Cyclooxygenase 2 inhibitors and thrombogenicity production: comment on the article by Crofford et al

Identification of Characteristic Autoantibodies Associated With Deficiency Pattern in Traditional Chinese Medicine of Rheumatoid Arthritis Using Protein Chips

Background: Rheumatoid arthritis (RA) is an autoimmune disease. Based on traditional Chinese medicine (TCM) theory, deficiency pattern (DP) which leads to specific treatment principles in clinical management is a crucial pattern diagnosis among RA patients, and autoantibodies have potential implications in TCM pattern classification. The purpose of this study was to identify specific RA DP-associated autoantibodies.

Methods: RA DP patients, RA nondeficiency pattern (NDP) patients and healthy controls (HCs) were recruited for this study. Then, clinical data and sera from all subjects were collected. After that, the sera were probed with protein chips, which were constructed by known RA related autoantigens, to screen for DP-associated candidate autoantibodies. Lastly, candidate autoantibodies were validated via enzyme-linked immunosorbent assay (ELISA) and function was evaluated by network analysis.

Results: Protein chips results showed that RA patients have higher levels of anti-vascular endothelial growth factor (VEGF) A165 antibodies than HC (P < 0.005); anti-VEGFA165 antibodies levels of patients with RA DP were lower than patients with RA NDP (P < 0.05). The results of the ELISA also showed statistically significant differences in anti-VEGFA165 antibodies between the RA and HC group (P < 0.0001); and there were statistically significant differences in anti-VEGFA165 antibodies between the RA DP and RA NDP group (P < 0.05). Network analysis results suggested IL-6 signaling pathway has a significant effect on VEGFA165 in RA patients.

Conclusion: Autoantibodies identification in RA using protein chips help in understanding DP in TCM. Discovery of anti-VEGFA165 antibodies may provide the possibility for clinical precision treatment.

Raging the War Against Inflammation With Natural Products

Over the last few decade Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) are the drugs of choice for treating numerous inflammatory diseases including rheumatoid arthritis. The NSAIDs produces anti-inflammatory activity via inhibiting cyclooxygenase enzyme, responsible for the conversation of arachidonic acid to prostaglandins. Likewise, cyclooxegenase-2 inhibitors (COX-2) selectively inhibit the COX-2 enzyme and produces significant anti-inflammatory, analgesic, and anti-pyretic activity without producing COX-1 associated gastrointestinal and renal side effects. In last two decades numerous selective COX-2 inhibitors (COXIBs) have been developed and approved for various inflammatory conditions. However, data from clinical trials have suggested that the prolong use of COX-2 inhibitors are also associated with life threatening cardiovascular side effects including ischemic heart failure and myocardial infection. In these scenario secondary metabolites from natural product offers a great hope for the development of novel anti-inflammatory compounds. Although majority of the natural product based compounds exhibit more selectively toward COX-1. However, the data suggest that slight structural modification can be helpful in developing COX-2 selective secondary metabolites with comparative efficacy and limited side effects. This review is an effort to highlight the secondary metabolites from terrestrial and marine source with significant COX-2 and COX-2 mediated PGE2 inhibitory activity, since it is anticipated that isolates with ability to inhibit COX-2 mediated PGE2 production would be useful in suppressing the inflammation and its classical sign and symptoms. Moreover, this review has highlighted the potential lead compounds including berberine, kaurenoic acid, α-cyperone, curcumin, and zedoarondiol for further development with the help of structure-activity relationship (SAR) studies and their current status.

A cohort study to evaluate cardiovascular risk of selective and nonselective cyclooxygenase inhibitors (COX-Is) in arthritic patients attending orthopedic department of a tertiary care hospital

Background:

Cyclooxygenase-2 inhibitors (COX-2-Is) have recently been concerned in the occurrence of adverse cardiovascular (CV) events. Rofecoxib and valdecoxib has been withdrawn from the market, but celecoxib, etoricoxib and parecoxib continues to be used. Other nonsteroidal anti-inflammatory drugs (NSAIDs) may also increase the risk of CV events. However, clinical trial databases for COX-2-Is had created lots of controversies regarding cardiovascular safety of selective and nonselective cyclooxygenase inhibitors (COX-Is). This study was, conducted to assess and compare the CV risk of COX-Is in arthritic patients over a period of time.

Materials and Methods:

In this prospective cohort study adult arthritics of either sex those were freshly diagnosed or taking COX-Is for < 3 months; were included. Patients were grouped into nonselective and selective COX-2-I groups with reference to treatment they received. The CV risk factors like blood pressure (BP), blood sugar level (BSL), lipid profile, body mass index (BMI) were assessed and compared; demography of CV risk factors was also studied. Data obtained was analysed using Student's ‘t’-test of OpenEpi statistical software.

Results:

Study clearly revealed that all NSAIDs exhibit variable CV risk; however, selective COX-2-Is found to exhibit more CV risk. BMI, BP and lipid profile; the potential CV risk factors, showed significant impairment in selective COX-2-Is group; P < 0.01, P < 0.001 and P < 0.05, respectively, compared to baseline and P < 0.05 vs. nonselective COX-Is for BMI.

Conclusions:

This study portrays the potential CV risk of selective COX-2-Is; confirms and re-evaluate the results of earlier studies in this regard.

Do some inhibitors of COX-2 increase the risk of thromboembolic events?: Linking pharmacology with pharmacoepidemiology

Inhibitors of the cyclo-oxygenase (COX)-2 isoenzyme were developed with the expectation that their use would be accompanied by a reduction in adverse reactions thought to be mediated through COX-1 compared with conventional nonselective NSAIDs. However, the results of some clinical studies and other evidence have led to the hypothesis that use of COX-2 inhibitors may contribute to an increased risk of adverse thromboembolic (TE) events. In this review, we have evaluated the evidence from small-scale in vitro and in vivo pharmacological studies, clinical trials and large-scale pharmacoepidemiological studies and commented on the relationship between the pharmacological characteristics related to thromboembolic events and the clinical effects in large-scale clinical trials and pharmacoepidemiological studies. Overall, the pharmacological evidence suggests that a prothrombotic effect of COX-2 selective inhibitors is plausible. To date, despite the results from the Vioxx Gastrointestinal Outcome Research (VIGOR) study from which the clinical concern regarding cardiovascular TE risk arose, the published data from other randomised controlled trials (RCTs), retrospective observational studies and spontaneous reporting schemes provide a conflicting body of evidence on the TE risk with COX-2 inhibitors. Concerns that COX-2 inhibitors may be associated with prothrombotic effects remain and these need to be addressed in large scale, RCTs designed specifically to investigate the possibility of an excess of adverse cardiovascular outcomes in users of some or all selective COX-2 inhibitors, both with and without concomitant low-dose aspirin (acetylsalicylic acid). Consideration must also be given to other pathophysiological mechanisms for potential cardiovascular risk linked with inhibition of COX-2. In view of the evidence reviewed, it is recommended that selective COX-2 inhibitors should be prescribed with caution, only in patients with conditions for which these drugs have proven efficacy and with careful monitoring of outcomes and adverse events. This is particularly important in the elderly, in patients with cardiovascular/renal disease and in patients with other risk factors that might predispose them to adverse events.