Design, synthesis and biological evaluation of novel pyrazole sulfonamide derivatives as dual COX-2/5-LOX inhibitors

Unveiling a novel pyrazolopyrimidine scaffold as a dual COX-2/5-LOX inhibitor with immunomodulatory potential: Design, synthesis, target prediction, anti-inflammatory activity, and ADME-T with docking simulation

Dual-target COX-2/5-LOX inhibitors are regarded as a rational strategy for the design of potent anti-inflammatory agents with favorable safety profiles. In this study, novel pyrazolo[1,5-a]pyrimidine derivatives were synthesized, developed, and screened for their ability to inhibit the cyclooxygenase-2 enzyme in vitro, with comparisons made to the established inhibitors Celecoxib and Meloxicam. Spectroscopic analyses confirmed the structure of the designed derivatives. The target prediction using AI was performed to identify potential targets that could be engaged through Swiss target prediction database. The SAR study was established by incorporating various substituents and nuclei into the pyrazolopyrimidine pharmacophore. The synthesized pyrazolopyrimidines exhibited IC50 values ranging from 53.32 ± 4.43 to 254.90 ± 6.45 nM, in comparison to Celecoxib (IC50 = 6.73 ± 5.69 nM) and Meloxicam (IC50 = 52.35 ± 6.66 nM). Notably, compound 5a was identified as the most active derivative, demonstrating an IC50 of 53.32 ± 4.43 nM. The three most prominent pyrazolopyrimidine derivatives, 3a, 5a, and 6a, were subsequently evaluated for their ability to inhibit the COX-1 and 5-LOX enzymes. Compounds 3a, 5a, and 6a demonstrated inhibitory activity against COX-1, with IC50 values of 476.45 ± 16.56, 757.51 ± 2.61, and 169.13 ± 5.77 nM, respectively. These derivatives 3a, 5a, and 6a showed significant selectivity index values of 7.91, 14.20, and 2.80, respectively, toward COX-2 rather than COX-1 in comparison to Meloxicam (SI = 0.75) and Celecoxib (SI = 2.35). Moreover, compound 5a exhibited 86 % inhibition compared to Zileuton's 88 %, while compounds 3a and 6a displayed inhibition rates of 84 % and 80 %, respectively, at a concentration of 100 μM. The most potent compound 5a, demonstrated the highest 5-LOX inhibitory activity, with IC50 of 2.292 ± 0.14 μM. The most promising pyrazolopyrimidine derivative 5a demonstrated a down-regulation of TNF-α and IL-6 gene expression by approximately 0.3826-fold and 0.2732-fold, respectively, when compared to Celecoxib, which induced reductions of 0.2320-fold and 0.2730-fold in these cytokines to promote apoptosis in RAW264.7 cells. Finally, in-silico ADME-T and docking simulations were conducted to predict the oral bioavailability, toxicity, and binding interactions with binding affinity.

Discovery of Safe COX-2 Inhibitors: Achieving Reduced Colitis Side Effects through Balanced COX Inhibition

The severe adverse effects associated with imbalanced cyclooxygenase-2 (COX-2) inhibition continue to pose significant challenges in the development of contemporary anti-inflammatory drugs. In recent years, the approach to COX-2 inhibitor drug development has shifted from a focus on highly selective inhibition of COX-2 to a strategy that emphasizes more moderate selectivity. The amino acid sequence and structural similarities between inducible COX-2 and constitutive cyclooxygenase-1 (COX-1) isoforms present both substantial opportunities and challenges for the design of next generation of balanced COX-2 inhibitors. As part of our ongoing research into the discovering novel and safer COX-2 inhibitors, we reported herein a highly potent and balanced COX-2 inhibitor 21 d (IC50 value=1.35 μM, selectivity profile (IC50 (COX-1)/IC50 (COX-2)=22.34)). In vivo assays demonstrated that 21 d significantly alleviated histological damage and provided robust protection against dextran sulfate sodium (DSS)-induced acute colitis.

A review of the patent literature surrounding TRPV1 modulators

INTRODUCTION

TRPV1, a pivotal therapeutic target for chronic pain and pruritus, has been validated in the pathogenesis of several pathologies from diabetes to cancer. Despite the constellation of chemical structures and strategies, none of these molecules has yet been clinically developed as a new drug application due to safety concerns, particularly in thermoregulation. Thus, clinical development of TRPV1 modulators remains a challenge.

AREAS COVERED

This review covers the patent literature on TRPV1 modulators (2019-2024, PubMed, Google Patents, and Espacenet), from orthosteric ligands to innovative compounds of biotechnological origin such as interfering RNAs or antibodies, and dual modulators that can act on TRPV1 and associated proteins in different tissues.

EXPERT OPINION

Therapeutic strategies that preferentially act on dysfunctional TRPV1 channels appear essential, along with a superior understanding of the underlying mechanisms affecting changes in core body temperature (CBT). Recent findings describing differential receptor interactions of antagonists that do not affect CBT may pave the way to the next generation of orally active TRPV1 inhibitors. Although we have thus far experienced a bitter feeling in TRPV1 drug development, the recent progress in different disciplines, including human-based preclinical models, will set an interdisciplinary approach to design and develop clinically relevant TRPV1 modulators.

A Comprehensive Review on the Advancements of Dual COX-2/5-LOX Inhibitors as Anti-Inflammatory Drugs

Chronic pain and inflammation are widespread clinical issues that significantly affect patients' quality of life and are often associated with serious conditions such as arthritis, cancer, and cardiovascular disease. Effective management of inflammation is therefore a major public health priority. Current anti-inflammatory treatments-including non-steroidal anti-inflammatory drugs (NSAIDs), corticosteroids, disease-modifying antirheumatic drugs (DMARDs), and biologics-offer symptomatic relief but are frequently limited by side effects such as gastrointestinal toxicity, immunosuppression, or cardiovascular risks. Moreover, most of these therapies target only a single pathway in the inflammatory cascade. Dual inhibitors of COX-2 and 5-LOX have emerged as a promising therapeutic class, as they simultaneously block two key enzymes involved in prostaglandin and leukotriene synthesis. This dual-action approach offers enhanced efficacy and may reduce adverse effects linked to selective or non-selective COX inhibition. This review discusses the underlying mechanisms of inflammation, evaluates current treatment options, and highlights the pharmacological advantages and development status of dual COX-2/5-LOX inhibitors as a next-generation strategy for inflammation management.

Review of the recent advances of pyrazole derivatives as selective COX-2 inhibitors for treating inflammation

Pyrazole heterocycle is regarded as an extremely significant agent for the therapy of inflammation. Celecoxib, lonazolac, deracoxib, and phenylbutazone are examples of commercially approved pyrazole drugs with COX-2 inhibitory potential for curing inflammation. There have been recently many reviews for the biological significance of pyrazole derivatives. This review talks about pyrazole derivatives with anti-inflammatory activity and also sheds the light on the recent updates on pyrazole research with an emphasis on some synthetic pathways utilized to construct this privileged scaffold and structure activity relationship that accounts for the anti-inflammatory activity in an attempt to pave the opportunity for medicinal chemists to develop novel anti-inflammatory agents with better COX-2 selectivity.

Sulfonamide-Pyrazole derivatives as next-generation Cyclooxygenase-2 enzyme inhibitors: From molecular design to in vivo efficacy

The current research focuses on the design and synthesis of celecoxib analogues incorporating sulphonamide and pyrazole moieties (4, 5, 6a-e, and 7a-f) with the aim of achieving a broad range of COX-2 selectivity in vitro. Among these, compounds 6b-d, 7a, 7e, and 7d exhibited potent inhibition, with IC50 values ranging between 0.05 and 0.08 μM, and were selected for in vivo evaluation using the formalin-induced paw edema model. To further assess the safety profile of compound 6d, a histopathological examination of paw tissue was conducted alongside routine blood analyses evaluating key liver and kidney function parameters, including creatinine, urea, AST, and ALT levels. The results indicated normal profiles, comparable to reference drugs celecoxib and indomethacin. Additionally, compound 6d was evaluated for its effect on inflammatory biomarkers using ELISA assays. Markedly, 6d elicited a remarkable reduction in TNF-α (71.43 %) and PGE2 (77.11 %) levels, surpassing the effects of both celecoxib and indomethacin, confirming its potent anti-inflammatory properties. In terms of analgesic activity, Importantly, cardiac toxicity assessment revealed no adverse effects associated with compound 6d. Finally, compound 6d underwent in silico analysis, including molecular docking and molecular dynamics simulations, which confirmed its selective interaction with the COX-2 active site and favorable free insertion into the selectivity side pocket.

Recent highlights in the synthesis and biological significance of pyrazole derivatives

Aza-heterocyclic scaffolds are privileged cores in the composition of their potential therapeutic profiles and versatile synthetic intermediates. Pyrazole is one of the frequently studied compounds of "azole" family and consists of nitrogen in a 1,2 linking sequence. These motifs possess a wide-spectrum of applications in the field of pharmaceuticals, agrochemicals, polymer chemistry, cosmetics, food industries and more. In addition, functionalized pyrazole derivatives are frequently used as ligands in coordination chemistry and metal-catalysed reactions. As exemplified by numerous recent reports, pyrazoles are highly promising pharmacophores with excellent therapeutic applications. Owing to their aromaticity, the ring structures have many reactive positions, where electrophilic, nucleophilic, alkylation and oxidative reactions might occur. The structural adroitness and diversity of pyrazole cores further emanated numerous fused bicyclic skeletons with various biological applications. In this review, we highlight the recent synthetic methods developed for the preparation of functionalized pyrazole derivatives (From 2017 to present). In addition, we have also covered the notable biological activities (anti-cancer, anti-inflammatory, anti-bacterial and anti-viral) of this ubiquitous core. Herein, we emphasised the synthesis of pyrazoles from variety of precursors such as, alkynes, α,β-unsaturated carbonyl compounds, diazo reagents, nitrile imines, diazonium salts, 1,3-dicarbonyl compounds and etc. Moreover, the recent synthetic methodologies focusing on the preparation of pyrazolines and pyrazolones and variously fused-pyrazoles are also included. Authors expect this review could significantly help the researchers in finding elegant novel tools to synthesize pyrazole skeletons and expand their biological evaluation.

Design, synthesis, and evaluation of benzhydrylpiperazine-based novel dual COX-2/5-LOX inhibitors with anti-inflammatory and anti-cancer activity

Piperazine derivatives were screened using the ChEMBL database, paving the way for the design, synthesis, and evaluation of a novel series of dual COX-2/5-LOX inhibitors and identifying their role in mitigating cancer cell proliferation. Compound 9d with 4-Cl substitution at the terminal phenyl ring showed promising inhibition of COX-2 (IC50 = 0.25 ± 0.03 μM) and 5-LOX (IC50 = 7.87 ± 0.33 μM), outperforming the standards celecoxib (IC50 = 0.36 ± 0.023 μM) and zileuton (IC50 = 14.29 ± 0.173 μM), respectively. The two most active derivatives 9d and 9g indicated a significant anti-inflammatory response in a paw edema model by inhibiting PGE2, IL-6, and TNF-α and an increase in IL-10 concentrations. Interestingly, 9d effectively reduced pain by 55.78%, closely comparable to the 59.09% exhibited by the standard indomethacin, and was also devoid of GI, liver, kidney, and cardiac toxicity. Furthermore, 9d demonstrated anti-cancer potential against in vitro A549, COLO-205, and MIA-PA-CA-2 human cancer cell lines and an in vivo Drosophila cancer model. The pharmacokinetic investigations revealed that 9d has good oral absorption characteristics.

Design, synthesis and anti-inflammatory assessment of certain substituted 1,2,4-triazoles bearing tetrahydroisoquinoline scaffold as COX 1/2-inhibitors

Aiming to discover effective and safe non-steroidal anti-inflammatory agents, a new set of 1,2,4-triazole tetrahydroisoquinoline hybrids 9a-g, 11a-g and 12a-g was synthesized and evaluated as inhibitors of COX-1 and COX-2. In order to overcome the adverse effects of highly selective COX-2 and non-selective COX-2 inhibitors, the compounds of this study were designed with the goal of obtaining moderately selective COX-2 inhibitors. In this study compounds 9e, 9g and 11f are the most effective derivatives against COX-2 with IC50 values 0.87, 1.27 and 0.58 µM, respectively which are better than or comparable to the standard drug celecoxib (IC50 = 0.82 µM) but with lower selectivity indices as required by our goal design. The results of the in vivo anti-inflammatory inhibition test revealed that compounds 9e, 9g and 11f displayed a higher significant anti-inflammatory activity than celecoxib at all-time intervals. In addition, these compounds significantly decreased the production of inflammatory mediators PGE-2, TNF-ɑ and IL-6. Compounds 9e, 9g and 11f had a safe gastric profile compared to indomethacin, also compound 11f (ulcerogenic index = 1.33) was less ulcerous than the safe celecoxib (ulcerogenic index = 3). Moreover, histopathological investigations revealed a normal architecture of both paw skin and gastric mucosa after oral treatment of rats with compound 11f. Furthermore, molecular docking studies were performed on COX-1 and COX-2 to study the binding pattern of compounds 9e, 9g and 11f on both isoenzymes.

Exploring the Potential Biological Activities of Pyrazole-Based Schiff Bases as Anti-Diabetic, Anti-Alzheimer's, Anti-Inflammatory, and Cytotoxic Agents: In Vitro Studies with Computational Predictions

In this innovative research, we aim to reveal pyrazole-based Schiff bases as new multi-target agents. In this context, we re-synthesized three sets of pyrazole-based Schiff bases, 5a-f, 6a-f, and 7a-f, to evaluate their biological applications. The data from in vitro biological assays (including antioxidant and scavenging activities, anti-diabetes, anti-Alzheimer's, and anti-inflammatory properties) of the pyrazole-based Schiff bases 5a-f, 6a-f, and 7a-f showed that the six pyrazole-based Schiff bases 5a, 5d, 5e, 5f, 7a, and 7f possess the highest biological properties among the compounds evaluated. The cytotoxicity against lung (A549) and colon (Caco-2) human cancer types, as well as normal lung (WI-38) cell lines, was evaluated. The data from the cytotoxicity investigation demonstrated that the three Schiff bases 5d, 5e, and 7a are active against lung (A549) cells, while the two Schiff bases 5e and 7a exhibited the highest cytotoxicity towards colon (Caco-2) cells. Additionally, the enzymatic activities against caspase-3 and Bcl-2 of the six pyrazole-based Schiff bases 5a, 5d, 5e, 5f, 7a, and 7f were evaluated. Furthermore, we assessed the in silico absorption, distribution, metabolism, and toxicity (ADMT) properties of the more potent pyrazole-based Schiff bases. After modifying the structures of the six pyrazole-based Schiff bases, we plan to further extend the studies in the future.

Exploring of novel oxazolones and imidazolones as anti-inflammatory and analgesic candidates with cyclooxygenase inhibitory action

Aim: Over the last few decades, therapeutic needs have led to a search for safer COX-2 inhibitors with potential anti-inflammatory and analgesic activity. Materials & methods: A new series of oxazolone and imidazolone derivatives 3a-c and 4a-r were synthesized and evaluated as anti-inflammatory and analgesic agents. COX-1/COX-2 isozyme selectivity testing and molecular docking were performed. Results: All compounds showed good activities comparable to those of the reference, celecoxib. The most active compounds 3a, 4a, 4c, 4e and 4f showed promising gastric tolerability with an ulcer index lower than that of celecoxib. The molecular docking of p-methoxyphenyl derivative 4c showed alkyl interaction with the side pocket His75 of COX-2 and achieved the best anti-inflammatory activity, with a COX-2 selectivity index better than that of celecoxib.

Investigations of new N1-substituted pyrazoles as anti-inflammatory and analgesic agents having COX inhibitory activity

Background: The search is ongoing for ideal anti-inflammatory and analgesic agents with promising potency and reasonable selectivity. Methods: New N1-substituted pyrazoles with or without an acetamide linkage were synthesized and evaluated for their anti-inflammatory and analgesic activities. COX inhibitory testing, molecular docking, molecular dynamics simulation and antiproliferative activity assessments were performed. Results: All compounds exhibited anti-inflammatory activity up to 90.40% inhibition. They also exhibited good analgesic activity with up to 100% protection. N1-benzensulfonamides 3d, 6c and 6h were preferentially selective agents toward COX-2. Compound 3d showed good cytotoxicity against MCF-7 and HTC116 cancer cell lines. Molecular modeling studies predicted the binding pattern of the most active compounds. Molecular dynamics confirmed the docking results. All compounds showed remarkable pharmacokinetic properties.

In-silico based Designing of benzo[d]thiazol-2-amine Derivatives as Analgesic and Anti-inflammatory Agents

BACKGROUND

Benzo[d]thiazoles represent a significant class of heterocyclic compounds renowned for their diverse pharmacological activities, including analgesic and antiinflammatory properties. This molecular scaffold holds substantial interest among medicinal chemists owing to its structural versatility and therapeutic potential. Incorporating the benzo[d]thiazole moiety into drug molecules has been extensively investigated as a strategy to craft novel therapeutics with heightened efficacy and minimized adverse effects.

AIMS

The aim of the present research work was to design, synthesize and characterize the new benzo[d]thiazol-2-amine derivatives as potent analgesic and anti-inflammatory agents.

MATERIALS AND METHODS

The synthesis of the presented benzo[d]thiazol-2-amine derivatives was performed by condensing-(4-chlorobenzylidene) benzo[d]thiazol-2-amine with a number of substituted phenols in the presence of potassium iodide and anhydrous potassium carbonate in dry acetone. IR spectroscopy, 1HNMR spectroscopy, 13CNMR spectroscopy and Mass spectroscopy methods were used to characterize the structural properties of all 13 newly synthesized derivatives. The molecular properties of these newly synthesized derivatives were estimated to study the attributes of drug-like candidates. Benzo[d]thiazol-2-amine derivatives were molecularly docked with selective enzymes COX-1 and COX-2. Analgesic and anti-inflammatory activities of synthesized compounds were evaluated by using albino rats.

RESULTS

Findings of the research suggested that compounds G3, G4, G6, G8 and G11 possess higher binding affinity than diclofenac sodium, when docking was performed with enzyme COX-1. Compounds G1, G3, G6, G8 and G10 showed lower binding affinity than Indomethacin when docking was performed with enzyme COX-2. In vitro evaluation of the COX-1 and COX-2 enzyme inhibitory activities was performed for synthesized compounds.

DISCUSSION

Compounds G10 and G11 exhibited significant COX-1 and COX-2 enzyme inhibitory action with an IC50 value of 5.0 and 10 μM, respectively. Using the hot plate method and the carrageenan-induced rat paw edema model, the synthesized compounds were screened for their biological activities, including analgesic and anti-inflammatory activities. Highest analgesic action was exhibited by derivative G11 and the compound G10 showed the highest anti-inflammatory response. Inhibition of COX may be considered as a mechanism of action of these compounds.

CONCLUSION

It was concluded that synthesized derivatives G10 and G11 exhibited significant analgesic and anti-inflammatory effect; therefore, the said compounds may be subjected to further clinical investigation for establishing these as future compounds for the treatment of pain and inflammation.

Progress in the development of TRPV1 small-molecule antagonists: Novel Strategies for pain management

Transient receptor potential vanilloid 1 (TRPV1) channels are widely distributed in sensory nerve endings, the central nervous system, and other tissues, functioning as ion channel proteins responsive to thermal pain and chemical stimuli. In recent years, the TRPV1 receptor has garnered significant interest as a potential therapeutic approach for various pain-related disorders, particularly TRPV1 antagonists. The present review offers a comprehensive, systematic exploration of both first- and second-generation TRPV1 antagonists in the context of pain management. Antagonists are categorized and explicated according to their structural characteristics. Detailed examination of binding modes, structural features, and pharmacological activities, alongside a critical appraisal of the advantages and limitations inherent to typical compounds within each structural category, are undertaken. Detailed discussions of the binding modes, structural features, pharmacological activities, advantages, and limitations of typical compounds within each structural category offer valuable insights and guidance for the future research and development of safer, more effective, and more targeted TRPV1 antagonists.

Dual COX-2/15-LOX inhibitors: A new avenue in the prevention of cancer

Dual cyclooxygenase 2/15-lipoxygenase inhibitors constitute a valuable alternative to classical non-steroidal anti-inflammatory drugs (NSAIDs) and selective COX-2 (cyclooxygenase-2) inhibitors for the treatment of inflammatory diseases, as well as preventing the cancer. Indeed, these latter present diverse side effects, which are reduced or absent in dual-acting agents. In this review, COX-2 and 15-LOX (15-lipoxygenase) pathways are first described in order to highlight the therapeutic interest of designing such compounds. Various structural families of dual inhibitors are illustrated. This study discloses various structural families of dual 15-LOX/COX-2 inhibitors, thus pave the way to design potentially-active anticancer agents with balanced dual inhibition of these enzymes.

Dual-target inhibitors based on COX-2: a review from medicinal chemistry perspectives

Inhibitors of COX-2 constitute a class of anti-inflammatory analgesics, showing potential against certain types of cancer. However, such inhibitors are associated with cardiovascular toxicity. Moreover, although single-target molecules possess specificity for particular targets, they often lead to poor safety, low efficacy and drug resistance due to compensatory mechanisms. A new generation of dual-target drugs that simultaneously inhibit COX-2 and another target is showing strong potential to treat cancer or reduce adverse cardiac effects. The present perspective focuses on the structure and functions of COX-2, and its role as a therapeutic target. It also explores the current state and future possibilities for dual-target strategies from a medicinal chemistry perspective.

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.

Design, Synthesis, Biological Evaluation, and Molecular Docking Study of 4,6-Dimethyl-5-aryl/alkyl-2-[2-hydroxy-3-(4-substituted-1-piperazinyl)propyl]pyrrolo[3,4-c]pyrrole-1,3(2H,5H)-diones as Anti-Inflammatory Agents with Dual Inhibition of COX and LOX

In the present study, we characterize the biological activity of a newly designed and synthesized series of 15 compounds 2-[2-hydroxy-3-(4-substituted-1-piperazinyl)propyl] derivatives of pyrrolo[3,4-c]pyrrole 3a-3o. The compounds were obtained with good yields of pyrrolo[3,4-c]pyrrole scaffold 2a-2c with secondary amines in C₂H₅OH. The chemical structures of the compounds were characterized by ¹H-NMR, ¹³C-NMR, FT-IR, and MS. All the new compounds were investigated for their potencies to inhibit the activity of three enzymes, i.e., COX-1, COX-2, and LOX, by a colorimetric inhibitor screening assay. In order to analyze the structural basis of interactions between the ligands and cyclooxygenase/lipooxygenase, experimental data were supported by the results of molecular docking simulations. The data indicate that all of the tested compounds influence the activity of COX-1, COX-2, and LOX.

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.

Synthesis and biological evaluation of N-(benzene sulfonyl)acetamide derivatives as anti-inflammatory and analgesic agents with COX-2/5-LOX/TRPV1 multifunctional inhibitory activity

In this study, a series of structurally novel N-(benzene sulfonyl) acetamide derivatives were designed, synthesized, and biologically evaluated as COX-2/5-LOX/TRPV1 multitarget inhibitors for anti-inflammatory and analgesic therapy. Among them, 9a and 9b displayed favorable COX-2 (9a IC₅₀ = 0.011 μM, 9b IC₅₀ = 0.023 μM), 5-LOX (9a IC₅₀ = 0.046 μM, 9b IC₅₀ = 0.31 μM) and TRPV1 (9a IC₅₀ = 0.008 μM, 9b IC₅₀ = 0.14 μM) inhibitory activities. The pharmacokinetic (PK) study of 9a in SD rats at the dosage of 10 mg/kg demonstrated a high oral exposure, an acceptable clearance and a favorable bioavailability (Cmax = 5807.18 ± 2657.83 ng/mL, CL = 3.24 ± 1.47 mL/min/kg, F = 96.8 %). Further in vivo efficacy studies illustrated that 9a was capable of ameliorating formalin-induced pain and inhibiting capsaicin-induced ear edema.

Crystallographic study, biological assessment and POM/Docking studies of pyrazoles-sulfonamide hybrids (PSH): Identification of a combined Antibacterial/Antiviral pharmacophore sites leading to in-silico screening the anti-Covid-19 activity

The discovery and development of new potent antimicrobial and antioxidant agents is an essential lever to protect living beings against pathogenic microorganisms and free radicals. In this regard, new functionalized pyrazoles have been synthesized using a simple and accessible approach. The synthesized aminobenzoylpyrazoles 3a-h and pyrazole-sulfonamides 4a-g were obtained in good yields and were evaluated in vitro for their antimicrobial and antioxidant activities. The structures of the synthesized compounds were determined using IR, NMR, and mass spectrometry. The structure of the compound 4b was further confirmed by single crystal X-ray diffraction. The results of the in vitro screening show that the synthesized pyrazoles 3 and 4 exhibit a promising antimicrobial and antioxidant activities. Among the tested compounds, pyrazoles 3a, 3f, 4e, 4f, and 4g have exhibited remarkable antimicrobial activity against some microorganisms. In addition, compounds 3a, 3c, 3e, 4a, 4d, 4f, and 4g have shown a significant antioxidant activity in comparison with the standard butylhydroxytoluene (BHT). Hence, compounds 3a, 4f, and 4g represent interesting dual acting antimicrobial and antioxidant agents. In fact, pyrazole derivatives bearing sulfonamide moiety (4a-g) have displayed an important antimicrobial activity compared to pyrazoles 3a-h, this finding could be attributed to the synergistic effect of the pyrazole and sulfonamide pharmacophores. Furthermore, Molecular docking results revealed a good interaction of the synthesized compounds with the target proteins and provided important information about their interaction modes with the target enzyme. The results of the POM bioinformatics investigations (Petra, Osiris, Molinspiration) show that the studied heterocycles present a very good non toxicity profile, an excellent bioavailability, and pharmacokinetics. Finally, an antiviral pharmacophore (O δ-, O δ-) was evaluated in the POM investigations and deserves all our attention to be tested against Covid-19 and its Omicron and Delta mutants.

Rational Design and Synthesis of New Selective COX-2 Inhibitors with In Vivo PGE2-Lowering Activity by Tethering Benzenesulfonamide and 1,2,3-Triazole Pharmacophores to Some NSAIDs

New selective COX-2 inhibitors were designed and synthesized by tethering 1,2,3-triazole and benzenesulfonamide pharmacophores to some NSAIDs. Compounds 6b and 6j showed higher in vitro COX-2 selectivity and inhibitory activity (IC₅₀ = 0.04 µM and S.I. = 329 and 312, respectively) than celecoxib (IC₅₀ = 0.05 µM and S.I. = 294). Compound 6e revealed equipotent in vitro COX-2 inhibitory activity to celecoxib. Furthermore, 6b and 6j expressed more potent relief of carrageenan-induced paw edema thickness in mice than celecoxib, with ED₅₀ values of 11.74 µmol/kg and 13.38 µmol/kg vs. 16.24 µmol/kg, respectively. Compounds 6b and 6j inhibited the production of PGE2 with a % inhibition of PGE2 production of 90.70% and 86.34%, respectively, exceeding celecoxib’s percentage (78.62%). Moreover, 6b and 6j demonstrated a gastric safety profile comparable to celecoxib. In conclusion, compounds 6b and 6j better achieved the target goal as more potent and selective COX-2 inhibitors than celecoxib in vitro and in vivo.

Non-steroidal anti-inflammatory drugs: recent advances in the use of synthetic COX-2 inhibitors

Cyclooxygenase (COX) enzymes comprise COX-1 and COX-2 isoforms and are responsible for prostaglandin production. Prostaglandins have critical roles in the inflammation pathway and must be controlled by administration of selective nonsteroidal anti-inflammatory drugs (NSAIDs). Selective COX-2 inhibitors have been among the most used NSAIDs during the ongoing coronavirus 2019 pandemic because they reduce pain and protect against inflammation-related diseases. In this framework, the mechanism of action of both COX isoforms (particularly COX-2) as inflammation mediators must be reviewed. Moreover, proinflammatory cytokines such as tumor necrosis factor-α and interleukin (IL)-6, IL-1β, and IL-8 must be highlighted due to their major participation in upregulation of the inflammatory reaction. Structural and functional analyses of selective COX-2 inhibitors within the active-site cavity of COXs could enable introduction of lead structures with higher selectivity and potency against inflammation with fewer adverse effects. This review focuses on the biological activity of recently discovered synthetic COX-2, dual COX-2/lipoxygenase, and COX-2/soluble epoxide hydrolase hybrid inhibitors based primarily on the active motifs of related US Food and Drug Administration-approved drugs. These new agents could provide several advantages with regard to anti-inflammatory activity, gastrointestinal protection, and a safer profile compared with those of the NSAIDs celecoxib, valdecoxib, and rofecoxib.

A Review of the Recent Development in the Synthesis and Biological Evaluations of Pyrazole Derivatives

Pyrazoles are five-membered heterocyclic compounds that contain nitrogen. They are an important class of compounds for drug development; thus, they have attracted much attention. In the meantime, pyrazole derivatives have been synthesized as target structures and have demonstrated numerous biological activities such as antituberculosis, antimicrobial, antifungal, and anti-inflammatory. This review summarizes the results of published research on pyrazole derivatives synthesis and biological activities. The published research works on pyrazole derivatives synthesis and biological activities between January 2018 and December 2021 were retrieved from the Scopus database and reviewed accordingly.

Unexpected ring opening of pyrazolines with activated alkynes: synthesis of 1H-pyrazole-4,5-dicarboxylates and chromenopyrazolecarboxylates

1H-Pyrazole-4,5-dicarboxylates and chromenopyrazole carboxylates were prepared by reacting pyrazolines with activated alkynes under neat conditions without a catalyst. The products were formed via unexpected ring opening of pyrazolines with the elimination of styrene/ethylene. These types of transformations are unknown and the products formed were confirmed using their spectral/analytical data. In addition, the structures of compounds 5e and 5n were confirmed by single-crystal X-ray analysis. Control experiments were conducted to support the proposed reaction mechanism.

Targeted Separation of COX-2 Inhibitor from Pterocephalus hookeri Using Preparative High-Performance Liquid Chromatography Directed by the Affinity Solid-Phase Extraction HPLC System

Pterocephalus hookeri, as a kind of popular traditional Tibetan medicine, is reputed to treat inflammatory related diseases. In the present work, a cyclooxygenase-2 functionalized affinity solid-phase extraction HPLC system was developed and combined with preparative-HPLC for rapidly screening and separating cyclooxygenase-2 ligand from P. hookeri extracts. Firstly, ligands of cyclooxygenase-2 were screened from extracts by affinity solid-phase extraction HPLC system. Then directed by the screening results, the recognized potential active compounds were targeted separated. As a result, the major cyclooxygenase-2 inhibitor of P. hookeri was obtained with a purity of >95%, which was identified as sylvestroside I. To test the accuracy of this method, the anti-inflammatory activity of sylvestroside I was inspected in lipopolysaccharide-induced RAW 264.7 cells. The results show that sylvestroside I significantly suppressed the release of prostaglandin E₂ with dose-dependent, which was in good agreement with the screening result of the affinity solid-phase method. This method of integration of screening and targeted separation proved to be very efficient for the recognition and isolation of cyclooxygenase-2 inhibitors from natural products.

Synthetically-tailored and nature-derived dual COX-2/5-LOX inhibitors: Structural aspects and SAR

Inflammation is a most complex pathological process that gives birth to different diseases. Different inflammatory mediators are released during an inflammation responsible for acute pain and chronic inflammatory diseases like cancer, asthma, rheumatoid arthritis, osteoarthritis, neurodegenerative diseases, metabolic and cardiovascular disorders. The arachidonic acid pathway, which results in the production of inflammatory mediators, provides several targets for anti-inflammatory intervention. The most popularly used medications for inflammation are non-steroidal anti-inflammatory agents (NSAIDs) but it has some limitations, in particular traditional NSAIDs which inhibit the COX pathway non-selectively, producing gastrointestinal side effects, and other adverse effects like stroke and renal failure. On the other hand, selective COX-2 inhibitors commonly known as 'coxibs' produce cardiovascular side effects. Frequent inhibition of either cyclooxygenase or lipoxygenase enzyme switches the metabolism of arachidonic acid from one to another which could lead to serious consequences. Therefore, a need to develop novel, effective and safe anti-inflammatory agents which can inhibit the release of both prostaglandins and leukotrienes from the respective cyclooxygenase and lipoxygenase pathways has emerged. This resulted in the discovery of new anti-inflammatory agents derived from natural and synthetic sources as dual COX-2/5-LOX inhibitors. To further contribute towards the discovery in this field, we have attempted to summarize structural features and pharmacological activities of heterocyclic scaffolds and natural products explored as dual COX-2/5-LOX inhibitors. We have emphasized the designing of the dual inhibitors inspired by the previously reported COX-2 and 5-LOX inhibitors. This outline could render us to identify the best pharmacophores catering to dual COX-2/5-LOX inhibitory activity while improving their efficiency as anti-inflammatory agents.

Conventional and Microwave-Assisted Synthesis, Antitubercular Activity, and Molecular Docking Studies of Pyrazole and Oxadiazole Hybrids

Microwave-assisted organic reaction enhancement (MORE) has become more important in synthetic organic chemistry for efficient resource utilization. In this study, we synthesized bioactive compounds using both traditional and microwave methods. Microwave-assisted synthesis takes less time and produces higher yields and quality than conventional approaches. We reported the synthesis of N'-(1-(2-(3-(4-chlorophenyl)-1-phenyl-1H-pyrazol-4-yl)-5-phenyl-1,3,4-oxadiazol-3(2H)-yl)ethylidene) substituted hydrazides (4a-t). We also tested them against two strains: M. tuberculosis H₃₇Ra and M. bovis BCG. Against M. tuberculosis H₃₇Ra, the compounds 4e, 4h, 4k, 4p, and 4s were the most effective. Compounds 4f, 4g, and 4s showed significant activity against M. bovis BCG. The structures of newly synthesized molecules were determined using spectral methods. Furthermore, molecular docking investigations into the active site of mycobacterial InhA yielded well-clustered solutions for these compounds' binding modalities producing a binding affinity in the range of -10.366 to -8.037. Theoretical results were in good accord with the observed experimental values. The docking score of compound 4e was -10.366, and the Glide energy was -66.459 kcal/mol.

Small molecule compounds with good anti-inflammatory activity reported in the literature from 01/2009 to 05/2021: a review

Inflammation and disease are closely related. Inflammation can induce various diseases, and diseases can promote inflammatory response, and two possibly induces each other in a bidirectional loop. Inflammation is usually treated using synthetic anti-inflammatory drugs which are associated with several adverse effects hence are not safe for long-term use. Therefore, there is need for anti-inflammatory drugs which are not only effective but also safe. Several researchers have devoted to the research and development of effective anti-inflammatory drugs with little or no side effects. In this review, we studied some small molecules with reported anti-inflammatory activities and hence potential sources of anti-inflammatory agents. The information was retrieved from relevant studies published between January 2019 and May, 2021 for review. This review study was aimed to provide relevant information towards the design and development of effective and safe anti-inflammation agents.

Methyl linked pyrazoles: Synthetic and Medicinal Perspective

Pyrazoles, an important and well known class of the azole family, have been found to show a large number of applications in various fields specially of medicinal chemistry. Among pyrazole derivatives, particularly, methyl substituted pyrazoles have been reported as the potent medicinal scaffolds that exhibit a wide spectrum of biological activities. The present review is an attempt to highlight the detailed synthetic approaches for methyl substituted pyrazoles along with in depth analysis of their respective medical significances till March2021. It is hoped that literature sum-up in the form of present review article would certainly be a great tool to assist the medicinal chemists for generating new leads possessing pyrazole nucleus with high efficacy and less microbial resistance.

Novel 1,5-diaryl pyrazole-3-carboxamides as selective COX-2/sEH inhibitors with analgesic, anti-inflammatory, and lower cardiotoxicity effects

COX-2 selective drugs have been withdrawn from the market due to cardiovascular side effects, just a few years after their discovery. As a result, a new series of 1,5-diaryl pyrazole carboxamides 19-31 was synthesized as selective COX-2/sEH inhibitors with analgesic, anti-inflammatory, and lower cardiotoxic properties. The target compounds were synthesized and tested in vitro against COX-1, COX-2, and sEH enzymes. Compounds 20, 22 and 29 exhibited the most substantial COX-2 inhibitory activity (IC₅₀ values: 0.82-1.12 µM) and had SIs of 13, 18, and 16, respectively, (c.f. celecoxib; SI = 8). Moreover, compounds 20, 22, and 29 were the most potent dual COX-2/sEH inhibitors, with IC₅₀ values of 0.95, 0.80, and 0.85 nM against sEH, respectively, and were more potent than the standard AUDA (IC₅₀ = 1.2 nM). Furthermore, in vivo studies revealed that these compounds were the most active as analgesic/anti-inflammatory derivatives with a good cardioprotective profile against cardiac biomarkers and inflammatory cytokines. Finally, the most active dual inhibitors were docked inside COX-2/sEH active sites to explain their binding modes.

Design and synthesis of novel 4-fluorobenzamide-based derivatives as promising anti-inflammatory and analgesic agents with an enhanced gastric tolerability and COX-inhibitory activity

Responding to the great demand of developing potent NSAIDs with an enhanced safety profile and reasonable selectivity, in the present study novel 4-fluorobenzamide derivatives were synthesized and screened for their anti-inflammatory and analgesic activities using carrageenan-induced rat paw edema method and acetic acid-induced abdominal writhing in mice, respectively. All the new target compounds except the carbamothioylhydrazine series (5a-d), and the 4-fluorophenyl thiadiazolo derivative 6b showed promising anti-inflammatory activity ranged between 53.43 and 92.36% inhibition of edema (at 3 h) compared to the reference standard indomethacin (65.64%). All the newly synthesized compounds showed potent analgesic activity ranged between 71 and 100 % writhing protection compared to indomethacin (74.06%). Moreover, the most active compounds; the ester hybrids 2a,b, the thioureido quinazolinones 4b,c, and the thiadiazole congener 6a, showed promising gastric tolerability with ulcer index ranged between 0 and 6.60 compared to indomethacin (12.13). The thioureido quinazolinone derivatives 4b,c showed the most potent anti-inflammatory and analgesic activities with a remarkable gastric tolerability compared to the other derivatives. The 4-chlorophenyl derivative 4b is considered the most promising analogue showing 92.36% inhibition of edema, 100% writhing protection in analgesia testing, and a COX-2 selectivity index of 5.75 which was better than that of indomethacin and celecoxib standards (selectivity index = 0.27 and 4.55; respectively). Moreover, it showed an ulcer index equals zero with gastric acidity and mucin levels comparable to that of the control group indicating its minor effect on gastric cell physiology and its high tolerability. Molecular docking studies predicted the binding pattern of the newly synthesized compounds in COX-1 and COX-2 enzymes confirming the ability of the most active candidates to satisfy the structural features required for binding and rationalized their selectivity based on their docking binding patterns and scores. Furthermore, the newly synthesized 4-fluorobenzamide derivatives possess promising predicted pharmacokinetic properties indicated by calculating their key physicochemical parameters and absorption percentages.

Synthesis and computational studies of novel fused pyrimidinones as a promising scaffold with analgesic, anti-inflammatory and COX inhibitory potential

Addressing the global need for the development of safe and potent NSAIDs, new series of oxadiazolo and thiadiazolo fused pyrmidinones were synthesized and initially tested for their analgesic activity. All tested compounds showed promising analgesic activity compared with the reference standard indomethacin. Moreover, anti-inflammatory activity evaluation, ulcerogenic liability, and in vitro COX-1, COX-2 enzyme inhibition assays were also performed for the most active derivatives. The methoxyphenyl piperazinyl derivative 3d showed analgesic activity surpassing indomethacin with protection of 100%, and 83%; respectively. Also 3d showed good anti-inflammatory activity with relatively lower ulcer index compared with other tested compounds, and potent COX-1 and COX-2 inhibitory activity with IC₅₀ = 0.140, 0.007 μm, respectively, and with a selectivity index of 20.00 which was better than the reference standards and the other tested congeners. Additionally, compounds 3b, 3g and 3h revealed moderate selectivity (SI = 3.53, 3.70 and 5.87, respectively). Moreover, in silico physicochemical parameters revealed that the new fused pyrimidinones demonstrated promising pharmacokinetic properties. Furthermore, computational studies in form of 2D-quantitative structure-activity relationship (2D-QSAR) and 3D-pharmacophore confirmed the potential analgesic properties of the new target compounds.

The Role of Organic Small Molecules in Pain Management

In this review, a timeline starting at the willow bark and ending in the latest discoveries of analgesic and anti-inflammatory drugs will be discussed. Furthermore, the chemical features of the different small organic molecules that have been used in pain management will be studied. Then, the mechanism of different types of pain will be assessed, including neuropathic pain, inflammatory pain, and the relationship found between oxidative stress and pain. This will include obtaining insights into the cyclooxygenase action mechanism of nonsteroidal anti-inflammatory drugs (NSAID) such as ibuprofen and etoricoxib and the structural difference between the two cyclooxygenase isoforms leading to a selective inhibition, the action mechanism of pregabalin and its use in chronic neuropathic pain, new theories and studies on the analgesic action mechanism of paracetamol and how changes in its structure can lead to better characteristics of this drug, and cannabinoid action mechanism in managing pain through a cannabinoid receptor mechanism. Finally, an overview of the different approaches science is taking to develop more efficient molecules for pain treatment will be presented.

Novel iodinated quinazolinones bearing sulfonamide as new scaffold targeting radiation induced oxidative stress

Reactive oxygen species (ROS) play an integral role in the pathogenesis of most diseases. This work presents the design and synthesis of fourteen new diiodoquinazolinone derivatives bearing benzenesulfonamide moiety with variable acetamide tail and evaluation of their ability to activate nuclear factor erythroid 2-related factor 2 (Nrf2) using its classical target NAD(P)H: quinone oxidoreductase 1 (NQO1) in Hepa1c1c7 murine hepatoma cells. The N-(2-chloropyridin-3-yl)-2-((6,8-diiodo-4-oxo-3-(4-sulfamoylphenyl)-3,4-dihydroquinazolin-2-yl)thio) acetamide 17 was the most potent NQO1 inducer (CD = 25 µM) with free radical scavenging activity (IC50 = 28 µM) and in vivo median lethal dose (LD50) of 500 mg/Kg. The possible radioprotective activity of compound 17 was evaluated in (7 Gy) irradiated mice. Compound 17 showed a reduction in radiation induced oxidative stress as evidenced by the lower levels of ROS, malondialdehyde (MDA) and NQO1 in liver tissues. Moreover, compound 17 showed improvement in the complete blood count (CBC) of irradiated mice and decreased mortality over 30 days following irradiation. Additionally, docking studies inside the Nrf2-binding site of Kelch-like ECH associated protein 1 (Keap1), the main negative regulator of Nrf2, confirmed that 17 revealed the same interactions with the key amino acids as those of the co-crystallized ligand. This study identifies 17 as a novel antioxidant that protects against the harmful effect of radiation.

Heterocyclic Compounds: Pharmacology of Pyrazole Analogs From Rational Structural Considerations

Low quality of life and life-threatening conditions often demand pharmacological screening of lead compounds. A spectrum of pharmacological activities has been attributed to pyrazole analogs. The substitution, replacement, or removal of functional groups on a pyrazole ring appears consistent with diverse molecular interactions, efficacy, and potency of these analogs. This mini-review explores cytotoxic, cytoprotective, antinociceptive, anti-inflammatory, and antidepressant activities of some pyrazole analogs to advance structure-related pharmacological profiles and rational design of new analogs. Numerous interactions of these derivatives at their targets could impact future research considerations and prospects while offering opportunities for optimizing therapeutic activity with fewer adverse effects.

Febuxostat-based amides and some derived heterocycles targeting xanthine oxidase and COX inhibition. Synthesis, in vitro and in vivo biological evaluation, molecular modeling and in silico ADMET studies

Various febuxostat derivatives comprising carboxamide functionalities and different substituted heterocycles were synthesized and evaluated for their biological activities as xanthine oxidase (XO) and cyclooxygenase (COX) inhibitors. All the tested compounds exhibited variable in vitro XO inhibitory activities (IC₅₀ values 0.009-0.077 µM), among which the analog 17 has emerged as the most potent derivative (IC₅₀ 0.009 µM), representing nearly 3-times the potency of febuxostat (IC₅₀ 0.026 µM). The same analogs were further investigated for their in vitro COX-1 and COX-2 inhibitory activity, where fifteen analogs demonstrated recognizable COX-2 inhibitory potential (IC₅₀ values range 0.04 - 0.1 µM), when correlated with celecoxib (IC₅₀ 0.05 µM), together with appreciable selectivity indices. Compounds 5a, 14b, 17, 19c, 19e and 21b that showed significant in vitro XO and/ or COX inhibitory potentials were further investigated for their in vivo hypouricemic as well as anti-inflammatory activities. Interestingly, the in vivo results were concordant with the collected in vitro data. Docking of compounds 5a, 14b, 17, 19c, 19e and 21b with the active sites of XO and COX-2 isozymes demonstrated superior binding profile compared with the reported ligands (febuxostat and celecoxib, respectively). Their docking scores were reasonable and cohering to a great extent with their corresponding in vitro IC₅₀ values. Moreover, in silico computation of the predicted pharmacokinetic and toxicity properties (ADMET), together with the ligand efficiency (LE) of the same six compounds suggesting their liability to act as new orally active drug candidates with a predicted high safety profile.

Novel 1,2,4-triazine-quinoline hybrids: The privileged scaffolds as potent multi-target inhibitors of LPS-induced inflammatory response via dual COX-2 and 15-LOX inhibition

Based on the observed pharmacophoric structural features for the reported dual COX/15-LOX inhibitors and inspired by the abundance of COX/LOX inhibitory activities reported for the 1,2,4-triazine and quinoline scaffolds, we designed and synthesized novel 1,2,4-triazine-quinoline hybrids (8a-n). The synthesized hybrids were evaluated in vitro as dual COXs/15-LOX inhibitors. The new triazine-quinoline hybrids (8a-n) exhibited potent COX-2 inhibitory profiles (IC₅₀ = 0.047-0.32 μM, SI ∼ 20.6-265.9) compared to celecoxib (IC₅₀ = 0.045 μM, SI ∼ 326). Moreover, they revealed potent inhibitory activities against 15-LOX enzyme compared to reference quercetin (IC₅₀ = 1.81-3.60 vs. 3.34 μM). Hybrid 8e was the most potent and selective dual COX-2/15-LOX inhibitor (COX-2 IC₅₀ = 0.047 μM, SI = 265.9, 15-LOX IC₅₀ = 1.81 μM). These hybrids were further challenged by their ability to inhibit NO, ROS, TNF-α, IL-6 inflammatory mediators, and 15-LOX product, 15-HETE, production in LPS-activated RAW 264.7 macrophages cells. Compound 8e was the most potent hybrid in reducing ROS and 15-HETE levels showing IC₅₀ values of 1.02 μM (11-fold more potent than that of celecoxib, IC₅₀ = 11.75 μM) and 0.17 μM (about 43 times more potent than celecoxib, IC₅₀ = 7.46 μM), respectively. Hybrid 8h exhibited an outstanding TNF-α inhibition with IC₅₀ value of 0.40 μM which was about 25 times more potent than that of celecoxib and diclofenac (IC₅₀ = 10.69 and 10.27 μM, respectively). Docking study of the synthesized hybrids into the active sites of COX-2 and 15-LOX enzymes ensures their favored binding affinity. To our knowledge, herein we reported the first 1,2,4-triazine-quinoline hybrids as dual COX/15-LOX inhibitors.

Evaluation of the in vitro anti-inflammatory and cytotoxic potential of ethanolic and aqueous extracts of Origanum syriacum and Salvia lanigera leaves

In this study, the chemical compositions of the ethanolic and aqueous extracts of the leaves of Origanum syriacum and Salvia lanigera were identified based on GC-MS spectrometric analyses. The in vitro anti-inflammatory potential of the different extracts was evaluated by determining the membrane stabilization of human red blood cells and the percent inhibition of the COX1/2, 5LOX, and sPLA2-V enzymes. Both ethanolic extracts showed maximum membrane stabilization (≤ 91%, at 100 μg/mL) compared to the aqueous extracts (≤ 45%) and the reference drug diclofenac sodium (90.75%). The membrane-stabilizing effects of the ethanolic extracts could be directly correlated to their anti-inflammatory activity. While both ethanolic fractions strongly inhibited the 5LOX and COX-1 enzymes at 100 μg/mL, only the O. syriacum ethanolic extract selectively inhibited sPLA2-V (99.35%, at 50 μg/mL). The differences in the pharmacological efficiencies of the different extracts could be attributed to the variation in their chemical compositions particularly the content of oxygenated monoterpenoids. Additionally, none of the ethanolic extracts demonstrated cytotoxicity to human colorectal cancer cell lines (HCT-116 and Lovo), even at the highest concentration tested (200 μg/mL). The safe profiles of these extracts towards the tested cell lines may be due to the absence of the toxic phthalic acid ester substances. Collectively, these findings clearly suggest that the studied ethanolic extracts of O. syriacum and S. lanigera can be considered interesting candidates for the treatment of human inflammatory diseases related to oxidative stress and microbial infections.

Design, synthesis, biological evaluation, and computational studies of novel thiazolo-pyrazole hybrids as promising selective COX-2 inhibitors: Implementation of apoptotic genes expression for ulcerogenic liability assessment

A novel series of thiazolo-pyrazole hybrids has been prepared and assessed for their in vitro COX-1/COX-2 inhibitory activity. Compound 6c exhibited the most selective COX-2 inhibition profile (SI of 264) not far of Celecoxib (294). In-vivo anti-inflammatory activity revealed that compound 6d exhibited the highest activity (97.30% inhibition of edema) exceeding reference standard Indomethacin (84.62% inhibition of edema). The ulcerogenic liability tested, using gross, microscopic, biochemical analysis and apoptotic genes expression, showed that compound 6b matched the optimal candidate activity (ulcer index = 120, selectivity index of ~ 162 and 77% in-vivo inhibition of edema). Meanwhile, compound 6 m (ulcer index = 0) showcased the highest safety profile. Molecular modeling analysis and drug likeness studies presented appreciated agreement with the biological evaluation.

Direct Access for the Regio- and Stereoselective Synthesis of N-Alkenylpyrazoles and Chromenopyrazoles

A highly regio- and stereoselective method was developed for the preparation of N-alkenylpyrazoles and chromenopyrazoles by the reaction of N-tosylhydrazones and salicyl N-tosylhydrazones with alkynes under neat conditions in the presence of La(OTf)₃. The present study was found to be efficient and convenient for direct access to N-alkenylpyrazoles and chromenopyrazoles through C-C, C-N, and C-O bond forming reactions. Structure assignment of N-alkenylpyrazole compound 5c was confirmed by X-ray analysis.

Synthesis of imidazole-pyrazole conjugates bearing aryl spacer and exploring their enzyme inhibition potentials

Developing improved enzyme inhibitors is an effective therapy to counter various diseases. Aiming to build up biologically active templates, a new series of bis-diazoles conjugated with an aryl linker was designed and prepared through a convenient synthetic approach. Synthesized derivatives 6(a-m), having different substitutions at the 2^nd position of the imidazole nucleus, depict the scope of present study. These compounds were characterized through spectroscopic methods and further examined for their in vitro enzyme inhibitory potentials against two selected enzymes: α-glucosidase and lipoxygenase (LOX). Overall, this series was found to be effective against α-glucosidase and moderately active against LOX enzyme. Compound 6k was the most potent α-glucosidase inhibitor with IC₅₀ = 54.25 ± 0.67 µM as compared to reference drug acarbose (IC₅₀ = 375.82 ± 1.76 µM). The docked conformation revealed the involvement of substituent's heteroatoms with amino acid residue Gly280 through hydrogen bonding. The most active LOX inhibitor was 6a with IC₅₀ = 41.75 ± 0.04 µM as compared to standard baicalein (IC₅₀ = 22.4 ± 1.3 µM). Docking model of 6a suggested the strong interaction of imidazole's nitrogen with iron atom of the active pocket of enzyme. Other features like lipophilicity, bulkiness of compounds, pi-pi interactions and/or pi-alkyl interactions also affected the inhibiting potentials of all prepared scaffolds.

Synthesis, Anti-Inflammatory Activity and Molecular Docking Studies of 1,4,5,6-Tetrahydropyrimidine-2-Carboxamides

Background: Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most commonly used drugs in the world. The widespread use of NSAIDs is associated with a number of serious side effects and complications observed for both selective and non-selective COX inhibitors. Therefore, the search for new COX inhibitors, which along with their effectiveness will have minimal side effects, is a very important and urgent task. Methods: This work studied the synthesis of new 1,4,5,6-tetrahydropyrimidine-2-carboxamides based on the reaction of 2-morpholin-4-yl-N-(het)aryl-2-thioxoacetamides with 1,3-diaminopropane. All obtained compounds were tested for anti-inflammatory activity in vitro and in silico conditions. All synthesized 1,4,5,6-tetrahydropyrimidine-2-carboxamides were tested for influence on the course of the exudative phase of the inflammatory process based on the carrageenan model of paw edema of laboratory nonlinear heterosexual white rats weighing 220-250 g, using Diclofenac as a reference. Optimization of the geometry of the studied structures and molecular docking was carried out using the ArgusLab 4.0.1 software package. Results: The target products were obtained with yields of 71-98% and easily isolated from the reaction mixture. The best anti-inflammatory activity was found in N-(4-chlorophenyl)-1,4,5,6-tetrahydropyrimidine-2-carboxamide and in N-[4-chloro-3-(trifluoromethyl)phenyl]-1,4,5,6-tetrahydropyrimidine-2-carboxamide, suppression of the inflammatory response was 46.7 and 46.4%, respectively. The results of molecular docking with COX-1 and COX-2 enzymes were in good agreement with the experimental data, R2 ˃ 0.92 and R2 ˃ 0.83, respectively. Conclusion: The compounds under study were shown to be promising as potential anti-inflammatory agents.