Pulegone Prevents Hypertension through Activation of Muscarinic Receptors and Cyclooxygenase Pathway in L-NAME-Induced Hypertensive Rats.

The current study was designed to determine pulegone's antihypertensive and vasoprotective activity in L-NAME-induced hypertensive rats. Firstly, the hypotensive dose-response relationship of pulegone was evaluated in normotensive anesthetized rats using the invasive method. Secondly, the mechanism involved in hypotensive activity was determined in the presence of pharmacological drugs such as atropine/muscarinic receptor blocker (1 mg/kg), L-NAME/NOS inhibitor (20 mg/kg), and indomethacin/COX inhibitor (5 mg/kg) in anesthetized rats. Furthermore, studies were carried out to assess the preventive effect of pulegone in L-NAME-induced hypertensive rats. Hypertension was induced in rats by administering L-NAME (40 mg/kg) orally for 28 days. Rats were divided into six groups which were treated orally with tween 80 (placebo), captopril (10 mg/kg), and different doses of pulegone (20 mg/kg, 40 mg/kg, and 80 mg/kg). Blood pressure, urine volume, sodium, and body weight were monitored weekly. After 28 days, the effect of pulegone on lipid profile, hepatic markers, antioxidant enzymes, and nitric oxide was estimated from the serum of treated rats. Moreover, plasma mRNA expression of eNOS, ACE, ICAM1, and EDN1 was measured using real-time PCR. Results show that pulegone dose-dependently decreased blood pressure and heart rate in normotensive rats, with the highest effect at 30 mg/kg/i.v. The hypotensive effect of pulegone was reduced in the presence of atropine and indomethacin, whereas L-NAME did not change its hypotensive effect. Concurrent treatment with pulegone for four weeks in L-NAME-treated rats caused a reduction in both systolic blood pressure and heart rate, reversed the reduced levels of serum nitric oxide (NO), and ameliorated lipid profile and oxidative stress markers. Treatment with pulegone also improved the vascular response to acetylcholine. Plasma mRNA expression of eNOS was reduced, whereas ACE, ICAM1, and EDN1 levels were high in the L-NAME group, which was facilitated by pulegone treatment. To conclude, pulegone prevented L-NAME-induced hypertension by demonstrating a hypotensive effect through muscarinic receptors and cyclooxygenase pathway, indicating its use as a potential candidate in managing hypertension.

Effect of Calamintha officinalis on Vascular Contractility and Angiotensinconverting Enzyme-2.

AIMS: The study aimed to assess the antihypertensive activity of Calamintha officinalis. BACKGROUND: Calamintha officinalis (CO) is a medicinal and aromatic herb as well as an antihypertensive plant that is widely used for its medicinal properties in several regions. OBJECTIVE: This study aimed to evaluate the effect of the aqueous extract of Calamintha officinalis (AECO) on vasorelaxant activity and arterial blood pressure under normal and hypertensive states in rats. Additionally, the effect of AECO on vascular angiotensin-converting enzyme 2 (ACE-2) was assessed. METHODS: In the current study, AECO (100 mg/Kg) was prepared, and its antihypertensive ability was assessed in L-NG-Nitro arginine methyl ester (L-NAME)-induced hypertensive rats. Blood pressure and heart rate were recorded for 6 h for the acute experiment and during seven days for the subchronic treatment. RESULTS: The results indicated that AECO reduced the systolic, diastolic, and mean arterial blood pressure in hypertensive rats. In addition, the study showed that AECO exerts a vasorelaxant ability through the sGC-cGMP induction pathway, vascular cyclooxygenase pathway, and the opening of K+ channels. However, AECO had no inhibitory effect on aortic ACE-2. CONCLUSION: The study illustrates the beneficial action of AECO as an antihypertensive and vasorelaxant agent.

The antinociceptive effect of local or systemic parecoxib combined with lidocaine/clonidine intravenous regional analgesia for complex regional pain syndrome type I in the arm.

We evaluated the efficacy of local or systemic parecoxib combined with lidocaine/clonidine IV regional analgesia in complex regional pain syndrome (CRPS) type 1 in a dominant upper limb. Thirty patients with CRPS type 1 were divided into three groups. The control group (CG) received both IV saline in the healthy limb and IV loco-regional 1 mg/kg of lidocaine + 30 mug of clonidine, diluted to a 10-mL volume with saline. The systemic parecoxib group (SPG) received a regional block similar to that administered to the CG but with systemic 20 mg of parecoxib, whereas the IV regional anesthesia with parecoxib group (IVRAPG) received an extra IV 5 mg of loco-regional parecoxib compared with the CG. The block was performed once a week for 3 consecutive weeks. Analgesia was evaluated by the 10-cm visual analog scale (VAS) and rescue analgesic consumption. The IVRAPG showed less daily ketoprofen (milligrams) consumption in the second and third weeks compared with the other groups (P < 0.05). The IVRAPG also showed less ketoprofen consumption when comparing the first and second week with the third week (P < 0.05). The VAS score comparison among groups revealed that groups were similar during the first and second week observation, although the IVRAPG showed smaller VAS scores in the third week compared with both CG and SPG (P < 0.05). We conclude the IV 5 mg of parecoxib was an effective antiinflammatory drug combined with clonidine/lidocaine loco-regional block in CRPS type 1.

The risk for myocardial infarction with cyclooxygenase-2 inhibitors: a population study of elderly adults.

BACKGROUND: Cyclooxygenase-2 (COX-2) selective inhibitors have been marketed since 1999 as safer alternatives to nonsteroidal anti-inflammatory drugs (NSAIDs). Debate about their cardiac safety has culminated in the recent withdrawal of rofecoxib. Additional studies are needed to better understand this risk and to determine whether this safety concern represents a class effect. OBJECTIVE: To assess the influence of various NSAIDs on the risk for a first myocardial infarction (MI). DESIGN: Population-based, retrospective cohort study analyzed using a time-matched, nested case-control approach. SETTING: Quebec, Canada. PARTICIPANTS: 113,927 elderly persons without previous MI and newly treated with an NSAID between 1 January 1999 and 30 June 2002. MEASUREMENTS: NSAID exposure and occurrence of MI assessed by using Quebec's administrative health databases. RESULTS: Compared with no use of NSAIDs in the year preceding the event, current use of rofecoxib was associated with an increased risk for an acute MI (rate ratio [RR], 1.24 [95% CI, 1.05 to 1.46]) that was more pronounced at higher doses (RR, 1.73 [CI, 1.09 to 2.76]). The concomitant use of aspirin appears to decrease the risk associated with low-dose rofecoxib (RR, 1.00 [CI, 0.77 to 1.28]) but not with high-dose rofecoxib (RR, 2.36 [CI, 1.27 to 4.39]). No increased risks were observed with celecoxib (RR, 0.99 [CI, 0.85 to 1.16]) or the other NSAIDs. LIMITATIONS: The study could not completely account for all potential confounders, including over-the-counter use of aspirin and ibuprofen. CONCLUSIONS: These results provide evidence of an increased risk for acute MI in current users of rofecoxib among elderly persons with no history of MI. This risk appears greater at higher doses. Aspirin use mitigates the risk associated with low-dose but not high-dose rofecoxib. There was no evidence of an increased risk with the other NSAIDs.

Improvements with esomeprazole in patients with upper gastrointestinal symptoms taking non-steroidal antiinflammatory drugs, including selective COX-2 inhibitors.

OBJECTIVES: Upper gastrointestinal (GI) symptoms are common in patients using non-steroidal antiinflammatory drugs (NSAIDs) including selective cyclooxygenase (COX)-2 inhibitors and may be acid related. We therefore assessed esomeprazole treatment for upper GI symptoms in these patients. METHODS: A total of 794 and 848 continuous NSAID users, free of gastroduodenal ulcers, erosive esophagitis, and Helicobacter pylori, were enrolled into two identical, multinational, multicenter double-blind studies (NASA1, SPACE1). Moreover, 608 and 556 patients were randomized to receive 4 wk esomeprazole 20 mg, or 40 mg, or placebo once daily. The primary variable was the patient-reported change in the upper GI symptom (pain, discomfort, or burning in the upper abdomen) score on a 7-graded severity scale (0-6) from the 7 days prior to treatment to the last 7 days in the study. RESULTS: Esomeprazole was associated with highly significant symptom improvement compared to placebo. Symptom improvements were 2.30 mean [SD 1.63] on esomeprazole 20 mg and 2.03 [1.56] on esomeprazole 40 mg versus 1.64 [1.57] on placebo in NASA1 and 2.17 [1.34] and 2.12 [1.48]versus 1.56 [1.26], respectively, in SPACE1 (all placebo comparisons at least p < 0.001). Esomeprazole-improved symptoms in patients taking selective COX-2 inhibitors, with changes of 2.21 [1.46] and 1.92 [1.38]versus 1.64 [1.46] in NASA1 and 2.20 [1.26] and 2.24 [1.62]versus 1.58 [1.37] in SPACE1 (all placebo comparisons at least p < 0.05), as well as those on non-selective NSAIDs. Esomeprazole was well tolerated and associated with significant improvements in HRQL. CONCLUSION: Esomeprazole 20 mg and 40 mg improve upper GI symptoms associated with continuous, daily NSAID therapy, including selective COX-2 inhibitors.

Relationship between cyclooxygenase-2 inhibition and thrombogenesis.

Recently there has been considerable interest in the role of cyclooxygenase-2 (COX-2) in thrombosis and myocardial infarction. A large number of clinical and basic studies have focused on whether COX-2 inhibitors can induce a prothrombotic disorder and increase the risk of cardiovascular thrombosis. This article reviews (1) the roles of COX-2 in the metabolism of prostaglandins; (2) the influence of COX-2 inhibition in the platelet aggregation and the antithrombotic function of vascular endothelium; (3) the roles of COX-2 inhibition in atherothrombosis; and (4) clinical trials that examine COX-2 inhibition in relationship to the risk of myocardial infarction. Based on the published data, this review suggests that COX-2 plays varying and sometimes conflicting roles in thrombogenesis, in prostaglandins' metabolism of endothelium in healthy or dysfunctional conditions, and in atherothrombosis. Future investigations under different pathologic conditions are needed to fully understand the net effect of COX-2 inhibition on thrombogenesis. The roles of COX-2 in the pathophysiologic process of cardiovascular thrombosis are diverse and controversial, and need to be further studied to guide clinical practice.

Roles of endogenous prostaglandins and cyclooxygenase izoenzymes in mucosal defense of inflamed rat stomach.

Endogenous prostaglandins (PGs) are involved in adaptive gastric protection against acute injury, and cyclooxygenase (COX)-1 is responsible for the production of PGs in this phenomenon. In the present study, we examined the effect of various COX inhibitors on gastric ulcerogenic and acid secretory responses following daily exposure of the stomach to iodoacetamide (IA) and investigated the role for COX isozyme in gastric protection under subchronic mucosal irritation. Gastric mucosal irritation was induced by addition of 0.1% IA to drinking water, and the gastric mucosa was examined on the 6th day. Indomethacin (5 mg/kg) or SC-560 (selective COX-1 inhibitor, 5 mg/kg) or rofecoxib (selective COX-2 inhibitor, 5 mg/kg) was given p.o. twice 24 hr and 3 hr before the termination of IA treatment. Giving IA in drinking water for 5 days produced minimal damage in the stomach. The damage was significantly worsened by indomethacin, resulting in hemorrhagic lesions. Both SC-560 and rofecoxib also aggravated such lesions, although the effect of rofecoxib was more pronounced. Treatment with IA decreased acid secretion in pylorus-ligated stomachs, and this change was significantly reverted by indomethacin as well as SC-560 and rofecoxib. Mucosal PGE2 content was increased following IA treatment, with apparent expression of COX-2 mRNA in the stomach, and the increased PGE2 production was significantly suppressed by SC-560 and rofecoxib as well as indomethacin. These results suggest that endogenous PGs derived from both COX-1 and COX-2 are involved in the mucosal defense of the inflamed stomach, partly by decreasing acid secretion and contribute to maintaining the mucosal integrity under such conditions.

Anti-inflammatory mode of isoflavone glycoside sophoricoside by inhibition of interleukin-6 and cyclooxygenase-2 in inflammatory response.

Soy, high dietary intake for the oriental population, is a main source of isoflavonoids. Sophoricoside (SOP) an isoflavone glycoside was isolated from immature fruits of Sophora japonica (Leguminosae family) and its inhibitory effect on chemical mediators involved in inflammatory response was investigated in this study. SOP inhibited the interleukin (IL)-6 bioactivity with an IC50 value of 6.1 microM whereas it had no effects on IL-1beta and TNF-alpha bioactivities. SOP was identified as a selective inhibitor of cyclooxygenase (COX)-2 activity with an IC50 value of 4.4 microM, but did not show inhibitory effect on the synthesis of COX-2. However, SOP had no effect on the production of reactive oxygen species including superoxide anions and nitric oxide. These results revealed that in vitro anti-inflammatory action of SOP is significantly different from that of genistein known as a phytoestrogen of soy products. This experimental study has documented an importance of dietary soy isoflavonoids as multifunctional agents beneficial to human health, and will help to clarify protective mechanisms of SOP against inflammatory conditions.

Nonsteroidal antiinflammatory drugs and a selective cyclooxygenase 2 inhibitor uncouple mitochondria in intact cells.

OBJECTIVE: Uncoupling of isolated mitochondria by nonsteroidal antiinflammatory drugs (NSAIDs) has been considered relevant to the development of gastrointestinal (GI) side effects. We investigated the occurrence of NSAID-induced uncoupling of mitochondria in intact cells (rat thymocytes) compared with the effects of a selective cyclooxygenase 2 (COX-2) inhibitor. METHODS: Oxygen consumption and mitochondrial membrane potential were simultaneously measured amperometrically and by distribution of radioactive tracer molecules, respectively, in the presence and absence of pharmacologically relevant concentrations of the NSAIDs indomethacin and diclofenac and the selective COX-2 inhibitor SC-236. Analysis of data by a technique related to top-down elasticity analysis permitted assessment of the influence of these compounds on individual components of cellular energy metabolism. RESULTS: Indomethacin, diclofenac, and SC-236 increased proton leak in isolated mitochondria. Both diclofenac and SC-236 significantly stimulated proton leak in intact cells and simultaneously inhibited substrate oxidation and ATP turnover. Oxygen consumption rates of isolated cells remained unchanged over a wide concentration range of the drugs, despite significant effects on subsystems of cellular energy metabolism. CONCLUSION: NSAIDs and selective COX-2 inhibitors have significant and equally directed effects on cellular energy metabolism. They both uncouple mitochondrial respiration and inhibit substrate oxidation and ATP turnover. However, the topical effect and selective COX-2 inhibition may not be sufficient to cause NSAID-like damage to the GI tract.

COX-2: where are we in 2003?--distinction from NSAIDs becoming blurred.

The distinction between cyclooxygenase-2-selective inhibitors (CSIs) and nonsteroidal anti-inflammatory drugs ultimately must be clinical and must be clinically and economically relevant. This distinction needs to be demonstrated in a substantial and clinically relevant difference in the respective rates of serious adverse reactions of the upper gastrointestinal tract. Event-driven, randomized, blinded, controlled trials with sufficient power are required to resolve uncertainties concerning the relative risk of thrombotic cardiovascular events in patients taking CSIs who have risk factors for these events. Patients and situations more representative of those in primary-care practice - elderly, comorbidities, comedication - need to be included in larger studies to provide a better understanding of the risks and benefits of CSIs.

Safety of selective cyclooxygenase-2 inhibitors in inflammatory bowel disease.

OBJECTIVES: Nonsteroidal anti-inflammatory drugs (NSAIDs) are relatively contraindicated in patients with inflammatory bowel disease (IBD) for fear of disease aggravation. Cyclooxygenase-2 inhibitors have fewer GI side effects than traditional NSAIDs in unselected patients. We report the safety of these agents in patients with IBD. METHODS: Patients with Crohn's disease, ulcerative colitis, or pouchitis who used celecoxib or rofecoxib were identified from computerized prescription records. A retrospective chart review was conducted. Concomitant medications, past NSAID use, indication for cyclooxygenase-2 inhibitor, dose, and duration were obtained. IBD disease activity before cyclooxygenase-2 inhibitor use was graded using a modified disease activity index. Change in disease activity was graded as improved, no change, or worsened. Patients were contacted to provide data not found in the charts. The proportion of patients receiving cyclooxygenase-2 inhibitors who experienced exacerbation of IBD was determined. RESULTS: Eleven patients were treated with celecoxib (median dose = 200 mg/day), and 16 patients were treated with rofecoxib (median dose = 25 mg/day). Median duration of therapy was 9 months (range = 1 wk-22 months). The drug was beneficial in 14 patients, of partial benefit in eight, and of no benefit in five. Two patients (7.4%) (95% CI = 2-23%) had aggravations of IBD. Three patients (11%) had other adverse events (renal insufficiency, rash, and asymptomatic colonic ulceration). All adverse events were reversible. CONCLUSIONS: Our preliminary results suggest that cyclooxygenase-2 inhibitors may be safe and beneficial in most patients with IBD. A placebo-controlled trial to confirm these preliminary observations is needed.