Nonsteroidal Anti-Inflammatory Drugs (NSAIDs): Progress in Small Molecule Drug Development

In vivo analgesic, anti-inflammatory and molecular docking studies of S-naproxen derivatives

In the current studies two naproxen derivatives (NPD) were evaluated for analgesic and anti-inflammatory properties. The acetic acid and hot plate animal models were used to screen the compounds for analgesic potential. While the anti-inflammatory potential was evaluated through animal paw edema, induced by several inflammatory mediators (carrageenan, bradykinin, and prostaglandin E2), the xylene-induced ear edema was also used as an inflammatory model. Both NPDs showed significant (p < 0.001) antinociceptive effects in the acetic acid-induced writhing paradigm. In the case of the hot plate, the NPD 1 at the tested dose of 5 mg/kg enhanced the latency time after 60 min of injection, which remained significant (p < 0.001) up to the end of the experiment duration. The maximum percent inhibition of NPD 1 was 87.53. The naloxone injection significantly lowered the latency time of NPD 1 as compared to NPD 2. Regarding the anti-inflammatory effect, both of the tested NPDs demonstrated a significant reduction in paw edema against various inflammatory mediators, as mentioned above; however, the anti-inflammatory effect of NPD 1 was better. The maximal percent inhibition by NPD 1 and 2 was 43.24 (after 60 min) and 45.93 (after 90 min). A considerable effect also resulted from xylene-induced ere edema. Further, a molecular docking study was carried out to investigate the binding modes of the NPD. The docking analysis revealed that the NPD significantly interacted with the COX2 enzyme. Furthermore, molecular dynamics simulation was carried out for the docked complexes. The MD simulation analysis revealed the high stability of the two naproxen derivatives.

Paradigms and Success Stories of Natural Products in Drug Discovery Against Neurodegenerative Disorders (NDDs)

Neurodegenerative disorders (NDDs) are multifaceted complex disorders that have put a great health and economic burden around the globe nowadays. The multi-factorial nature of NDDs has presented a great challenge in drug discovery and continuous efforts are in progress in search of suitable therapeutic candidates. Nature has a great wealth of active principles in its lap that has cured the human population since ancient times. Natural products have revealed several benefits over conventional synthetic medications and scientists have shifted their vision towards exploring the therapeutic potentials of natural products in the past few years. The structural mimicking of natural compounds to endogenous ligands has presented them as a potential therapeutic candidate to prevent the development of NDDs. In the presented review, authors have summarized demographical facts about various NDDs including Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD) and various types of sclerosis in the brain. The significant findings of new active principles of natural origin along with their therapeutic potentials on NDDs have been included. Also, a description of clinical trials and patents on natural products has been enlisted in this compilation. Although natural products have shown promising success in drug discovery against NDDs, still their use is associated with several ethical issues which need to be solved in the upcoming time.

Antiviral PROTACs: Opportunity borne with challenge

Proteolysis targeting chimera (PROTAC) degradation of pathogenic proteins by hijacking of the ubiquitin-proteasome-system has become a promising strategy in drug design. The overwhelming advantages of PROTAC technology have ensured a rapid and wide usage, and multiple PROTACs have entered clinical trials. Several antiviral PROTACs have been developed with promising bioactivities against various pathogenic viruses. However, the number of reported antiviral PROTACs is far less than that of other diseases, e.g., cancers, immune disorders, and neurodegenerative diseases, possibly because of the common deficiencies of PROTAC technology (e.g., limited available ligands and poor membrane permeability) plus the complex mechanism involved and the high tendency of viral mutation during transmission and replication, which may challenge the successful development of effective antiviral PROTACs. This review highlights the important advances in this rapidly growing field and critical limitations encountered in developing antiviral PROTACs by analyzing the current status and representative examples of antiviral PROTACs and other PROTAC-like antiviral agents. We also summarize and analyze the general principles and strategies for antiviral PROTAC design and optimization with the intent of indicating the potential strategic directions for future progress.

Nonsteroidal Anti-Inflammatory Drug Conjugated with Gadolinium (III) Complex as an Anti-Inflammatory MRI Agent

Studies have been actively conducted to ensure that gadolinium-based contrast agents for magnetic resonance imaging (MRI) are accompanied by various biological functions. A new example is the anti-inflammatory theragnostic MRI agent to target inflammatory mediators for imaging diagnosis and to treat inflammatory diseases simultaneously. We designed, synthesized, and characterized a Gd complex of 1,4,7-tris(carboxymethylaza) cyclododecane-10-azaacetylamide (DO3A) conjugated with a nonsteroidal anti-inflammatory drug (NSAID) that exerts the innate therapeutic effect of NSAIDs and is also applicable in MRI diagnostics. Gd-DO3A-fen (0.1 mmol/kg) was intravenously injected into the turpentine oil-induced mouse model, with Gd-DO3A-BT as a control group. In the in vivo MRI experiment, the contrast-to-noise ratio (CNR) was higher and persisted longer than that with Gd-DO3A-BT; specifically, the CNR difference was almost five times at 2 h after injection. Gd-DO3A-fen had a binding affinity (K_a) of 6.68 × 10⁶ M^-1 for the COX-2 enzyme, which was 2.1-fold higher than that of fenbufen, the original NSAID. In vivo evaluation of anti-inflammatory activity was performed in two animal models. In the turpentine oil-induced model, the mRNA expression levels of inflammatory parameters such as COX-2, TNF-α, IL-1β, and IL-6 were reduced, and in the carrageenan-induced edema model, swelling was suppressed by 72% and there was a 2.88-fold inhibition compared with the saline group. Correlation analysis between in vitro, in silico, and in vivo studies revealed that Gd-DO3A-fen acts as an anti-inflammatory theragnostic agent by directly binding to COX-2.

Effects of Non-steroidal Anti-inflammatory Drugs (NSAIDs) and Gastroprotective NSAIDs on the Gastrointestinal Tract: A Narrative Review

Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used for their anti-inflammatory, antipyretic, and analgesic properties. However, their use is often associated with gastrointestinal tract (GIT) side effects due to the inhibition of both cyclooxygenase (COX)-1 and COX-2 enzymes, leading to a decrease in gastroprotective prostaglandins (PG). To minimize these adverse effects, various approaches have been explored, including selective COX-2 inhibitors, NO-NSAIDs (nitric oxide-releasing NSAIDs), and dual COX/LOX (lipoxygenase) NSAIDs. However, the effects of these gastroprotective NSAIDs on the GIT and their efficacy remains uncertain. This review aims to provide an overview of the current understanding of the effects of traditional NSAIDs and gastroprotective NSAIDs on GIT. We discuss the underlying mechanisms of GIT damage caused by NSAIDs, including mucosal injury, ulceration, and bleeding, and the potential of gastroprotective NSAIDs to mitigate these effects. We also summarize recent studies on the efficacy and safety of various gastroprotective NSAIDs and highlight the limitations and challenges of these approaches. The review concludes with recommendations for future research in this field.

Recent Applications of the Multicomponent Synthesis for Bioactive Pyrazole Derivatives

Pyrazole and its derivatives are considered a privileged N-heterocycle with immense therapeutic potential. Over the last few decades, the pot, atom, and step economy (PASE) synthesis of pyrazole derivatives by multicomponent reactions (MCRs) has gained increasing popularity in pharmaceutical and medicinal chemistry. The present review summarizes the recent developments of multicomponent reactions for the synthesis of biologically active molecules containing the pyrazole moiety. Particularly, it covers the articles published from 2015 to date related to antibacterial, anticancer, antifungal, antioxidant, α-glucosidase and α-amylase inhibitory, anti-inflammatory, antimycobacterial, antimalarial, and miscellaneous activities of pyrazole derivatives obtained exclusively via an MCR. The reported analytical and activity data, plausible synthetic mechanisms, and molecular docking simulations are organized in concise tables, schemes, and figures to facilitate comparison and underscore the key points of this review. We hope that this review will be helpful in the quest for developing more biologically active molecules and marketed drugs containing the pyrazole moiety.

PROTACs: great opportunities for academia and industry (an update from 2020 to 2021)

PROteolysis TArgeting Chimeras (PROTACs) technology is a new protein-degradation strategy that has emerged in recent years. It uses bifunctional small molecules to induce the ubiquitination and degradation of target proteins through the ubiquitin–proteasome system. PROTACs can not only be used as potential clinical treatments for diseases such as cancer, immune disorders, viral infections, and neurodegenerative diseases, but also provide unique chemical knockdown tools for biological research in a catalytic, reversible, and rapid manner. In 2019, our group published a review article “PROTACs: great opportunities for academia and industry” in the journal, summarizing the representative compounds of PROTACs reported before the end of 2019. In the past 2 years, the entire field of protein degradation has experienced rapid development, including not only a large increase in the number of research papers on protein-degradation technology but also a rapid increase in the number of small-molecule degraders that have entered the clinical and will enter the clinical stage. In addition to PROTAC and molecular glue technology, other new degradation technologies are also developing rapidly. In this article, we mainly summarize and review the representative PROTACs of related targets published in 2020–2021 to present to researchers the exciting developments in the field of protein degradation. The problems that need to be solved in this field will also be briefly introduced.

Indomethacin-based PROTACs as pan-coronavirus antiviral agents

Indomethacin (INM), a well-known non-steroidal anti-inflammatory drug, has recently gained attention for its antiviral activity demonstrated in drug repurposing studies against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Although the mechanism of action of INM is not yet fully understood, recent studies have indicated that it acts at an early stage of the coronaviruses (CoVs) replication cycle. In addition, a proteomic study reported that the anti-SARS-CoV-2 activity of INM could be also ascribed to its ability to inhibit human prostaglandin E synthase type 2 (PGES-2), a host protein which interacts with the SARS-CoV-2 NSP7 protein. Although INM does not potently inhibit SARS-CoV-2 replication in infected Vero E6 cells, here we have explored for the first time the application of the Proteolysis Targeting Chimeras (PROTACs) technology in order to develop more potent INM-derived PROTACs with anti-CoV activity. In this study, we report the design, synthesis, and biological evaluation of a series of INM-based PROTACs endowed with antiviral activity against a panel of human CoVs, including different SARS-CoV-2 strains. Two PROTACs showed a strong improvement in antiviral potency compared to INM. Molecular modelling studies support human PGES-2 as a potential target of INM-based antiviral PROTACs, thus paving the way toward the development of host-directed anti-CoVs strategies. To the best of our knowledge, these PROTACs represent the first-in-class INM-based PROTACs with antiviral activity and also the first example of the application of PROTACs to develop pan-coronavirus agents.

Siloxy Esters as Traceless Activators of Carboxylic Acids: Boron-Catalyzed Chemoselective Asymmetric Aldol Reaction*

The catalytic asymmetric aldol reaction is among the most useful reactions in organic synthesis. Despite the existence of many prominent reports, however, the late-stage, chemoselective, catalytic, asymmetric aldol reaction of multifunctional substrates is still difficult to achieve. Herein, we identified that in situ pre-conversion of carboxylic acids to siloxy esters facilitated the boron-catalyzed direct aldol reaction, leading to the development of carboxylic acid-selective, catalytic, asymmetric aldol reaction applicable to multifunctional substrates. Combining experimental and computational studies rationalized the reaction mechanism and led to the proposal of Si/B enediolates as the active species. The silyl ester formation facilitated both enolization and catalyst turnover by acidifying the α-proton of substrates and attenuating poisonous Lewis bases to the boron catalyst.

Effect of treatment with resiniferatoxin in an experimental model of pulpal inflammatory in mice

AIM

To evaluate whether treatment with resiniferatoxin (RTX) is capable of lowering the plasma levels of PGE₂ and TNF-α, as well as histopathological parameters in inflammation of pulp tissue in a mouse experimental model.

METHODOLOGY

Ten groups of six BALB/c mice were formed as follows: healthy group (H_C ), healthy group treated with RTX (H_RTX ), two groups with pulp inflammation at 14 and 18 hours (PI₁₄ /PI₁₈ ), six groups with pulpal inflammation plus treatment with Ibuprofen (IBU₁₄ /IBU₁₈ ), dexamethasone (DEX₁₄ /DEX₁₈ ) and resiniferatoxin (RTX₁₄ /RTX₁₈ ) at 14 and 18 hours, respectively. Pulpal inflammation was induced through occlusal exposure of the pulp of the maxillary first molar. The plasma levels of PGE₂ and TNF-α and the histological parameters of the pulp tissue of the H_C and H_RTX groups were evaluated at the time of acquiring the animals. In the other groups, the plasma levels of PGE₂ and TNF-α and the histopathological parameters were evaluated at 14 and 18 hours after pulp damage. Plasma levels of PGE₂ and TNF-α were quantified by ELISA, and the histopathological parameters were evaluated by H/E staining. Statistical significance was determined by one-way analysis of variance (ANOVA) to test for overall differences between group means.

RESULTS

A significant increase (*p < .05) in plasma levels of PGE₂ and TNF-α occurred 14 and 18 hours after pulp damage. In addition, treatment with RTX significantly decreased (*p < .05) the plasma levels of PGE₂ and TNF-α at 14 and 18 hours after pulp damage, as well as the infiltrate of inflammatory cells at 18 hours after pulp damage, similarly to treatment with ibuprofen and dexamethasone.

CONCLUSION

It was possible to detect systemic levels of PGE₂ and TNF-α at 14 and 18 hours after pulp damage. Likewise, treatment with RTX was associated with an anti-inflammatory effect similar to treatment with ibuprofen and dexamethasone. These findings place resiniferatoxin as a therapeutic alternative in the treatment of inflammatory diseases in Dentistry.

Recent Advances in the Synthesis of Ibuprofen and Naproxen

Herein, we review the recent progress in the synthesis of representative nonsteroidal anti-inflammatory drugs (NSAIDs), ibuprofen and naproxen. Although these drugs were discovered over 50 years ago, novel practical and asymmetric approaches are still being developed for their synthesis. In addition, this endeavor has enabled access to more potent and selective derivatives from the key frameworks of ibuprofen and naproxen. The development of a synthetic route to ibuprofen and naproxen over the last 10 years is summarized, including developing methodologies, finding novel synthetic routes, and applying continuous-flow chemistry.

N-(3-Cyano-4,5,6,7-tetrahydrobenzothiophen-2-yl)-2-[[5-[(1,5-dimethyl-3-oxo-2-phenylpyrazol-4-yl)amino]-1,3,4-thiadiazol-2-yl]sulfanyl]acetamide

The small pyrazolone-bearing molecules attract attention and are widely explored in drug design as pharmacological agents. The new pyrazolone-thiadiazole hybrid molecule N-(3-cyano-4,5,6,7-tetrahydrobenzothiophen-2-yl)-2-[[5-[(1,5-dimethyl-3-oxo-2-phenylpyrazol-4-yl)amino]-1,3,4-thiadiazol-2-yl]sulfanyl]acetamide (3) has been synthesized following a two-stage protocol using simple, convenient transformations and cheap, commercially available reagents. The compound’s structure was confirmed using 1H, 13C nuclear magnetic resonance (NMR), and liquid chromatography–mass spectrometry (LC–MS) spectra. The anti-inflammatory potency of 3 was evaluated in silico using molecular docking. The docking studies results suggest that title compound 3 is of great interest for further structure optimization and in-depth studies as a possible 5-lipoxygenase (5-LOX) inhibitor.

Orally Administered NSAIDs-General Characteristics and Usage in the Treatment of Temporomandibular Joint Osteoarthritis-A Narrative Review

Background: Temporomandibular joint osteoarthritis (TMJ OA) is a degenerative joint disease. The aim of this review was to present the general characteristics of orally administered nonsteroidal anti-inflammatory drugs (NSAIDs) and to present the efficacy of NSAIDs in the treatment of TMJ OA. Methods: PubMed database was analyzed with the keywords: "(temporomandibular joint) AND ((disorders) OR (osteoarthritis) AND (treatment)) AND (nonsteroidal anti-inflammatory drug)". After screening of 180 results, 6 studies have been included in this narrative review. Results and Conclusions: Nonsteroidal anti-inflammatory drugs are one of the most commonly used drugs for alleviation of pain localized in the orofacial area. The majority of articles predominantly examined and described diclofenac sodium in the treatment of pain in the course of TMJ OA. Because of the limited number of randomized studies evaluating the efficacy of NSAIDs in the treatment of TMJ OA, as well as high heterogeneity of published researches, it seems impossible to draw up unequivocal recommendations for the usage of NSAIDs in the treatment of TMJ OA. However, it is highly recommended to use the lowest effective dose of NSAIDs for the shortest possible time. Moreover, in patients with increased risk of gastrointestinal complications, supplementary gastroprotective agents should be prescribed.

Non-steroidal anti-inflammatory drugs (NSAIDs) and organ damage: A current perspective

Owing to the efficacy in reducing pain and inflammation, non-steroidal anti-inflammatory drugs (NSAIDs) are amongst the most popularly used medicines confirming their position in the WHO's Model List of Essential Medicines. With escalating musculoskeletal complications, as evident from 2016 Global Burden of Disease data, NSAID usage is evidently unavoidable. Apart from analgesic, anti-inflammatory and antipyretic efficacies, NSAIDs are further documented to offer protection against diverse critical disorders including cancer and heart attacks. However, data from multiple placebo-controlled trials and meta-analyses studies alarmingly signify the adverse effects of NSAIDs in gastrointestinal, cardiovascular, hepatic, renal, cerebral and pulmonary complications. Although extensive research has elucidated the mechanisms underlying the clinical hazards of NSAIDs, no review has extensively collated the outcomes on various multiorgan toxicities of these drugs together. In this regard, the present review provides a comprehensive insight of the existing knowledge and recent developments on NSAID-induced organ damage. It precisely encompasses the current understanding of structure, classification and mode of action of NSAIDs while reiterating on the emerging instances of NSAID drug repurposing along with pharmacophore modification aimed at safer usage of NSAIDs where toxic effects are tamed without compromising the clinical benefits. The review does not intend to vilify these 'wonder drugs'; rather provides a careful understanding of their side-effects which would be beneficial in evaluating the risk-benefit threshold while rationally using NSAIDs at safer dose and duration.

(3,3″)-Linked Biflavanones from Ouratea spectabilis and Their Effects on the Release of Proinflammatory Cytokines in THP-1 Cells

Ouratea spectabilis is an arborous species traditionally used in Brazil as an anti-inflammatory agent. Four new (3,3″)-linked biflavanone O-methyl ethers, named ouratein A (1), B (2), C (3), and D (4), were isolated from the bark extract of the species. Ouratein A (1) is an enantiomer of neochamagesmine A, which has never been described before. The structures were elucidated by extensive spectroscopic data analyses, whereas their absolute configurations were defined by electronic circular dichroism data. Ouratein D (4) inhibited in vitro the release of the pro-inflammatory cytokine CCL2 by lipopolysaccharide-stimulated THP-1 cells (IC₅₀ of 3.1 ± 1.1 μM), whereas TNF and IL-1β release were not reduced by any of the biflavanones. These findings show ouratein D (4) as a selective CCL2 inhibitor, which may have potential for the development of new anti-inflammatory agents to prevent or treat cardiovascular diseases.

Synthesis of Novel Benzodifuranyl; 1,3,5-Triazines; 1,3,5-Oxadiazepines; and Thiazolopyrimidines Derived from Visnaginone and Khellinone as Anti-Inflammatory and Analgesic Agents

Novel (4-methoxy or 4,8-dimethoxy)-3-methyl-N-(6-oxo-2-thioxo-1,2,3, 6-tetrahydro- pyrimidin-4-yl) benzo [1,2-b: 5, 4-b'] difuran-2-carboxamide (5a-b) has been synthesized by the reaction of visnagenone-ethylacetate (2a) or khellinone-ethylacetate (2b) with 6-aminothiouracil in dimethylformamide or refluxing of benzofuran-oxy-N-(2-thioxopyrimidine) acetamide (4a-b) in sodium ethoxide to give the same products (5a,b) in good yields. Thus, compounds 5a-b are used as an initiative to prepare many new heterocyclic compounds such as 2-(4-(3-methylbenzodifuran- 2-carbox-amido) pyrimidine) acetic acid (6a-b), N-(thiazolo[3, 2-a]pyrimidine)-3-methylbenzo- difuran-2-carboxamide (7a-b), N-(2-thioxopyrimidine)-methylbenzodifuran-2-carbimidoylchloride (8a-b), N-(2-(methyl-thio) pyrimidine)-3-methylbenzodifuran-2-carbimidoylchloride (9a-b), N-(2, 6 -di(piperazine or morpholine)pyrimidine)-1-(3-methylbenzodifuran)-1-(piperazine or morpholine) methanimine(10a-d), 8-(methylbenzodifuran)-thiazolopyrimido[1,6-a][1,3,5]triazine-3,5-dione (11a -b), 8-(3-methyl benzodifuran)-thiazolopyrimido[6,1-d][1,3,5]oxadiazepine-trione (12a-b), and 2,10 -di(sub-benzylidene)-8-(3-methylbenzodifuran)-thiazolopyrimido[6,1-d][1,3,5]oxadiazepine-3,5,11- trione (13a-f). All new chemical structures were illustrated on the basis of elemental and spectral analysis (IR, NMR, and MS). The new compounds were screened as cyclooxygenase-1/ cyclooxygenase-2 (COX-1/COX-2) inhibitors and had analgesic and anti-inflammatory activities. The compounds 10a-d and 13a-f had the highest inhibitory activity on COX-2 selectivity, with indices of 99-90, analgesic activity of 51-42% protection, and anti-inflammatory activity of 68%-59%. The inhibition of edema for the same compounds, 10a-d and 13a-f, was compared with sodium diclofenac as a standard drug.

New pyrazole derivatives possessing amino/methanesulphonyl pharmacophore with good gastric safety profile: Design, synthesis, cyclooxygenase inhibition, anti-inflammatory activity and histopathological studies

New series of pyrazole derivatives Va-c, VIa-c, VIIa-f, and VIII possessing amino/methanesulphonyl moiety as COX-2 pharmacophore were designed and synthesized. All compounds were evaluated for both in vitro COX inhibition and in vivo anti-inflammatory activities and all of them were more potent against COX-2 than COX-1 isozyme and showed good in vivo anti-inflammatory activity. Compounds Va, VIa, VIc and VIIa-c showed good COX-2 SI (246.8-353.8) in comparison with the COX-2 selective drug; celecoxib (326.7). Also, they showed good anti-inflammatory activity with edema inhibition (51-86 and 83-96%) relative to celecoxib (60.6 and 82.8%) after 3 and 5 h respectively. Additionally, these potent derivatives Va, VIa, VIc and VIIa-c were significantly less ulcerogenic (ulcer indexes = 0.7-2.0) than indomethacin (ulcer index = 21.3) and were of acceptable ulcerogenicity when compared with the non-ulcerogenic reference drug celecoxib (ulcer index = 1.3). The obtained ulcerogenic liability data revealed the gastric safety of these derivatives which was confirmed by the histopathological studies. Docking study was performed for all synthesized derivatives to explain their interaction with COX-2 receptor active site.

Phenotypic screening of nonsteroidal anti-inflammatory drugs identified mefenamic acid as a drug for the treatment of schistosomiasis

Background

Treatment and control of schistosomiasis, one of the most insidious and serious parasitic diseases, depend almost entirely on a single drug, praziquantel. Since the funding for drug development for poverty-associated diseases is very limited, drug repurposing is a promising strategy. In this study, 73 nonsteroidal anti-inflammatory drugs (NSAIDs) commonly used in medical and veterinary fields were evaluated for their anti-schistosomal properties.

Methods

The efficacy of NSAIDs was first tested against adult Schistosoma mansoni ex vivo using phenotypic screening strategy, effective drugs were further tested in a murine model of schistosomiasis. The disease parameters measured were worm and egg burden, hepato- and splenomegaly.

Findings

From 73 NSAIDs, five (mefenamic acid, tolfenamic acid, meclofenamic acid, celecoxib, and diclofenac) were identified to effectively kill schistosomes. These results were further supported by scanning electron microscopy analysis. In addition, the octanol-water partition coefficient, both for neutral and ionized species, revealed to be a critical property for the ex vivo activity profile. Compounds were then tested in vivo using both patent and a prepatent S. mansoni infection in a mouse model. The most effective NSAID was mefenamic acid, which highly reduced worm burden, egg production, and hepato- and splenomegaly.

Interpretation

The treatment regimen used in this study is within the range for which mefenamic acid has been used in clinical practice, thus, it is demonstrated the capacity of mefenamic acid to act as a potent anti-schistosomal agent suitable for clinical repurposing in the treatment of schistosomiasis.

New pyrazole derivatives: Synthesis, anti-inflammatory activity, cycloxygenase inhibition assay and evaluation of mPGES

New pyrazole derivatives 2-5 were synthesized and evaluated for their COX-1 and COX-2 inhibitory activity in vitro. All compounds showed good inhibitory activity at a nanomolar level and most compounds exhibited selectivity towards COX-2 inhibition. Compounds 2a, 3b, 4a, 5b and 5e exhibited IC₅₀ towards COX-2 enzyme of 19.87, 39.43, 61.24, 38.73 and 39.14 nM, respectively. Furthermore, compounds 3b, 4a, 5b and 5e exhibited a selectivity index of 22.21, 14.35, 17.47 and 13.10, respectively. The most active compounds were further subjected to in vivo anti-inflammatory assay. The tested compounds showed better or comparable activity to celecoxib as positive control. In order to explore their binding mode and selectivity behaviour, molecular docking in the active site of COX-2 was carried out for these derivatives. Analysis of the docked poses of the compounds showed that they adopt similar conformations to the highly selective COX-2 inhibitor, SC-558. The docking pose of compound 3b was confirmed by molecular dynamics. All the tested compounds exhibited potent inhibitory effect on the production of PGE₂, in addition to their inhibition of COX-2 enzyme.

Promising anti-inflammatory effects of chalcones via inhibition of cyclooxygenase, prostaglandin E2, inducible NO synthase and nuclear factor κb activities

Chalcones (1, 3-Diphenyl-2-propen-1-one) consist of a three carbon α, β-unsaturated carbonyl system and act as precursors for the biosynthesis of flavonoids in plants. However, laboratory synthesis of various chalcones has also been reported. Both natural and synthetic chalcones are known to exhibit a variety of pharmacological activities such as anti-inflammatory, antitumor, antibacterial, antifungal, antimalarial and antituberculosis. These promising activities, ease of synthesis and simple chemical structure have awarded chalcones considerable attraction. This review focuses on the anti-inflammatory effects of chalcones, caused by their inhibitory action primarily against the activities and expressions of four key inflammatory mediators viz., cyclooxygenase, prostaglandin E₂, inducible NO synthase, and nuclear factor κB. Various methodologies for the synthesis of chalcones have been discussed. The potency of recently synthesized chalcones is given in terms of their IC₅₀ values. Structure-Activity Relationships (SARs) of a variety of chalcone derivatives have been discussed. Computational methods were applied to calculate the ideal orientation of a typical chalcone scaffold against three enzymes, namely, cyclooxygenase-1, cyclooxygenase-2 and inducible NO synthase for the formation of stable complexes. The global market of anti-inflammatory drugs and its expected growth (from 2018 to 2026) have been discussed. SAR analysis, docking studies, and future prospects all together provide useful clues for the synthesis of novel chalcones of improved anti-inflammatory activities.

Pyrimidine-based fluorescent COX-2 inhibitors: synthesis and biological evaluation

The cyclooxygenase-2 (COX-2) enzyme is overexpressed in a variety of cancers and mediates inflammatory processes that aid the growth and progression of malignancies. Three novel and selective fluorescent COX-2 inhibitors have been designed and synthesized on the basis of previously reported pyrimidine-based COX-2 inhibitors and the 7-nitrobenzofurazan fluorophore. In vitro evaluation of COX-1/COX-2 isozyme inhibition identified N-(2-((7-nitro-benzo[c][1,2,5]oxadiazol-4-yl)amino)propyl)-4-[4-(methylsulfonyl)phenyl]-6-(trifluoro-methyl)-pyrimidin-2-amine (6) as a novel potent and selective COX-2 inhibitor (IC50 = 1.8 μM). Lead compound (6) was further evaluated for its ability to selectively visualize COX-2 isozyme in COX-2 expressing human colon cancer cell line HCA-7 using confocal microscopy experiments.

Cycloartane-type sapogenol derivatives inhibit NFκB activation as chemopreventive strategy for inflammation-induced prostate carcinogenesis

Chronic inflammation is associated to 25% of cancer cases according to epidemiological data. Therefore, inhibition of inflammation-induced carcinogenesis can be an efficient therapeutic approach for cancer chemoprevention in drug development studies. It is also determined that anti-inflammatory drugs reduce cancer incidence. Cell culture-based in vitro screening methods are used as a fast and efficient method to investigate the biological activities of the biomolecules. In addition, saponins are molecules that are isolated from natural sources and are known to have potential for tumor inhibition. Studies on the preparation of analogues of cycloartane-type sapogenols (9,19-cyclolanostanes) have so far been limited. Therefore we have decided to direct our efforts toward the exploration of new anti-tumor agents prepared from cycloastragenol and its production artifact astragenol. The semi-synthetic derivatives were prepared mainly by oxidation, condensation, alkylation, acylation, and elimination reactions. After preliminary studies, five sapogenol analogues, two of which were new compounds (2 and 3), were selected and screened for their inhibitory activity on cell viability and NFκB signaling pathway activity in LNCaP prostate cancer cells. We found that the astragenol derivatives 1 and 2 as well as cycloastragenol derivatives 3, 4, and 5 exhibited strong inhibitory activity on NFκB signaling leading the repression of NFκB transcriptional activation and suppressed cell proliferation. The results suggested that these molecules might have significant potential for chemoprevention of prostate carcinogenesis induced by inflammatory NFκB signaling pathway.

A novel small molecule chaperone of rod opsin and its potential therapy for retinal degeneration

Rhodopsin homeostasis is tightly coupled to rod photoreceptor cell survival and vision. Mutations resulting in the misfolding of rhodopsin can lead to autosomal dominant retinitis pigmentosa (adRP), a progressive retinal degeneration that currently is untreatable. Using a cell-based high-throughput screen (HTS) to identify small molecules that can stabilize the P23H-opsin mutant, which causes most cases of adRP, we identified a novel pharmacological chaperone of rod photoreceptor opsin, YC-001. As a non-retinoid molecule, YC-001 demonstrates micromolar potency and efficacy greater than 9-cis-retinal with lower cytotoxicity. YC-001 binds to bovine rod opsin with an EC50 similar to 9-cis-retinal. The chaperone activity of YC-001 is evidenced by its ability to rescue the transport of multiple rod opsin mutants in mammalian cells. YC-001 is also an inverse agonist that non-competitively antagonizes rod opsin signaling. Significantly, a single dose of YC-001 protects Abca4 -/- Rdh8 -/- mice from bright light-induced retinal degeneration, suggesting its broad therapeutic potential.

Thiazoles and Thiazolidinones as COX/LOX Inhibitors

Inflammation is a natural process that is connected to various conditions and disorders such as arthritis, psoriasis, cancer, infections, asthma, etc. Based on the fact that cyclooxygenase isoenzymes (COX-1, COX-2) are responsible for the production of prostaglandins that play an important role in inflammation, traditional treatment approaches include administration of non-steroidal anti-inflammatory drugs (NSAIDs), which act as selective or non-selective COX inhibitors. Almost all of them present a number of unwanted, often serious, side effects as a consequence of interference with the arachidonic acid cascade. In search for new drugs to avoid side effects, while maintaining high potency over inflammation, scientists turned their interest to the synthesis of dual COX/LOX inhibitors, which could provide numerous therapeutic advantages in terms of anti-inflammatory activity, improved gastric protection and safer cardiovascular profile compared to conventional NSAIDs. Τhiazole and thiazolidinone moieties can be found in numerous biologically active compounds of natural origin, as well as synthetic molecules that possess a wide range of pharmacological activities. This review focuses on the biological activity of several thiazole and thiazolidinone derivatives as COX-1/COX-2 and LOX inhibitors.

Design, synthesis and biological evaluation of hybrid nitroxide-based non-steroidal anti-inflammatory drugs

Dual-acting hybrid anti-oxidant/anti-inflammatory agents were developed employing the principle of pharmacophore hybridization. Hybrid agents were synthesized by combining stable anti-oxidant nitroxides with conventional non-steroidal anti-inflammatory drugs (NSAIDs). Several of the hybrid nitroxide-NSAID conjugates displayed promising anti-oxidant and anti-inflammatory effects on two Non-Small Cell Lung Cancer (NSCLC) cells (A549 and NCI-H1299) and in ameliorating oxidative stress induced in 661 W retinal cells. One ester-linked nitroxide-aspirin analogue (27) delivered better anti-inflammatory effects (cyclooxygenase inhibition) than the parent compound (aspirin), and also showed similar reactive oxygen scavenging activity to the anti-oxidant, Tempol. In addition, a nitroxide linked to the anti-inflammatory drug indomethacin (39) significantly ameliorated the effects of oxidative stress on 661 W retinal neurons at efficacies greater or equal to the anti-oxidant Lutein. Other examples of the hybrid conjugates displayed promising anti-cancer activity, as demonstrated by their inhibitory effects on the proliferation of A549 NSCLC cells.

Ruthenium–arene complexes with NSAIDs: synthesis, characterization and bioactivity

Two non-steroidal antiinflammatory drugs indomethacin and mefenamic acid were coordinated to Ru(ii)–arenes to afford four new complexes.

Alleviating Promotion of Inflammation and Cancer Induced by Nonsteroidal Anti-Inflammatory Drugs

Clinical Relevance

Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) including aspirin are of intensive use nowadays. These drugs exert their activity via the metabolism of arachidonic acid (AA) by cyclooxygenase inhibition. Though beneficial for health in some instances, both unspecific and specific cyclooxygenase inhibitor activity interfere with AA metabolism producing also proinflammatory lipids that may promote cancer.

Materials and Methods

This review is based on available literature on clinical uses, biochemical investigations, molecular medicine, pharmacology, toxicity, and epidemiology-clinical studies on NSAIDs and other drugs that may be used accordingly, which was collected from electronic (SciFinder, Medline, Science Direct, and ACS among others) and library searches of books and journals.

Results

Relevant literature supports the notion that NDSAID use may also promote proinflammatory biochemical events that are also related to precancerous predisposition. Several agents are proposed that may be employed in immediate future to supplement and optimize treatment with NSAIDs. In this way serious side effects arising from promotion of inflammation and cancer, especially in chronic NSAID users and high risk groups of patients, could be avoided.

Impact of FDA-Approved Drugs on the Prostaglandin Transporter OATP2A1/SLCO2A1

To understand interaction of drugs with the prostaglandin transporter OATP2A1/SLCO2A1 that regulates disposition of prostaglandins, we explored the impact of 636 drugs in an FDA-approved drug library on 6-carboxyfluorescein (6-CF) uptake by OATP2A1-expressing HEK293 cells (HEK/2A1). Fifty-one and 10 drugs were found to inhibit and enhance 6-CF uptake by more than 50%, respectively. Effect of the 51 drugs on 6-CF uptake was positively correlated with that on PGE₂ uptake (r = 0.64, p < 0.001). Among those, 5 drugs not structurally related to prostaglandins, suramin, pranlukast, zafirlukast, olmesartan medoxomil, and losartan potassium, exhibited more than 90% PGE₂ uptake inhibition. Inhibitory affinity of suramin to OATP2A1 was the highest (IC_50,2A1 of 0.17 μM), and its IC₅₀ values to MRP4-mediated PGE₂ transport (IC_50,MRP4) and PGE₂ synthesis in human U-937 cells treated with phorbol 12-myristate 13-acetate (IC_50,Syn) were 73.6 and 336.7 times higher than IC_50,2A1, respectively. Moreover, structure-activity relationship study in 29 nonsteroidal anti-inflammatory drugs contained in the library displayed inhibitory activities of anthranilic acid derivatives, but enhancing effects of propionic acid derivatives. These results demonstrate that suramin is a potent selective inhibitor of OATP2A1, providing a comprehensive information about drugs in clinical use that interact with OATP2A1.

Pyrrole and Fused Pyrrole Compounds with Bioactivity against Inflammatory Mediators

A new series of pyrrolopyridines and pyrrolopyridopyrimidines have been synthesized from aminocyanopyrroles. The synthesized compounds have been characterized by FTIR, ¹H-NMR and mass spectroscopy. The final compounds have been screened for in vitro pro-inflammatory cytokine inhibitory and in vivo anti-inflammatory activity. The biological results revealed that among all tested compounds some fused pyrroles, namely the pyrrolopyridines 3i and 3l, show promising activity. A docking study of the active synthesized molecules confirmed the biological results and revealed a new binding pose in the COX-2 binding site.

Role of the liver X receptors in skin physiology: Putative pharmacological targets in human diseases

Liver X receptors (LXRs) are members of the nuclear receptor superfamily that have been shown to regulate various physiological functions such as lipid metabolism and cholesterol homeostasis. Concordant reports have elicited the possibility to target them to cure many human diseases including arteriosclerosis, cancer, arthritis, and diabetes. The high relevance of modulating LXR activities to treat numerous skin diseases, mainly those with exacerbated inflammation processes, contrasts with the lack of approved therapeutic use. This review makes an assessment to sum up the findings regarding the physiological roles of LXRs in skin and help progress towards the therapeutic and safe management of their activities. It focuses on the possible pharmacological targeting of LXRs to cure or prevent selected skin diseases.