Relationship Between Cyclooxygenase-2 Inhibition and Thrombogenesis

Active ingredients targeting Nrf2 in the Mongolian medicine Qiwei Putao powder: Systematic pharmacological prediction and validation for chronic obstructive pulmonary disease treatment

ETHNOPHARMACOLOGY RELEVANCE

Qiwei Putao powder (Uzhumu-7 in Mongolian) is a traditional Mongolian medicine, which has been widely used for alleviating cough and dyspnea, especially in aged individuals in both Inner Mongolia Autonomous Region and Xinjiang Uygur Autonomous Region of China. However, the active ingredients and exact pharmacological mechanism remain unclear.

MATERIALS AND METHODS

The protective effect of Qiwei Putao powder (QPP) on mice with cigarette smoke (CS)- and lipopolysaccharide (LPS)-induced chronic obstructive pulmonary disease (COPD) was assessed by histopathological hematoxylin and eosin staining, lung coefficient determination and measurement of cytokine levels. The bioactive ingredients and potential targets of the QPP were screened and detected with network pharmacology method and ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF-MS). The mechanism and efficacy of active ingredients were further validated in COPD mice with immunohistochemistry tests, cytokine level measurement and RT-PCR. The expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2) in the nucleus, interleukin (IL)-1β, superoxide dismutase (SOD), malondialdehyde (MDA) and tumor necrosis factor-alpha (TNF-α) were detected by enzyme-linked immunosorbent assay (ELISA) kits to evaluate oxidative stress and inflammatory conditions in vivo after treatment. The expression of Nrf2 and downstream genes was detected by RT-PCR.

RESULTS

QPP can alleviate pathological changes in the lung during COPD progression. Sixty-one bioactive molecules were identified in QPP, 42 candidate compounds present in UPLC-Q/TOF-MS and 30 predicted COPD-related targets were generated by in silico analysis. A therapeutic network was constructed with all potential targets to predict the preventive effects of the targets on respiratory disease as well as cardiovascular diseases, nervous system diseases, musculoskeletal diseases and bacterial infections. Targets related to inflammation, immunity and oxidative stress (prostaglandin-endoperoxide synthase 2, PTGS2; Nrf2; heat shock protein 90 alpha class A1, HSP90AA1; nitric oxide synthase, NOS2A; etc.) influenced COPD progression the most. We found that Nrf2 promotes a cell antioxidant response and is a key common target in the response to treatment with isoliquiritigenin (ISL), pterostilbene (PTE) and quercetin (QUE), the highly absorbed active ingredients in the formula. The data showed a strong synergistic protective role of these three molecules against the death of human type II alveolar adenocarcinoma (A549) cells through Nrf2 activation following H₂O₂ exposure and provide pharmacological mechanism of QPP in COPD treatment.

5-Lipoxygenase metabolic contributions to NSAID-induced organ toxicity

Cyclooxygenase (COX)-1, COX-2, and 5-lipoxygenase (5-LOX) enzymes produce effectors of pain and inflammation in osteoarthritis (OA) and many other diseases. All three enzymes play a key role in the metabolism of arachidonic acid (AA) to inflammatory fatty acids, which contribute to the deterioration of cartilage. AA is derived from both phospholipase A(2) (PLA(2)) conversion of cell membrane phospholipids and dietary consumption of omega-6 fatty acids. Nonsteroidal antiinflammatory drugs (NSAIDs) inhibit the COX enzymes, but show no anti-5-LOX activity to prevent the formation of leukotrienes (LTs). Cysteinyl LTs, such as LTC(4), LTD(4), LTE(4), and leukoattractive LTB(4) accumulate in several organs of mammals in response to NSAID consumption. Elevated 5-LOX-mediated AA metabolism may contribute to the side-effect profile observed for NSAIDs in OA. Current therapeutics under development, so-called "dual inhibitors" of COX and 5-LOX, show improved side-effect profiles and may represent a new option in the management of OA.

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 effect of hydroxyapatite nanocrystals on microvascular endothelial cell viability and functions

To favor bone reconstitution with biomaterials endothelial cells should maintain proper functions to drive angiogenesis. To this aim nanocrystals of hydroxyapatite (HA) have been synthesized and characterized on endothelial cells. Microvascular endothelial cells have been exposed to stoichiometric HA nanocrystals. Cell morphology and organization of cytoskeletal proteins have been monitored by SEM analysis and immunofluorescence. Biochemical markers of physiological and pathological responses of endothelial cells, endothelial constitutive nitric oxide synthase, and cycloxygenase-2 (ecNOS and COX-2, respectively) have been measured by immunofluorescence. Crystallized HA sustained endothelial survival without any cytotoxic effect. At the observation with SEM, endothelial cell morphology was maintained in the presence of HA. The localization and organization of beta-actin documented the formation of stress fibers, indicating an activation of endothelial cells induced by HA nanocrystals. Immunohistochemistry for biochemical key signaling pathways in endothelium demonstrated that nanocrystals of HA maintained the expression of ecNOS and did not increase COX-2 expression. In conclusion, the present findings indicate that HA nanocrystals exhibit high biocompatibility for microvascular endothelium. In the presence of HA nanocrystals endothelial cells maintain biochemical markers of healthy endothelium. They do not acquire a proinflammatory or thrombogenic phenotype, but express markers of functioning endothelium that might contribute to angiogenesis.

Tissue-specific modulation of cyclooxygenase-2 (Cox-2) expression in the uterus and the v. cava by estrogens and phytoestrogens

Cyclooxygenase 2 (Cox-2), an enzyme involved in prostaglandin production, is a key player in the development of pathologic changes, such as colorectal cancer, arteriosclerosis and thrombosis. In this study, we investigated the effects of estrogens, selective estrogen receptor modulators (SERMs), pure antiestrogens and phytoestrogens on the tissue-specific expression of Cox-2 in the uterus and the v. cava of ovariectomized female rats. Cox-2 expression could be detected in the uterine epithelium and in the endothelium of the v. cava. Cox-2 expression was time-dependently stimulated after administration of 17beta estradiol (E2) in the uterus. In the v. cava, E2 treatment resulted in a stimulated expression of the progesterone receptor (PR), a gene known to be regulated by E2, whereas Cox-2 was simultaneously down-regulated. Administration of the pure antiestrogen faslodex (Fas) had no effect on Cox-2 expression. In contrast, administration of tamoxifen (Tam) resulted in a decrease of Cox-2 expression in the v. cava but does not stimulate Cox-2 expression in the uterus. Interestingly, the same expression pattern of Cox-2 could be detected after dose-dependent administration of genistein (Gen). Here, down-regulation of Cox-2 could already be detected after administration of merely 0.5 mg/(kgBW) Gen, a dose where no effects on uterine weight were observed. In summary, our results demonstrate a reverse tissue-specific regulation of Cox-2 expression by estrogens in the v. cava and uterus indicating the existence of complex molecular mechanisms which have to be characterized in future studies. Remarkably, Tam and the phytoestrogen Gen, both share the ability to decrease the expression of Cox-2 in the v. cava without effecting its uterine expression. These observations may be of great importance with respect to potential beneficial or adverse effects of estrogens, SERMs and phytoestrogens on the cardiovascular tissue.

Risk of hemorrhagic stroke with aspirin use: an update

BACKGROUND

Low-dose aspirin is an important therapeutic option in the secondary prevention of myocardial infarction (MI) and ischemic stroke, especially in light of its unique cost-effectiveness and widespread availability. In addition, based on the results of a number of large studies, aspirin is also widely used in the primary prevention of MI. This review provides an update of the available data to offer greater clarity regarding the risks of aspirin with respect to hemorrhagic stroke, as well as insights regarding patient selection to minimize the risk of this complication.

SUMMARY OF REVIEW

In the secondary prevention of cardiovascular, cerebrovascular, and ischemic events, the evidence supports that the benefits of aspirin treatment significantly outweigh the risk of a major hemorrhage. The evidence from primary prevention of MI studies, including that from the recent Women's Health Study evaluation of aspirin use in healthy women, demonstrate that the increased risk for hemorrhagic stroke is small, is comparable to the secondary prevention studies, and fails to achieve statistical significance. A reasonable estimate of the risk of hemorrhagic stroke associated with the use of aspirin in primary prevention patients is 0.2 events per 1000 patient-years, which is comparable to estimates of the risk associated with the use of aspirin in secondary prevention patients.

CONCLUSIONS

When considering whether aspirin is appropriate, the absolute therapeutic cardiovascular benefits of aspirin must be balanced with the possible risks associated with its use, with the most serious being hemorrhagic stroke.

Pancreatic cancer and thromboembolic disease

Thromboembolic disease is a common complication of pancreatic cancer and is causally associated with the generation of an intrinsic hypercoagulable state. Pancreatic-cancer cells activate platelets and express several procoagulant factors, including tissue factor and thrombin. The activation of coagulation is not simply an epiphenomenon, but might also be related to enhanced tumour growth and angiogenesis. Clinical manifestations of thromboembolic disease in pancreatic cancer include deep venous thrombosis, pulmonary embolism, disseminated intravascular coagulation, portal vein thrombosis, and arterial thromboembolism. Reported incidences of disease range from 17% to 57%. Treatment options include warfarin and low-molecular-weight heparins. Studies over the past decade suggest that long-term use of these heparins in both primary and secondary prevention of venous thromboembolic disease improves outcomes in comparison with warfarin. Further research is needed to understand better the morbidity and mortality associated with this disease in pancreatic cancer and to optimise strategies of prevention and treatment.