE was characterized for metabolism and cytotoxicity and its in vivo transscleral delivery in pigmented rats. Aqueous solubilities of CSA, CMA, and CAA were 300-, 182-, and 76-fold higher, respectively, than celecoxib. Melanin binding affinity and capacity were significantly lower than for celecoxib for all three prodrugs. Rank order for the % in vitro transport across bovine sclera and SCRPE was CSA > CMA ~ CAA ~ celecoxib, with the transport being 8-fold higher for CSA than celecoxib. CSA was further assessed for its metabolic stability and in vivo delivery. CSA showed optimum metabolic stability in all eye tissues with only 10-20% conversion to parent celecoxib in 30 min. Metabolic enzymes responsible for bioconversion included amidases, esterase, and cytochrome P-450. In vivo delivery in pigmented BN rats showed that CSA had 4.7-, 1.4-, 3.3-, 6.0-, and 4.5-fold higher delivery to sclera, choroid-RPE, retina, vitreous, and lens than celecoxib. CSA has no cytotoxicity in ARPE-19 cells in the concentration range of 0.1 to 1000 μM. Celecoxib succinamidic acid, a soluble prodrug of celecoxib with reduced melanin binding, enhances transscleral retinal delivery of celecoxib.

Effect of celecoxib on proliferation, collagen expression, ERK1/2 and SMAD2/3 phosphorylation in NIH/3T3 fibroblasts

In the present study, the effects of celecoxib on proliferation, collagen expression, ERK1/2 and SMAD2/3 phosphorylation in NIH/3T3 fibroblasts were investigated. NIH/3T3 fibroblasts stimulated with fibroblast growth factor-2 (FGF-2) or transforming growth factor-β1 (TGF-β1) were examined in the presence of celecoxib. Proliferation was assessed by MTT assays; ERK1/2 expression and SMAD2/3 expression were assessed by quantitative RT-PCR and western blotting; ERK1/2 phosphorylation and SMAD2/3 phosphorylation were assessed by western blot analysis. The results indicated that celecoxib could suppress cell proliferation stimulated by FGF-2 (IC(50) FGF+group, 75±1.9μmol/l) and TGF-β1 (IC(50) TGF+group, 48±1.4μmol/l), by inhibiting ERK1/2 phosphorylation but not ERK1/2 expression. Celecoxib also suppressed collagen expression (0.35-fold COL3 and 0.43-fold COL1 at 320μmol/l celecoxib relative to the untreated control after stimulation with TGF-β1 for 3h, P<0.01), by inhibiting SMAD2/3 phosphorylation but not SMAD2/3 expression. The suppression of NIH/3T3 fibroblast proliferation and collagen expression upon stimulation by FGF-2 and TGF-β1 is likely a result of the inhibition of ERK1/2 and SMAD2/3 phosphorylation by celecoxib.

Delivery of celecoxib for treating diseases of the eye: influence of pigment and diabetes

IMPORTANCE OF THE FIELD

Age-related macular degeneration (AMD) and diabetic retinopathy (DR) are two major causes of blindness. In these disorders, growth factors such as vascular endothelial growth factor (VEGF) are upregulated, leading to either enhanced vascular permeability or proliferation of endothelium. While corticosteroid therapies available at present suffer from side effects including cataracts and elevated intraocular pressure, anti-VEGF antibody therapies require frequent intravitreal injections, a procedure that can potentially lead to retinal detachment or endophthalmitis. Thus, there is a need to develop safe, sustained release therapeutic approaches for treating AMD and DR.

AREAS COVERED IN THIS REVIEW

This review discusses the pharmacological basis for using celecoxib, an anti-inflammatory drug capable of selectively inhibiting cycloxygenase 2, in treating AMD and DR. In addition, this article discusses the safety, delivery advantage and efficacy of celecoxib by transscleral retinal delivery, a periocular delivery approach that is less invasive to the globe compared with intravitreal injections.

WHAT THE READER WILL GAIN

The reader will gain insights into the development of a pharmacological agent and a sustained release delivery system for treating DR and AMD. Further, the reader will gain insights into the influence of eye physiology including pigmentation and disease states such as DR on retinal drug delivery.

TAKE HOME MESSAGE

Transscleral sustained delivery of anti-inflammatory agents is a viable option for treating retinal disorders.

Anti-proliferation activity of celecoxib in cholangitis

AIM: To investigate the application value of celecoxib in treating chronic proliferative cholangitis (CPC).

METHODS: Thirty healthy male Sprague-Dawley rats were randomly divided into three groups: sham-operation group (n = 10), CPC model group (n = 10), and celecoxib therapy group (n = 10). CPC was induced in rats by inserting a 5-0 nylon suture into the common bile duct up to the porta hepatis retrogradely through the vater papilla. Rats in the sham-operation group only underwent abdominal wall incision and suturing. Celecoxib [50 mg/(kg·d)] was injected into the abdominal cavity of each rat in the therapy group from day 1 after operation. All rats were executed 1 wk after operation. The anti-proliferation activity of celecoxib was evaluated by hematoxylin and eosin (HE) staining, periodic acid-Schiff (PAS) staining, Masson staining and immunohistochemistry staining of the biliary epithelial mucosa, submucosal gland and collagen fiber in the bile duct wall of CPC rats.

RESULTS: The proliferative degree of the biliary epithelial mucosa and submucosal gland as well as the fibrotic degree of the biliary wall in the celecoxib therapy group were obviously lower than those in the CPC group, but still higher than those in the sham-operation group. Immunohistochemistry analysis showed that the expression intensity of cyclooxygenase 2 (COX-2) in the celecoxib therapy group was obviously inferior to that in the CPC model group (IA: 8.62 ± 0.19 vs 35.27 ± 0.43, P < 0.05), but close to that in the sham-operation group (IA: 8.62 ± 0.19 vs 8.41 ± 0.13, P > 0.05).

CONCLUSION: By down-regulating COX-2 expression, celecoxib can effectively inhibit the hyperplasia of the biliary epithelial mucosa, submucosal gland, and collagen fiber and reduce the amount of mucous glycoprotein secreted by the submucosal gland, thus holding the promise for controlling CPC and reducing the recurrence of intrahepatic bile duct stones.

Nonsteroidal anti-inflammatory drugs in ophthalmology

Nonsteroidal anti-inflammatory drugs (NSAIDs) are increasingly employed in ophthalmology to reduce miosis and inflammation, manage scleritis, and prevent and treat cystoid macular edema associated with cataract surgery. In addition, they may decrease postoperative pain and photophobia associated with refractive surgery and may reduce the itching associated with allergic conjunctivitis. In recent years, the U.S. Food and Drug Administration has approved new topical NSAIDs, and previously approved NSAIDs have been reformulated. These additions and changes result in different pharmacokinetics and dosing intervals, which may offer therapeutic advantages. For example, therapeutic effects on diabetic retinopathy and age-related macular degeneration may now be achievable. We provide an updated review on NSAIDs and a summary of their current uses in ophthalmology with attention to potential future applications.

The effects of nepafenac and amfenac on retinal angiogenesis

PURPOSE

Nepafenac is a potent NSAID that rapidly penetrates the eye following topical ocular administration. In the eye, nepafenac is converted to amfenac, which has unique time-dependent inhibitory properties for COX-1 and COX-2. The purpose of the present study was to investigate the capacity of amfenac to inhibit discrete aspects of the angiogenic cascade in vitro, and to test the efficacy of amfenac and nepafenac in vivo, using the rat OIR model.

METHODS

Müller cells were treated with amfenac, celecoxib (COX-2), or SC-560 (COX-1), and hypoxia-induced VEGF and PGE(2) assessed. Endothelial cells were treated with amfenac, celecoxib, or SC-560, and VEGF-induced proliferation and tube formation assessed. Rat pups were subjected to OIR, received intravitreal injections of amfenac, celecoxib, or SC-560, and neovascularization (NV), prostanoid production, and VEGF assessed. Other OIR-exposed pups were treated with topical nepafenac, ketorolac, or diclofenac, and inhibition of NV assessed.

RESULTS

Amfenac treatment failed to inhibit hypoxia-induced VEGF production. Amfenac treatment significantly inhibited VEGF-induced tube formation and proliferation by EC. Amfenac treatment significantly reduced retinal prostanoid production and NV in OIR. Nepafenac treatment significantly reduced retinal NV in OIR; ketorolac and diclofenac had no effect.

CONCLUSIONS

Nepafenac and amfenac inhibit OIR more effectively than the commercially available topical and injectable NSAIDs used in this study. Our data suggests there are COX-dependent and COX-independent mechanisms by which amfenac inhibits OIR. Because it is bioavailable to the posterior segment following topical delivery, nepafenac appears to be a promising advancement in the development of therapies for neovascular eye diseases.

Luteinizing hormone-releasing hormone receptor-targeted deslorelin-docetaxel conjugate enhances efficacy of docetaxel in prostate cancer therapy

Docetaxel, a chemotherapeutic agent currently used for improving survival of prostate cancer patients, suffers from low therapeutic index. The objective of this study was to prepare a new docetaxel derivative conjugated to deslorelin, a luteinizing hormone-releasing hormone (LHRH) superagonist, and to determine whether it enhances docetaxel potency in vitro and in vivo. Because docetaxel is not amenable for conjugation with peptides, we introduced a -COOH group in docetaxel, forming docetaxel-hemiglutarate, and subsequently conjugated this to serine in deslorelin, forming deslorelin-docetaxel. Fourier-transform IR, (1)H-nuclear magnetic resonance, and liquid chromatography-mass spectrometry analyses confirmed deslorelin-docetaxel formation. Antiproliferative efficacy in LNCaP and PC-3 cell lines over 24, 48, and 72 hours exhibited the order deslorelin-docetaxel > docetaxel, whereas deslorelin alone had no effect, with deslorelin-docetaxel potency being 15-fold greater than docetaxel at 72 h. Further, cells pretreated with antisense oligonucleotide against LHRH receptor exhibited decreased deslorelin-docetaxel efficacy, without any change in docetaxel efficacy. Thus, deslorelin-docetaxel efficacy is likely mediated via LHRH receptor. Cell cycle analysis showed that docetaxel treatment led to arrest in G(2)-M phase, whereas deslorelin-docetaxel treatment allowed greater progression to apoptosis in both cell lines, with deslorelin-docetaxel exerting 5-fold greater apoptosis compared with docetaxel in prostate cancer cell lines. Antitumor efficacy studies in PC-3 prostate xenograft-bearing mice indicated the efficacy order deslorelin-docetaxel > docetaxel >> deslorelin > PBS, with deslorelin-docetaxel exerting approximately 5.5-fold greater tumor growth inhibition than docetaxel alone. Thus, deslorelin-docetaxel prepared in this study retains pharmacologic effects of both docetaxel and deslorelin while enhancing the antiproliferative, apoptotic, and antitumor efficacy of docetaxel by several folds in prostate cancer therapy.

Inhibition of COX-2 and activation of peroxisome proliferator-activated receptor gamma synergistically inhibits proliferation and induces apoptosis of human pancreatic carcinoma cells

Although inhibition of cyclooxygenase-2 (COX-2) or activation of peroxisome proliferators-activated receptor gamma (PPAR-gamma) leads to growth inhibition in malignancies, the synergistic anti-tumor effects of combination of COX-2 inhibitor (NS-398) and PPAR-gamma agonist (rosiglitazone) on the human pancreatic cancer cells remains unknown. Here, we evaluated the effects of NS-398 and/or rosiglitazone on the cell proliferation and apoptosis in a pancreatic cancer cell line, SW1990. NS-398 and rosiglitazone decreased cell proliferation in a dose- and time-dependent manner. Proliferating cell nuclear antigen (PCNA) labeling index significantly decreased in the cells treated with either NS-398 or rosiglitazone. Both NS-398 and rosiglitazone alone induced apoptotic cell death of SW1990. The combination of NS-398 and rosiglitazone exerted synergistic effects on proliferation inhibition, and apoptosis induction in SW1990 cells, with down-regulation of Bcl-2 and up-regulation of Bax expression. Our results indicate that simultaneous targeting of COX-2 and PPAR-gamma inhibits pancreatic cancer development more effectively than targeting each molecule alone.

Effect of diabetes on transscleral delivery of celecoxib

PURPOSE

To investigate the effects of diabetes on transscleral retinal delivery of celecoxib in albino and pigmented rats.

METHODS

Albino (Sprague Dawley-SD) and pigmented (Brown Norway-BN) rats were made diabetic by a single intraperitoneal injection of streptozotocin (60 mg/kg) following 24 h of fasting and diabetes was confirmed (blood glucose>250 mg/dL). Two months after diabetes induction, the integrity of blood-retinal-barrier in control versus diabetic rats from both strains was compared by using FITC-dextran leakage assay. Fifty microliter suspension of celecoxib (3 mg/rat) was injected periocularly in both the strains in one eye, 2 months following diabetes induction. The animals were euthanized at the end of 0.25, 0.5, 1, 2, 3, 4, 8, and 12 h post-dosing and celecoxib levels in ocular tissues and plasma were estimated using a HPLC assay.

RESULTS

Diabetes (2-month duration) resulted in 2.4 and 3.5 fold higher blood-retinal barrier leakage in diabetic SD and BN rats, respectively, compared to controls. The area under tissue celecoxib concentration versus time curves (AUC) for sclera, cornea, and lens were not significantly different between control and diabetic animals. However, retinal and vitreal AUCs of celecoxib in treated eyes were approximately 1.5-fold and 2-fold higher in diabetic SD and BN rats, respectively, as compared to the controls.

CONCLUSIONS

Transscleral retinal and vitreal delivery of celecoxib is significantly higher in diabetic animals of both strains. The increase in retinal delivery of celecoxib due to diabetes is higher in pigmented rats compared to albino rats. Higher delivery of celecoxib in diabetic animals compared to control animals can be attributed to the disruption of blood-retinal barrier due to diabetes.

Effects of Celecoxib and Nimesulide on the Proliferation of Ectopic Endometrial Stromal Cells in vitro

The effects of cyclooxygenase 2 (COX-2) selective inhibitors on the proliferation of ectopic endometrial stromal cells in vitro were investigated. Ectopic endometrial stromal cells were treated with either celecoxib or nimesulide for 24 and 48 h. The results showed that (i) both celecoxib and nimesulide inhibited the proliferation of ectopic endometrial stromal cells in vitro in a time- and dose-dependent manner; (ii) the expression of prostaglandin E2 was significantly inhibited by both celecoxib and nimesulide in a dose-dependent manner; (iii) the percentage of apoptotic cells was significantly higher for cells treated with celecoxib or nimesulide than for untreated cells; and (iv) the percentage of the cells in the G0/G1 phase increased after the cells were treated with either agent in a dose-dependent manner. These data suggest that celecoxib and nimesulide inhibited proliferation of ectopic endometrial stromal cells by inducing apoptosis and blocking the cell cycle at the G0/G1 phase.

Celecoxib but not the combination of celecoxib+atorvastatin prevents the development of monocrotaline-induced pulmonary hypertension in the rat

The present study aimed to assess the effects of a COX-2 inhibitor, celecoxib, a HMG-CoA reductase inhibitor, atorvastatin, and the association of both on monocrotaline (MC)-induced pulmonary hypertension in rats. Celecoxib (Cib, 25 mg kg(-1) day(-1)), atorvastatin (AS, 10 mg kg(-1) day(-1)) or vehicle, were given orally, separately or in combination, for 26 days to Wistar male rats injected or not with MC (60 mg/kg intraperitoneally). At 4 weeks, MC-injected rats developed a severe pulmonary hypertension, with an increase in lung to body weight ratio (L/BW), right ventricular pressure (RVP in mmHg, 31 +/- 3 and 14 +/- 1 for MC and control groups, respectively, P < 0.05) and right ventricle/left ventricle + septum weight ratio (RV/LV+S) associated with a decrease in acetylcholine- and sodium-nitroprusside-induced pulmonary artery vasodilation in vitro. Hypertensive pulmonary arteries exhibited an increase in wall thickness (wall thickness to external diameter ratio, 0.42 +/- 0.01 vs 0.24 +/- 0.01 for MC and control groups, respectively, P < 0.001). Whole lung eNOS expression was decreased, and an increase in apoptosis, evaluated by cleaved caspase-3 expression, was evidenced by Western blotting. Cib (RVP in mmHg, 19 +/- 3 and 31 +/- 3 for MC+Cib and MC groups, respectively, P < 0.05), but neither AS nor AS+Cib significantly limited the development of pulmonary hypertension (P < 0.05), although the three treatments exhibited protective effects against MC-induced lung and right ventricle hypertrophy evaluated by L/BW and RV/(LV+S) ratios, respectively (P < 0.05). AS, Cib and AS+Cib treatments reduced MC-induced thickening of small intrapulmonary artery wall (0.42 +/- 0.01, 0.24 +/- 0.01, 0.26 +/- 0.01 and 0.28 +/- 0.01 for MC, MC+AS, MC+Cib and MC+AS+Cib groups, respectively, P < 0.001). In control rats, Cib reduced acetylcholine-induced pulmonary artery vasorelaxation. Treatment of MC rats by either Cib or AS did not modify acetylcholine-induced pulmonary artery relaxation, whereas combination of both drugs significantly worsened it (P < 0.05). AS, but neither Cib nor the combination of both, prevented apoptosis (AS, P < 0.05) and partially restored eNOS expression (AS, P < 0.05) in whole lung of MC rats. In conclusion, celecoxib exhibited beneficial effects against the development of monocrotaline-induced pulmonary artery hypertension and right ventricular hypertrophy. These beneficial effects of celecoxib might be, at least partly, explained by its effects on pulmonary artery thickening and pulmonary hypertrophy, even if it did not show any effect on pulmonary artery vasorelaxation and whole lung eNOS expression or apoptosis. The combination of celecoxib and atorvastatin was unable to prevent MC-induced pulmonary hypertension, decreased endothelium-dependent vasorelaxation and showed a trend toward an increased in RVP that deserves further studies.