Defining the COX inhibitor selectivity of NSAIDs: implications for understanding toxicity

Anticancer potential of NSAID-derived tris(pyrazolyl)methane ligands in iron(II) sandwich complexes

Tris(pyrazolyl)methane (tpm), 2,2,2-tris(pyrazolyl)ethanol (tpmOH) and its esterification derivatives with ibuprofen and flurbiprofen (tpmIBU and tpmFLU) were used as ligands to obtain complexes of the type [Fe(tpmX)2]Cl2 (1-4). The tpmIBU and tpmFLU ligands and corresponding complexes 3 and 4 were characterized by IR and multinuclear NMR spectroscopy, and the structure of tpmIBU was elucidated by single crystal X-ray diffraction. Complexes 1-4 were also assessed for their behaviour in aqueous media (solubility in D2O, octanol/water partition coefficient, stability in physiological-like conditions). The antiproliferative activity of ligands and complexes was determined on A2780, A2780cis and A549 cancer cell lines and the non-cancerous HEK 293T and BJ cell lines. The ligands and complexes were investigated for their ability to inhibit COX-2 (cyclooxygenase) and HNE (4-hydroxynonenal) enzymes. Complexes 3 and 4 exhibited cytotoxicity that may be attributed predominantly to their bioactive fragments, while DNA binding and enhancement of ROS production do not appear to play any significant role.

Inflammatory-stimuli-responsive turn-on NIR fluorogenic theranostic prodrug: adjuvant delivery of diclofenac and hydrogen sulfide attenuates acute inflammatory disorders

Prolonged use of very commonly prescribed non-steroidal anti-inflammatory drugs (NSAIDs) is often associated with undesired side effects, including gastrointestinal ulcers due to the non-selective inhibition of cyclooxygenases. We describe the development of an inflammatory-stimuli-responsive turn-on fluorogenic theranostic prodrug DCF-HS for adjuvant drug delivery. Upon activation by reactive oxygen species (ROS), the prodrug releases diclofenac DCF (active drug) and the NIR fluorophore DCI-NH2 along with carbonyl sulfide (COS). The second activation of COS by the enzyme carbonic anhydrase (CA) generates hydrogen sulfide (H2S). The prodrug was conveniently synthesized using multi-step organic synthesis. The UV-Vis and fluorescence studies revealed the selective reactivity of DCF-HS towards ROS such as H2O2 in the aqueous phase and the desired uncaging of the drug DCF with turn-on NIR fluorescent reporter under physiological conditions. Furthermore, the release of fluorophore DCI-NH2 and drug DCF was confirmed using the reverse phase HPLC method. Compatibility of prodrug activation was studied next in the cellular medium. The prodrug DCF-HS was non-toxic in a representative cancer cell line (HeLa) and a macrophage cell line (RAW 264.7) up to 100 μM concentration, indicating its biocompatibility. The intracellular ROS-mediated activation of the prodrug with the release of NIR dye DCI-NH2 and H2S was investigated in HeLa cells using the H2S-selective probe WSP2. The anti-inflammatory activity of the active drug DCF from the prodrug DCF-HS was studied in the lipopolysaccharide (LPS)-induced macrophage cell line and compared to that of the parent drug DCF using western blot analysis and it was found that the active drug resulted in pronounced inhibition of COX-2 in a dose-dependent manner. Finally, the anti-inflammatory potential of the prodrug and the turn-on fluorescence were validated in the inflammation-induced Wister rat models.

Pharmacotherapeutic monitoring of dipyrone in northeastern Brazilian donkeys (Equus asinus)

This study aimed to monitor the effects of dipyrone following multiple administrations in northeastern donkeys. Ten castrated male donkeys, aged 6.4 ± 3 years and weighing 130.6 ± 9.8 kg, were administered dipyrone (25 mg/kg IV) every 12 h, resulting in six administrations (D1 to D6) per animal. Blood samples were collected over a 72 h monitoring period. A validated UHPLC-MS/MS method was employed to determine the plasma concentrations of the 4- methylaminoantipyrine (4-MAA) and 4-aminoantipyrine (4-AA). The calculated pharmacokinetic variables of 4-MAA after D1 and D6 were, respectively: Cmax (μg/mL) = 163.60 ± 179.72 and 178.79 ± 196.94; T1/2beta (h) = 2.65 ± 0.65 and 3.37 ± 1.03; and AUC0-t (μg/mL × h) = 240.38 ± 130.87 and 373.52 ± 78.85. The same variables for 4-AA were: Cmax, (μg/mL) = 0.44 ± 0.27 and 0.90 ± 0.31, T1/2beta (h) = 14.77 ± 13.13 and 35.97 and AUC0-t (μg/mL × h) = 3.20 ± 0.43 and 27.73 ± 11.99. Concentrations of 4-MAA exceeded the minimum concentration required for 50% inhibition of cyclooxygenases 1 and 2. However, an accumulation of 4-AA, was observed. Further clinical studies are necessary to ascertain the implications of these findings on the pharmacodynamic response to dipyrone in northeastern donkeys.

Recent progression on phytochemicals and pharmacological properties of the filamentous cyanobacterium Lyngbya sp

The distribution and phytochemistry of the non-nitrogen fixing, filamentous cyanobacterium (blue-green alga) Lyngbya sp., and the inherent antimicrobial and anticancer activities of its phycochemicals as well as of the biosynthesized nanoparticles as their pharmaceutical potencies are considered. Several phycocompounds of curio, apramide, apratoxin, benderamide, cocosamides, deoxymajusculamide, flavonoids, lagunamides, lipids, proteins, amino acids, lyngbyabellin, lyngbyastatin, majusculamide, peptides, etc. were isolated from Lyngbya sp., which had a lot of potential pharmaceutical activities; those compounds had antibacterial, antiviral, antifungal, anticancer, antioxidant, anti-inflammatory, ultraviolet protectant, and other activities. Particularly, several Lyngbya phycocompounds had potent antimicrobial potencies, seen through in vitro controlling of several frequently encountered multidrug-resistant (MDR) clinically belligerent strains of pathogenic bacteria isolated from clinical samples. The aqueous extracts of Lyngbya sp. were used for the synthesis of silver and copper oxide nanoparticles, which were used in pharmacological trials too. The nanoparticles biosynthesized with Lyngbya sp. had several uses such as biofuel, agro-based applications, in cosmetics, and industrial uses as biopolymers, and being potent antimicrobial and anticancer agents and in drug-delivery too, as medical applications. It could be concluded that the Lyngbya phycochemicals and the biosynthesized nanoparticles have future uses as antimicrobial namely as bacterial and fungal and anti-cancer agents, with promising medical and industrial uses.

First Generation of Antioxidant Precursors for Bioisosteric Se-NSAIDs: Design, Synthesis, and In Vitro and In Vivo Anticancer Evaluation

The introduction of selenium (Se) into organic scaffolds has been demonstrated to be a promising framework in the field of medicinal chemistry. A novel design of nonsteroidal anti-inflammatory drug (NSAID) derivatives based on a bioisosteric replacement via the incorporation of Se as diacyl diselenide is reported. The antioxidant activity was assessed using the DPPH radical scavenging assay. The new Se-NSAID derivatives bearing this unique combination showed antioxidant activity in a time- and dose-dependent manner, and also displayed different antiproliferative profiles in a panel of eight cancer cell lines as determined by the MTT assay. Ibuprofen derivative 5 was not only the most antioxidant agent, but also selectively induced toxicity in all the cancer cell lines tested (IC50 < 10 µM) while sparing nonmalignant cells, and induced apoptosis partially without enhancing the caspase 3/7 activity. Furthermore, NSAID derivative 5 significantly suppressed tumor growth in a subcutaneous colon cancer xenograft mouse model (10 mg/kg, TGI = 72%, and T/C = 38%) without exhibiting any apparent toxicity. To our knowledge, this work constitutes the first report on in vitro and in vivo anticancer activity of an unprecedented Se-NSAID hybrid derivative and its rational use for developing precursors for bioisosteric selenocompounds with appealing therapeutic applications.

Post-traumatic stress disorder burden among female Syrian war refugees is associated with dysmenorrhea severity but not with the analgesics

Dysmenorrhea association with post-traumatic stress disorder (PTSD) has not been studied in refugees. We aimed to examine the associations between dysmenorrhea severity, dysmenorrhea analgesics self-medications, and PTSD in a cohort of Syrian war refugees residing in Jordan.<br /> This is a cross-sectional study based on predetermined inclusion criteria held at Caritas primary care centers in Jordanian districts between September and October 2022. The participants’ demographics and analgesic self-medication type were recorded through a structured questionnaire. The dysmenorrhea severity was measured by (working ability, location, intensity, days of pain, and dysmenorrhea) WaLiDD scale, PTSD was measured by Davidson trauma scale (DTS)-DSM-IV.<br /> Data from 347 Syrian female war refugees were analyzed. The multivariate analysis showed that dysmenorrhea severity demonstrated significantly higher estimates for PTSD (10.48 [6.72-14.23], p=0.001), however, the analgesic type was not associated with PTSD burden.<br /> In conclusion, dysmenorrhea severity, but not self-medication, was associated with a higher PTSD burden.

Sustained release of locally delivered celecoxib provides pain relief for osteoarthritis: a proof of concept in dog patients

OBJECTIVE

Drug delivery platforms that allow for gradual drug release after intra-articular administration have become of much interest as a treatment strategy for osteoarthritis (OA). The aim of this study was to investigate the safety and efficacy of an intra-articular sustained release formulation containing celecoxib (CXB), a cyclooxygenase-2 (COX-2) selective inhibitor.

METHODS

Amino acid-based polyesteramide microspheres (PEAMs), a biodegradable and non-toxic platform, were loaded with CXB and employed in two in vivo models of arthritis: an acute inflammatory arthritis model in rats (n = 12), and a randomized controlled study in chronic OA dog patients (n = 30). In parallel, the bioactivity of sustained release of CXB was evaluated in monolayer cultures of primary dog chondrocytes under inflammatory conditions.

RESULTS

Sustained release of CXB did not alleviate acute arthritis signs in the rat arthritis model, based on pain measurements and synovitis severity. However, in OA dog patients, sustained release of CXB improved limb function as objective parameter of pain and quality of life based on gait analysis and owner questionnaires. It also decreased pain medication dependency over a 2-month period and caused no adverse effects. Prostaglandin E2 levels, a marker for inflammation, were lower in the synovial fluid of CXB-treated dog OA patients and in CXB-treated cultured dog chondrocytes.

CONCLUSION

These results show that local sustained release of CXB is less suitable to treat acute inflammation in arthritic joints, while safe and effective in treating pain in chronic OA in dogs.

Carborane Analogues of Fenoprofen Exhibit Improved Antitumor Activity

Fenoprofen is a widely used nonsteroidal anti-inflammatory drug (NSAID) against rheumatoid arthritis, degenerative joint disease, ankylosing spondylitis and gout. Like other NSAIDs, fenoprofen inhibits the synthesis of prostaglandins by blocking both cyclooxygenase (COX) isoforms, COX-1 the "house-keeping" enzyme and COX-2 the induced isoform from pathological stimuli. Unselective inhibition of both COX isoforms results in many side effects, but off-target effects have also been reported. The steric modifications of the drugs could afford the desired COX-2 selectivity. Furthermore, NSAIDs have shown promising cytotoxic properties. The structural modification of fenoprofen using bulky dicarba-closo-dodecaborane(12) (carborane) clusters and the biological evaluation of the carborane analogues for COX inhibition and antitumor potential showed that the carborane analogues exhibit stronger antitumor potential compared to their respective aryl-based compounds.

Establishment of quantitative indicators for an efficient treatment on masticatory muscle pain

BACKGROUND

Although several studies have investigated effective treatments for masticatory muscle pain (MMP), no unified conclusion has been drawn regarding the effectiveness of these treatments.

OBJECTIVES

This study aimed to define quantitative indicators for predicting the outcome of MMP treatment.

MATERIALS AND METHODS

In total, patients aged 20-70 years were recruited and divided into the MMP (n = 24) and control (n = 36) groups, based on the presence of MMP according to the Diagnostic Criteria for Temporomandibular Disorders. At pretreatment, the MMP group was assessed using quantitative indicators such as subjective pain levels, pain duration, graded chronic pain scale (GCPS), and perceived stress scale (PSS). Salivary alpha-amylase (sAA) and interleukin-6 (IL-6) levels were analyzed. The masticatory muscle palpation score and the range of mouth opening were measured. At posttreatment, subjective pain levels, mouth opening, and treatment/medication duration were examined. The PSS and sAA levels were assessed in the control group.

RESULTS

sAA levels in the MMP group were significantly higher than those in the control group (p < .05). The masseter muscle palpation score (MPS) showed a positive correlation with IL-6 levels (ρ = 0.503, p < .05) and a negative correlation with nonsteroidal anti-inflammatory drug (NSAID) treatment period (ρ = -0.462, p < .05). The temporalis muscle palpation score (TPS) was positively correlated with pain duration and GCPS grade (ρ = 0.483, p < .05, and ρ = 0.445, p < .05, respectively).

CONCLUSIONS

Treatment with NSAIDs was effective in the MMP group with high MPS and IL-6 levels, but not in the MMP group with high TPS, pain duration, and GCPS grade.

Anti-inflammatory potential of digested Brassica sprout extracts in human macrophage-like HL-60 cells

Cruciferous vegetables have been reported to be a great source of anti-inflammatory compounds. Specifically, sprouts from the Brassicaceae family stand out for their high content of glucosinolates (and their bioactive derivatives, isothiocyanates), phenolic acids, and anthocyanins. Despite the evident anti-inflammatory activity of certain Brassica phytochemicals such as sulforaphane or phenolic acids, the effect of digested Brassica vegetables on inflammation remains understudied. In this work, we aimed to evaluate the anti-inflammatory potential of the bioaccessible forms of cruciferous bioactives (from red cabbage sprouts (RCS) and red radish sprouts (RRS)) obtained upon in vitro gastrointestinal digestion in the HL-60 macrophage-like differentiated human cell line. The study was performed under basal conditions or stimulated with a low dose of LPS for 24 hours as a validated in vitro model of chronic inflammation. The cell viability was determined by MTT assay. The gene expression and production of pro-inflammatory cytokines TNF-α, IL-6 and IL-1β were determined by RT-qPCR and ELISA respectively. Our results revealed no cytotoxicity with any of the treatments in LPS-stimulated macrophage-like HL60 cells. Regarding cytokine production, digestates significantly decreased the production of the three pro-inflammatory cytokines at concentrations of 50 and 100 μg mL^-1 except for IL-1β treated with RCS digestates. Furthermore, the RT-qPCR analysis showed a decrease in the relative expression of pro-inflammatory cytokines in LPS-stimulated cells treated with RRS digestates at 100 μg mL^-1 but not with red cabbage digestates. In conclusion, RRS bioaccessible compounds in the extracts could be used as dietary coadjuvants given their potential anti-inflammatory effect on this in vitro model of chronic inflammation.

Interpreting the Benefit and Risk Data in Between-Drug Comparisons: Illustration of the Challenges Using the Example of Mefenamic Acid versus Ibuprofen

Evidence-based pain therapy should rely on precisely defined and personalized criteria. This includes balancing the benefits and risks not only of single drugs but often requires complex between-drug comparisons. Non-steroidal anti-inflammatory drugs (NSAIDs) have been available for several decades and their use is described in an abundance of guidelines. Most of these guidelines recommend that ‘the selection of a particular NSAID should be based on the benefit-risk balance for each patient’. However, head-to-head studies are often lacking or of poor quality, reflecting the lower standards for clinical research and regulatory approval at the time. The inconsistency of approved indications between countries due to national applications adds to the complexity. Finally, a fading research interest once drugs become generic points to a general deficit in the post-marketing evaluation of medicines. Far from claiming completeness, this narrative review aimed to illustrate the challenges that physicians encounter when trying to balance benefits and risks in a situation of incomplete and inconsistent data on longstanding treatment concepts. Ibuprofen and mefenamic acid, the most frequently sold NSAIDs in Austria, serve as examples. The illustrated principles are, however, not specific to these drugs and are generalizable to any comparison of older drugs in daily clinical practice.

Neural circuits mediating circulating interleukin-1β-evoked fever in the absence of prostaglandin E2 production

Infectious diseases and inflammatory conditions recruit the immune system to mount an appropriate acute response that includes the production of cytokines. Cytokines evoke neurally-mediated responses to fight pathogens, such as the recruitment of thermoeffectors, thereby increasing body temperature and leading to fever. Studies suggest that the cytokine interleukin-1β (IL-1β) depends upon cyclooxygenase (COX)-mediated prostaglandin E₂ production for the induction of neural mechanisms to elicit fever. However, COX inhibitors do not eliminate IL-1β-induced fever, thus suggesting that COX-dependent and COX-independent mechanisms are recruited for increasing body temperature after peripheral administration of IL-1β. In the present study, we aimed to build a foundation for the neural circuit(s) controlling COX-independent, inflammatory fever by determining the involvement of brain areas that are critical for controlling the sympathetic outflow to brown adipose tissue (BAT) and the cutaneous vasculature. In anesthetized rats, pretreatment with indomethacin, a non-selective COX inhibitor, did not prevent BAT thermogenesis or cutaneous vasoconstriction (CVC) induced by intravenous IL-1β (2 µg/kg). BAT and cutaneous vasculature sympathetic premotor neurons in the rostral raphe pallidus area (rRPa) are required for IL-1β-evoked BAT thermogenesis and CVC, with or without pretreatment with indomethacin. Additionally, activation of glutamate receptors in the dorsomedial hypothalamus (DMH) is required for COX-independent, IL-1β-induced BAT thermogenesis. Therefore, our data suggests that COX-independent mechanisms elicit activation of neurons within the DMH and rRPa, which is sufficient to trigger and mount inflammatory fever. These data provide a foundation for elucidating the brain circuits responsible for COX-independent, IL-1β-elicited fevers.

Stimuli-responsive prodrug of non-steroidal anti-inflammatory drug diclofenac: self-immolative drug release with turn-on near-infrared fluorescence

Reactive oxygen species (ROS)-responsive near infrared (NIR) fluorogenic prodrug DCI-ROS is developed for the self-immolative release of diclofenac (DCF) with turn-on fluorescence. The non-toxic prodrug exhibited turn-on red fluorescence with endogenous ROS in cancer cells and inhibited COX-2 expression in the inflammation-induced macrophage cells. The prodrug strategy thus would be helpful for the controlled fluorogenic delivery of DCF for inflammatory diseases.

The Impact of Lifestyle on Prostate Cancer: A Road to the Discovery of New Biomarkers

Prostate cancer (PCa) is one of the most common cancers among men, and its incidence has been rising through the years. Several risk factors have been associated with this disease and unhealthy lifestyles and inflammation were appointed as major contributors for PCa development, progression, and severity. Despite the advantages associated with the currently used diagnostic tools [prostate-specific antigen(PSA) serum levels and digital rectal examination (DRE)], the development of effective approaches for PCa diagnosis is still necessary. Finding lifestyle-associated proteins that may predict the development of PCa seems to be a promising strategy to improve PCa diagnosis. In this context, several biomarkers have been identified, including circulating biomarkers (CRP, insulin, C-peptide, TNFα-R2, adiponectin, IL-6, total PSA, free PSA, and p2PSA), urine biomarkers (PCA3, guanidine, phenylacetylglycine, and glycine), proteins expressed in exosomes (afamin, vitamin D-binding protein, and filamin A), and miRNAs expressed in prostate tissue (miRNA-21, miRNA-101, and miRNA-182). In conclusion, exploring the impact of lifestyle and inflammation on PCa development and progression may open doors to the identification of new biomarkers. The discovery of new PCa diagnostic biomarkers should contribute to reduce overdiagnosis and overtreatment.

Analysis of the anti-inflammatory potential of Brassica bioactive compounds in a human macrophage-like cell model derived from HL-60 cells

BACKGROUND

Chronic inflammatory diseases are major causes of global morbidity and mortality. Acute inflammation is meant to protect the body against foreign agents, but it also plays a major role in tissue repairment. Several mediators are involved in this process, including pro-inflammatory cytokines produced by macrophages. Occasionally, if the inflammatory response is not resolved, the acute inflammatory process can evolve into a chronic inflammation. Natural compounds from vegetables are considered as an important source of active agents with potential to treat or prevent inflammatory related pathologies and could be used as an alternative of the therapeutic agents currently in use, such as non-steroidal anti-inflammatory drugs (NSAIDs), which present several side effects.

METHODS

In this research work we evaluated in vitro the anti-inflammatory activity of a series of ten phytochemicals present in Brassica, measured as the potential of those compounds to reduce the production of key pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β) by a human macrophage-like cell model of HL-60 cells RESULTS: Most of the tested phytochemicals (including the most representative bioactive molecules of the major classes of compounds present in cruciferous foods such as glucosinolates, isothiocyanates, hydroxycinnamic acids, flavonols and anthocyanins) demonstrated significant anti-inflammatory activity at micromolar level in the absence of cytotoxic effects in this human macrophage-like cell model.

CONCLUSION

These data confirm that phytochemicals commonly obtained from Brassica may be potential therapeutic leads to treat or prevent human chronic inflammation and related diseases.

Computational Analysis and Biological Activities of Oxyresveratrol Analogues, the Putative Cyclooxygenase-2 Inhibitors

Polyphenols are a large family of naturally occurring phytochemicals. Herein, oxyresveratrol was isolated from ethanolic crude extracts of Artocarpus lacucha Buch.-Ham., and chemically modified to derive its lipophilic analogues. Biological screening assays showed their inhibitory potency against cyclooxygenase-2 (COX-2) with very low cytotoxicity to the MRC-5 normal cell lines. At the catalytic site of COX-2, docking protocols with ChemPLP, GoldScore and AutoDock scoring functions were carried out to reveal hydrogen bonding interactions with key polar contacts and hydrophobic pi-interactions. For more accurate binding energetics, COX-2/ligand complexes at the binding region were computed in vacuo and implicit aqueous solvation using M06-2X density functional with 6-31G+(d,p) basis set. Our computational results confirmed that dihydrooxyresveratrol (4) is the putative inhibitor of human COX-2 with the highest inhibitory activity (IC₅₀ of 11.50 ± 1.54 µM) among studied non-fluorinated analogues for further lead optimization. Selective substitution of fluorine provides a stronger binding affinity; however, lowering the cytotoxicity of a fluorinated analogue to a normal cell is challenging. The consensus among biological activities, ChemPLP docking score and the binding energies computed at the quantum mechanical level is obviously helpful for identification of oxyresveratrol analogues as a putative anti-inflammatory agent.

Ficus vogelii methanol leaf extract ameliorates inflammation and arthritis by modulating osmotic fragility in C57BL/6J mice

The study evaluated the membrane-stabilizing potentials in red blood cells and anti-inflammatory properties in C57BL/6J mice of the methanol leaf extract of Ficus vogelii. Animals were treated orally with different doses of the extract (50, 100, 200 mg/kg) for 30 days and their blood was measured for membrane stability at different saline concentrations. Diclofenac (12.5 mg/kg) or Indomethacin (10 mg/kg) was used as standard in the anti-inflammatory studies. The mean corpuscular fragility (MCF) values and their corresponding percentage stabilization increased significantly (p≤0.05) in the treatment groups compared to the negative control. Treatment of mice with 50, 100 and 200 mg/kg of the extract significantly (p≤0.05) inhibited carrageenan-induced paw oedema in mice. The highest dose (200 mg/kg) showed lower anti-inflammatory activity compared to Diclofenac (12.5 mg/kg). Daily administration of the extract significantly (p≤0.05) suppressed adjuvant-induced paw arthritis by day 15 and 30 post arthritis induction. Ficus vogelii extract inhibited granuloma formation significantly. The anti-inflammatory effects of methanol leaf extract of Ficus vogelii on granuloma formation were comparable to that of Indomethacin (10 mg/kg). In summary, this study showed that the methanol leaf extract of Ficus vogelii possessed membrane-stabilizing potentials and anti-inflammatory properties, therefore, providing further proof that the leaves contain an active compound with potent anti-inflammatory activity.

Mollusc-Derived Brominated Indoles for the Selective Inhibition of Cyclooxygenase: A Computational Expedition

Inflammation plays an important role in different chronic diseases. Brominated indoles derived from the Australian marine mollusk Dicathais orbita (D. orbita) are of interest for their anti-inflammatory properties. This study evaluates the binding mechanism and potentiality of several brominated indoles (tyrindoxyl sulfate, tyrindoleninone, 6-bromoisatin, and 6,6′-dibromoindirubin) against inflammatory mediators cyclooxygenases-1/2 (COX-1/2) using molecular docking, followed by molecular dynamics simulation, along with physicochemical, drug-likeness, pharmacokinetic (pk), and toxicokinetic (tk) properties. Molecular docking identified that these indole compounds are anchored, with the main amino acid residues, positioned in the binding pocket of the COX-1/2, required for selective inhibition. Moreover, the molecular dynamics simulation based on root mean square deviation (RMSD), radius of gyration (Rg), solvent accessible surface area (SASA), and root mean square fluctuation (RMSF) analyses showed that these natural brominated molecules transit rapidly to a progressive constant configuration during binding with COX-1/2 and seem to accomplish a consistent dynamic behavior by maintaining conformational stability and compactness. The results were comparable to the Food and Drug Administration (FDA)-approved selective COX inhibitor, aspirin. Furthermore, the free energy of binding for the compounds assessed by molecular mechanics–Poisson–Boltzmann surface area (MM–PBSA) confirmed the binding capacity of indoles towards COX-1/2, with suitable binding energy values except for the polar precursor tyrindoxyl sulfate (with COX-1). The physicochemical and drug-likeness analysis showed zero violations of Lipinski’s rule, and the compounds are predicted to have excellent pharmacokinetic profiles. These indoles are projected to be non-mutagenic and free from hepatotoxicity, with no inhibition of human ether-a-go–go gene (hERG) I inhibitors, and the oral acute toxicity LD₅₀ in rats is predicted to be similar or lower than aspirin. Overall, this work has identified a plausible mechanism for selective COX inhibition by natural marine indoles as potential therapeutic candidates for the mitigation of inflammation.

Pharmacology of the Equine Foot: Medical Pain Management for Laminitis

One of the biggest challenges in managing laminitis in horses remains the control of pain. The best analgesic approach is a multimodal approach, including nonsteroidal anti-inflammatory drugs, opioids, and/or constant rate infusions of α-2 agonists, ketamine, and lidocaine. Recent literature indicates that amitriptyline and soluble epoxide hydrolase inhibitor might be beneficial. Clinically oriented studies will be needed if they have a place in laminitis pain management. The systemic pain control can be combined with local techniques such as long-acting local anesthetics or epidural catheterization that allows for administration of potent analgesic therapy with a lower risk of negative side effects.

Hetero-Bis-Conjugation of Bioactive Molecules to Half-Sandwich Ruthenium(II) and Iridium(III) Complexes Provides Synergic Effects in Cancer Cell Cytotoxicity

Four bipyridine-type ligands variably derivatized with two bioactive groups (taken from ethacrynic acid, flurbiprofen, biotin, and benzylpenicillin) were prepared via sequential esterification steps from commercial 2,2'-bipyridine-4,4'-dicarboxylic acid and subsequently coordinated to ruthenium(II) p-cymene and iridium(III) pentamethylcyclopentadienyl scaffolds. The resulting complexes were isolated as nitrate salts in high yields and fully characterized by analytical and spectroscopic methods. NMR and MS studies in aqueous solution and in cell culture medium highlighted a substantial stability of ligand coordination and a slow release of the bioactive fragments in the latter case. The complexes were assessed for their antiproliferative activity on four cancer cell lines, showing cytotoxicity to the low micromolar level (equipotent with cisplatin). Additional biological experiments revealed a multimodal mechanism of action of the investigated compounds, involving DNA metalation and enzyme inhibition. Synergic effects provided by specific combinations of metal and bioactive fragments were identified, pointing toward an optimal ethacrynic acid/flurbiprofen combination for both Ru(II) and Ir(III) complexes.

The Role of Prostaglandins in Different Types of Cancer

The prostaglandins constitute a family of lipids of 20 carbon atoms that derive from polyunsaturated fatty acids such as arachidonic acid. Traditionally, prostaglandins have been linked to inflammation, female reproductive cycle, vasodilation, or bronchodilator/bronchoconstriction. Recent studies have highlighted the involvement of these lipids in cancer. In this review, existing information on the prostaglandins associated with different types of cancer and the advances related to the potential use of them in neoplasm therapies have been analyzed. We can conclude that the effect of prostaglandins depends on multiple factors, such as the target tissue, their plasma concentration, and the prostaglandin subtype, among others. Prostaglandin D2 (PGD₂) seems to hinder tumor progression, while prostaglandin E2 (PGE₂) and prostaglandin F2 alpha (PGF_2α) seem to provide greater tumor progression and aggressiveness. However, more studies are needed to determine the role of prostaglandin I2 (PGI₂) and prostaglandin J2 (PGJ₂) in cancer due to the conflicting data obtained. On the other hand, the use of different NSAIDs (non-steroidal anti-inflammatory drugs), especially those selective of COX-2 (cyclooxygenase 2), could have a crucial role in the fight against different neoplasms, either as prophylaxis or as an adjuvant treatment. In addition, multiple targets, related to the action of prostaglandins on the intracellular signaling pathways that are involved in cancer, have been discovered. Thus, in depth research about the prostaglandins involved in different cancer and the different targets modulated by them, as well as their role in the tumor microenvironment and the immune response, is necessary to obtain better therapeutic tools to fight cancer.

New nitric oxide-releasing indomethacin derivatives with 1,3-thiazolidine-4-one scaffold: Design, synthesis, in silico and in vitro studies

In this study we present design and synthesis of nineteen new nitric oxide-releasing indomethacin derivatives with 1,3-thiazolidine-4-one scaffold (NO-IND-TZDs) (6a-s), as a new safer and efficient multi-targets strategy for inflammatory diseases. The chemical structure of all synthesized derivatives (intermediaries and finals) was proved by NMR and mass spectroscopic analysis. In order to study the selectivity of NO-IND-TZDs for COX isoenzymes (COX-1 and COX-2) a molecular docking study was performed using AutoDock 4.2.6 software. Based on docking results, COX-2 inhibitors were designed and 6o appears as the most selective derivative which showed an improved selective index compared with indomethacin (IND) and diclofenac (DCF), used as reference drugs. The biological evaluation of 6a-s, using in vitro assays has included the anti-inflammatory and antioxidant effects as well as the nitric oxide (NO) release. Referring to the anti-inflammatory effects, the most active compound was 6i, which was more active than IND and aspirin (ASP) in term of denaturation effect, on bovine serum albumin (BSA), as indirect assay to predict the anti-inflammatory effect. An appreciable anti-inflammatory effect, in reference with IND and ASP, was also showed by 6k, 6c, 6q, 6o, 6j, 6d. The antioxidant assay revealed the compound 6n as the most active, being 100 times more active than IND. The compound 6n showed also the most increase capacity to release NO, which means is safer in terms of gastro-intestinal side effects. The ADME-Tox study revealed also that the NO-IND-TZDs are generally proper for oral administration, having optimal physico-chemical and ADME properties. We can conclude that the compounds 6i and 6n are promising agents and could be included in further investigations to study in more detail their pharmaco-toxicological profile.

Synthesis, Inhibitory Activity, and In Silico Modeling of Selective COX-1 Inhibitors with a Quinazoline Core

Selective cyclooxygenase-1 (COX-1) inhibition has got into the spotlight with the discovery of COX-1 upregulation in various cancers and the cardioprotective role of COX-1 in control of thrombocyte aggregation. Yet, COX-1-selective inhibitors are poorly explored. Thus, three series of quinazoline derivatives were prepared and tested for their potential inhibitory activity toward COX-1 and COX-2. Of the prepared compounds, 11 exhibited interesting COX-1 selectivity, with 8 compounds being totally COX-1-selective. The IC50 value of the best quinazoline inhibitor was 64 nM. The structural features ensuring COX-1 selectivity were elucidated using in silico modeling.

Evaluation of Selective COX-2 Inhibition and In Silico Study of Kuwanon Derivatives Isolated from Morus alba

Six kuwanon derivatives (A/B/C/E/H/J) extracted from the roots of Morus alba L. were evaluated to determine their cyclooxygenase (COX)-1 and 2 inhibitory effects. Cyclooxygenase (COX) is known as the target enzyme of nonsteroidal anti-inflammatory drugs (NSAIDs), which are the most widely used therapeutic agents for pain and inflammation. Among six kuwanon derivatives, kuwanon A showed selective COX-2 inhibitory activity, almost equivalent to that of celecoxib, a known COX inhibitor. Kuwanon A showed high COX-2 inhibitory activity (IC₅₀ = 14 μM) and a selectivity index (SI) range of >7.1, comparable to celecoxib (SI > 6.3). To understand the mechanisms underlying this effect, we performed docking simulations, fragment molecular orbital (FMO) calculations, and pair interaction energy decomposition analysis (PIEDA) at the quantum-mechanical level. As a result, kuwanon A had the strongest interaction with Arg120 and Tyr355 at the gate of the COX active site (−7.044 kcal/mol) and with Val89 in the membrane-binding domain (−6.599 kcal/mol). In addition, kuwanon A closely bound to Val89, His90, and Ser119, which are residues at the entrance and exit routes of the COX active site (4.329 Å). FMO calculations and PIEDA well supported the COX-2 selective inhibitory action of kuwanon A. It showed that the simulation and modeling results and experimental evidence were consistent.

Alkaloids of Adhatoda vasica Nees. as potential inhibitors of cyclooxygenases - an in-silico study

Eicosanoid pathways play a crucial role in the progression and resolution of inflammation. NSAIDs act as anti-inflammatory agents by inhibiting both the isoforms of cyclooxygenases (COXs) whereas, COXIBs act as specific COX-2 inhibitors. Excessive usage of the same is linked with gastrointestinal bleeding and increased cardiovascular risk, respectively. The current in-silico study was aimed at evaluating the potential of major alkaloids of A. vasica (vasicine (VAS), vasicinone (VAE), and Deoxyvasicine (DOV)) as inhibitors of COXs. The results of the computed binding energy (ΔG) indicate that Celecoxib (CEL), DOV, and VAS have a higher affinity to COX-2, while VAE has a higher affinity to COX-1, and Mefenamic acid (MEF) was not selective. Among the alkaloids, VAE exhibited the best ΔG (of -8.2 kcal/mol) with COX-1, while VAS exhibited the best ΔG (of -8.2 kcal/mol) with COX-2. This was comparable to the ΔG exhibited by Mefenamic acid (-8.7 kcal/mol with both the COXs). With their potential to remain gastroprotective while having the ability to inhibit enzymes of both the prostaglandin and leukotriene pathways, the alkaloids of A. vasica could be promising leads for the design of Eicosanoid pathway modulators/inhibitors.Communicated by Ramaswamy H. Sarma.

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.

Antiinflammatory Medicinal Plants from the Ugandan Greater Mpigi Region Act as Potent Inhibitors in the COX-2/PGH2 Pathway

Our study investigates 16 medicinal plants via assessment of inhibition of proinflammatory enzymes such as cyclooxygenases (COX). The plants are used by traditional healers in the Greater Mpigi region in Uganda to treat inflammation and related disorders. We present results of diverse in vitro experiments performed with 76 different plant extracts, namely, (1) selective COX-2 and COX-1 inhibitor screening; (2) 15-LOX inhibition screening; (3) antibacterial resazurin assay against multidrug-resistant Staphylococcus aureus, Listeria innocua, Listeria monocytogenes, and Escherichia coli K12; (4) DPPH assay for antioxidant activity; and (5) determination of the total phenolic content (TPC). Results showed a high correlation between traditional use and pharmacological activity, e.g., extracts of 15 out of the 16 plant species displayed significant selective COX-2 inhibition activity in the PGH₂ pathway. The most active COX-2 inhibitors (IC₅₀ < 20 µg/mL) were nine extracts from Leucas calostachys, Solanum aculeastrum, Sesamum calycinum subsp. angustifolium, Plectranthus hadiensis, Morella kandtiana, Zanthoxylum chalybeum, and Warburgia ugandensis. There was no counteractivity between COX-2 and 15-LOX inhibition in these nine extracts. The ethyl acetate extract of Leucas calostachys showed the lowest IC₅₀ value with 0.66 µg/mL (COX-2), as well as the most promising selectivity ratio with 0.1 (COX-2/COX-1). The TPCs and the EC₅₀ values for DPPH radical scavenging activity showed no correlation with COX-2 inhibitory activity. This led to the assumption that the mechanisms of action are most likely not based on scavenging of reactive oxygen species and antioxidant activities. The diethyl ether extract of Harungana madagascariensis stem bark displayed the highest growth inhibition activity against S. aureus (MIC value: 13 µg/mL), L. innocua (MIC value: 40 µg/mL), and L. monocytogenes (MIC value: 150 µg/mL). This study provides further evidence for the therapeutic use of the previously identified plants used medicinally in the Greater Mpigi region.

Synthesis, inhibitory activity and in silico docking of dual COX/5-LOX inhibitors with quinone and resorcinol core

Based on the significant anti-inflammatory activity of natural quinone primin (5a), series of 1,4-benzoquinones, hydroquinones, and related resorcinols were designed, synthesized, characterized and tested for their ability to inhibit the activity of cyclooxygenase (COX-1 and COX-2) and 5-lipoxygenase (5-LOX) enzymes. Structural modifications resulted in the identification of two compounds 5b (2-methoxy-6-undecyl-1,4-benzoquinone) and 6b (2-methoxy-6-undecyl-1,4-hydroquinone) as potent dual COX/5-LOX inhibitors. The IC50 values evaluated in vitro using enzymatic assay were for compound 5b IC50 = 1.07, 0.57, and 0.34 μM and for compound 6b IC50 = 1.07, 0.55, and 0.28 μM for COX-1, COX-2, and 5-LOX enzyme, respectively. In addition, compound 6d was identified as the most potent 5-LOX inhibitor (IC50 = 0.14 μM; reference inhibitor zileuton IC50 = 0.66 μM) from the tested compounds while its inhibitory potential against COX enzymes (IC50 = 2.65 and 2.71 μM for COX-1 and COX-2, respectively) was comparable with the reference inhibitor ibuprofen (IC50 = 4.50 and 2.46 μM, respectively). The most important structural modification leading to increased inhibitory activity towards both COXs and 5-LOX was the elongation of alkyl chain in position 6 from 5 to 11 carbons. Moreover, the monoacetylation in ortho position of bromo-hydroquinone 13 led to the discovery of potent (IC50 = 0.17 μM) 5-LOX inhibitor 17 (2-bromo-6-methoxy-1,4-benzoquinone) while bromination stabilized the hydroquinone form. Docking analysis revealed the interaction of compounds with Tyr355 and Arg120 in the catalytic site of COX enzymes, while the hydrophobic parts of the molecules filled the hydrophobic substrate channel leading up to Tyr385. In the allosteric catalytic site of 5-LOX, compounds bound to Tyr142 and formed aromatic interactions with Arg138. Taken together, we identified optimal alkyl chain length for dual COX/5-LOX inhibition and investigated other structural modifications influencing COX and 5-LOX inhibitory activity.

Potential Therapeutic Options for COVID-19: Current Status, Challenges, and Future Perspectives

The COVID-19 pandemic represents an unprecedented challenge for the researchers to offer safe, tolerable, and effective treatment strategies for its causative agent known as SARS-CoV-2. With the rapid evolution of the pandemic, even the off-label use of existing drugs has been restricted by limited availability. Several old antivirals, antimalarial, and biological drugs are being reconsidered as possible therapies. The effectiveness of the controversial treatment options for COVID-19 such as nonsteroidal antiinflammatory drugs, angiotensin 2 conversion enzyme inhibitors and selective angiotensin receptor blockers was also discussed. A systemic search in the PubMed, Science Direct, LitCovid, Chinese Clinical Trial Registry, and ClinicalTrials.gov data bases was conducted using the keywords "coronavirus drug therapy," passive immunotherapy for COVID-19', "convalescent plasma therapy," (CPT) "drugs for COVID-19 treatment," "SARS-CoV-2," "COVID-19," "2019-nCoV," "coronavirus immunology," "microbiology," "virology," and individual drug names. Systematic reviews, case presentations and very recent clinical guidelines were included. This narrative review summarizes the available information on possible therapies for COVID-19, providing recent data to health professionals.

Synthesis of Hydroxybenzofuranyl-pyrazolyl and Hydroxyphenyl-pyrazolyl Chalcones and Their Corresponding Pyrazoline Derivatives as COX Inhibitors, Anti-inflammatory and Gastroprotective Agents

Five new series of hydroxybenzofuranyl-pyrazolyl chalcones 3a,b, hydroxyphenyl-pyrazolyl chalcones 6a-c and their corresponding pyrazolylpyrazolines 4a, d, 7a-c and 8a-f have been synthesized and evaluated for their in vitro cyclooxygenase (COX)-1 and COX-2 inhibitory activity. All the synthesized compounds exhibited dual COX-1 and COX-2 inhibitory activity with obvious selectivity against COX-2. The pyrazolylpyrazolines 4a-d and 8a-f bearing two vicinal aryl moieties in the pyrazoline nucleus showed more selectivity towards COX-2. Within these two series, derivatives 4c, d and 8d-f bearing the benzenesulfonamide group were the most selective. Compounds 4a-d and 8a-f were further subjected to in vivo anti-inflammatory screening, ulcerogenic liability and showed good anti-inflammatory activity with no ulcerogenic effect. In addition compounds 4c and 8d as examples showed prostaglandin (PG)E2 inhibition % 44.23 and 51.4 respectively, tumor necrosis factor α (TNFα) inhibition % 33.48 and 41.41 respectively and gastroprotective effect in ethanol induced rodent gastric ulcer model. In addition, to explore the binding mode and selectivity of our compounds, 8d and celecoxib were docked into the active site of COX-1 and COX-2. It was found that compound 8d exhibited a binding pattern and interactions similar to that of celecoxib with COX-2 active site, while bitter manner of interaction than celecoxib to COX-1 active site.

Daily Aspirin Use Associated With Reduced Risk For Fibrosis Progression In Patients With Nonalcoholic Fatty Liver Disease

BACKGROUND & AIMS

There are few data from prospective studies on the effects of aspirin on fibrosis in patients with nonalcoholic fatty liver disease (NAFLD).

METHODS

We performed a prospective cohort study of 361 adults with biopsy-confirmed NAFLD, from 2006 through 2015, examined every 3-12 months for incident advanced fibrosis defined using serial measurements of validated indices (the Fibrosis-4, NAFLD fibrosis score, and aspartate aminotransferase to platelet ratio indices). Histologic analyses of liver biopsies collected at baseline were performed by a blinded pathologist. Information collected at baseline and at each examination included frequency and duration of aspirin and nonsteroidal anti-inflammatory drug (NSAID) use. Using multivariable-adjusted logistic regression, we estimated the association of aspirin use with prevalent steatohepatitis (NASH) and fibrosis. Using multivariable-adjusted Cox proportional hazards modeling, we estimated the association between aspirin use and risk for fibrosis progression.

RESULTS

At enrollment, 151 subjects used aspirin daily. Compared with non-regular use, daily aspirin use was associated with significantly lower odds of NASH (adjusted odds ratio, 0.68; 95% CI, 0.37-0.89) and fibrosis (adjusted odds ratio, 0.54; 95% CI, 0.31-0.82). Among individuals with baseline F0-F2 fibrosis (n = 317), 86 developed advanced fibrosis over 3692 person-years. Daily aspirin users had significantly lower risk for developing incident advanced fibrosis vs non-regular users (adjusted hazard ratio [aHR], 0.63; 95% CI, 0.43-0.85). This relationship appeared to be duration dependent (adjusted P trend=.026), with the greatest benefit found with at least 4 years or more of aspirin use (aHR, 0.50; 95% CI, 0.35-0.73). Conversely, use of nonaspirin NSAIDs was not associated with risk for advanced fibrosis (aHR, 0.93; 95% CI, 0.81-1.05).

CONCLUSIONS

In a prospective study of patients with biopsy-proven NAFLD, daily aspirin use was associated with less severe histologic features of NAFLD and NASH, and lower risk for progression to advanced fibrosis with time.

N-Butyrylated hyaluronic acid ameliorates gout and hyperuricemia in animal models

Context: Hyaluronic acid (HA) plays critical roles in the structural skeleton, joint lubrication, renal function and cell signaling. We previously showed that partially N-butyrylated, low molecular weight, hyaluronic acid (BHA) exhibited an anti-inflammatory effect in cultured human macrophage, where inflammation was induced either by a TL-4 agonist or the low molecular weight HA itself, in dose-dependent fashion. Objectives: To investigate the anti-inflammatory, antioxidative, and antihyperuricemic effects of BHA using animal models of acute gouty arthritis and hyperuricemia. Materials and methods: The anti-inflammatory effect of articular BHA (10 and 50 μg) injections was evaluated by measuring joint swelling and the serum levels of inflammatory cytokines in a model of acute gouty arthritis induced by intra-articular injection of monosodium urate crystals in Wistar rats (n = 10/group), in comparison to the control group with saline injection. Antioxidative and antihyperuricemic activities were investigated using intraperitoneal injections of oteracil potassium and yeast extract hyperuricemic Balb/C mice, which were treated with intraperitoneal injection of BHA at day 6-8 in the model. Results: In the gouty arthritis rat model, BHA at a higher dosage (50 μg) demonstrated a strong anti-inflammatory effect by reducing the degree of articular swelling and the serum levels of IL-1β, IL-8, IFN-γ, and MCP-1 by 5.56%, 6.55%, 15.58% and 33.18%. In the hyperuricemic mouse model, lower dosage BHA (10 μg) was sufficient to provide antioxidative activities by significantly decreasing the ROS levels in both serum and liver by 14.87% and 8.04%, while improving liver SOD by 12.77%. Intraperitoneal injection of BHA suppressed uric acid production through reducing liver XO activity by 19.78% and decreased the serum uric acid level in hyperuricemic mice by 30.41%. Conclusions: This study demonstrated for the first time that BHA exhibits anti-inflammatory, antioxidative and antihyperuricemic effects in vivo, suggesting a potential therapeutic application of BHA in gouty arthritis and hyperuricemia.

Increased Basal Blood Histamine Levels in Patients with Self-Reported Hypersensitivity to Non-Steroidal Anti-Inflammatory Drugs

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAIDs) represent one of the most prevalent causes of drug hypersensitivity reactions (DHRs), yet the underlying processes are far from clear. Despite the established role of histamine in allergic reactions, its precise implication in DHRs is elusive.

OBJECTIVES

This study aimed to explore the connection of basal blood histamine levels to the reported NSAID hypersensitivity.

METHODS

Sixteen patients reporting hypersensitivity reactions to a single or multiple NSAIDs and/or paracetamol and 18 healthy volunteers serving as the normal control group enrolled in the study. The medical history was recorded and histamine was quantified spectrophotofluorometrically in whole peripheral blood and plasma.

RESULTS

Compared to the normal group, plasma but not whole blood histamine levels were significantly higher in patients (p < 0.001), mainly in the subgroup reporting hypersensitivity to a single agent (p < 0.001). Plasma histamine levels were significantly correlated with the culprit drug selectivity for cyclooxygenase (COX) isozymes (p < 0.001), with higher levels being obtained in patients reporting reactions to COX-1 than to COX-2 selective inhibitors (p < 0.05).

CONCLUSIONS

The findings provide first evidence connecting basal blood histamine levels to the reported NSAID-triggered DHRs. Prospective studies are expected to decipher the contribution of histamine-associated parameters to the mechanisms underlying DHRs.

Distinct characteristics of the substrate binding between highly homologous catalase-related allene oxide synthase and hydroperoxide lyase

A catalase-related allene oxide synthase (cAOS) or a hydroperoxide lyase (cHPL) fused together with an 8R-lipoxygenase is involved in the stress signaling of corals via an arachidonic acid pathway. cAOS gives rise to α-ketol and cyclopentenone, while cHPL catalyzes the cleavage of 8R-hydroperoxyeicosatetraenoic acid (8R-HpETE) to C8-oxo acid and C12 aldehyde. In silico analysis of the substrate entry sites of highly identical coral cAOS and cHPL indicated that two positively charged residues of cAOS, K60 and K107, and the corresponding residues of cHPL, E60 and K107, may be involved in the anchoring of the carboxy group of polyunsaturated fatty acid (PUFA) hydroperoxides. A mutational analysis of cAOS and cHPL revealed that K60 or E60 and K107 were not necessary in the tethering of 8R-HpETE, however, the E60 of cHPL was essential in the productive binding of PUFA hydroperoxides. The substrate preferences of cAOS and cHPL were determined with hydroperoxy derivatives of C18, C20, C22 PUFAs, anandamide (AEA), 1-arachidonoyl glycerol (1-AG) and selected methylated substrates. Although cAOS and cHPL were able to metabolize different free PUFA substrates and arachidonoyl derivatives, only cHPL catalyzed the reaction with methylated PUFA hydroperoxides. The differences in the substrate binding and preferences between cAOS and cHPL can be explained by the distinct properties of their substrate entry sites. The current study demonstrated that homologous PUFA metabolizing enzymes may contribute to the versatile usage of the substrate pool.

Association Between Aspirin Use and Risk of Hepatocellular Carcinoma

Importance

Prospective data on the risk of hepatocellular carcinoma (HCC) according to dose and duration of aspirin therapy are limited.

Objective

To examine the potential benefits of aspirin use for primary HCC prevention at a range of doses and durations of use within 2 prospective, nationwide populations.

Design, Setting, and Participants

Pooled analysis of 2 prospective US cohort studies: the Nurses' Health Study and the Health Professionals Follow-up Study. Data were accessed from November 1, 2017, through March 7, 2018. A total of 133 371 health care professionals who reported data on aspirin use, frequency, dosage, and duration of use biennially since 1980 in women and 1986 in men were included. Individuals with a cancer diagnosis at baseline (except nonmelanoma skin cancer) were excluded.

Main Outcomes and Measures

Cox proportional hazards regression models were used to calculate multivariable adjusted hazard ratios (HRs) and 95% CIs for HCC.

Results

Of the 133 371 participants, 87 507 were women and 45 864 were men; in 1996, the median time of follow-up, the mean (SD) age was 62 (8) years for women and 64 (8) years for men. Over more than 26 years of follow-up encompassing 4 232 188 person-years, 108 incident HCC cases (65 women, 43 men) were documented. Compared with nonregular use, regular aspirin use (≥2 standard-dose [325-mg] tablets per week) was associated with reduced HCC risk (adjusted HR, 0.51; 95% CI, 0.34-0.77). This benefit appeared to be dose related: compared with nonuse, the multivariable-adjusted HR for HCC was 0.87 (95% CI, 0.51-1.48) for up to 1.5 standard-dose tablets per week, 0.51 (95% CI, 0.30-0.86) for more than 1.5 to 5 tablets per week, and 0.49 (95% CI, 0.28-0.96) for more than 5 tablets per week (P for trend = .006). Significantly lower HCC risk was observed with increasing duration (P for trend = .03); this decrease was apparent with use of 1.5 or more standard-dose aspirin tablets per week for 5 or more years (adjusted HR, 0.41; 95% CI, 0.21-0.77). In contrast, use of nonaspirin nonsteroidal anti-inflammatory drugs was not significantly associated with HCC risk (adjusted HR, 1.09; 95% CI, 0.78-1.51).

Conclusions and Relevance

This study suggests that regular, long-term aspirin use is associated with a dose-dependent reduction in HCC risk, which is apparent after 5 or more years of use. Similar associations were not found with nonaspirin NSAIDs. Further research appears to be needed to clarify whether aspirin use represents a feasible strategy for primary prevention against HCC.

Determination of the Lipophilicity of Ibuprofen, Naproxen, Ketoprofen, and Flurbiprofen with Thin-Layer Chromatography

The lipophilicity is an important parameter that influences the activity of the drugs in the human body. The reversed phase high performance thin layer chromatography was applied to determine the Log P values of ibuprofen, ketoprofen, naproxen, and flurbiprofen. The stationary phase used in the study was silica-gel coated plates. The mobile phase was the mixture of acetonitrile and water in different proportions. The content of acetonitrile varied in 5% increments from 50% to 80%. The Rm0 values were determined for the compounds with a known Log P and for the analyzed substances (ibuprofen, naproxen, ketoprofen, and flurbiprofen). The Log P values were calculated for the analyzed compounds using the regression curve Rm0 = f(Log P) parameters for the compounds with the known lipophilicity. Flurbiprofen is characterized by the highest Log P value: 3.82. The lowest one is noted for ketoprofen: 2.66. The determined Log P values of tested compounds were similar to the values calculated by the software.

Continuing war on pain: a personalized approach to the therapy with nonsteroidal anti-inflammatory drugs and opioids

Successful pain management requires the delivery of analgesia with minimal risk of adverse drug reactions. Nonsteroidal anti-inflammatory drugs and opioids remain the mainstay of treatment for the majority of patients. Unfortunately, almost 50% of all patients experience inadequate pain relief and serious side effects. Allelic variants in genes coding for target proteins, transporters and enzymes, which govern analgesic drugs action and their fate in the organism, might explain inter-individual variability in pain severity and in drug-induced pain relief and toxicities. Additionally, it seems that epigenetic changes contribute to the highly variable response to pain treatment. Therefore, pharmacogenomic testing might be a valuable tool for personalization of pain treatment, with a multidisciplinary team approach involved.

Pathology, Chemoprevention, and Preclinical Models for Target Validation in Barrett Esophagus

Despite esophageal adenocarcinoma (EAC) being the most widespread among gastrointestinal cancers, with an 11-fold increase in the risk of cancer for patients with Barrett esophagus (BE), its prognosis is still poor. There is a critical need to better perceive the biology of cancer progression and identification of specific targets that are the hallmark of BE's progression. This review explores the established animal models of BE, including genetic, surgical and nonsurgical approaches, potential chemoprevention targets, and the reasoning behind their applications to prevent Barrett-related EAC. The key methodological features in the design feasibility of relevant studies are also discussed. Cancer Res; 78(14); 3747-54. ©2018 AACR.

Discovery of new indomethacin-based analogs with potentially selective cyclooxygenase-2 inhibition and observed diminishing to PGE2 activities

New ring-extended analogs of indomethacin were designed based on the structure of active binding site of both COX-1 and COX-2 isoenzymes and the interaction pattern required for selective inhibition of COX-2 to improve its selectivity against COX-2. The strategy adopted for designing the new inhibitors involved i) ring extension of indomethacin to reduce the possibility of analogs to be accommodated into the narrow hydrophobic tunnel of COX-1, ii) deletion of carboxylic acid to reduce the possibility of inhibitor to form salt bridge with Arg120 and eventually prevent COX-1 inhibition, and iii) introduction of methylsulfonyl group to increase the opportunity of the analogs to interact with the polar side pocket that's is crucial for inhibition process of COX-2. The three series of tetrahydrocarbazoles involving 4, 5, 9, 10 and 12 were synthesized in quantitative yields adopting limited number of reaction steps, and applying laboratory friendly reaction conditions. In vitro and in vivo assays for data profiling the new candidates revealed the significant improvement in the potency and selectivity against COX-2 of 6-methoxytetrahydrocarbazole 4 (IC₅₀ = 0.97 μmol) to verify the effect of ring extension in comparison to indomethacin (IC₅₀ = 2.63 μmol), and 6-methylsulfonyltetrahydrocarbazole 10a (IC₅₀ = 0.28 μmol) to verify the effect of ring extension and introduction of methylsulfonyl group. 9-(4-chlorobenzoyl)-6-(methylsulfonyl)-1,2,3,9-tetrahydro-4H-carbazol-4-one 12a showed the most potential and selective activity against COX-2 (IC₅₀ = 0.23 μmol) to be with superior potency to Celecoxib (IC₅₀ = 0.30 μmol). Consistently, 12a was the most active with all the other anti-inflammatory test descriptors and its activity in diminishing the PGE2 with the other analogs confirmed the elaboration of new class of selective COX-2 inhibitors beyond the diarylsulfonamides as a previously common class of selective COX-2 inhibitors. Molecular docking study revealed the high binding score of compound 12a (-30.78 kcal/mol), with less clash contribution (7.2) that is close to indomethacin. Also, 12a showed low conformation entropy score (1.40). Molecular dynamic (MD) simulation identified the equilibrium of both potential and kinetic energies.

Mechanisms, Cofactors, and Augmenting Factors Involved in Anaphylaxis

Anaphylaxis is an acute and life-threatening systemic reaction. Many triggers have been described, including food, drug, and hymenoptera allergens, which are the most frequently involved. The mechanisms described in anaphylactic reactions are complex and implicate a diversity of pathways. Some of these mechanisms may be key to the development of the anaphylactic reaction, while others may only modify its severity. Although specific IgE, mast cells, and basophils are considered the principal players in anaphylaxis, alternative mechanisms have been proposed in non-IgE anaphylactic reactions. Neutrophils, macrophages, as well as basophils, have been involved, as have IgG-dependent, complement and contact system activation. A range of cationic substances can induce antibody-independent mast cells activation through MRGPRX2 receptor. Cofactors and augmenting factors may explain why, in some patients, food allergen exposure can cause anaphylaxis, while in other clinical scenario it can be tolerated or elicits a mild reaction. With the influence of these factors, food allergic reactions may be induced at lower doses of allergen and/or become more severe. Exercise, alcohol, estrogens, and some drugs such as Non-steroidal anti-inflammatory drugs, angiotensin-converting enzyme inhibitors, β-blockers, and lipid-lowering drugs are the main factors described, though their mechanisms and signaling pathways are poorly understood.

COX Inhibition Profile and Molecular Docking Studies of Some 2-(Trimethoxyphenyl)-Thiazoles

Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used therapeutic agents that exhibit frequent and sometimes severe adverse effects, including gastrointestinal ulcerations and cardiovascular disorders. In an effort to obtain safer NSAIDs, we assessed the direct cyclooxygenase (COX) inhibition activity and we investigated the potential COX binding mode of some previously reported 2-(trimethoxyphenyl)-thiazoles. The in vitro COX inhibition assays were performed against ovine COX-1 and human recombinant COX-2. Molecular docking studies were performed to explain the possible interactions between the inhibitors and both COX isoforms binding pockets. Four of the tested compounds proved to be good inhibitors of both COX isoforms, but only compound A3 showed a good COX-2 selectivity index, similar to meloxicam. The plausible binding mode of compound A3 revealed hydrogen bond interactions with binding site key residues including Arg120, Tyr355, Ser530, Met522 and Trp387, whereas hydrophobic contacts were detected with Leu352, Val349, Leu359, Phe518, Gly526, and Ala527. Computationally predicted pharmacokinetic profile revealed A3 as lead candidate. The present data prove that the investigated compounds inhibit COX and thus confirm the previously reported in vivo anti-inflammatory screening results suggesting that A3 is a suitable candidate for further development as a NSAID.

Anti-Gouty Arthritis and Antihyperuricemia Effects of Sunflower (Helianthus annuus) Head Extract in Gouty and Hyperuricemia Animal Models

This study was performed to investigate the therapeutic effects and possible mechanisms of sunflower (Helianthus annuus) head extract (SHE) on gout. First, the components of sunflower head powder and SHE were analyzed systematically. SHE, especially SHEB (extracted with 20% ethanol and 80% double-distilled water), strongly suppressed the swelling of the ankles in rats with acute gout induced by monosodium urate (MSU) crystals and reduced the levels of uric acid and xanthine oxidase (XO) in mice with hyperuricemia induced by oteracil potassium and yeast extract powder. Hematoxylin and eosin staining indicated that SHEB reduced inflammation cells and increased the joint space in the ankle compared with the control rats with MSU-induced gout. In the rats with acute gout, among 13 detected inflammatory cytokines, SHEB significantly enhanced the serum levels of interleukin-10 and the monocyte chemoattractant protein 1α. In the mice with hyperuricemia, SHEB reduced the levels of glutathione peroxidase, superoxide dismutase, malondialdehyde, and nitrogen monoxide in liver tissues. The potential therapeutic effects of SHE on gout are probably due to the production of anti-inflammatory cytokines and the suppression of XO activity via the modulation of oxidative stress status.

Clinical Pharmacology and Cardiovascular Safety of Naproxen

The voluntary withdrawal of Vioxx (rofecoxib) from the market in 2004, as well as the 2005 and 2014 US FDA Advisory Committee meetings about non-steroidal anti-inflammatory drugs (NSAIDs) and cardiovascular risk, have raised questions surrounding the use of NSAIDs in at-risk populations. This paper discusses the cardiovascular safety profile of naproxen in the context of the NSAID class. The balance of evidence suggests that cardiovascular risk correlates with cyclooxygenase (COX)-2 selectivity, and the low COX-2 selectivity of naproxen results in a lower cardiovascular risk than that of other NSAIDs. The over-the-counter (OTC) use of naproxen is expected to pose minimal cardiovascular risk; however, the benefit-risk ratio and appropriate use should be considered at an individual patient level, particularly to assess underlying conditions that may increase the risk of events. Likewise, regulatory authorities should revisit label information periodically to ensure labeling reflects the current understanding of benefits and risks.