Nonsteroidal Anti-Inflammatory Drug-Induced Gastroduodenal Bleeding: Risk Factors and Prevention Strategies

Evaluating thromboprophylaxis in the sickle cell disease population: Navigating the evidence gap

Sickle cell disease (SCD) arises from beta-globin gene mutations, with global estimates indicating around 500 000 affected neonates in 2021. In the United States, it is considered rare, impacting fewer than 200 000 individuals. The key pathogenic flaw lies in mutant haemoglobin S, prone to polymerization under low oxygen conditions, causing erythrocytes to adopt a sickled shape. This leads to complications like vascular occlusion, haemolytic anaemia, inflammation and organ damage. Beyond erythrocyte abnormalities however, there is a body of literature highlighting the hypercoagulable state that is likely a contributor to many of the complications we see in SCD. The persistent activation of the coagulation cascade results in thromboembolic events, notably venous thromboembolism (VTE) which is independently associated with increased mortality in both adults and children with SCD. While the increased risk of VTE in the SCD population seems well established, there is a lack of guidelines for thromboprophylaxis in this population. This Wider Perspective will describe the hypercoagulable state and increased thrombosis risk in the SCD population, as well as advocate for the development of evidence-based guidelines to aid in the prevention of VTE in SCD.

The Protective Effect of Walnut Oligopeptides against Indomethacin-Induced Gastric Ulcer in Rats

The aim of this study was to investigate the potential protective effects of walnut oligopeptides (WOPs) on indomethacin-induced gastric ulcers in rats. The rats were divided into the following groups: normal group, model group, omeprazole group (0.02 g/kg), and WOPs groups (0.22, 0.44, and 0.88 g/kg, respectively). After receiving gavage once per day for 30 consecutive days, the rats were injected intraperitoneally with indomethacin 48 mg/kg to induce gastric ulcers. Then, the serum inflammatory cytokines and gastric prostaglandin E2 (PGE2), oxidative stress-related indicators, and the RNA expression of COX-1 and COX-2 were measured. The results revealed that WOPs confer significant gastroprotection on gastric ulcers caused by indomethacin, regulating inflammatory cytokines, oxidative stress, and prostaglandins synthesis, and enhancing the expression of COX-1 and COX-2 in gastric tissue, thus exerting its protective effect on gastric mucosa. The gastroprotective mechanism may be related to the involvement of the arachidonic acid metabolism and upregulation of tryptophan, phenylalanine, tyrosine, and alpha-Linolenic acid metabolism synthesis in vivo.

Interaction of Oxicam Derivatives with the Artificial Models of Biological Membranes-Calorimetric and Fluorescence Spectroscopic Study

The modified 1,2-benzothiazine analogues designed as new drug candidates and discussed in this paper are oxicam derivatives. Oxicams are a class of non-steroidal anti-inflammatory drugs (NSAIDs). Their biological target is cyclooxygenase (COX), a membrane protein associated with the phospholipid bilayer. In recent decades, it has been proven that the biological effect of NSAIDs may be closely related to their interaction at the level of the biological membrane. These processes are often complicated and the biological membranes themselves are very complex. Therefore, to study these mechanisms, simplified models of biological membranes are used. To characterize the interaction of six oxicam derivatives with DPPC, DMPC and EYPC, artificial models of biological membranes (multi-bilayers or liposomes), differential scanning calorimetry (DSC) and fluorescence spectroscopy techniques were applied. In spectroscopic measurements, two fluorescent probes (Laurdan and Prodan) localized in different membrane segments were used. All tested oxicam derivatives interacted with the lipid bilayers and may penetrate the artificial models of biological membranes. They intercalated into the lipid bilayers and were located in the vicinity of the polar/apolar membrane interface. Moreover, a good drug candidate should not only have high efficiency against a molecular target but also exhibit strictly defined ADMET parameters, therefore these activities of the studied compounds were also estimated.

Synthesis of new hexahydropyrimido[1,2-a]azepine derivatives bearing functionalized aryl and heterocyclic moieties as anti-inflammatory agents

New hexahydropyrimido[1,2-a]azepine derivatives bearing functionalized aryl and heterocyclic moieties were synthesized as anti-inflammatory agents with better safety profiles. All synthesized compounds were assessed in vitro for their COX-1 and COX-2 inhibition activities. The most selective compounds, 2f, 5 and 6, were further evaluated for their in vivo anti-inflammatory activity and PGE2 inhibitory activity. To rationalize their selectivity, molecular docking within COX-1 and COX-2 binding sites was performed. Their physicochemical properties and drug-like nature profile were also calculated. The good activity and selectivity of compounds 2f, 5 and 6 were rationalized using a molecular docking study and supported by in vivo studies. These promising findings are encouraging for performing future investigations of these derivatives.

Increased susceptibility of aging gastric mucosa to injury and delayed healing: Clinical implications

In this editorial we comment on the article by Fukushi K et al published in the recent issue of the World Journal of Gastroenterology 2018; 24(34): 3908-3918. We focus specifically on the mechanisms of the anti-thrombotic action of aspirin, gastric mucosal injury and aging-related increased susceptibility of gastric mucosa to injury. Aspirin is widely used not only for the management of acute and chronic pain and arthritis, but also importantly for the primary and secondary prevention of cardiovascular events such as myocardial infarcts and strokes. Clinical trials have consistently shown that antiplatelet therapy with long term, low dose aspirin (LDA) - 75 to 325 mg daily, dramatically reduces the risk of non-fatal myocardial infarcts, stroke and mortality in patients with established arterial diseases. However, such treatment considerably increases the risk of gastrointestinal (GI) ulcerations and serious bleeding by > 2-4 fold, especially in aging individuals. This risk is further increased in patients using LDA together with other antiplatelet agents, other nonsteroidal anti-inflammatory agents (NSAIDs) and/or alcohol, or in patients with Helicobacter pylori (H. pylori) infection. Previous studies by our group and others have demonstrated prominent structural and functional abnormalities in gastric mucosa of aging individuals (which we refer to as aging gastric mucosa or “aging gastropathy”) compared to the gastric mucosa of younger individuals. Aging gastric mucosa has impaired mucosal defense, increased susceptibility to injury by a variety of noxious agents such as aspirin, other NSAIDs and ethanol, and delayed and impaired healing of injury. The mechanism underlying these abnormalities of aging gastric mucosa include reduced mucosal blood flow causing hypoxia, upregulation of PTEN, activation of pro-apoptotic caspase-3 and caspase-9, and reduced survivin (anti-apoptosis protein), importin-α (nuclear transport protein), vascular endothelial growth factor, and nerve growth factor. The decision regarding initiation of a long-term LDA therapy should be made after a careful consideration of both cardiovascular and GI risk factors. The latter include a previous history of GI bleeding and/or ulcers, age ≥ 70, male gender, concurrent use of other NSAIDs, alcohol consumption and H. pylori infection. Furthermore, the incidence of GI ulcers and bleeding can be reduced in patients on long term LDA treatment by several measures. Clinicians treating such patients should test for and eradicate H. pylori, instruct patients to avoid alcohol and non-aspirin NSAIDs, including cyclooxygenase-2-selective NSAIDs, and prescribe proton pump inhibitors in patients on LDA therapy. In the future, clinicians may be able to prescribe one of several potential new drugs, which include aspirin associated with phosphatidylcholine (PL2200), which retains all property of aspirin but reduces by approximately 50% LDA-induced GI ulcerations.

Contribution of Helicobacter pylori infection to the risk of peptic ulcer bleeding in patients on nonsteroidal anti-inflammatory drugs, antiplatelet agents, anticoagulants, corticosteroids and selective serotonin reuptake inhibitors

BACKGROUND

Nonsteroidal anti-inflammatory drugs, low-dose aspirin, non-aspirin antiplatelet agents, anticoagulants, selective serotonin reuptake inhibitors and corticosteroids increase the risk of gastroduodenal bleeding.

AIM

To determine in a retrospective cohort study the contribution of Helicobacter pylori infection to the risk of peptic ulcer bleeding in patients taking these drugs.

METHODS

Among patients with peptic ulcer disease diagnosed by endoscopy from 01/2004 to 12/2014 (N = 1719, 60% males, age 65.8 ± 14.5), 56.9% had peptic ulcer bleeding (cases) and 43.1% uncomplicated peptic ulcer disease (controls). Demographics, intake of nonsteroidal anti-inflammatory drugs, aspirin, non-aspirin antiplatelet agents, anticoagulants, selective serotonin reuptake inhibitors, proton pump inhibitors and corticosteroids were documented. H. pylori status was determined by histology, rapid urease test or serology. Adjusted odds ratios (OR) were estimated by logistic regression analysis.

RESULTS

Helicobacter pylori infection increased the risk of peptic ulcer bleeding in nonsteroidal anti-inflammatory drug and aspirin users (OR = 2.91, 95% CI = 1.71-4.98 and OR = 2.23, 95% CI = 1.52-3.28, respectively), but not in patients on anticoagulants, selective serotonin reuptake inhibitor or corticosteroid therapy. H. pylori-positive status substantially increased the risk of peptic ulcer bleeding in patients on non-aspirin antiplatelet agents (OR = 4.37, 95% CI = 1.28-14.99), concomitant aspirin/nonsteroidal anti-inflammatory drug intake (OR = 5.85, 95% CI = 1.68-20.36) and combined antiplatelet therapy (OR = 8.43, 95% CI = 1.09-65.17). After further adjustment for proton pump inhibitor intake, H. pylori infection was still a risk factor for peptic ulcer bleeding in nonsteroidal anti-inflammatory drug and aspirin users.

CONCLUSIONS

Helicobacter pylori infection increases the risk of peptic ulcer bleeding in peptic ulcer disease patients on nonsteroidal anti-inflammatory drugs, aspirin and non-aspirin antiplatelet agents. H. pylori-positive patients on combined antiplatelet therapy carry the highest risk for peptic ulcer bleeding.

Utilization of gastroprotective strategies for nonsteroidal anti-inflammatory drug-induced gastrointestinal events in a major teaching hospital

Background and purpose

Clinical guidelines recommend the prescribing of gastroprotective strategies in nonsteroidal anti-inflammatory drug (NSAID) users with risk factors for gastrointestinal (GI) ulcer or ulcer complications. However, these guidelines are not often translated into clinical practice. Therefore, the aim of this study was to investigate the utilization of gastroprotective strategies for NSAID-induced upper GI events in at-risk users in a major teaching hospital.

Patients and methods

A cross-sectional, observational, pharmacy-based study was conducted in a major Asian institution with both primary and secondary health care services. This study involved the screening of prescriptions for regular NSAIDs, and patients who met the inclusion criteria were recruited and interviewed using a questionnaire.

Results

Of the 409 participants recruited, 83.1% had at least one GI risk factor, of whom 70.3% did not receive appropriate gastroprotection. The most common GI risk factor was the use of high-dose NSAIDs (69.2%), followed by participants aged 65 years and older (22%) and concomitant use of low-dose aspirin (11.7%). Appropriate gastroprotective strategies utilized consisted of the use of a cyclooxygenase (COX)-2 inhibitor alone or a nonselective NSAID plus a proton pump inhibitor (PPI) in the moderate-risk group and a COX-2 inhibitor plus a PPI in the high-risk group. Gastroprotective strategies were underutilized in 67.1% of at-risk participants and overutilized in 59.4% of those without risk factors. Co-prescription of a histamine-2 receptor antagonist at lower-than-recommended doses constituted 59% of the inappropriate gastroprotective agents used. Logistic regression analysis revealed patients aged 65 years and older (odds ratio, 1.89; 95% CI =1.15–3.09) as a predictor for the prescribing of gastroprotection by the clinicians.

Conclusion

Approximately 70% of at-risk NSAID users, mainly on high-dose NSAIDs, were not prescribed appropriate gastroprotective strategies. Further measures are warranted to improve the safe prescribing of regular NSAIDs.

Definition of Prostaglandin E2-EP2 Signals in the Colon Tumor Microenvironment That Amplify Inflammation and Tumor Growth

Inflammation in the colon contributes significantly to colorectal cancer development. While aspirin reduces the colorectal cancer risk, its action mechanism, especially in inflammation in tumor microenvironment, still remains obscure. Here, we examined this issue by subjecting mice deficient in each prostaglandin (PG) receptor to colitis-associated cancer model. Deficiency of PGE receptor subtype EP2 selectively reduced, and deficiency of EP1 and EP3 enhanced, the tumor formation. EP2 is expressed in infiltrating neutrophils and tumor-associated fibroblasts in stroma, where it regulates expression of inflammation- and growth-related genes in a self-amplification manner. Notably, expression of cytokines such as TNFα and IL6, a chemokine, CXCL1, a PG-producing enzyme, COX-2, and Wnt5A was significantly elevated in tumor lesions of wild-type mice but this elevation was significantly suppressed in EP2-deficient mice. Intriguingly, EP2 stimulation in cultured neutrophils amplified expression of TNFα, IL6, CXCL1, COX-2, and other proinflammatory genes synergistically with TNFα, and EP2 stimulation in cultured fibroblasts induced expression of EP2 itself, COX-2, IL6, and Wnt genes. EP2 expression in infiltrating neutrophils and tumor-associated fibroblasts was also found in clinical specimen of ulcerative colitis-associated colorectal cancer. Bone marrow transfer experiments suggest that EP2 in both cell populations is critical for tumorigenesis. Finally, administration of a selective EP2 antagonist potently suppressed tumorigenesis in this model. Our study has thus revealed that EP2 in neutrophils and tumor-associated fibroblasts promotes colon tumorigenesis by amplifying inflammation and shaping tumor microenvironment, and suggests that EP2 antagonists are promising candidates of aspirin-alternative for chemoprevention of colorectal cancer.

Therapeutic potential of hydrazones as anti-inflammatory agents

Hydrazones are a special class of organic compounds in the Schiff base family. Hydrazones constitute a versatile compound of organic class having basic structure (R₁R₂C=NNR₃R₄). The active centers of hydrazone, that is, carbon and nitrogen, are mainly responsible for the physical and chemical properties of the hydrazones and, due to the reactivity toward electrophiles and nucleophiles, hydrazones are used for the synthesis of organic compound such as heterocyclic compounds with a variety of biological activities. Hydrazones and their derivatives are known to exhibit a wide range of interesting biological activities like antioxidant, anti-inflammatory, anticonvulsant, analgesic, antimicrobial, anticancer, antiprotozoal, antioxidant, antiparasitic, antiplatelet, cardioprotective, anthelmintic, antidiabetic, antitubercular, trypanocidal, anti-HIV, and so forth. The present review summarizes the efficiency of hydrazones as potent anti-inflammatory agents.