Structural and functional basis of cyclooxygenase inhibition

PINK1 insufficiency can be exploited as a specific target for drug combinations inducing mitochondrial pathology-mediated cell death in gastric adenocarcinoma

There exist very limited non-hazardous therapeutic strategies except for surgical resection and lymphadenectomy against gastric cancer (GC) despite being the third leading cause of cancer deaths worldwide. This study proposes an innovative treatment approach against GC using a drug combination strategy that manipulates mitochondrial dynamics in conjunction with the induction of mitochondrial pathology-mediated cell death. Comparative analysis was done with gastric adenocarcinoma and normal cells by qPCR, western blot, microscopic immunocytochemistry, and live cell imaging. In this study, impairment of dynamin-related protein 1 (Drp1)-mediated mitochondrial fission by Mdivi-1 created an imbalance in mitochondrial structural dynamics in indomethacin-treated AGS cells in which mitophagy-regulator protein PINK1 is downregulated. These drug combinations with the individual sub-lethal doses ultimately led to the activation of cell death machinery upregulating pro-apoptotic proteins like Bax, Puma, and Noxa. Interestingly, this combinatorial therapy did not affect normal gastric epithelial cells significantly and also no significant upregulation of death markers was observed. Moreover, the drug combination strategy also retarded cell migration and reduced stemness in GC cells. In summary, this study offers a pioneering specific therapeutic strategy for GC treatment, sparing normal cells providing opportunities for minimal drug-mediated toxicity utilizing mitochondria as a viable and specific target for anti-cancer therapy in gastric cancer.

Selective COX-2 Inhibitors as Neuroprotective Agents in Traumatic Brain Injury

Traumatic brain injury (TBI) is a significant contributor to mortality and morbidity in people, both young and old. There are currently no approved therapeutic interventions for TBI. Following TBI, cyclooxygenase (COX) enzymes generate prostaglandins and reactive oxygen species that perpetuate inflammation, with COX-1 and COX-2 isoforms providing differing responses. Selective COX-2 inhibitors have shown potential as neuroprotective agents. Results from animal models of TBI suggest potential treatment through the alleviation of secondary injury mechanisms involving neuroinflammation and neuronal cell death. Additionally, early clinical trials have shown that the use of celecoxib improves patient mortality and outcomes. This review aims to summarize the therapeutic effects of COX-2 inhibitors observed in TBI animal models, highlighting pertinent studies elucidating molecular pathways and expounding upon their mechanistic actions. We then investigated the current state of evidence for the utilization of COX-2 inhibitors for TBI patients.

Novel anti-inflammatory agents featuring phenoxy acetic acid moiety as a pharmacophore for selective COX-2 inhibitors: Synthesis, biological evaluation, histopathological examination and molecular modeling investigation

Inflammation management presents a critical challenge in modern medicine, with nonsteroidal anti-inflammatory drugs (NSAIDs) being a widely used therapeutic option. However, their efficacy is often accompanied by significant gastrointestinal adverse effects, necessitating the exploration of safer alternatives, particularly through the investigation of cyclooxygenase-2 (COX-2) inhibitors. This study endeavors to address this imperative through the synthesis and evaluation of pyrazoline-phenoxyacetic acid derivatives. Among the synthesized compounds, 6a and 6c emerged as promising candidates, demonstrating potent COX-2 inhibition with IC50 values of 0.03 µM for both and selectivity index = 365.4 and 196.9, respectively. Furthermore, these compounds exhibited efficacy in mitigating formalin-induced edema in male Wistar rats, accompanied by favorable safety profiles upon histological examination of vital organs. Comprehensive safety assessments, including evaluation of creatinine, AST, and ALT enzymatic as well as troponin T and creatine kinase-MB levels, further reinforce the promising attributes of the synthetic candidates. Molecular docking studies endorsed by molecular dynamic simulations corroborate the biological findings, elucidating significant protein-ligand interactions at COX-2 active sites indicative of therapeutic potential.

Evaluation of gastrointestinal tract lesions and serum malondialdehyde levels after repeated oral administration of phenylbutazone in horses

Phenylbutazone (PBZ) is a widely used nonsteroidal anti-inflammatory drug for horses. However, because of its gastrointestinal side effects, its administration requires careful attention in veterinary practice. Malondialdehyde (MDA) is a serum biomarker associated with increased damage to the equine gastrointestinal system. This study investigated the hematological effects and alterations in the gastrointestinal tract and assessed serum MDA concentrations following repeated oral PBZ administration at clinical doses. Fourteen horses were randomly divided into control and treatment groups. All horses in the treatment group were administered 4.4 milligrams per kilogram of body weight of PBZ syrup orally twice a day for 7 days, whereas the control group received syrup as a placebo. The development of gastrointestinal side effects was investigated using gastroscopy, abdominal ultrasound, and fecal pH; serum MDA concentrations were assessed using a commercially available enzyme-linked immunosorbent assay kit. Data were compared between PBZ-treated and control horses before and after the treatment period. The treatment group exhibited decreased albumin and total protein concentrations. Moreover, this group exhibited a higher thickness of the right dorsal colon wall (p = 0.03) and had higher scores for squamous gastric ulcers (p = 0.01). Fecal pH was lower in the treatment group than in the control group after PBZ administration (p < 0.01). Although MDA concentrations were higher in the treatment group after PBZ administration, they did not differ significantly from those of the control group. This study highlighted the changes in hematological and gastrointestinal lesions resulting from PBZ administration in horses at clinical doses, even without clinical signs. However, MDA may not be an optimal biomarker for the early detection of gastrointestinal damage due to PBZ treatment in horses.

In-silico structural studies on anti-inflammatory activity of phytocompounds from the genus Andrographis

Plant species from the genus Andrographis were used in Ayurveda and in other folklore medicines for treating ailments for centuries. In this study, we have hypothesized to evaluate the secondary metabolites as potent anti-inflammatory agents from the genus Andrographis. A library of secondary metabolites of the said genus was curated from the PubChem database and was subjected to energy minimization using UCSF Chimera software employing the AMBER force field. Initially, molecular docking was performed to evaluate the binding affinity of the curated library against the enzymes cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), and 5-Lipoxygenase (5-LOX) using AutoDock Vina. This resulted in shortlisting of two metabolites Echioidinin 5-O-glucoside was bound and 5,2',6'-Trihydroxy-6,7,8-trimethoxy flavone 2'-O-glucoside with high binding affinity than standard drugs Ibuprofen and Zileuton. In addition, molecular dynamic simulation studies confirm that these compounds form relatively more stable complexes than standard drugs with the above-said enzymes. The free binding energy values using MMGBSA of the above said ligands with COX-1, COX-2, and 5-LOX were found to be -49.18 kcal/mol, -38.60 kcal/mol, and -54.27 kcal/mol respectively, Whereas the standards have -21.77 kcal/mol, -9.96 kcal/mol, and -10.29 kcal/mol. Moreover, the in-silico ADMET analysis confirms the druggability of the shortlisted compounds. Later, this work will act as a base for in-vitro and in-vivo experimental studies to validate the anti-inflammatory potential of the same.Communicated by Ramaswamy H. Sarma.

Investigation of the Anti-Inflammatory Properties of Bioactive Compounds from Olea europaea: In Silico Evaluation of Cyclooxygenase Enzyme Inhibition and Pharmacokinetic Profiling

In a landmark study, oleocanthal (OLC), a major phenolic in extra virgin olive oil (EVOO), was found to possess anti-inflammatory activity similar to ibuprofen, involving inhibition of cyclooxygenase (COX) enzymes. EVOO is a rich source of bioactive compounds including fatty acids and phenolics; however, the biological activities of only a small subset of compounds associated with Olea europaea have been explored. Here, the OliveNetTM library (consisting of over 600 compounds) was utilized to investigate olive-derived compounds as potential modulators of the arachidonic acid pathway. Our first aim was to perform enzymatic assays to evaluate the inhibitory activity of a selection of phenolic compounds and fatty acids against COX isoforms (COX-1 and COX-2) and 15-lipoxygenase (15-LOX). Olive compounds were found to inhibit COX isoforms, with minimal activity against 15-LOX. Subsequent molecular docking indicated that the olive compounds possess strong binding affinities for the active site of COX isoforms, and molecular dynamics (MD) simulations confirmed the stability of binding. Moreover, olive compounds were predicted to have favorable pharmacokinetic properties, including a readiness to cross biological membranes as highlighted by steered MD simulations and umbrella sampling. Importantly, olive compounds including OLC were identified as non-inhibitors of the human ether-à-go-go-related gene (hERG) channel based on patch clamp assays. Overall, this study extends our understanding of the bioactivity of Olea-europaea-derived compounds, many of which are now known to be, at least in part, accountable for the beneficial health effects of the Mediterranean diet.

Effects of low-dose acetylsalicylic acid on the inflammatory response to experimental sleep restriction in healthy humans

BACKGROUND

Sleep deficiencies, such as manifested in short sleep duration or insomnia symptoms, are known to increase the risk for multiple disease conditions involving immunopathology. Inflammation is hypothesized to be a mechanism through which deficient sleep acts as a risk factor for these conditions. Thus, one potential way to mitigate negative health consequences associated with deficient sleep is to target inflammation. Few interventional sleep studies investigated whether improving sleep affects inflammatory processes, but results suggest that complementary approaches may be necessary to target inflammation associated with sleep deficiencies. We investigated whether targeting inflammation through low-dose acetylsalicylic acid (ASA, i.e., aspirin) is able to blunt the inflammatory response to experimental sleep restriction.

METHODS

46 healthy participants (19F/27M, age range 19-63 years) were studied in a double-blind randomized placebo-controlled crossover trial with three protocols each consisting of a 14-day at-home monitoring phase followed by an 11-day (10-night) in-laboratory stay (sleep restriction/ASA, sleep restriction/placebo, control sleep/placebo). In the sleep restriction/ASA condition, participants took low-dose ASA (81 mg/day) daily in the evening (22:00) during the at-home phase and the subsequent in-laboratory stay. In the sleep restriction/placebo and control sleep/placebo conditions, participants took placebo daily. Each in-laboratory stay started with 2 nights with a sleep opportunity of 8 h/night (23:00-07:00) for adaptation and baseline measurements. Under the two sleep restriction conditions, participants were exposed to 5 nights of sleep restricted to a sleep opportunity of 4 h/night (03:00-07:00) followed by 3 nights of recovery sleep with a sleep opportunity of 8 h/night. Under the control sleep condition, participants had a sleep opportunity of 8 h/night throughout the in-laboratory stay. During each in-laboratory stay, participants had 3 days of intensive monitoring (at baseline, 5th day of sleep restriction/control sleep, and 2nd day of recovery sleep). Variables, including pro-inflammatory immune cell function, C-reactive protein (CRP), and actigraphy-estimated measures of sleep, were analyzed using generalized linear mixed models.

RESULTS

Low-dose ASA administration reduced the interleukin (IL)-6 expression in LPS-stimulated monocytes (p<0.05 for condition*day) and reduced serum CRP levels (p<0.01 for condition) after 5 nights of sleep restriction compared to placebo administration in the sleep restriction condition. Low-dose ASA also reduced the amount of cyclooxygenase (COX)-1/COX-2 double positive cells among LPS-stimulated monocytes after 2 nights of recovery sleep following 5 nights of sleep restriction compared to placebo (p<0.05 for condition). Low-dose ASA further decreased wake after sleep onset (WASO) and increased sleep efficiency (SE) during the first 2 nights of recovery sleep (p<0.001 for condition and condition*day). Baseline comparisons revealed no differences between conditions for all of the investigated variables (p>0.05 for condition).

CONCLUSION

This study shows that inflammatory responses to sleep restriction can be reduced by preemptive administration of low-dose ASA. This finding may open new therapeutic approaches to prevent or control inflammation and its consequences in those experiencing sleep deficiencies.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03377543.

In silico and in vivo study of anti-inflammatory activity of Morinda longissima (Rubiaceae) extract and phytochemicals for treatment of inflammation-mediated diseases

ETHNOPHARMACOLOGICAL RELEVANCE

Traditionally, the plant Morinda longissima Y.Z.Ruan (Rubiaceae) is used by ethnic people in Vietnam for the treatment of liver diseases and hepatitis.

AIM OF THE STUDY

The study was designed to assess the efficacy of the 95% ethanolic extract of Morinda longissima roots (MLE) in experimental immune inflammation. The phytochemical variation of root extract and the chemical structures of natural compounds were also investigated using HPLC-DAD-HR-MS analysis.

MATERIALS AND METHODS

Three different doses (100, 200, and 300 mg/kg b.w.) of MLE were chosen to determine anti-inflammatory activity. The mice were given orally extracts and monitored their behavior and mortality for 14 days to evaluate acute toxicity. The volume of the paw and the histopathological evaluation were carried out. The polyphenolic phytoconstituents of MLE extract were identified using LC/MS analysis. The anti-inflammatory efficacy in silico and molecular docking simulations of these natural products were evaluated based on their cyclooxygenase (COX)-1 and 2 inhibitory effects.

RESULTS

This investigation showed the 95% ethanolic extract of Morinda longissima roots was found non-toxic up to 2000 mg/kg dose level in an acute study, neither showed mortality nor treatment-related signs of toxicity in mice. Eight anthraquinones and anthraquinone glycosides of Morinda longissima roots were identified by HPLC-DAD-HR-MS analysis. In the in vivo experiments, MLE was found to possess powerful anti-inflammatory activities in comparison with diclofenac sodium. The highest anti-inflammatory activity of MLE in mice was observed at a dose of 300 mg/kg body weight. The in silico analysis showed that seven out the eight anthraquinones and anthraquinone glycosides possess a selectivity index RCOX-2/COX-1 lower than 1, indicating that these compounds are selective against the COX-2 enzyme in the following the order: rubiadin-3-methyl ether < morindone morindone-6-methyl ether < morindone-5-methyl ether < damnacanthol < rubiadin < damnacanthol-3-O-β-primeveroside. The natural compounds with the best selectivity against the COX-2 enzyme are quercetin (9), rubiadin-3-methyl ether (7), and morindone (4), with RCOX2/COX1 ratios of 0.02, 0.03, and 0.19, respectively. When combined with the COX-2 protein in the MD research, quercetin and rubiadin-3-methyl ether greatly stabilized the backbone proteins and ligands.

CONCLUSION

In conclusion, the anthraquinones and ethanolic extract of Morinda longissima roots may help fight COX-2 inflammation. To develop novel treatments for inflammatory disorders linked to this one, these chemicals should be investigated more in the future.

M. Abdelbaky M, Garcia-Granda S, Maurya A, Pal M, Siddiqui Z, Shukla R, Pathak SK, Srivastava R, Shukla VK, Prasad O, Sinha L. Structural Characterization, Spectroscopic Profile, Molecular Docking, ADMET Properties, Molecular Dynamics Simulation Studies, and Molecular Mechanics Generalized Born Surface Area Analysis of 5-(Adamantan-1-yl)-4-butyl-2,4-dihydro-3H-1,2,4-triazole-3-thione as a Potential COX Inhibitor

Employing a synergistic combination of theoretical density functional theory (DFT) and experimental techniques, we conducted a comprehensive analysis elucidating the structural and pharmacological attributes of 5-(adamantan-1-yl)-4-butyl-2,4-dihydro-3H-1,2,4-triazole-3-thione (5A4BT) as a potent COX inhibitor. The X-ray crystallographic data of 5A4BT showed the pivotal role played by weak interactions, notably π-π and C-H-π interactions, alongside hydrogen bonding, in orchestrating the intricate supramolecular architectures within the crystalline lattice. A quantitative analysis of the arrangement of the crystal structure, as well as both inter- and intramolecular interactions, was conducted using Hirshfeld surfaces and 2D fingerprint plots. Additionally, a comprehensive examination of the IR spectra was undertaken, employing both experimental methods and theoretical DFT techniques, to elucidate the vibrational characteristics of the compound. The strength of intermolecular N-H···S hydrogen bonding and charge transfer within the system was assessed through natural bonding orbital analysis. Moreover, Bader's atoms in molecules theory was employed to estimate the strength of intermolecular hydrogen bonds, revealing strong interactions within the 5A4BT dimer. The title compound exhibited binding affinities of -6.4 and -6.5 kcal/mol for COX1 (PDB 3KK6) and COX2 (1CX2) target proteins, respectively. For the first time, predictions regarding ADMET properties, drug-likeness, and toxicity, including favorable bioavailability, along with 100 ns molecular dynamics simulations, binding free energy, and energy decomposition per residue in the binding cavity of the protein from molecular mechanics generalized born surface area approach, collectively indicate the potential of 5A4BT as a nonselective COX inhibitor.

Vicinal diaryl pyrazole with tetrazole/urea scaffolds as selective angiotensin converting enzyme-1/cyclooxygenase-2 inhibitors: Design, synthesis, anti-hypertensive, anti-fibrotic, and anti-inflammatory

As a hybrid weapon, two novel series of pyrazoles, 16a-f and 17a-f, targeting both COX-2 and ACE-1-N-domain, were created and their anti-inflammatory, anti-hypertensive, and anti-fibrotic properties were evaluated. In vitro, 17b and 17f showed COX-2 selectivity (SI = 534.22 and 491.90, respectively) compared to celecoxib (SI = 326.66) and NF-κB (IC50 1.87 and 2.03 μM, respectively). 17b (IC50 0.078 μM) and 17 f (IC50 0.094 μM) inhibited ACE-1 comparable to perindopril (PER) (IC50 0.048 μM). In vivo, 17b decreased systolic blood pressure by 18.6%, 17b and 17f increased serum NO levels by 345.8%, and 183.2%, respectively, increased eNOS expression by 0.97 and 0.52 folds, respectively and reduced NF-κB-p65 and P38-MAPK expression by -0.62, -0.22, -0.53, and -0.24 folds, respectively compared to  l-NAME (-0.34, -0.45 folds decline in NF-κB-p65 and P38-MAPK, respectively). 17b reduced ANG-II expression which significantly reversed the cardiac histological changes induced by L-NAME.

Fenamates and ibuprofen as foundational components in the synthesis of innovative, targeted COX-2 anti-inflammatory drugs, undergoing thorough biopharmacological assessments and in-silico computational studies

Cyclooxygenase-2 plays a vital role in inflammation by catalyzing arachidonic acid conversion toward prostaglandins, making it a prime therapeutic objective. Selective COX-2 inhibitors represent significant progress in anti-inflammatory therapy, offering improved efficacy and fewer side effects. This study describes the synthesis of novel anti-inflammatory compounds from established pharmaceutically marketed agents like fenamates III-V and ibuprofen VI. Through rigorous in vitro testing, compounds 7b-c, and 12a-b demonstrated substantial in vitro selective inhibition, with IC50 values of 0.07 to 0.09 μM, indicating potent pharmacological activity. In vivo assessment, particularly focusing on compound 7c, revealed significant anti-inflammatory effects. Markedly, it demonstrated the highest inhibition of paw thickness (58.62 %) at the 5-hr mark compared to the carrageenan group, indicating its potency in mitigating inflammation. Furthermore, it exhibited a rapid onset of action, with a 54.88 % inhibition observed at the 1-hr mark. Subsequent comprehensive evaluations encompassing analgesic efficacy, histological characteristics, and toxicological properties indicated that compound 7c did not induce gastric ulcers, in contrast to the ulcerogenic tendency associated with mefenamic acid. Moreover, compound 7c underwent additional investigations through in silico methodologies such as molecular modelling, field alignment, and density functional theory. These analyses underscored the therapeutic potential and safety profile of this novel compound, warranting further exploration and development in the realm of pharmaceutical research.

A Fast-Binding, Functionally Reversible, COX-2 Radiotracer for CNS PET Imaging

Cyclooxygenase-2 (COX-2) is an enzyme that plays a pivotal role in peripheral inflammation and pain via the prostaglandin pathway. In the central nervous system (CNS), COX-2 is implicated in neurodegenerative and psychiatric disorders as a potential therapeutic target and biomarker. However, clinical studies with COX-2 have yielded inconsistent results, partly due to limited mechanistic understanding of how COX-2 activity relates to CNS pathology. Therefore, developing COX-2 positron emission tomography (PET) radiotracers for human neuroimaging is of interest. This study introduces [11C]BRD1158, which is a potent and uniquely fast-binding, selective COX-2 PET radiotracer. [11C]BRD1158 was developed by prioritizing potency at COX-2, isoform selectivity over COX-1, fast binding kinetics, and free fraction in the brain. Evaluated through in vivo PET neuroimaging in rodent models with human COX-2 overexpression, [11C]BRD1158 demonstrated high brain uptake, fast target-engagement, functional reversibility, and excellent specific binding, which is advantageous for human imaging applications. Lastly, post-mortem samples from Huntington's disease (HD) patients and preclinical HD mouse models showed that COX-2 levels were elevated specifically in disease-affected brain regions, primarily from increased expression in microglia. These findings indicate that COX-2 holds promise as a novel clinical marker of HD onset and progression, one of many potential applications of [11C]BRD1158 human PET.

NSAIDs do not prevent exercise-induced performance deficits or alleviate muscle soreness: A placebo-controlled randomized, double-blinded, cross-over study

Non-steroidal anti-inflammatory drugs (NSAIDs) are frequently consumed by athletes to manage muscle soreness, expedite recovery, or improve performance. Despite the prevalence of NSAID use, their effects on muscle soreness and performance, particularly when administered prophylactically, remain unclear. This randomized, double-blind, counter-balanced, crossover study examined the effect of consuming a single dose of each of three NSAIDs (celecoxib, 200 mg; ibuprofen, 800 mg; flurbiprofen, 100 mg) or placebo 2 h before on muscle soreness and performance following an acute plyometric training session. Twelve healthy adults, aged 18-42 years, completed a standardized plyometric exercise session consisting of 10 sets of 10 repetitions at 40 % 1-repetition maximum (1RM) on a leg press device. During exercise, total work, rating of perceived exertion, and heart rate were measured. Maximum voluntary contraction force (MVC), vertical jump height, and muscle soreness were measured before exercise and 4-h and 24-h post-exercise. We found no significant differences in total work, heart rate, or rating of perceived exertion between treatments. Additionally, no significant differences in muscle soreness or vertical jump were observed between treatments. Ibuprofen and flurbiprofen did not prevent decrements in MVC, but celecoxib attenuated decreases in MVC 4-h post exercise (p < 0.05). This study suggests that athletes may not benefit from prophylactic ibuprofen or flurbiprofen treatment to prevent discomfort or performance decrements associated with exercise, but celecoxib may mitigate short-term performance decrements.

NMI-SO2Cl2-Mediated Amide Bond Formation: Facile Synthesis of Some Dihydrotriazolopyrimidine Amide Derivatives as Potential Anti-Inflammatory and Anti-Tubercular Agents

Facile access to some novel biologically relevant dihydrotriazolopyrimidine carboxylic acid-derived amide analogues using NMI/SO2Cl2, and aromatic and aliphatic primary and secondary amines, is reported herein. The role of N-methylimidazole (NMI) as the base and sulfuryl chloride (SO2Cl2) as the coupling reagent has been effectively realized in accessing these molecules in good to excellent yields. The feasibility of the developed protocol has also been extended to the gram-scale synthesis of N-benzylbenzamide in a 75% yield from benzoic acid and benzyl amine. The newly synthesized compounds were tested via in vitro anti-inflammatory and anti-tubercular activity studies. The compounds 6aa and 6be were found to be the most active anti-inflammatory agents, whereas 6cb and 6ch were found to exhibit promising anti-tubercular potency when compared to other synthesized molecules. The structure-activity relationship (SAR) studies revealed the importance of the presence of electron-donating functionalities in enhancing the anti-inflammatory potential of the newly synthesized molecules. However, the presence of electron-withdrawing substituents was found to be significant for improving their anti-tubercular potency.

Antiarthritic activity of Physalis peruviana fruit extract via inhibition of inflammatory mediators: Integrated in vitro, in vivo and in silico study

ETHNOPHARMACOLOGICAL RELEVANCE

P. peruviana fruit, native to Andean region, is cultivated worldwide for its adaptability to various soil natures and climatic conditions. It is increasingly consumed for its high nutritional profile and history of ethnomedical uses including treatment of arthritis. Little pharmacological evidences support this folk use except for previous in vitro study that reported significant inhibition of protein denaturation.

AIM OF THE STUDY

The study aims at providing new in vivo evidence on antiarthritic activity of P. peruviana fruits in vivo that justifies its traditional use through mechanism-based experiment.

MATERIAL AND METHODS

Inhibition of inflammatory mediators is considered one of the key treatments to alleviate painful symptoms of rheumatoid arthritis (RA). Anti-inflammatory activity was assessed against COX-1 and COX-2 activity in vitro. Serum TNFα, IL-1β and IL-6 were traced using in vivo model of adjuvant-induced arthritis. Gross/inflammatory changes in rat paw, relative mass indices of spleen and liver were further investigated together with joint tissue histoarchitecture. Seven metabolites from different phytochemical classes, that were previously reported in P. peruviana fruit, were evaluated in silico against TNF-α target protein (PDB ID: 2AZ5) to assess their inhibitory effect. This was followed by assessment of their drug-likeness based on Lipinski's rule according to their physicochemical and pharmacokinetic properties.

RESULTS

High dose of extract (E-1000 mg) improved adjuvant-induced cachexia and attenuated immune-inflammatory responses in paw and serum parameters, with equipotent effect to MTX, in addition to minimal side effect profile on spleen and liver. Histopathological study of knee joint tissues confirmed dose-dependent improvement in arthritic groups treated with P. peruviana fruit extracts. The insilico study recommended steroidal lactones withaperuvin E/C and hydroxywithanolide E as promising lead compounds for inhibiting TNF enzyme as evidenced by docking scores of 6.301, 5.488 and 5.763 kcal/mol, respectively, fitting as well the Lipinski's rule of drug likeness.

CONCLUSION

The study provided novel approach that rationalize folk use of P. peruviana fruit in treatment of arthritis.

Computational screening of potential anti-inflammatory leads from Jeevaneeya Rasayana plants targeting COX-2 and 5- LOX by molecular docking and dynamic simulation approaches

Inflammation plays a pivotal role in various pathological processes, ranging from routine injuries and infections to cancer. Cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) are two major enzymes involved in the formation of lipid mediators of inflammation, such as prostaglandins and leukotrienes, through the arachidonic acid pathway. Despite the frequent use of nonsteroidal anti-inflammatory drugs for managing inflammatory disorders by inhibiting these enzymes, there is a wide spectrum of adverse effects linked to their usage. Jeevaneeya Rasayana (JR), a polyherbal formulation traditionally used in India, is renowned for its anti-inflammatory properties. The present study aimed to identify the potential phytocompounds in JR plants against COX-2 and 5-LOX, utilizing molecular docking and dynamic simulations. Among the 429 identified phytocompounds retrieved from publicly available data sources, Terrestribisamide and 1-(9Z-octadecenoyl)-sn-glycero-3-phosphoethanolamine have shown potential binding affinity and favorable interactions with COX-2 and 5-LOX arachidonic acid binding sites. The physicochemical properties and ADMET profiles of these compounds determined their drug-likeness and pharmacokinetics features. Additional validation using molecular dynamics simulations, SASA, Rg, and MM-PBSA binding energy calculations affirmed the stability of the complex formed between those compounds with target proteins. Together, the study identified the effectual binding potential of those bioactive compounds against COX-2 and 5-LOX, providing a viable approach for the development of effective anti-inflammatory medications.

Synthesis, molecular docking, analgesic, anti-inflammatory, and ulcerogenic evaluation of thiophene-pyrazole candidates as COX, 5-LOX, and TNF-α inhibitors

The thiophene bearing pyrazole derivatives (7a-j) were synthesized and examined for their in vitro cyclooxygenase, 5-lipoxygenase, and tumour inducing factor-α inhibitory activities followed by the in vivo analgesic, anti-inflammatory, and ulcerogenic evaluations. The synthesized series (7a-j) were characterized using 1H NMR, 13C NMR, FT-IR, and mass spectral analysis. Initially, the compounds (7a-j) were evaluated for their in vitro cyclooxygenase, 5-lipoxygenase, and tumour inducing factor-α inhibitory activities and the compound (7f) with two phenyl substituents in the pyrazole ring and chloro substituent in the thiophene ring and the compound (7g) with two phenyl substituents in the pyrazole ring and bromo substituent in the thiophene ring were observed as potent compounds among the series. The compounds (7f and 7g) with effective in vitro potentials were further analyzed for analgesic, anti-inflammatory, and ulcerogenic evaluations. Also, to ascertain the binding affinities of compounds (7a-j), docking assessments were carried out and the ligand (7f) with the highest binding affinity was docked to know the interactions of the ligand with amino acids of target proteins.

Crystallization from solution versus mechanochemistry to obtain double-drug multicomponent crystals of ethacridine with salicylic/acetylsalicylic acids

Salicylic and acetylsalicylic acids and ethacridine have complementary bioactive properties. They can be combined to obtain double-drug multicomponent crystals. Their reactivity in different environments was explored to obtain the possible compounds, stable at different hydration degrees. Solution, liquid-assisted grinding, and dry preparation approaches were applied to the couples of reactants in different stoichiometric ratios. Four compounds were obtained, and three out of them were stable and reproducible enough to determine their structures using SCXRD or PXRD methods. When coupled to ethacridine, salicylic acid gave two stable structures (1 and 3, both showing 1:1 ratio but different hydration degree) and a metastable one (5), while acetylsalicylic acid only one structure from solution (2 in 1:1 ratio), while LAG caused hydrolysis and formation of the same compound obtained by LAG of ethacridine with salicylic acid. While solution precipitation gave dihydrated (1) or monohydrated (2) structures with low yields, LAG of salicylic acid and ethacridine allowed obtaining an anhydrous salt complex (3) with a yield close to 1. The structures obtained by solution crystallizations maximize π(acridine)-π(acridine) contacts with a less compact packing, while the LAG structure is more compact with a packing driven by hydrogen bonds. For all compounds, NMR, ATR-FTIR, and Hirshfeld surface analysis and energy framework calculations were performed.

A Contemporary Review on the Critical Role of Nonsteroidal Anti-inflammatory Agents in Colorectal Cancer Therapy

Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) are widely recognized as effective pain relievers and function by inhibiting the cyclooxygenase enzyme (COXs). Moreover, they have been found to participate in various cellular processes through different signaling pathways, such as WNT, MAPK, NF-κB, and PI3K/AKT/mTOR. This makes them potential candidates for chemoprevention of several malignancies, particularly colorectal cancer (CRC). However, the use of NSAIDs in cancer prevention and treatment is a complex issue due to their adverse effects and gastrointestinal toxicity. Therefore, it is crucial to explore combination therapies that can minimize side effects while maximizing synergistic effects with other agents and to evaluate the success rate of such approaches in both pre-clinical and clinical studies. In this review, we aim to provide an overview of the effects of NSAIDs in the prevention and treatment of CRC. We will focus on elucidating the possible mechanisms of action of these drugs, the signaling pathways involved in CRC, and the potential synergistic effects when combined with other therapeutic agents.

Synthesis and In vitro and In silico Anti-inflammatory Activity of New Thiazolidinedione-quinoline Derivatives

BACKGROUND

Inflammation is a series of complex defense-related reactions. The inflammation cascade produces various pro-inflammatory mediators. Unregulated production of these pro-inflammatory mediators can lead to a wide range of diseases, including rheumatoid arthritis, sepsis, and inflammatory bowel disease. In the literature, the anti-inflammatory action of quinoline and thiazolidinedione nuclei are well established, alone, and associated with other nuclei. The synthesis of hybrid molecules is a strategy for obtaining more efficient molecules due to the union of pharmacophoric nuclei known to be related to pharmacological activity.

OBJECTIVES

Based on this, this work presents the synthesis of thiazolidinedione-quinoline molecular hybrids and their involvement in the modulation of cytokines involved in the inflammatory reaction cascade.

METHODS

After synthesis and characterization, the compounds were submitted to cell viability test (MTT), ELISA IFN-γ and TNF-α, adipogenic differentiation, and molecular docking assay with PPARy and COX-2 targets.

RESULTS

LPSF/ZKD2 and LPSF/ZKD7 showed a significant decrease in the concentration of IFN- γ and TNF-α, with a dose-dependent behavior. LPSF/ZKD4 at a concentration of 50 μM significantly reduced IL-6 expression. LPSF/ZKD4 demonstrates lipid accumulation with significant differences between the untreated and negative control groups, indicating a relevant agonist action on the PPARγ receptor. Molecular docking showed that all synthesized compounds have good affinity with PPARγ e COX-2, with binding energy close to -10,000 Kcal/mol.

CONCLUSION

These results demonstrate that the synthesis of quinoline-thiazolidinedione hybrids may be a useful strategy for obtaining promising candidates for new anti-inflammatory agents.

Synthesis and anti-inflammatory activity of novel firocoxib analogues with balanced COX inhibition

The adverse effects caused by nonselective and selective cyclooxygenase-2 (COX-2) inhibitors remain a challenge for current anti-inflammatory medications. A balanced inhibition of COX-1/-2 represents a promising strategy for the development of novel COX-2 inhibitors. In this study, we present the design and synthesis of a novel series of firocoxib analogues incorporating an amide bond to facilitate essential hydrogen bonding with amino residues in COX-2. The synthesized analogs were evaluated for their inhibitory activity against both COX-1 and COX-2 enzymes. Among them, compound 9d demonstrated potent and balanced inhibition. Inhibition of COX enzymes by 9d in lipopolysaccharide (LPS)-stimulated murine RAW264.7 macrophages resulted in the suppression of the NF-κB signaling pathway to reduced expression of pro-inflammatory factors such as inducible nitric oxide synthase (iNOS), COX-2, nitric oxide (NO), and reactive oxygen species (ROS). The remarkable in vitro anti-inflammatory activity exhibited by 9d positions it as a promising candidate for further development as a novel lead compound for inflammation treatment.

Anti-inflammatory and Antimicrobial Potential of 1, 3, 4-oxadiazoles and its Derivatives: A Review

1, 3, 4-oxadiazole and its derivatives have significant anti-inflammatory and antimicrobial property. Their precise mechanism of action is not known but it is postulated that they act by inhibiting the biosynthesis of certain prostaglandins. 1, 3, 4-oxadiazoles are a class of heterocyclic compounds with wide variety of biological and pharmacological activities. They have been reported to possess analgesic, antimicrobial, antipyretic and anti-inflammatory properties. These compounds are also active against a number of other inflammatory conditions such as arthritis, gout etc. A wide variety of these compounds have been synthesized and some of them are under clinical trials. In this review article, anti-inflammatory and antimicrobial activity of the 1, 3, 4- oxadiazole shall be discussed.

Design, Synthesis, In vitro and In vivo Evaluation of New Imidazo[1,2-a]pyridine Derivatives as Cyclooxygenase-2 Inhibitors

BACKGROUND

Cyclooxygenase-2 (COX-2), the key enzyme in the arachidonic acid conversion to prostaglandins, is one of the enzymes associated with different pathophysiological conditions, such as inflammation, cancers, Alzheimer's, and Parkinson's disease. Therefore, COX-2 inhibitors have emerged as potential therapeutic agents in these diseases.

OBJECTIVE

The objective of this study was to design and synthesize novel imidazo[1,2-a]pyridine derivatives utilizing rational design methods with the specific aim of developing new potent COX-2 inhibitors. Additionally, we sought to investigate the biological activities of these compounds, focusing on their COX-2 inhibitory effects, analgesic activity, and antiplatelet potential. We aimed to contribute to the development of selective COX-2 inhibitors with enhanced therapeutic benefits.

METHODS

Docking investigations were carried out using AutoDock Vina software to analyze the interaction of designed compounds. A total of 15 synthesized derivatives were obtained through a series of five reaction steps. The COX-2 inhibitory activities were assessed using the fluorescent Cayman kit, while analgesic effects were determined through writing tests, and Born's method was employed to evaluate antiplatelet activities.

RESULTS

The findings indicated that the majority of the tested compounds exhibited significant and specific inhibitory effects on COX-2, with a selectivity index ranging from 51.3 to 897.1 and IC50 values of 0.13 to 0.05 μM. Among the studied compounds, derivatives 5e, 5f, and 5j demonstrated the highest potency with IC50 value of 0.05 μM, while compound 5i exhibited the highest selectivity with a selectivity index of 897.19. In vivo analgesic activity of the most potent COX-2 inhibitors revealed that 3-(4-chlorophenoxy)-2-[4-(methylsulfonyl) phenyl] imidazo[1,2-a]pyridine (5j) possessed the most notable analgesic activity with ED50 value of 12.38 mg/kg. Moreover, evaluating the antiplatelet activity showed compound 5a as the most potent for inhibiting arachidonic acidinduced platelet aggregation. In molecular modeling studies, methylsulfonyl pharmacophore was found to be inserted in the secondary pocket of the COX-2 active site, where it formed hydrogen bonds with Arg-513 and His-90.

CONCLUSION

The majority of the compounds examined demonstrated selectivity and potency as inhibitors of COX-2. Furthermore, the analgesic effects observed of potent compounds can be attributed to the inhibition of the cyclooxygenase enzyme.

A Computational Method for the Binding Mode Prediction of COX-1 and COX-2 Inhibitors: Analyzing the Union of Coxibs, Oxicams, Propionic and Acetic Acids

Among the biological targets extensively investigated to improve inflammation and chronic inflammatory conditions, cyclooxygenase enzymes (COXs) occupy a prominent position. The inhibition of these enzymes, essential for mitigating inflammatory processes, is chiefly achieved through Non-Steroidal Anti-Inflammatory Drugs (NSAIDs). In this work, we introduce a novel method-based on computational molecular docking-that could aid in the structure-based design of new compounds or the description of the anti-inflammatory activity of already-tested compounds. For this, we used eight crystal complexes (four COX-1 and COX-2 each), and each pair had a specific NSAID: Celecoxib, Meloxicam, Ibuprofen, and Indomethacin. This selection was based on the ligand selectivity towards COX-1 or COX-2 and their binding mode. An interaction profile of each NSAID was compiled to detect the residues that are key for their binding mode, highlighting the interaction made by the Me group. Furthermore, we rigorously validated our models based on structural accuracy (RMSD < 1) and (R2 > 70) using eight NSAIDs and thirteen compounds with IC50 values for each enzyme. Therefore, this model can be used for the binding mode prediction of small and structurally rigid compounds that work as COX inhibitors or the prediction of new compounds that are designed by means of a structure-based approach.

Comprehensive phytochemical characterization of Persea americana Mill. fruit via UPLC/HR-ESI-MS/MS and anti-arthritic evaluation using adjuvant-induced arthritis model

Persea americana Mill. (avocado fruit) has many health benefits when added to our diet due to various pharmacological activities, such as preventing bone loss and inflammation, modulating immune response and acting as an antioxidant. In the current study, the total ethanol extract (TEE) of the fruit was investigated for in vitro antioxidant and anti-inflammatory activity via DPPH and cyclooxygenase enzyme inhibition. Biological evaluation of the antiarthritic effect of the fruit extract was further investigated in vivo using Complete Freund's Adjuvant (CFA) arthritis model, where the average percentages of body weight change, inhibition of paw edema, basal paw diameter/weight and spleen index were estimated for all animal groups. Inflammatory mediators such as serum IL-6 and TNF-α were also determined, in addition to histopathological examination of the dissected limbs isolated from all experimental animals. Eighty-one metabolites belonging to different chemical classes were detected in the TEE of P. americana fruit via UPLC/HR-ESI-MS/MS. Two classes of lyso-glycerophospholipids; lyso-glycerophosphoethanolamines and lysoglycerophosphocholines were detected for the first time in avocado fruit in the positive mode. The TEE of fruit exhibited significant antioxidant and anti-inflammatory activity in vitro. In vivo anti-arthritic activity of the fruit TEE improved paw parameters, inflammatory mediators and spleen index. Histopathological findings showed marked improvements in the arthritic condition of the excised limbs. Therefore, avocado fruit could be proposed to be a powerful antioxidant and antiarthritic natural product.

Malvidin and Its Mono- and Di-Glucosides Forms: A Study of Combining Both In Vitro and Molecular Docking Studies Focused on Cholinesterase, Butyrylcholinesterase, COX-1 and COX-2 Activities

Malvidin, one of the six most prominent anthocyanins found in various fruits and vegetables, may possess a wide range of health-promoting properties. The biological activity of malvidin and its glycosides is not entirely clear and has been relatively less frequently studied compared to other anthocyanins. Therefore, this study aimed to determine the relationship between the structural derivatives of malvidin and their anti-cholinergic and anti-inflammatory activity. The study selected malvidin (Mv) and its two sugar derivatives: malvidin 3-O-glucoside (Mv 3-glc) and malvidin 3,5-O-diglucoside (Mv 3,5-diglc). The anti-inflammatory activity was assessed by inhibiting the enzymes, specifically COX-1 and COX-2. Additionally, the inhibitory effects on cholinesterase activity, particularly acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), were evaluated. Molecular modeling was also employed to examine and visualize the interactions between enzymes and anthocyanins. The results revealed that the highest inhibitory capacity at concentration 100 µM was demonstrated by Mv 3-glc in relation to AChE (26.3 ± 3.1%) and BChE (22.1 ± 3.0%), highlighting the crucial role of the glycoside substituent at the C3 position of the C ring in determining the inhibitory efficiency of these enzymes. In addition, the glycosylation of malvidin significantly reduced the anti-inflammatory activity of these derivatives compared to the aglycone form. The IC50 parameter demonstrates the following relationship for the COX-1 enzyme: Mv (12.45 ± 0.70 µM) < Mv 3-glc (74.78 ± 0.06 µM) < Mv 3,5-diglc (90.36 ± 1.92 µM). Similarly, for the COX-2 enzyme, we have: Mv (2.76 ± 0.16 µM) < Mv 3-glc (39.92 ± 3.02 µM) < Mv 3.5-diglc (66.45 ± 1.93 µM). All tested forms of malvidin exhibited higher activity towards COX-2 compared to COX-1, indicating their selectivity as inhibitors of COX-2. Theoretical calculations were capable of qualitatively replicating most of the noted patterns in the experimental data, explaining the impact of deprotonation and glycosylation on inhibitory activity. It can be suggested that anthocyanins, such as malvidins, could be valuable in the development of treatments for inflammatory conditions and Alzheimer's disease and deserve further study.

Inhibitory Effect of Salicin on Staphylococcus aureus Coagulase

The massive use of antibiotics has resulted in an alarming increase in antibiotic resistance in Staphylococcus aureus (S. aureus). This study aimed to identify the inhibitory effect of salicin on S. aureus. Coagulase (Coa) activity was assessed using in vitro Coa assays and Western blot, thermal shift assay (TSA), fluorescence quenching and molecular docking experiments were conducted to verify the interaction between salicin and Coa. An in vivo mouse pneumonia model demonstrated that salicin can reduce the virulence of S. aureus. In vitro Coa assays elucidated that salicin directly inhibited Coa activity. The Western blot and TSA results suggested that salicin did not block the expression of Coa but affected the thermal stability of the protein by binding to Coa. The fluorescence quenching, molecular docking and molecular dynamics assays have found that the most promising binding site between salicin and Coa was GLN-97. The pneumonia model of mice infected with S. aureus revealed that salicin could not only reduce the content of lung bacteria in mice but also prolong their survival. Salicin was identified as a novel anti-infective candidate compound with the potential to target Coa and inhibit its activity by binding to it, which would facilitate the development of roadmaps for future research.

Defining the Conformational Ensembles Associated with Ligand Binding to Cyclooxygenase-2

Cyclooxygenases (COX) catalyze the committed step in the production of prostaglandins responsible for the maintenance of physiological homeostasis. While crystal structures of COX in complex with substrates and inhibitors have provided insight into the molecular interactions governing their binding, they have not uncovered specific details related to the protein conformational motions responsible for important aspects of the COX function. We created a cysteine-free COX-2 construct and introduced a free cysteine at position-122 to enable labeling with 3-bromo-1,1,1-trifluoroacetone (BTFA). Placement of the label adjacent to the cyclooxygenase channel entrance permitted the detection of alterations upon ligand binding. 19F-nuclear magnetic resonance spectroscopy (19F-NMR) was then used to probe the conformational ensembles arising from BTFA-labeled COX-2 constructs in the presence and absence of ligands known to allosterically activate or inhibit COX-2. 19F-NMR analyses performed in the presence of the time-dependent inhibitor flurbiprofen, as well as Arg-120, Tyr-355, and Glu-524 mutations, led to the classification of two ensembles as representing the relaxed and tightened states of the cyclooxygenase channel entrance. A third ensemble, generated in the presence of arachidonic acid and the Y355F mutant and modulated by the allosteric potentiators palmitic acid and oleic acid and the nonallosteric substrates 2-arachidonoyl glycerol ether and anandamide, was classified as being related to the allosteric regulation of COX activity. The ensemble-based insight into COX function demonstrated here complements the static information derived from crystal structure analyses, collectively providing a more detailed framework of the dynamics involved in the regulation of COX catalysis and inhibition.

Fragment merging approach for the design of thiazole/thiazolidine clubbed pyrazoline derivatives as anti-inflammatory agents: Synthesis, biopharmacological evaluation and molecular modeling studies

Fragment merging approach was applied for the design of thiazole/thiazolidinone clubbed pyrazoline derivatives 5a-e, 6a-c, 7 and 10a-d as dual COX-2 and 5-LOX inhibitors. Compounds 5a, 6a, and 6b were the most potent and COX-2 selective inhibitors (IC50= 0.03-0.06 μM, SI = 282.7-472.9) with high activity against 5-LOX (IC50 = 4.36-4.86 μM), while compounds 5b and 10a were active and selective 5-LOX inhibitors with IC50 = 2.43 and 1.58 μM, respectively. In vivo assay and histopathological examination for most active candidate 6a revealed significant decrease in inflammation with higher safety profile in comparison to standard drugs. Compound 6a exhibited the same orientation and binding interactions as the reference COX-2 and 5-LOX inhibitors (celecoxib and quercetin, respectively). Consequently, compound 6a has been identified as a potential lead for further optimization and the development of safe and effective anti-inflammatory drugs.

Evaluation of Anti-Inflammatory and Anti-Tubercular Activity of 4-Methyl-7-Substituted Coumarin Hybrids and Their Structure Activity Relationships

Four sets of previously synthesized 4-methyl-7-substituted coumarin derivatives were screened for their in vitro anti-inflammatory and anti-tubercular activities. The anti-inflammatory potential of 3a-t, 5a-o, 6a-n, and 7a-f synthesized compounds was evaluated by an anti-denaturation assay using diclofenac sodium as the reference standard. Evaluation of the anti-tuberculous activity of the mentioned compounds was performed by the Resazurin test method against four different TB strains using rifampicin and isoniazid as reference drugs. Based on the anti-inflammatory results, compounds 3o, 5f, 6c, and 7d proved to be the most active compounds in their respective series. Additionally, compounds 3k-n, 5b-d, 6d-f, 6k, 7a, and 7f were found to be the most potent anti-tuberculous agents. In fact, most of the screened compounds exhibited promising activity profiles compared to the respective standard drugs. The structure-activity connections revealed a few intriguing aspects, indicating that the presence of electron-donating and nitrogen-rich fragments boost the anti-inflammatory effects of the examined compounds. However, the presence of electron-withdrawing substituents was required to boost the anti-tubercular activity of the evaluated compounds.

Stress-mediated aggregation of disease-associated proteins in amyloid bodies

The formation of protein aggregates is a hallmark of many neurodegenerative diseases and systemic amyloidoses. These disorders are associated with the fibrillation of a variety of proteins/peptides, which ultimately leads to cell toxicity and tissue damage. Understanding how amyloid aggregation occurs and developing compounds that impair this process is a major challenge in the health science community. Here, we demonstrate that pathogenic proteins associated with Alzheimer's disease, diabetes, AL/AA amyloidosis, and amyotrophic lateral sclerosis can aggregate within stress-inducible physiological amyloid-based structures, termed amyloid bodies (A-bodies). Using a limited collection of small molecule inhibitors, we found that diclofenac could repress amyloid aggregation of the β-amyloid (1-42) in a cellular setting, despite having no effect in the classic Thioflavin T (ThT) in vitro fibrillation assay. Mapping the mechanism of the diclofenac-mediated repression indicated that dysregulation of cyclooxygenases and the prostaglandin synthesis pathway was potentially responsible for this effect. Together, this work suggests that the A-body machinery may be linked to a subset of pathological amyloidosis, and highlights the utility of this model system in the identification of new small molecules that could treat these debilitating diseases.

Synthesis and in silico studies of some new pyrrolidine derivatives and their biological evaluation for analgesic and anti-inflammatory activity

BACKGROUND

An array of commercially viable intermediate molecules necessary for the synthesis of a variety of bioactive molecules are chemically synthesized by pyrrolidine and its derivatives, which play a significant role in drug design and development process.

AIM

The aim of the present research work was to explore the synthesis of some new pyrrolidine derivatives and to perform their in silico studies and finally evaluation of analgesic and anti-inflammatory activity.

OBJECTIVE

The purpose of this study was to synthesis new pyrrolidine derivatives, examine how they affected the COX-1 and COX-2 enzymes computationally, and to screen their in vivo analgesic and anti-inflammatory activity on laboratory animals.

METHOD

The new pyrrolidine derivatives were synthesized by condensing N-(3-acetylphenyl)-2-(pyrrolidin-1-yl)acetamide with substituted aniline in ethanol in the presence of catalytic amounts of glacial acetic acid. The structures of novel pyrrolidine derivatives were characterised using IR, NMR, and mass spectroscopy. Several molecular properties of the newly synthesized derivatives were calculated in order to evaluate the nature of the drug-like candidate. A specific reference cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) enzyme was used to dock the newly synthesized pyrrolidine derivatives.

RESULTS

From the observed data, it was noted that amongst all newly synthesized compounds, A-1 and A-4 exhibited the highest anti-inflammatory and analgesic effects, respectively.

CONCLUSION

On the basis of findings of present research, it was concluded that A-1 and A-4 might be utilized as a promising new lead compound for Non-Steroidal Anti-Inflammatory Drug (NSAIDs) development.

Exploration of NMI-MsCl mediated amide bond formation for the synthesis of novel 3,5-substituted-1,2,4-oxadiazole derivatives: synthesis, evaluation of anti-inflammatory activity and molecular docking studies

We herein report the facile synthesis of a series of 3,5-substituted-1,2,4-oxadiazole derivatives 9a-e and 10a-e in good to excellent yields by employing NMI-MsCl mediated amide bond formation reaction. The anti-inflammatory potential of the newly synthesized compounds were evaluated by anti-denaturation assay using diclofenac sodium as the reference drug. The compounds 9a and 9d demonstrated promising activity profile when compared to the reference standard. The SAR and molecular docking studies were also carried out for obtaining more details about the profound activity profile of the synthesized molecules. The synthesized compounds were docked against two target proteins TGF-β and IL-1 by AutoDock vina and Auto Dock 4.2.

Synthesis, Biological, Spectroscopic and Computational Investigations of Novel N-Acylhydrazone Derivatives of Pyrrolo[3,4-d]pyridazinone as Dual COX/LOX Inhibitors

Secure and efficient treatment of diverse pain and inflammatory disorders is continually challenging. Although NSAIDs and other painkillers are well-known and commonly available, they are sometimes insufficient and can cause dangerous adverse effects. As yet reported, derivatives of pyrrolo[3,4-d]pyridazinone are potent COX-2 inhibitors with a COX-2/COX-1 selectivity index better than meloxicam. Considering that N-acylhydrazone (NAH) moiety is a privileged structure occurring in many promising drug candidates, we decided to introduce this pharmacophore into new series of pyrrolo[3,4-d]pyridazinone derivatives. The current paper presents the synthesis and in vitro, spectroscopic, and in silico studies evaluating the biological and physicochemical properties of NAH derivatives of pyrrolo[3,4-d]pyridazinone. Novel compounds 5a-c-7a-c were received with high purity and good yields and did not show cytotoxicity in the MTT assay. Their COX-1, COX-2, and 15-LOX inhibitory activities were estimated using enzymatic tests and molecular docking studies. The title N-acylhydrazones appeared to be promising dual COX/LOX inhibitors. Moreover, spectroscopic and computational methods revealed that new compounds form stable complexes with the most abundant plasma proteins-AAG and HSA, but do not destabilize their secondary structure. Additionally, predicted pharmacokinetic and drug-likeness properties of investigated molecules suggest their potentially good membrane permeability and satisfactory bioavailability.

Platinum(IV) Derivatives of [Pt(1S,2S-diaminocyclohexane)(5,6-dimethyl-1,10-phenanthroline)] with Diclofenac Ligands in the Axial Positions: A New Class of Potent Multi-action Agents Exhibiting Selectivity to Cancer Cells

The platinum(II) complex [Pt(1S,2S-diaminocyclohexane)(5,6-dimethyl-1,10-phenanthroline)]²⁺ (Pt^II56MeSS, 1) exhibits high potency across numerous cancer cell lines acting by a multimodal mechanism. However, 1 also displays side toxicity and in vivo activity; all details of its mechanism of action are not entirely clear. Here, we describe the synthesis and biological properties of new platinum(IV) prodrugs that combine 1 with one or two axially coordinated molecules of diclofenac (DCF), a non-steroidal anti-inflammatory cancer-selective drug. The results suggest that these Pt(IV) complexes exhibit mechanisms of action typical for Pt(II) complex 1 and DCF, simultaneously. The presence of DCF ligand(s) in the Pt(IV) complexes promotes the antiproliferative activity and selectivity of 1 by inhibiting lactate transporters, resulting in blockage of the glycolytic process and impairment of mitochondrial potential. Additionally, the investigated Pt(IV) complexes selectively induce cell death in cancer cells, and the Pt(IV) complexes containing DCF ligands induce hallmarks of immunogenic cell death in cancer cells.

Dual synergistic inhibition of COX and LOX by potential chemicals from Indian daily spices investigated through detailed computational studies

Cyclooxygenase (COX) and Lipoxygenase (LOX) are essential enzymes for arachidonic acid (AA) to eicosanoids conversion. These AA-derived eicosanoids are essential for initiating immunological responses, causing inflammation, and resolving inflammation. Dual COX/5-LOX inhibitors are believed to be promising novel anti-inflammatory agents. They inhibit the synthesis of prostaglandins (PGs) and leukotrienes (LTs), but have no effect on lipoxin formation. This mechanism of combined inhibition circumvents certain limitations for selective COX-2 inhibitors and spares the gastrointestinal mucosa. Natural products, i.e. spice chemicals and herbs, offer an excellent opportunity for drug discovery. They have proven anti-inflammatory properties. However, the potential of a molecule to be a lead/ drug candidate can be much more enhanced if it has the property of inhibition in a dual mechanism. Synergistic activity is always a better option than the molecule's normal biological activity. Herein, we have explored the dual COX/5-LOX inhibition property of the three major potent phytoconsituents (curcumin, capsaicin, and gingerol) from Indian spices using in silico tools and biophysical techniques in a quest to identify their probable inhibitory role as anti-inflammatory agents. Results revealed the dual COX/5-LOX inhibitory potential of curcumin. Gingerol and capsaicin also revealed favorable results as dual COX/5-LOX inhibitors. Our results are substantiated by target similarity studies, molecular docking, molecular dynamics, energy calculations, DFT, and QSAR studies. In experimental inhibitory (in vitro) studies, curcumin exhibited the best dual inhibitory activities against COX-1/2 and 5-LOX enzymes. Capsaicin and gingerol also showed inhibitory potential against both COX and LOX enzymes. In view of the anti-inflammatory potential these spice chemicals, this research could pave the way for more scientific exploration in this area for drug discovery.

Design and Development of COX-II Inhibitors: Current Scenario and Future Perspective

Innate inflammation beyond a threshold is a significant problem involved in cardiovascular diseases, cancer, and many other chronic conditions. Cyclooxygenase (COX) enzymes are key inflammatory markers as they catalyze prostaglandins production and are crucial for inflammation processes. While COX-I is constitutively expressed and is generally involved in "housekeeping" roles, the expression of the COX-II isoform is induced by the stimulation of different inflammatory cytokines and also promotes the further generation of pro-inflammatory cytokines and chemokines, which affect the prognosis of various diseases. Hence, COX-II is considered an important therapeutic target for drug development against inflammation-related illnesses. Several selective COX-II inhibitors with safe gastric safety profiles features that do not cause gastrointestinal complications associated with classic anti-inflammatory drugs have been developed. Nevertheless, there is mounting evidence of cardiovascular side effects from COX-II inhibitors that resulted in the withdrawal of market-approved anti-COX-II drugs. This necessitates the development of COX-II inhibitors that not only exhibit inhibit potency but also are free of side effects. Probing the scaffold diversity of known inhibitors is vital to achieving this goal. A systematic review and discussion on the scaffold diversity of COX inhibitors are still limited. To address this gap, herein we present an overview of chemical structures and inhibitory activity of different scaffolds of known COX-II inhibitors. The insights from this article could be helpful in seeding the development of next-generation COX-II inhibitors.

Discovery of andrographolide hit analog as a potent cyclooxygenase-2 inhibitor through consensus MD-simulation, electrostatic potential energy simulation and ligand efficiency metrics

Cyclooxygenase-2 (COX-2) is the key enzyme responsible for the conversion of arachidonic acid to prostaglandins that display pro-inflammatory properties and thus, it is a potential target protein to develop anti-inflammatory drugs. In this study, chemical and bio-informatics approaches have been employed to find a novel potent andrographolide (AGP) analog as a COX-2 inhibitor having better pharmacological properties than aspirin and rofecoxib (controls). The full amino acid sequenced human Alpha fold (AF) COX-2 protein (604AA) was selected and validated for its accuracy against the reported COX-2 protein structures (PDB ID: 5F19, 5KIR, 5F1A, 5IKQ and 1V0X) followed by multiple sequence alignment analysis to establish the sequence conservation. The systematic virtual screening of 237 AGP analogs against AF-COX-2 protein yielded 22 lead compounds based on the binding energy score (< - 8.0 kcal/mol). These were further screened out to 7 analogs by molecular docking analysis and investigated further for ADMET prediction, ligand efficiency metrics calculations, quantum mechanical analysis, MD simulation, electrostatic potential energy (EPE) docking simulation, and MM/GBSA. In-depth analysis revealed that AGP analog A3 (3-[2-[(1R,4aR,5R,6R,8aR)-6-hydroxy-5,6,8a-trimethyl-2-methylidene-3,4,4a,5,7,8-hexahydro-1H-naphthalen-1-yl]ethylidene]-4-hydroxyoxolan-2-one) forms the most stable complex with the AF-COX-2 showing the least RMSD value (0.37 ± 0.03 nm), a good number of hydrogen bonds (protein-ligand H-bond = 11, and protein H-bond = 525), minimum EPE score (- 53.81 kcal/mol), and lowest MM-GBSA before and after simulation (- 55.37 and - 56.25 kcal/mol, respectively) value compared to other analogs and controls. Thus, we suggest that the identified A3 AGP analog could be developed as a promising plant-based anti-inflammatory drug by inhibiting COX-2.

Synergistic Combination of Citrus Flavanones as Strong Antioxidant and COX-Inhibitor Agent

Recently, we demonstrated that a Citrus flavanone mix (FM) shows antioxidant and anti-inflammatory activity, even after gastro-duodenal digestion (DFM). The aim of this study was to investigate the possible involvement of the cyclooxygenases (COXs) in the anti-inflammatory activity previously detected, using a human COX inhibitor screening assay, molecular modeling studies, and PGE2 release by Caco-2 cells stimulated with IL-1β and arachidonic acid. Furthermore, the ability to counteract pro-oxidative processes induced by IL-1β was evaluated by measuring four oxidative stress markers, namely, carbonylated proteins, thiobarbituric acid-reactive substances, reactive oxygen species, and reduced glutathione/oxidized glutathione ratio in Caco-2 cells. All flavonoids showed a strong inhibitory activity on COXs, confirmed by molecular modeling studies, with DFM, which showed the best and most synergistic activity on COX-2 (82.45% vs. 87.93% of nimesulide). These results were also corroborated by the cell-based assays. Indeed, DFM proves to be the most powerful anti-inflammatory and antioxidant agent reducing, synergistically and in a statistically significant manner (p < 0.05), PGE2 release than the oxidative stress markers, also with respect to the nimesulide and trolox used as reference compounds. This leads to the hypothesis that FM could be an excellent antioxidant and COX inhibitor candidate to counteract intestinal inflammation.

Synthesis, Evaluation of Enzyme Inhibition and Redox Properties of Potential Dual COX-2 and 5-LOX Inhibitors

Various dual inhibitors of COX-2 and 5-LOX enzymes have been developed so far in order to obtain more effective and safer anti-inflammatory drugs. The aim of this study was to design and synthesize new dual COX-2 and 5-LOX inhibitors, and to evaluate their enzyme inhibition potential and redox properties. Thirteen compounds (1-13) were designed taking into account structural requirements for dual COX-2 and 5-LOX inhibition and antioxidant activity, synthesized, and structurally characterized. These compounds can be classified as N-hydroxyurea derivatives (1, 2 and 3), 3,5-di-tert-butylphenol derivatives (4, 5, 6, 7 and 13), urea derivatives (8, 9 and 10) and "type B hydroxamic acids" (11 and 12). COX-1, COX-2 and 5-LOX inhibitory activities were evaluated using fluorometric inhibitor screening kits. The evaluation of the redox activity of newly synthesized compounds was performed in vitro in the human serum pool using redox status tests. The prooxidative score, the antioxidative score and the oxy-score were calculated. Seven out of thirteen synthesized compounds (1, 2, 3, 5, 6, 11 and 12) proved to be dual COX-2 and 5-LOX inhibitors. These compounds expressed good COX-2/COX-1 selectivity. Moreover, dual inhibitors 1, 3, 5, 11 and 12 showed good antioxidant properties.

Interactions of N-Mannich Bases of Pyrrolo[3,4-c]pyrrole with Artificial Models of Cell Membranes and Plasma Proteins, Evaluation of Anti-Inflammatory and Antioxidant Activity

Despite the widespread and easy access to NSAIDs, effective and safe treatment of various inflammatory disorders is still a serious challenge because of the severe adverse effects distinctive to these drugs. The Mannich base derivatives of pyrrolo[3,4-c]pyrrole are potent, preferential COX-2 inhibitors with a COX-2/COX-1 inhibitory ratio better than meloxicam. Therefore, we chose the six most promising molecules and subjected them to further in-depth research. The current study presents the extensive biological, spectroscopic and in silico evaluation of the activity and physicochemical properties of pyrrolo[3,4-c]pyrrole derivatives. Aware of the advantages of dual COX-LOX inhibition, we investigated the 15-LOX inhibitory activity of these molecules. We also examined their antioxidant effect in several in vitro experiments in a protection and regeneration model. Furthermore, we defined how studied compounds interact with artificial models of cell membranes, which is extremely important for drugs administered orally with an intracellular target. The interactions and binding mode of the derivatives with the most abundant plasma proteins-human serum albumin and alpha-1-acid glycoprotein-are also described. Finally, we used computational techniques to evaluate their pharmacokinetic properties. According to the obtained results, we can state that pyrrolo[3,4-c]pyrrole derivatives are promising anti-inflammatory and antioxidant agents with potentially good membrane permeability.

Design, synthesis, and biological evaluation of new 2-(4-(methylsulfonyl)phenyl)-N-phenylimidazo[1,2-a]pyridin-3-amine as selective COX-2 inhibitors

Cyclooxygenase (COX), which plays a role in converting arachidonic acid to inflammatory mediators, could be inhibited by non-steroidal anti-inflammatory drugs (NSAIDs). Although potent NSAIDs are available for the treatment of pain, fever, and inflammation, some side effects, such as gastrointestinal ulcers, limit the use of these medications. In recent years, selective COX-2 inhibitors with a lower incidence of adverse effects attained an important position in medicinal chemistry. In order to introduce some new potent COX-2 inhibitors, a new series of 2-(4-(methylsulfonyl)phenyl)-N-phenylimidazo[1,2-a]pyridin-3-amines was designed, synthesized, and evaluated. The docking studies performed by AutoDock Vina demonstrated that docked molecules were positioned as well as a crystallographic ligand in the COX-2 active site, and SO₂Me pharmacophore was inserted into the secondary pocket of COX-2 and formed hydrogen bonds with the active site. The designed compounds were synthesized through two-step reactions. In the first step, different 1-(4-(methylsulfonyl)phenyl)-2-(phenylamino)ethan-1-one derivatives were obtained by the reaction of aniline derivatives and α-bromo-4-(methylsulfonyl)acetophenone. Then, condensation of intermediates with different 2-aminopyridines gave final compounds. Enzyme inhibition assay and formalin test were performed to evaluate the activity of these compounds. Among these compounds, 8-methyl-2-(4-(methylsulfonyl)phenyl)-N-(p-tolyl)imidazo[1,2-a]pyridin-3-amine (5n) exhibited the highest potency (IC₅₀ = 0.07 µM) and selectivity (selectivity index = 508.6) against COX-2 enzyme (selectivity index: COX-1 IC₅₀/COX-2 IC₅₀). The antinociceptive activity assessment via the formalin test showed that nine derivatives (5a, 5d, 5h, 5i, 5k, 5q, 5r, 5s, and 5t) possessed significant activity compared with the control group with a p value less than 0.05.

Mass spectrometry-based metabolomics approach and in vitro assays revealed promising role of 2,3-dihydroquinazolin-4(1H)-one derivatives against colorectal cancer cell lines

Colorectal cancer (CRC) is the most frequent form of gastrointestinal cancer and one of the major causes of human mortality worldwide. Many of the current CRC therapies have limitations due to multidrug resistance and/or severe side effects. Quinazoline derivatives are promising lead compounds with a wide range of pharmacological actions. In this study, the effect of seven synthesized 2,3-dihydroquinazolin-4(1H)-one analogues as potential anticancer agents against two CRC cell lines (HCT116 and SW480) was investigated using cell viability proliferation, migration, adhesion and invasion assays. A liquid chromatography-mass spectrometry (LC-MS/MS) metabolomics approach was used to identify the underlying biochemical pathways disturbed in treated-HCT116 cells. Cell viability proliferation assay revealed that four compounds (C2, C3, C5, and C7) had IC₅₀ < 10 µM with C5 displaying the most potent cytotoxic effect (IC₅₀ 1.4 and 0.3 µM against HCT116 and SW480, respectively). Additionally, the compounds showed suppression of wound closure after 72 h, and both C2 and C5 significantly decreased the number of adherent cells and suppressed HCT116 cells invasion. Metabolomics study revealed that C5 induced significant perturbations in the level of several metabolites including spermine, polyamines, glutamine, creatine and carnitine, and altered biochemical processes essential for cell proliferation and progression such as amino acids biosynthesis and metabolism, redox homeostasis, energy related processes (e.g., fatty acid oxidation, second Warburg like effect) and one-carbon metabolism. Our findings indicate that 2,3-dihydroquinazolin-4(1H)-one analogues, particularly C5, have promising anticancer properties, and shed light on the role of metabolomics in identifying new therapeutic targets and providing better understanding of the pathways altered in treated cancer cells.

Peptides Derived from a Plant Protease Inhibitor of the Coagulation Contact System Decrease Arterial Thrombus Formation in a Murine Model, without Impairing Hemostatic Parameters

Several plant protein inhibitors with anticoagulant properties have been studied and characterized, including the Delonix regia trypsin inhibitor (DrTI). This protein inhibits serine proteases (trypsin) and enzymes directly involved in coagulation, such as plasma kallikrein, factor XIIa, and factor XIa. In this study, we evaluated the effects of two new synthetic peptides derived from the primary sequence of DrTI in coagulation and thrombosis models to understand the mechanisms involved in the pathophysiology of thrombus formation as well as in the development of new antithrombotic therapies. Both peptides acted on in vitro hemostasis-related parameters, showing promising results, prolonging the Partially Activated Thromboplastin Time (aPTT) and inhibited platelet aggregation induced by adenosine diphosphate (ADP) and arachidonic acid. In murine models, for arterial thrombosis induced by photochemical injury, and platelet-endothelial interactions monitored by intravital microscopy, both peptides at doses of 0.5 mg/kg significantly extended the time of artery occlusion and modified the platelet adhesion and aggregation pattern with no changes in bleeding time, demonstrating the high biotechnological potential of both molecules.

Ferroptosis Inhibitors Suppress Prostaglandin Synthesis in Lipopolysaccharide-Stimulated Macrophages

Necrostatin-1 blocks ferroptosis via an unknown mechanism and necroptosis through inhibition of receptor-interacting protein kinase-1 (RIP1). We report that necrostatin-1 suppresses cyclooxygenase-2-dependent prostaglandin biosynthesis in lipopolysaccharide-treated RAW264.7 macrophages (IC₅₀ ∼ 100 μM). This activity is shared by necrostatin-1i (IC₅₀ ∼ 50 μM), which lacks RIP1 inhibitory activity, but not the RIP1 inhibitors necrostatin-1s or deschloronecrostatin-1s. Furthermore, we show that the potent ferroptosis inhibitors and related compounds ferrostatin-1, phenoxazine, phenothiazine, and 10-methylphenothiazine strongly inhibit cellular prostaglandin biosynthesis with IC₅₀'s in the range of 30 nM to 3.5 μM. None of the compounds inhibit lipopolysaccharide-mediated cyclooxygenase-2 protein induction. In the presence of activating hydroperoxides, the necrostatins and ferroptosis inhibitors range from low potency inhibition to stimulation of in vitro cyclooxygenase-2 activity; however, inhibitory potency is increased under conditions of low peroxide tone. The ferroptosis inhibitors are highly effective reducing substrates for cyclooxygenase-2's peroxidase activity, suggesting that they act by suppressing hydroperoxide-mediated activation of the cyclooxygenase active site. In contrast, for the necrostatins, cellular prostaglandin synthesis inhibition does not correlate with peroxidase-reducing activity but rather with the presence of a thiohydantoin substituent, which conveys the ability to reduce the endoperoxide intermediate prostaglandin H₂ to prostaglandin F_2α in vitro. This finding suggests that necrostatin-1 blocks cellular prostaglandin synthesis and ferroptosis via a redox mechanism distinct from action as a one-electron donor. The results indicate that a wide range of compounds derived from redox-active chemical scaffolds can block cellular prostaglandin biosynthesis.

Natural-Derived COX-2 Inhibitors as Anticancer Drugs: A Review of their Structural Diversity and Mechanism of Action

Cyclooxygenase-2 (COX-2) is a key-type enzyme playing a crucial role in cancer development, making it a target of high interest for drug designers. In the last two decades, numerous selective COX-2 inhibitors have been approved for various clinical conditions. However, data from clinical trials propose that the prolonged use of COX-2 inhibitors is associated with life-threatening cardiovascular side effects. The data indicate that a slight structural modification can help develop COX-2 selective inhibitors with comparative efficacy and limited side effects. In this regard, secondary metabolites from natural sources offer great hope for developing novel COX-2 inhibitors with potential anticancer activity. In recent years, various nature-derived organic scaffolds are being explored as leads for developing new COX-2 inhibitors. The current review attempts to highlight the COX-2 inhibition activity of some naturally occurring secondary metabolites, concerning their capacity to inhibit COX-1 and COX-2 enzymes and inhibit cancer development, aiming to establish a structure-activity relationship.

Exploring the Anti-Inflammatory Effect of Inulin by Integrating Transcriptomic and Proteomic Analyses in a Murine Macrophage Cell Model

Inulin is a natural polysaccharide classified as a soluble fiber with demonstrated prebiotic activity. Prebiotics can reduce intestinal and systemic inflammation through modulation of the gut microflora and their metabolites. Additionally, extensive research is illuminating the role of macrophages in the interaction between gut microbiota and many systemic inflammatory diseases. In this study, the anti-inflammatory properties of inulin were evaluated using a murine macrophage cell model (RAW 264.7) of inflammation, and the immunomodulatory mechanism was investigated using omics technologies. The cells underwent comprehensive transcriptomic and proteomic analyses to identify the mechanisms responsible for the observed anti-inflammatory phenotype. Functional analyses of these omics results revealed two potential mechanisms that may lead to an overall reduction in cytokine and chemokine transcription: the inhibition of the NF-κB signaling pathway, leading to the downregulation of proinflammatory factors such as COX2, and the promotion of the phase II defense protein Hmox1 via the Nrf2 pathway. This study provides promising targets for research on immune modulation by dietary fibers and offers new strategies for the design of functional ingredients, foods, and nutraceutical products, which could ultimately lead to personalized nutrition and improved consumer health.

Hydroxytriazenes incorporating sulphonamide derivatives: evaluation of antidiabetic, antioxidant, anti-inflammatory activities, and computational study

The existent investigation deals with synthesis, characterization, computational analysis, and biological activities of some hydroxytriazene derivatives containing sulphonamide moiety. The compounds were screened for antidiabetic, antioxidant, and anti-inflammatory activities. The antidiabetic activity was assessed using α-glucosidase and α-amylase inhibition assays with IC₅₀ values ranging from 32.0 to 759.13 μg/mL and 157.77 to 340.47 μg/mL while standard drug acarbose showed IC₅₀ values 12.21 and 69.74 μg/mL, respectively. The antioxidant activity was evaluated using DPPH and ABTS radical scavenging assays with IC₅₀ value ranging from 54.01 to 912.66 μg/mL and 33.22 to 128.11 μg/mL, and standard drug ascorbic acid showed IC₅₀ values 29.12 μg/mL and 69.13 μg/mL, respectively. Anti-inflammatory activity was investigated using the carrageenan-induced paw edema method, where percentage inhibition was up to 93.0 and 98.57 for 2 h and 4 h, respectively, and all the compounds were found to exhibit excellent anti-inflammatory activity. Moreover, prediction of activity spectra for substance and molecular docking were also performed. The PASS prediction hypothesized the potential of the compounds for anti-inflammatory activity, and docking results suggested the best binding pose for compounds 1b and 2b with the least energy value from which compounds can be considered as potent COX-2 inhibitors. Furthermore, possible interactions between hydroxytriazene analogues and the targets of antioxidant NADPH oxidase and antidiabetic human maltase-glucoamylase enzyme have been identified. The HOMO and LUMO analysis revealed charge transfer within the compounds. These findings suggested that the synthesized compounds can be potential agents for the treatment of diabetes and inflammation.

An Aspirin a Day: New Pharmacological Developments and Cancer Chemoprevention

Chemoprevention refers to the use of natural or synthetic agents to reverse, suppress, or prevent the progression or recurrence of cancer. A large body of preclinical and clinical data suggest the ability of aspirin to prevent precursor lesions and cancers, but much of the clinical data are inferential and based on descriptive epidemiology, case control, and cohort studies or studies designed to answer other questions (e.g., cardiovascular mortality). Multiple pharmacological, clinical, and epidemiologic studies suggest that aspirin can prevent certain cancers but may also cause other effects depending on the tissue or disease and organ site in question. The best-known biological targets of aspirin are cyclooxygenases, which drive a wide variety of functions, including hemostasis, inflammation, and immune modulation. Newly recognized molecular and cellular interactions suggest additional modifiable functional targets, and the existence of consensus molecular cancer subtypes suggests that aspirin may have differential effects based on tumor heterogeneity. This review focuses on new pharmacological developments and innovations in biopharmacology that clarify the potential role of aspirin in cancer chemoprevention.

Whole-Body PET Imaging in Humans Shows That 11C-PS13 Is Selective for Cyclooxygenase-1 and Can Measure the In Vivo Potency of Nonsteroidal Antiinflammatory Drugs

Both cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) convert arachidonic acid to prostaglandin H₂, which has proinflammatory effects. The recently developed PET radioligand ¹¹C-PS13 has excellent in vivo selectivity for COX-1 over COX-2 in nonhuman primates. This study sought to evaluate the selectivity of ¹¹C-PS13 binding to COX-1 in humans and assess the utility of ¹¹C-PS13 to measure the in vivo potency of nonsteroidal antiinflammatory drugs. Methods: Baseline ¹¹C-PS13 whole-body PET scans were obtained for 26 healthy volunteers, followed by blocked scans with ketoprofen (n = 8), celecoxib (n = 8), or aspirin (n = 8). Ketoprofen is a highly potent and selective COX-1 inhibitor, celecoxib is a preferential COX-2 inhibitor, and aspirin is a selective COX-1 inhibitor with a distinct mechanism that irreversibly inhibits substrate binding. Because blood cells, including platelets and white blood cells, also contain COX-1, ¹¹C-PS13 uptake inhibition from blood cells was measured in vitro and ex vivo (i.e., using blood obtained during PET scanning). Results: High ¹¹C-PS13 uptake was observed in major organs with high COX-1 density, including the spleen, lungs, kidneys, and gastrointestinal tract. Ketoprofen (1-75 mg orally) blocked uptake in these organs far more effectively than did celecoxib (100-400 mg orally). On the basis of the plasma concentration to inhibit 50% of the maximum radioligand binding in the spleen (in vivo IC ₅₀), ketoprofen (<0.24 μM) was more than 10-fold more potent than celecoxib (>2.5 μM) as a COX-1 inhibitor, consistent with the in vitro potencies of these drugs for inhibiting COX-1. Blockade of ¹¹C-PS13 uptake from blood cells acquired during the PET scans mirrored that in organs of the body. Aspirin (972-1,950 mg orally) blocked such a small percentage of uptake that its in vivo IC ₅₀ could not be determined. Conclusion: ¹¹C-PS13 selectively binds to COX-1 in humans and can measure the in vivo potency of nonsteroidal antiinflammatory drugs that competitively inhibit arachidonic acid binding to COX-1. These in vivo studies, which reflect the net effect of drug absorption and metabolism in all organs of the body, demonstrated that ketoprofen had unexpectedly high potency, that celecoxib substantially inhibited COX-1, and that aspirin acetylation of COX-1 did not block binding of the representative nonsteroidal inhibitor ¹¹C-PS13.