Thromboxane B2 Levels Research Articles

Thrombocytic activity in patients with arterial hypertension associated with metabolic syndrome

This work was aimed to elucidate the level of in vitro and in vivo aggregation activity of platelets and the functional significance of individual mechanisms of its regulation in patients with grade III arterial hypertension and metabolic syndrome. The study included 29 adult patients (15 men and 14 women) and 25 clinically healthy subjects of similar age. Biochemical, hematological and statistical methods were used. Marked dyslipidemia was associated with active lipid peroxidation. Plasma thromboxane B2 level was increased by 84,8% while 6-ketoprostaglandin F1α level was decreased by 17,9% and the total amount of NO metabolites by 28,7%. The degree of platelet aggregation and their aggregation with collagen 25,0 and 27,5% lower than the respective control values while the respective indices of their aggregation with ristomycin were 25,7 and 46,4% higher. The degree of platelet aggregation and their aggregation with ADP inducer were 25,7 and 58,4% higher than in control while the platelet-discocyte levels were reduced to 48,6 ± 0,4%. The sum of active platelet forms reached 51,4 ± 0,12% vs 17,9 ± 0,09% in control was, the number of small and large aggregates 18,6 ± 0,08 and 5,4 ± 0,04 per 1000 free platelets respectively vs 2,9 ± 0,06 и 0,2 ± 0,06 in control. Excess platelet activity in the patients was due to their enhanced adhesive and aggregative potential and reduced ability to disaggregate. The most important causs of thrombocytopathy was AH, negative changes in plasma lipid composition, and enhanced lipid peroxidation.

Sex differences in the role of phospholipase A2 -dependent arachidonic acid pathway in the perivascular adipose tissue function in pigs.

The fat surrounding blood vessels (perivascular adipose tissue or PVAT) releases vasoactive compounds that regulate vascular smooth muscle tone. There are sex differences in the regulation of vascular tone, but, to date, no study has investigated whether there are sex differences in the regulation of blood vessel tone by PVAT. This study has identified that the cyclooxygenase products thromboxane and PGF2α are released from coronary artery PVAT from pigs. Thromboxane appears to mediate the PVAT-induced contraction in arteries from females, whereas PGF2α appears to mediate the contraction in arteries from males. These sex differences in the role of these prostanoids in the PVAT-induced contraction can be explained by a greater release of thromboxane from PVAT from female animals and greater sensitivity to PGF2α in the porcine coronary artery from males. Previous studies have demonstrated that perivascular adipose tissue (PVAT) causes vasoconstriction. In this present study, we determined the role of cyclooxygenase-derived prostanoids in this contractile response and determined whether there were any sex differences in the regulation of vascular tone by PVAT. Contractions in isolated segments of coronary arteries were determined using isolated tissue baths and isometric tension recording. Segments were initially cleaned of PVAT, which was then re-added to the tissue bath and changes in tone measured over 1h. Levels of PGF2α and thromboxane B2 (TXB2 ) were quantified by ELISA, and PGF2α (FP) and thromboxane A2 (TP) receptor expression determined by Western blotting. In arteries from both male and female pigs, re-addition of PVAT caused a contraction, which was partially inhibited by the cyclooxygenase inhibitors indomethacin and flurbiprofen. The FP receptor antagonist AL8810 attenuated the PVAT-induced contraction in arteries from males, whereas the TP receptor antagonist GR32191B inhibited the PVAT-induced contraction in arteries from females. Although there was no difference in PGF2α levels in PVAT between females and males, PGF2α produced a larger contraction in arteries from males, correlating with a higher FP receptor expression. In contrast, release of TXB2 from PVAT from females was greater than from males, but there was no difference in the contraction by the TXA2 agonist U46619, or TP receptor expression in arteries from different sexes. These findings demonstrate clear sex differences in PVAT function in which PGF2α and TXA2 antagonists can inhibit the PVAT-induced vasoconstriction in male and female PCAs, respectively.

Role of prostaglandin E2 in bronchoconstriction-triggered cough response in guinea pigs

A feature of cough variant asthma is a heightened cough response to bronchoconstriction. The mediators of this response are unknown. This study was designed to elucidate the role of lipid mediators in bronchoconstriction-triggered cough response in an experimental animal model.We examined the influence of bronchoconstriction on cell components and mediators including prostaglandin E2 (PGE2) in bronchoalveolar lavage fluid (BALF). We studied the cough response to bronchoconstriction (CRB) by measuring the correlation between the increase in enhanced pause (Penh), an index of bronchoconstriction, and cough counts induced by methacholine (Mch) inhalation in conscious guinea pigs. We then examined the effects of intraperitoneal pretreatment with 16, 16-dimethyl-prostaglandin E2 (dm-PGE2) on CRB and cough counts.The total number of cells and cell components in the BALF were not influenced by bronchoconstriction. While levels of PGE2, prostaglandin I2, and cysteinyl leukotrienes were significantly increased, levels of prostaglandin D2, thromboxane B2, and substance P in the BALF were not. Dm-PGE2 significantly decreased the Mch-induced increase in Penh. Following bronchoconstriction by additional Mch inhalation, dm-PGE2 produced an increase in CRB and cough counts in a dose-dependent manner. Additionally, the heightened CRB following dm-PGE2 treatment was suppressed by pretreatment with PGE2 receptor (E-prostanoid EP) -1 and EP-3 antagonists in a dose-dependent manner, but not by EP-2 and EP-4 antagonists. The EP-1 antagonist also decreased cough counts.These results suggest that PGE2 acts as an exacerbating factor for bronchoconstriction-triggered cough. EP1 and EP3 may provide new therapeutic targets for cough variant asthma.

Antiplatelets and profibrinolytic activity of Citrullus colocynthis in control and high-fat diet-induced obese rats: mechanisms of action

The current study aimed to investigate the effect of Citrullus colocynthis (C. colocynthis) hydro-alcoholic extract on blood haemostasis in control and high-fat diet (HFD) induced obese rats. In control rats, the extract significantly enhanced bleeding time and plasma levels of tPA and significantly decreased plasma levels PAI-1 and serum levels of thromboxane B2 leading to inhibition of platelets aggregation. In HFD induced obese rats, similar effects were seen and the extract was also able to reverse HFD induced increases in fibrinogen and VWF. Searching for the mechanism, C. colocynthis acts by (1) inhibiting of food intake, (2) inhibiting the activity of pancreatic lipase, (3) decreasing levels of TNF-α and IL-6 and (4) decreasing circulatory levels of the prothrombotic adipokine, leptin and enhanced circulatory levels of the antithrombic adipokines and adiopnectin. In conclusion, C. colocynthis has antiplatelets and profibrinolytic activity in both control and HFD induced obese rats.

Aged garlic extract suppresses inflammation in apolipoprotein E‐knockout mice

Chronic inflammation plays a major role in the formation and progression of atherosclerotic plaques. To clarify the mode of action of aged garlic extract (AGE) to retard atherosclerosis, we investigated whether AGE suppresses the inflammation in apolipoprotein E-knockout (ApoE-KO) mice. ApoE-KO mice were fed standard diet with or without 3% AGE for 12 wk. AGE feeding inhibited the progression of atherosclerotic lesion by 27% and reduced the level of C-reactive protein (CRP) and thromboxane B2 (TXB2 ), a marker of platelet activation, in serum by 39 and 33%, respectively, compared to ApoE-KO mice without AGE treatment. AGE treatment also decreased the level of tumor necrosis factor alpha (TNF-α), a major stimulus inducing CRP production, in the liver by 35%. AGE decreased the level of interleukin-1 receptor-associated kinase 4 (IRAK4) by 60% and almost doubled the level of phospho-AMP-activated protein kinase (p-AMPK) in the liver. The anti-atherosclerotic effect of AGE involves the suppression of inflammation by reducing the serum level of CRP and TXB2 , and the protein level of TNF-α and IRAK4, and increasing AMPK activity in liver.

Serum adrenomedullin and urinary thromboxane B2 help early categorizing of acute kidney injury in decompensated cirrhotic patients: A prospective cohort study.

Increases in the systemic vasodilator adrenomedullin and the renal vasoconstrictors thromboxane A2 in cirrhotic patients are pathogenic factors for the development of functional acute kidney injury (AKI), including pre-renal azotemia (PRA) and hepatorenal syndrome (HRS), which is associated with high mortality. This study aims to find biomarkers that can diagnose HRS at an early stage, to enable treatment as soon as possible. Acute decompensated cirrhotic patients who had been admitted to hospital were enrolled in this prospective cohort study. Blood and urinary samples were collected immediately after admission. In addition to initially categorizing AKI cases into PRA, acute tubular necrosis (ATN), and HRS groups, their final diagnosis was adjudicated by a nephrologist and a hepatologist who checked the corrected and misclassification rates for significant biomarkers. The cut-off values for serum adrenomedullin and urinary thromboxane B2 (TXB2 ), when used as predictors for functional AKI (adrenomedullin >283 pg/mL, urinary TXB2 >978 [pg/mg urinary creatinine]), for HRS (adrenomedullin >428, urinary TXB2 >1604), and for good terlipressin plus albumin treatment responders (adrenomedullin >490, urinary TXB2 >1863), were observed. Patients with HRS who could be treated, due to high mortality, had significantly higher serum adrenomedullin and urinary TXB2 levels compared to HRS patients receiving standard treatment. In addition to predicting 60-day mortality, a combination of these two markers further increased diagnostic accuracy for HRS among functional AKI. Prompt diagnosis of HRS by differentiating it from PRA and ATN can be achieved by using serum adrenomedullin and urinary TXB2 in acute decompensated cirrhotic patients. In combination with severe clinical courses, these two markers are useful to select HRS patients who cannot be treated.

Guanosine exerts antiplatelet and antithrombotic properties through an adenosine-related cAMP-PKA signaling

BackgroundGuanosine is a natural product and an endogenous nucleoside that has shown to increase during myocardial ischemia. Platelets are critically involved in ischemic coronary events. It remains unknown, however, whether guanosine may affect platelet activation and function. We sought to investigate the potential antiplatelet and antithrombotic properties of guanosine and decipher the mechanisms behind. MethodsWe firstly assessed the effects of guanosine on platelet activation/aggregation upon stimulation with several platelet agonists including adenosine diphosphate (ADP), collagen, arachidonic acid (AA), and TRAP-6. Guanosine antithrombotic potential was also evaluated both in vitro (Badimon perfusion chamber) and in vivo (murine model). In addition we assessed any potential effect on bleeding. At a mechanistic level we determined the release of thromboxane B2, intraplatelet cAMP levels, the binding affinity on platelet membrane, and the activation/phosphorylation of protein kinase A (PKA), phospholipase C (PLC) and PKC. ResultsGuanosine markedly inhibited platelet activation/aggregation-challenged by ADP and, although to a lesser extent, also reduced platelet aggregation challenged by collagen, AA and TRAP-6. Guanosine significantly reduced thrombus formation both in vitro and in vivo without significantly affects bleeding. Guanosine antiplatelet effects were associated with the activation of the cAMP/PKA signaling pathway, and a reduction in thromboxane B2 levels and PLC and PKC phosphorylation. The platelet aggregation and binding affinity assays revealed that guanosine effects on platelets were mediated by adenosine. ConclusionGuanosine effectively reduces ADP-induced platelet aggregation and limits thrombotic risk. These antithrombotic properties are associated with the activation of the cAMP/PKA signaling pathway.

Reduced Antiplatelet Effect of Aspirin Does Not Predict Cardiovascular Events in Patients With Stable Coronary Artery Disease.

BackgroundIncreased platelet aggregation during antiplatelet therapy may predict cardiovascular events in patients with coronary artery disease. The majority of these patients receive aspirin monotherapy. We aimed to investigate whether high platelet‐aggregation levels predict cardiovascular events in stable coronary artery disease patients treated with aspirin.Methods and ResultsWe included 900 stable coronary artery disease patients with either previous myocardial infarction, type 2 diabetes mellitus, or both. All patients received single antithrombotic therapy with 75 mg aspirin daily. Platelet aggregation was evaluated 1 hour after aspirin intake using the VerifyNow Aspirin Assay (Accriva Diagnostics) and Multiplate Analyzer (Roche; agonists: arachidonic acid and collagen). Adherence to aspirin was confirmed by serum thromboxane B2. The primary end point was the composite of nonfatal myocardial infarction, ischemic stroke, and cardiovascular death. At 3‐year follow‐up, 78 primary end points were registered. The primary end point did not occur more frequently in patients with high platelet‐aggregation levels (first versus fourth quartile) assessed by VerifyNow (hazard ratio: 0.5 [95% CI, 0.3–1.1], P=0.08) or Multiplate using arachidonic acid (hazard ratio: 1.0 [95% CI, 0.5–2.1], P=0.92) or collagen (hazard ratio: 1.4 [95% CI, 0.7–2.8], P=0.38). Similar results were found for the composite secondary end point (nonfatal myocardial infarction, ischemic stroke, stent thrombosis, and all‐cause death) and the single end points. Thromboxane B2 levels did not predict any end points. Renal insufficiency was the only clinical risk factor predicting the primary and secondary end points.ConclusionsThis study is the largest to investigate platelet aggregation in stable coronary artery disease patients receiving aspirin as single antithrombotic therapy. We found that high platelet‐aggregation levels did not predict cardiovascular events.

Abstract 323: Metabolic Transformation of Fatty Acids Defines Resolving Versus Non-Resolving Inflammation in Obesity-Associated Heart Failure

Whether and how fat intake contributes to persistent inflammation in obesity is unclear. Here, we report the differential metabolic transformation of fatty acids in heart failure (HF) pathology in the setting of obesity. We used permanent coronary ligation to induce myocardial infarction (MI) leading to acute (d1), healing phase (d5) and subsequent chronic HF phase (d28) in male C57BL/6J mice, while maintaining naïve controls at day (d)0. Prior to MI, 100 two month-old mice were subjected to n-6 fatty acids (safflower oil; SO; 22Kcal) for 3 months, with subsequent randomized allocation of 50 mice to docosahexaenoic acid (DHA; 22Kcal) enriched n-3 fatty acids for the next 2 months, while maintaining SO control in the remaining 50 mice. Both groups gained significant weight and fat mass independent of lean mass confirmed by magnetic resonance imaging. Post-MI survival and left ventricular (LV) function was decreased in SO-fed mice with downregulation of multiple inflammation resolution mechanisms in the spleen, infarcted LV, and kidney. DHA increased Ly6C low macrophages, MRC, Arg-1, YM1 and FFAR4 (GPR120) during the acute and resolving phase from d1 to d5 post-MI as compared with SO-fed mice. DHA-improved post-MI survival at d28, together with increased levels of D-series resolvins (RvD1, RvD2, RvD4, RvD5), maresin 1, and RvE3, and lower levels of prostaglandins (PGD 2 , PGE 2 , PGF2 α ), leukotriene B 4 (LTB 4 ), 20-OH-LTB 4 , thromboxane B2 and lipoxin A 4 in the resolving phase. During chronic HF at d28 post-MI, DHA increased CD4 + /CD127 - with increased expression of FOXp3 in the LV. DHA reduced FFAR1-3 , neprilysin activity and simultaneously increased FFAR4 in the kidney as compared with SO post-MI. In contrast, SO-induced overactivation of pro-inflammatory FFAR1 (GPR40) and reduction of anti-inflammatory FFAR4 tracked with increased serum creatinine and IL-1β, and decreased ALX/ FPR2 in kidney at d28 post-MI. Overall, DHA intake modulates the splenocardiac resolving phase with generation of proresolving mediators, augmentation of Ly6C low macrophages, and suppression of prostaglandins post-MI. Thus, the metabolic transformation of n-3 and -6 fatty acids can regulate resolution versus non-resolution of inflammation in HF post-MI in the setting of obesity.

Acetylsalicylic acid in critically ill patients: a cross-sectional and a randomized trial.

BackgroundDespite decades of clinical use, the pharmacokinetics and the effects of acetylsalicylic acid (ASA) in critically ill patients remain ill‐defined. We aimed to investigate the pharmacokinetics and the effects of different ASA formulations during critical illness.DesignA cross‐sectional study and a randomized, parallel‐group trial were performed. Critically ill patients under chronic oral ASA treatment (100 mg enteric‐coated) were screened for high ‘on‐treatment’ platelet reactivity (HTPR) according to arachidonic acid‐induced whole‐blood aggregometry. Thirty patients with HTPR were randomized to receive 100 mg ASA intravenously, 100 mg enteric‐coated ASA bid (bis in die) or 81 mg chewable ASA (n = 10 per group). Serum thromboxane B2 (TXB2) levels, ASA and salicylic acid levels were quantified.ResultsOf 66 patients, 85% (95% confidence intervals 74–93%) had HTPR. Compared to baseline infusion of 100 mg, ASA significantly reduced platelet aggregation after 24 h to median 80% (Quartiles: 66–84%). Intake of 81 mg chewable ASA significantly reduced platelet aggregation to 75% (54–86%) after four hours, but increased it to 117% after 24 h (81–163%). Treatment with 100 mg enteric‐coated ASA bid decreased platelet aggregation after 24 h to median 56% (52–113%). Baseline TXB2 levels were median 0·35 ng/mL (0·07–0·94). Infusion of ASA or intake of 100 mg ASA bid reduced TXB2 levels to 0·07–0·18 ng/mL after 24 h, respectively. Chewable ASA reduced TXB2 levels only transiently. Pharmacokinetic analysis revealed highly variable absorption patterns of oral ASA formulations.ConclusionThere is a very high prevalence of HTPR in critically ill patients on peroral ASA therapy, caused by an incomplete suppression of TXB2 and/or by impaired absorption of ASA.

Once versus twice daily aspirin after coronary bypass surgery: a randomized trial

Background Acetyl-salicylic acid (ASA) hyporesponsiveness occurs transiently after coronary artery bypass graft (CABG) surgery and may compromise the effectiveness of ASA in reducing thrombotic graft failure. A reduced response to ASA 81 mg once-daily after CABG surgery is overcome by four times daily ASA dosing. Objectives To determine whether ASA 325 mg once-daily or 162 mg twice-daily overcomes a reduced response to ASA 81 mg once-daily after CABG surgery. Methods Adults undergoing CABG surgery were randomized to ASA 81 mg once-daily, 325 mg once-daily or 162 mg twice-daily. The primary outcome was median serum thromboxane B2 (TXB2 ) level on postoperative day 4. We pooled the results with those of our earlier study to obtain better estimates of the effect of ASA 325 mg once-daily or in divided doses over 24 h. Results We randomized 68 patients undergoing CABG surgery. On postoperative day 4, patients randomized to receive ASA 81 mg once-daily had a median day 4 TXB2 level of 4.2 ng mL-1 (Q1, Q3: 1.5, 7.5 ng mL-1 ), which was higher than in those randomized to ASA 162 mg twice-daily (1.1 ng mL-1 ; Q1, Q3: 0.7, 2.7 ng mL-1 ) and similar to those randomized to ASA 325 mg once-daily (1.9 ng mL-1 ; Q1, Q3: 0.9, 4.7 ng mL-1 ). Pooled data showed that the median TXB2 level on day 4 in groups receiving ASA 162 mg twice-daily or 81 mg four times daily was 1.1 ng mL-1 compared with 2.2 ng mL-1 in those receiving ASA 325 mg once-daily. Conclusions Multiple daily dosing of ASA is more effective than ASA 81 mg once-daily or 325 mg once-daily at suppressing serum TXB2 formation after CABG surgery. A twice-daily treatment regimen needs to be tested in a clinical outcome study.

Prevalence of Aspirin Resistance among Jordanian Patients with Cardiovascular Disease

Introduction: Despite the wide range of aspirin indications, there is a considerable amount of patients do not respond to aspirin, who also are referred to as aspirin non-responders or aspirin resistant patients. Aims and objectives: This study was carried out to prospectively evaluate the prevalence of aspirin resistance in Jordanian patients with cardiovascular disease and further clarify the clinical predictors of aspirin resistance. Materials and methods: Biochemical aspirin response was assessed based on the measurements of urinary11-dehydro thromboxane B2 (11-dhTxB2) levels using FDA approved diagnostic kit. Patients taking aspirin (75-325mg) for at least 7 days were prospectively enrolled from all stable cardiac patients presenting at Jordan University hospital outpatient clinics. Results: Eighty six (86) patients were enrolled in this study. Another twenty four healthy individuals were enrolled to function as a control group. The mean urinary levels of 11- dhTxB2/creatinine were significantly lower almost 3- times in patients in the primary and secondary aspirin prevention group compared with the control group (1567.58 vs. 4236.19 pg/mg, p-value >0.005). Thirty-one patients were found to be aspirin resistant with a prevalence of 36%. Conclusion: Our findings of aspirin resistance are particularly important given the large number of patients using this medication for prevention of atherothrombotic events. These results indicate that aspirin resistance should be diagnosed so that individuals with no response to aspirin can receive an alternative or an additional antiplatelet therapy.

Thrombopoietin and platelet aggregation in patients with stable coronary artery disease

Thrombopoietin (TPO) may facilitate platelet activation and aggregation. However, data on the impact of TPO on platelet aggregation in patients with stable coronary artery disease (CAD) are scarce. We aimed to investigate associations between TPO and platelet aggregation and activation in patients with stable coronary artery disease (CAD). We studied 900 stable CAD patients. Serum TPO was assessed by ELISA. Platelet aggregation was evaluated using the Multiplate Analyzer (agonists: arachidonic acid [AA] and collagen) and the VerifyNow Aspirin Assay. Platelet activation was evaluated by soluble (s)P-selectin. Cyclooxygenase-1 inhibition was evaluated by serum thromboxane B2 (TXB2). We found that TPO correlated weakly with platelet aggregation evaluated by Multiplate using AA (r = −0.09, p = 0.01) and collagen as agonists (r = −0.03, p = 0.43) and by VerifyNow (r = 0.07, p = 0.03). We found no correlation between TPO and sP-selectin (r = −0.01, p = 0.70). Independent predictors of AA-induced platelet aggregation by Multiplate included high levels of sP-selectin and serum TXB2, high platelet count, increasing age and body mass index, female sex, and active smoking. Independent predictors of TPO included low AA-induced platelet aggregation by Multiplate, high levels of hs-CRP, active smoking, and high platelet aggregation evaluated by VerifyNow. In conclusion, TPO levels did not correlate with platelet activation and only weak associations were found between TPO and platelet aggregation, suggesting that TPO did not substantially facilitate platelet aggregation in stable CAD patients.

Influence of nonsteroidal anti-inflammatory drugs on aspirin\u2019s antiplatelet effects and suggestion of the most suitable time for administration of both agents without resulting in interaction

BackgroundLow-dose aspirin irreversibly inhibits platelet cyclooxygenase-1 (COX-1) and suppresses platelet aggregation. It is effective for secondary prevention of cardiovascular events. Because nonsteroidal anti-inflammatory drugs (NSAIDs) reversibly bind with COX-1, the antiplatelet effects of aspirin may be suppressed when NSAIDs are co-administered. This interaction could be avoided by avoiding simultaneous administration; however, the minimum interval that should separate the administration of aspirin and loxoprofen is not well known. In this study, we investigated how to avoid the influence of NSAIDs on the antiplatelet effects of aspirin. An in vitro experiment was performed to investigate the influence of ibuprofen and loxoprofen at various concentrations on aspirin’s antiplatelet action.MethodsPlatelet aggregation and thromboxane B2 (TXB2) levels were measured after addition of aspirin only and NSAIDs plus aspirin to platelet-rich plasma. NSAIDs were used at their maximum plasma concentrations, the assumed concentration after 6 h (for loxoprofen only), and the assumed concentration after 12 h of taking one clinical dose. Platelet aggregation threshold index (PATI), defined as the putative stimulus concentration giving 50% aggregation, was calculated as an index of aggregation activity.ResultsPATI decreased in ibuprofen plus aspirin group compared to that in the aspirin only group, regardless of ibuprofen concentration. Furthermore, PATI significantly decreased when aspirin was added after loxoprofen-trans-OH addition at the maximum concentration (4.1 ± 0.1 μg/mL), compared to that in aspirin only group (5.9 ± 0.1 μg/mL). PATI showed no significant difference after addition of loxoprofen at the assumed concentration after 6 h (aspirin only group, 5.0 ± 0.5 μg/mL; loxoprofen-trans-OH plus aspirin group, 4.9 ± 0.4 μg/mL).In addition, TXB2 concentration tended to decrease with increasing PATI.ConclusionsIt is desirable to avoid ibuprofen co-administration with the usual once-daily low-dose aspirin therapy; however, a 6-h interval between loxoprofen and aspirin could avoid this potential interaction when loxoprofen is taken before aspirin.

Protective effects of marrubiin improve endometriosis through suppression of the expression of RANTES.

Marrubiin can improve blood and lymph microcirculation disturbance, and has pharmacological effects in myocardial protection, anti‑inflammation and anti‑oxidation. The aim of the present study was to evaluate the protective effects of marrubiin on endometriosis through suppression of the expression of regulated on activation, normal T cell expressed and secreted (RANTES). Endometriotic cells were implanted into the peritoneal cavity of mice, and these mice were injected estradiol benzoate (30µg/kg) once each day for 14days. The mice with endometriosis were then treated with 12, 25 or 50mg/kg marrubiin. Reverse transcription‑quantitative polymerase chain reaction was used to assess the mRNA expression of RANTES, and western blot analysis was used to analyze the protein expression of RANTES, TNF‑α and PGE2. Inflammation factors were measured by ELISA. Treatment with marrubiin effectively improved lesion regression and inhibited toxicity in the mouse model of endometriosis. Marrubiin significantly inhibited endometrial lesions and monocyte chemotaxis in the mice with endometriosis, and reduced U937 cell migration. Calcium mobilization, levels of tumor necrosis factor‑α and the secretion of RANTES were effectively suppressed by marrubiin treatment. The calcium levels were effectively induced, whereas the protein expression of prostaglandin E2 (PGE2) and formation of thromboxane B2 (TXB2) were effectively inhibited by marrubiin treatment. These findings indicated that the protective effect of marrubiin improved endometriosis in the mice through the suppression of inflammation and downregulation of the expression of RANTES, followed by mediation of the levels of calcium, PGE2 and TXB2.

Influence of acupoint-injection on TXB2 and 6-keto-PGF1a in patients with pseudobulbar palsy: a randomized controlled trial

To prove the feasibility and validity of Xing Nao Jing acupoint-injection (XNJ-AI) at Fengchi (GB 20) for pseudobulbar palsy caused by ischemic stroke (PBP-IS). An assessor-blinded, two-parallel-group, randomized controlled trial was conducted, and the patients with PBP-IS were recruited and randomly divided into two groups. Patients in the control group received oral aspirin (100 mg per day for 2 weeks). In addition to oral aspirin; patients in the treatment group received XNJ-AI at Fengchi (GB 20), once a day, for two weeks. The primary outcome was assessed by the water-swallowing test (WST). Thromboxane B2 (TXB2) and 6-keto-prostaglandin F1a (6-keto-PGF1a) in plasma were measured before and after the treatment. In the treatment group, the percentage of swallowing function no less than grade 3 before and after the treatment was 32% and 88%, respectively; in the control group, it was 28% and 76% before and after the treatment, respectively; the difference after the treatment between the two groups was statistically significant (P<0.05). There were statistical differences between pre- and post-treatment levels of plasma TXB2 and 6-keto-PGF1α in the two groups (both P<0.05). After the treatment, there were significant differences in the levels of plasma TXB2 and 6-keto-PGF1α between the two groups (both P<0.05). XNJ-AI at Fengchi (GB 20) can improve the patients’ swallowing function and balance the levels of TXB2 and 6-keto-PGF1α in plasma.

Studies on New Activities of Enantiomers of 2-(2-Hydroxypropanamido) Benzoic Acid: Antiplatelet Aggregation and Antithrombosis.

R-/S-2-(2-Hydroxypropanamido) benzoic acid (R-/S-HPABA), a marine-derived anti-inflammatory drug, however, the antiplatelet and antithrombotic effects have not been investigated. In this paper, the in vitro antiplatelet activities and in vivo antithrombotic effects of R-/S-HPABA were investigated, for the first time. The effects of R-/S-HPABA on platelet aggregation induced by adenosine diphosphate (ADP), collagen (COLL) and arachidonic acid (AA) were evaluated. In addition, the in vivo bleeding time, clotting time, collagen-epinephrine induced pulmonary thrombosis and common carotid artery thrombosis were also investigated in rats. R-/S-HPABA significantly inhibited ADP, COLL and AA induced platelet aggregation in rabbit platelet rich plasma in vitro compared with control group, to a degree similar to that of aspirin. Besides, R-/S-HPABA prolonged bleeding time and clotting time as well as increased the recovery rate obviously in pulmonary thrombosis. Moreover, the level of thromboxane B2 (TXB2) was decreased while the production of 6-keto-prostaglandin F1α (6-keto-PGF1α) was increased markedly by R-/S-HPABA. Furthermore, R-/S-HPABA reduced carotid artery thrombosis weight. These results illustrated that R-/S-HPABA could be a potent antiplatelet aggregation and antithrombotic agent.

Enteric Coating and Aspirin Nonresponsiveness in Patients With Type 2 Diabetes Mellitus

BackgroundA limitation of aspirin is that some patients, particularly those with diabetes, may not have an optimal antiplatelet effect. ObjectivesThe goal of this study was to determine if oral bioavailability mediates nonresponsiveness. MethodsThe rate and extent of serum thromboxane generation and aspirin pharmacokinetics were measured in 40 patients with diabetes in a randomized, single-blind, triple-crossover study. Patients were exposed to three 325-mg aspirin formulations: plain aspirin, PL2200 (a modified-release lipid-based aspirin), and a delayed-release enteric-coated (EC) aspirin. Onset of antiplatelet activity was determined by the rate and extent of inhibition of serum thromboxane B2 (TXB2) generation. Aspirin nonresponsiveness was defined as a level of residual serum TXB2 associated with elevated thrombotic risk (<99.0% inhibition or TXB2 >3.1 ng/ml) within 72 h after 3 daily aspirin doses. ResultsThe rate of aspirin nonresponsiveness was 15.8%, 8.1%, and 52.8% for plain aspirin, PL2200, and EC aspirin, respectively (p < 0.001 for both comparisons vs. EC aspirin; p = 0.30 for comparison between plain aspirin and PL2200). Similarly, 56% of EC aspirin–treated subjects had serum TXB2 levels >3.1 ng/ml, compared with 18% and 11% of subjects after administration of plain aspirin and PL2200 (p < 0.0001). Compared with findings for plain aspirin and PL2200, this high rate of nonresponsiveness with EC aspirin was associated with lower exposure to acetylsalicylic acid (63% and 70% lower geometric mean maximum plasma concentration [Cmax] and 77% and 82% lower AUC0–t [area under the curve from time 0 to the last time measured]) and 66% and 72% lower maximum decrease of TXB2, with marked interindividual variability. ConclusionsA high proportion of patients treated with EC aspirin failed to achieve complete inhibition of TXB2 generation due to incomplete absorption. Reduced bioavailability may contribute to “aspirin resistance” in patients with diabetes. (Pharmacodynamic Evaluation of PL2200 Versus Enteric-Coated and Immediate Release Aspirin in Diabetic Patients; NCT01515657)

Protective Effects of Total Flavones of Elaeagnus rhamnoides (L.) A. Nelson against Vascular Endothelial Injury in Blood Stasis Model Rats.

The aim was to evaluate the protective effects of total flavones of Elaeagnus rhamnoides (L.) A. Nelson (TFE) against vascular endothelial injury in blood stasis model rats and explore the potential mechanisms preliminarily. The model of blood stasis rat model with vascular endothelial injury was induced by subcutaneous injection of adrenaline combined with ice-water bath. Whole blood viscosity (WBV), histological examination, and prothrombin time (PT), activated partial thromboplastin time (APTT), and fibrinogen (FIB) were measured. Meanwhile, the levels of Thromboxane B2 (TXB2), 6-keto-PGF1α, von Willebrand factor (vWF), and thrombomodulin (TM) were detected. In addition, Quantitative Real-Time PCR (qPCR) was performed to identify PI3K, Erk2, Bcl-2, and caspase-3 gene expression. The results showed that TFE can relieve WBV, increase PT and APTT, and decrease FIB content obviously. Moreover, TFE might significantly downregulate the levels of TXB2, vWF, and TM in plasma and upregulate the level of 6-keto-PGF1α in plasma. Expressions of PI3K and Bcl-2 were increased and the expression of caspase-3 was decreased by TFE pretreatment in the rat model. Consequently, the study suggested that TFE may have the potential against vascular endothelial injury in blood stasis model rats induced by a high dose of adrenaline with ice-water bath.

Eicosanoids as Risk and Prognostic Factors for Acute Respiratory Distress Syndrome in Sepsis Patients

Although a number of studies have reported elevated levels of eicosanoids in acute lung injury with sepsis, the possibility that eicosanoids may act as risk and prognostic factors for sepsis patients who develop acute respiratory distress syndrome (ARDS) remains poorly studied. To clarify this aspect, we measured the levels of eicosanoids and used logistic regression analysis and receiver operating characteristic (ROC) curves to investigate whether eicosanoids could act as risk and prognostic factors for sepsis patients who develop ARDS. We conducted a casecontrol study comparing 13 sepsis patients with ARDS and 23 sepsis patients without ARDS. The plasma levels of leukotriene B4 (LTB4), 6-keto-prostaglandin F1α (6-keto-PGF1α) and thromboxane B2 (TXB2) were measured by radioimmunoassays as substitutes for the plasma levels of PGI2 and TXA2, which are unstable. The levels of eicosanoids in sepsis patients with ARDS were significantly higher than those in sepsis patients without ARDS. Logistic regression analysis revealed that LTB4 was the only risk factor for sepsis patients with ARDS (odds ratio, 1.10; P=0.02). The area under the ROC curve values for all eicosanoids were significantly greater than 0.5 (P<0.001), and the likelihood value for the TXB2 levels was higher than those of the other eicosanoids. We conclude that LTB4 may be an important risk factor for sepsis patients with ARDS, while TXA2 may be an important prognostic factor for sepsis patients with ARDS.