Synthesis, COX-2 inhibition, anti-inflammatory activity, molecular docking, and histopathological studies of new pyridazine derivatives.

Five new pyridazine scaffolds were synthesized and assessed for their inhibitory potential against both cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) compared with indomethacin and celecoxib. The majority of the synthesized compounds demonstrated a definite preference for COX-2 over COX-1 inhibition. Compounds 4c and 6b exhibited enhanced potency towards COX-2 enzyme with IC50 values of 0.26 and 0.18 µM, respectively, compared to celecoxib with IC50 = 0.35 µM. The selectivity index (SI) of compound 6b was 6.33, more than that of indomethacin (SI = 0.50), indicating the most predominant COX-2 inhibitory activity. Consequently, the in vivo anti-inflammatory activity of compound 6b was comparable to that of indomethacin and celecoxib and no ulcerative effect was detected upon the oral administration of compound 6b, as indicated by the histopathological examination. Moreover, compound 6b decreased serum plasma PEG2 and IL-1ß. To rationalize the selectivity and potency of COX-2 inhibition, a molecular docking study of compound 6b into the COX-2 active site was carried out. The COX-2 inhibition and selectivity of compound 6b can be attributed to its ability to enter the side pocket of the COX-2 enzyme and interact with the essential amino acid His90. Together, these findings suggested that compound 6b is a promising lead for the possible design of COX-2 inhibitors that could be employed as safe and effective anti-inflammatory drugs.

Discovery of novel thiazole derivatives containing pyrazole scaffold as PPAR-γ Agonists, α-Glucosidase, α-Amylase and COX-2 inhibitors; Design, synthesis and in silico study.

A novel series of thiazole derivatives with pyrazole scaffold 16a-l as hybrid rosiglitazone/celecoxib analogs was designed, synthesized and tested for its PPAR-γ activation, α-glucosidase, α-amylase and COX-2 inhibitory activities. Regarding the anti-diabetic activity, all compounds were assessed in vitro against PPAR-γ activation, α-glucosidase and α-amylase inhibition in addition to in vivo hypoglycemic activity (one day and 15 days studies). Compounds 16b, 16c, 16e and 16 k showed good PPAR-γ activation (activation % ≈ 72-79 %) compared to that of the reference drug rosiglitazone (74 %). In addition, the same derivatives 16b, 16c, 16e and 16 k showed the highest inhibitory activities against α-glucosidase (IC50 = 0.158, 0.314, 0.305, 0.128 µM, respectively) and against α-amylase (IC50 = 32.46, 23.21, 7.74, 35.85 µM, respectively) compared to the reference drug acarbose (IC50 = 0.161 and 31.46 µM for α-glucosidase and α-amylase, respectively). The most active derivatives 16b, 16c, 16e and 16 k also revealed good in vivo hypoglycemic effect comparable to that of rosiglitazone. In addition, compounds 16b and 16c had the best COX-2 selectivity index (S.I. = 18.7, 31.7, respectively) compared to celecoxib (S.I. = 10.3). In vivo anti-inflammatory activity of the target derivatives 16b, 16c, 16e and 16 k supported the results of in vitro screening as the derivatives 16b and 16c (ED50 = 8.2 and 24 mg/kg, respectively) were more potent than celecoxib (ED50 = 30 mg/kg). In silico docking, ADME, toxicity, and molecular dynamic studies were carried out to explain the interactions of the most active anti-diabetic and anti-inflammatory compounds 16b, 16c, 16e and 16 k with the target enzymes in addition to their physiochemical parameters.

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.

Explainable artificial intelligence-assisted virtual screening and bioinformatics approaches for effective bioactivity prediction of phenolic cyclooxygenase-2 (COX-2) inhibitors using PubChem molecular fingerprints.

Cyclooxygenase-2 (COX-2) inhibitors are nonsteroidal anti-inflammatory drugs that treat inflammation, pain and fever. This study determined the interaction mechanisms of COX-2 inhibitors and the molecular properties needed to design new drug candidates. Using machine learning and explainable AI methods, the inhibition activity of 1488 molecules was modelled, and essential properties were identified. These properties included aromatic rings, nitrogen-containing functional groups and aliphatic hydrocarbons. They affected the water solubility, hydrophobicity and binding affinity of COX-2 inhibitors. The binding mode, stability and ADME properties of 16 ligands bound to the Cyclooxygenase active site of COX-2 were investigated by molecular docking, molecular dynamics simulation and MM-GBSA analysis. The results showed that ligand 339,222 was the most stable and effective COX-2 inhibitor. It inhibited prostaglandin synthesis by disrupting the protein conformation of COX-2. It had good ADME properties and high clinical potential. This study demonstrated the potential of machine learning and bioinformatics methods in discovering COX-2 inhibitors.

Synthesis of acetaminophen-based coumarins as selective COX-2 inhibitors: An in vitro-in silico study.

Acetaminophen, a centrally-acting old analgesic drug, is a weak inhibitor of cyclooxygenase (COX) isoforms with some selectivity toward COX-2. This compound was used in this work as a precursor to create nine acetaminophen based coumarins (ACFs). To satisfy the aim of this work, which states the synthesis of acetaminophen-based coumarins as selective COX-2 inhibitors, the ACFs were subjected to two types of investigation: in vitro and in silico. Given the former type, the ACFs capacity to block COX-1 and COX-2 was investigated in lab settings. On the other hand, the in silico investigation included docking the chemical structures of ACFs into the active sites of these enzymes, predicting their anticipated toxicities, and determining the ADME characteristics. The results of the in vitro study revealed that the ACFs demonstrated good-to-excellent inhibitory properties against the enzymes under study. Also, these ACFs exhibited a high level of COX-2 selectivity, which improved as the capacity of  aromatic substitute for withdrawing electrons was enhanced. Results of docking were comparable to the in vitro investigation in case of COX-2. On the other hand, the in silico investigations indicated that the synthesized ACFs are safer than their precursor, acetaminophen, with a high potential to consider oral-administrated candidates.

Potential of Tryptamine Derivatives as Multi-Target Directed Ligands for Alzheimer's Disease: AChE, MAO-B, and COX-2 as Molecular Targets.

Extensive research has been dedicated to develop compounds that can target multiple aspects of Alzheimer's disease (AD) treatment due to a growing understanding of AD's complex multifaceted nature and various interconnected pathological pathways. In the present study, a series of biological assays were performed to evaluate the potential of the tryptamine analogues synthesized earlier in our lab as multi-target-directed ligands (MTDLs) for AD. To assess the inhibitory effects of the compounds, various in vitro assays were employed. Three compounds, SR42, SR25, and SR10, displayed significant AChE inhibitory activity, with IC50 values of 0.70 µM, 0.17 µM, and 1.00 µM, respectively. These values superseded the standard drug donepezil (1.96 µM). In the MAO-B inhibition assay, SR42 (IC50 = 43.21 µM) demonstrated superior inhibitory effects as compared to tryptamine and other derivatives. Moreover, SR22 (84.08%), SR24 (79.30%), and SR42 (75.16%) exhibited notable percent inhibition against the COX-2 enzyme at a tested concentration of 100 µM. To gain insights into their binding mode and to validate the biological results, molecular docking studies were conducted. Overall, the results suggest that SR42, a 4,5 nitro-benzoyl derivative of tryptamine, exhibited significant potential as a MTDL and warrants further investigation for the development of anti-Alzheimer agents.

Recent Updates in Understanding NSAID Hypersensitivity.

PURPOSE OF REVIEW: To provide a review of available literature regarding nonsteroidal anti-inflammatory drug (NSAID) hypersensitivity with an emphasis on more recent findings. RECENT FINDINGS: Oral provocation tests with aspirin are important for diagnosis and management in adult and pediatric populations with reported NSAID hypersensitivity. Risk of cross-reactivity to COX-2 inhibitors varies by NSAID hypersensitivity phenotype. COX-2 inhibitors are tolerated in aspirin-exacerbated respiratory disease. Reported NSAID allergy is associated with a higher risk of a substance use disorder. Effective treatment of underlying chronic spontaneous urticaria can allow tolerance of NSAIDs in NSAID-exacerbated cutaneous disease. The pathophysiology, cross-reactivity, and appropriate diagnostic evaluation differ between the 5 distinct NSAID hypersensitivity phenotypes. Further research into the pathophysiology of NSAID hypersensitivity in patients with and without underlying disease is needed.

Integrated strategy for the screening of cyclooxygenase-2 inhibitors from triterpenoid saponins in Clematis tangutica.

INTRODUCTION: Screening of novel cyclooxygenase-2 (COX-2) inhibitors from complex natural products is not an easy task. OBJECTIVES: To establish an efficient and feasible strategy for screening COX-2 inhibitors from triterpenoid saponins (TPSs) in Clematis tangutica. METHODS: Taking TPSs in C. tangutica as example, an optimized macroporous resin (MR) method was established for the enrichment of TPSs. High-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (HPLC-QTOFMS) was performed to establish the phytochemical profiling of TPSs. Molecular docking was performed to predict the ligand-target interactions and discover the active substances. Chemometric techniques were performed to visualize the structure-effect relationships. High-speed countercurrent chromatography and preparative HPLC were performed to prepare the targets. In vitro activity experiment of COX-2 was performed to verify the virtual screening results. RESULTS: TPSs in C. tangutica were well enriched with the recovery rate of (80.22 ± 2.37)%. Thirty-four kinds of TPSs of oleanane type were deduced by HPLC-QTOFMS. Five TPSs of clematangoside C, clematangoside D, clematangoticoside J, hederoside H1 , and hederasaponin B showed stronger binding abilities with COX-2. The structure with more sugar groups at C-28 may be more conducive to the combination with COX-2. Targets were prepared with purities all above 98%. The IC50 values of target TPSs were 6.03 ± 0.24, 12.44 ± 0.15, 9.36 ± 0.19, 4.78 ± 0.13, and 2.59 ± 0.11 µmol/L, respectively. CONCLUSION: The integrated strategy using MR, HPLC-QTOFMS, molecular docking, chemometrics, target preparation, and in vitro verification was feasible for rapidly screening COX-2 inhibitors from TPSs in C. tangutica.

1,4-Diaryl-1,2,3-triazole neolignan-celecoxib hybrids inhibit experimental arthritis induced by zymosan.

Rheumatoid arthritis (RA) is a chronic autoimmune disease that causes cartilage damage. Anti-inflammatories are widely used in the management of RA, but they can have side effects such as gastrointestinal and/or cardiovascular disorders. Studies published by our group showed that the synthesis of hybrid triazole analogs neolignan-celecoxib containing the substituent groups sulfonamide (L15) or carboxylic acid (L18) exhibited anti-inflammatory activity in an acute model of inflammation, inhibited expression of P-selectin related to platelet activation and did not induce gastric ulcer, minimizing the related side effects. In continuation, the present study evaluated the anti-inflammatory effects of these analogs in an experimental model of arthritis and on the functions of one of the important cells in this process, macrophages. Mechanical hyperalgesia, joint edema, leukocyte recruitment to the joint and damage to cartilage in experimental arthritis and cytotoxicity, spread of disease, phagocytic activity and nitric oxide (NO) and hydrogen peroxide production by macrophages were evaluated. Pre-treatment with L15 and L18 reduced mechanical hyperalgesia, joint edema and the influx of leukocytes into the joint cavity after different periods of the stimulus. The histological evaluation of the joint showed that L15 and L18 reduced cartilage damage and there was no formation of rheumatoid pannus. Furthermore, L15 and L18 were non-cytotoxic. The analogs inhibited the spreading, the production of NO and hydrogen peroxide. L15 decreased the phagocytosis. Therefore, L15 and L18 may be potential therapeutic prototypes to treat chronic inflammatory diseases such as RA.

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

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

Promising anti-Helicobacter pylori and anti-inflammatory metabolites from unused parts of Phoenix dactylifera CV 'Zaghloul': in vitro and in silico study.

CONTEXT: Date palm waste is an agricultural waste that accumulates in massive amounts causing serious pollution and environmental problems. OBJECTIVES: Date palm trees, Phoenix dactylifera Linn CV 'Zaghloul' (Arecaceae) grown in Egypt, leave behind waste products that were investigated to produce compounds with anti-Helicobacter pylori and anti-inflammatory activities. MATERIALS AND METHODS: Chromatographic workup of P. dactylifera aqueous methanol extract derived from fibrous mesh and fruit bunch (without fruit) afforded a new sesquiterpene lactone derivative, phodactolide A (1), along with ten known compounds (2-11), primarily identified as polyphenols. Chemical structures were unambiguously elucidated based on mass and 1D/2D NMR spectroscopy. All isolated compounds were assessed for their activities against H. pylori using broth micro-well dilution method and clarithromycin as a positive control. The anti-inflammatory response of isolated compounds was evaluated by inhibiting cyclooxygenase-2 enzyme using TMPD Assay followed by an in silico study to validate their mechanism of action using celecoxib as a standard drug. RESULTS: Compounds 4, 6 and 8-10 exhibited potent anti-H. pylori activity with MIC values ranging from 0.48 to 1.95 µg/mL that were comparable to or more potent than clarithromycin. For COX-2 inhibitory assay, 4, 7 and 8 revealed promising activities with IC50 values of 1.04, 0.65 and 0.45 µg/mL, respectively. These results were verified by molecular docking studies, where 4, 7 and 8 showed the best interactions with key amino acid residues of COX-2 active site. CONCLUSION: The present study characterizes a new sesquiterpene lactone and recommends 4 and 8 for future in vivo studies as plausible anti-ulcer remedies.

Design and Synthesis of Novel 1,3,4-Oxadiazole and 1,2,4-Triazole Derivatives as Cyclooxygenase-2 Inhibitors with Anti-inflammatory and Antioxidant activity in LPS-stimulated RAW264.7 Macrophages.

In an attempt to obtain new candidates with potential anti-inflammatory activity, two series of 1,3,4-oxadiazole based derivatives (8a-g) and 1,2,4-triazole based derivatives (10a,b and 11a-g) were synthesized and evaluated for their COX-1/COX-2 inhibitory activity. In vitro assays showed potent COX-2 inhibitory activity and selectivity of the novel designed compounds (IC50 = 0.04 - 0.16 µM, SI = 60.71 - 337.5) compared to celecoxib (IC50 = 0.045 µM, SI = 326.67). The anti-inflammatory and antioxidant activity of the synthesized compounds was investigated via testing their ability to inhibit pro-inflammatory [tumour necrosis factor (TNF-α) and interleukin-6 (IL-6)] and oxidative stress [nitric oxide (NO) and reactive oxygen species (ROS)] markers production in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. Most of the novel compounds exhibited potent anti-inflammatory and antioxidant activity. In particular, the novel compounds showed excellent IL-6 inhibitory activity (IC50 = 0.96 - 11.14 µM) when compared to celecoxib (IC50 = 13.04 µM) and diclofenac sodium (IC50 = 22.97 µM). Moreover, the most potent and selective COX-2 inhibitor 11c (IC50 = 0.04 µM, SI = 337.5) displayed significantly higher activity against NO and ROS production compared to celecoxib (IC50 = 2.60 and 3.01 µM vs. 16.47 and 14.30 µM, respectively). Molecular modelling studies of the novel designed molecules into COX-2 active sites analysed their binding affinity. In-silico simulation studies indicated their acceptable physicochemical properties and pharmacokinetic profiles. This study suggests that the novel synthesized COX-2 inhibitors exert potent anti-inflammatory and antioxidant activity, highlighting their potential as promising therapeutic agents for the treatment of inflammation and oxidative stress-related diseases.

Novel 1,3-diaryl pyrazole derivatives bearing methylsulfonyl moiety: Design, synthesis, molecular docking and dynamics, with dual activities as anti-inflammatory and anticancer agents through selectively targeting COX-2.

Three series of novel 1-aryl-3-(4-methylsulfonylphenyl) pyrazole derivatives were synthesized, characterized by several spectroscopic techniques, and investigated as potential anti-inflammatory and anticancer agents. The biological evaluation showed that almost all the synthesized compounds have significant potency and selectivity for the COX-2 enzyme over COX-1 with noticeable anti-inflammatory activity compared to celecoxib and indomethacin. Accordingly, compounds 8a, 8b, 8e, 8j, 8l, 9a, 9b, 9c, and 10b showed the best COX-2 inhibition (IC50 ranged from 0.059 to 0.079 µM) with good anti-inflammatory activity (% of edema inhibition ranged from 87.9 to 67.5). Moreover, compound 8b possessed the highest selectivity index regarding COX-2 isozyme (SI = 211) in comparison to celecoxib (SI = 312) with good in vivo anti-inflammatory activity (% edema inhibition = 77.70 after 5 h). Also, compounds 8a, 8b, 8j, 8l, and 9a showed ulcerogenic liability and histopathological changes close to celecoxib. Molecular docking and dynamics simulations were also conducted to illustrate the binding modes inside the COX-2 active site. Furthermore, all compounds were screened against three cancer cell line panels to determine their antiproliferative properties by MTT assay. Compounds 8a, 8b, and 8e along with their cyclized forms 9a, 9b, and 9c exhibited a considerable antiproliferative effect on liver (IC50: 6.81-19.71 µM), colon (IC50: 7.64-15.34 µM), and breast (IC50: 6.77-18.41 µM) cancer cell lines. More importantly, compounds 8a, 8e, 9a, and 9b were found to be safe on normal HEK-293T kidney cells in comparison to cancer. cells, especially compound 8e with IC50 value of 66.45 µM. Mechanistic studies demonstrated the apoptotic activity of the most active compounds 8a, 8e, 9a, and 9b on MCF-7 cancer cells by inducing a strong S phase cell cycle arrest suggesting that the mechanism of its antiproliferative activity may be through COX-2 inhibition. Finally, the hit compounds 8a, 8b and 9a were discovered to have selective COX-2 inhibitory activity and good anti-inflammatory activity with minimal ulcerogenic effect as well as potent anticancer activity.

Rational design of biodegradable sulphonamide candidates treating septicaemia by synergistic dual inhibition of COX-2/PGE2 axis and DHPS enzyme.

A new series of co-drugs was designed based on hybridising the dihydropteroate synthase (DHPS) inhibitor sulphonamide scaffold with the COX-2 inhibitor salicylamide pharmacophore through biodegradable linkage to achieve compounds with synergistic dual inhibition of COX-2/PGE2 axis and DHPS enzyme to enhance antibacterial activity for treatment of septicaemia. Compounds 5 b, 5j, 5n and 5o demonstrated potent in vitro COX-2 inhibitory activity comparable to celecoxib. 5j and 5o exhibited ED50 lower than celecoxib in carrageenan-induced paw edoema test with % PGE2 inhibition higher than celecoxib. Furthermore, 5 b, 5j and 5n showed gastric safety profile like celecoxib. Moreover, in vivo antibacterial screening revealed that, 5j showed activity against S.aureus and E.coli higher than sulfasalazine. While, 5o revealed activity against E.coli higher than sulfasalazine and against S.aureus comparable to sulfasalazine. Compound 5j achieved the target goal as potent inhibitor of COX-2/PGE2 axis and in vivo broad-spectrum antibacterial activity against induced septicaemia in mice.

Drug Design, Synthesis and Biological Evaluation of Heterocyclic Molecules as Anti-Inflammatory Agents.

Non-steroidal anti-inflammatory drugs (NSAIDs) are generally utilized for numerous inflammatory ailments. The long-term utilization of NSAIDs prompts adverse reactions such as gastrointestinal ulceration, renal dysfunction and hepatotoxicity; however, selective COX-2 inhibitors prevent these adverse events. Various scientific approaches have been employed to identify safer COX-2 inhibitors, as in any case, a large portion of particular COX-2 inhibitors have been retracted from the market because of severe cardiovascular events. This study aimed to develop and synthesize a novel series of indomethacin analogues with potential anti-inflammatory properties and fewer side effects, wherein carboxylic acid moiety was substituted using DCC/DMAP coupling. This study incorporates the docking of various indomethacin analogues to detect the binding interactions with COX-2 protein (PDB ID: 3NT1). MD simulation was performed to measure the stability and flexibility of ligand-protein interactions at the atomic level, for which the top-scoring ligand-protein complex was selected. These compounds were evaluated in vitro for COX enzymes inhibition. Likewise, selected compounds were screened in vivo for anti-inflammatory potential using the carrageenan-induced rat paw oedema method and their ulcerogenic potential. The acute toxicity of compounds was also predicted using in silico tools. Most of the compounds exhibited the potent inhibition of both COX enzymes; however, 3e and 3c showed the most potent COX-2 inhibition having IC50 0.34 µM and 1.39 µM, respectively. These compounds also demonstrated potent anti-inflammatory potential without ulcerogenic liability. The biological evaluation revealed that the compound substituted with 4-nitrophenyl was most active.

Green synthesis of therapeutically active 1,3,4-oxadiazoles as antioxidants, selective COX-2 inhibitors and their in silico studies.

A modest, competent and green synthetic procedure for novel coumarinyl-1,3,4-oxadiazolyl-2-mercaptobenzoxazoles 8i-t has been reported. Analysis of the docked (PDB ID: 5IKR; A-Chain) poses of the compounds illustrated that they adopt identical conformations to the extremely selective COX-2 inhibitor. The biological outcomes as well as computational study suggested that the compounds originated to have elevated resemblance towards COX-2 enzyme than COX-1. The compounds 8i, 8l, 8q, 8r, 8s and 8t emerged as most potent and selective COX-2 inhibitors in contrast with Mefenamic acid. The selectivity index of 8l, 8n and 8r was respectively found to be 33.95, 20.25 and 24.98 which manifested their high selectivity against COX-2. Interestingly, the compounds which were active as COX-2 inhibitors were also active as antioxidant agents.

Design, synthesis and biological evaluation of novel indanone containing spiroisoxazoline derivatives with selective COX-2 inhibition as anticancer agents.

OBJECTIVE: A new family of 3'-(Mono, di or tri-substituted phenyl)-4'-(4-(methylsulfonyl) phenyl) spiroisoxazoline derivatives containing indanone spirobridge was designed, synthesized, and evaluated for their selective COX-2 inhibitory potency and cytotoxicity on different cell lines. METHODS: A synthetic reaction based on 1,3-dipolar cycloaddition mechanism was applied for the regiospecific formation of various spiroisoxazolines. The activity of the newly synthesized compounds was determined using in vitro cyclooxygenase inhibition assay. The toxicity of the compounds was evaluated by MTT assay. In addition, induction of apoptosis, and expression levels of Bax, Bcl-2 and caspase-3 mRNA in MCF-7 cells were evaluated following exposure to compound 9f. The docking calculations and molecular dynamics simulation were performed to study the most probable modes of interactions of compound 9f upon binding to COX-2 enzyme. RESULTS: The docking results showed that the synthesized compounds were able to form hydrogen bonds with COX-2 involving methyl sulfonyl, spiroisoxazoline, meta-methoxy and fluoro functional groups. Spiroisoxazoline derivatives containing methoxy group at the C-3' phenyl ring meta position (9f and 9g) showed superior selectivity with higher potency of inhibiting COX-2 enzyme. Furthermore, compound 9f, which possesses 3,4-dimethoxyphenyl on C-3' carbon atom of isoxazoline ring, exhibited the highest COX-2 inhibitory activity, and also displayed the most potent cytotoxicity on MCF-7 cells with an IC50 value of 0.03 ± 0.01 µM, comparable with that of doxorubicin (IC50 of 0.062 ± 0.012 µM). The results indicated that compound 9f could promote apoptosis. Also, compared to the control group, the mRNA expression of Bax and caspase-3 significantly increased, while that of Bcl-2 significantly decreased upon exposure to compound 9f which may propose the activation of mitochondrial-associated pathway as the mechanism of observed apoptosis. CONCLUSION: In vitro biological evaluations accompanied with in silico studies revealed that indanone tricyclic spiroisoxazoline derivatives are good candidates for the development of new anti-inflammatory and anticancer (colorectal and breast) agents.

Investigation of indole functionalized pyrazoles and oxadiazoles as anti-inflammatory agents: Synthesis, in-vivo, in-vitro and in-silico analysis.

There are several potential side and adverse effects are found to be associated with the anti-inflammatory drugs in clinical practice. The long-term use of these clinical agents highly unsafe. It encouraged the development of novel heterocyclic compounds with potential anti-inflammatory activity and low to no toxicity. In present investigation, a total of 12 indole functionalized pyrazole and oxadiazole derivatives were designed, synthesized and evaluated for the in-vivo anti-inflammatory and analgesic potential. These compounds displayed comparable anti-inflammatory and analgesic potential to the reference drugs. Finally, molecular docking analysis was performed considering different anti-inflammatory targets to determine the mechanistic target of the designed molecules. Detailed analysis suggested that the molecules inhibit COX-2, preferably over other anti-inflammatory targets. The results suggested that two compounds (15c and 15f) were found promising candidates for the development of novel anti-inflammatory agents.

Synthesis and biological evaluation of new nicotinate derivatives as potential anti-inflammatory agents targeting COX-2 enzyme.

Two novel series derived from nicotinic acid were synthesized and evaluated for their inhibitory activity against cyclooxygenases COX-1 and COX-2, and their selectivity indices were determined. Celecoxib, diclofenac and indomethacin were used as reference drugs. All compounds showed highly potent COX-2 inhibitory activity and higher selectivity towards COX-2 inhibition compared to indomethacin. In addition, these compounds except 3a showed clear preferential COX-2 over COX-1 inhibition compared to diclofenac. Compounds 3b, 3e, 4c and 4f showed COX-2 inhibitory activity equipotent to celecoxib. Compounds 4c and 4f demonstrated selectivity indices 1.8-1.9 fold higher than celecoxib. These two most potent and COX-2 selective compounds were further tested in vivo for anti-inflammatory activity by means of carrageenan induced rat paw edema method. Ulcerogenic activity with histopathological studies were performed. The results showed no ulceration, which implies their safe gastric profile. Compound 4f exhibited the most potent in vivo anti-inflammatory activity comparable to all reference drugs. Further, compounds 4c and 4f were investigated for their influence on certain inflammatory cytokines TNF-α and IL-1ß in addition to PEG2. The findings revealed that these candidates could be identified as promising potent anti-inflammatory agents. Molecular docking of 4c and 4f in the COX-2 active site was performed to rationalize their COX-2 inhibitory potency. The results were found to be in line with the biological findings as they exerted more favorable interactions compared to that of celecoxib, explaining their remarkable COX-2 inhibitory activity.

Synthesis and Biological Evaluation of 1,3,5-Trisubstituted 2-Pyrazolines as Novel Cyclooxygenase-2 Inhibitors with Antiproliferative Activity.

A new series of 1,3,5-trisubstituted 2-pyrazolines for the inhibition of cyclooxygenase-2 (COX-2) were synthesized. The designed structures include a COX-2 pharmacophore SO2 CH3 at the para-position of the phenyl ring located at C-5 of a pyrazoline scaffold. The synthesized compounds were tested for in vitro COX-1/COX-2 inhibition and cell toxicity against human colorectal adenocarcinoma cell lines HT-29. The lead compound (4-chlorophenyl){5-[4-(methanesulfonyl)phenyl]-3-phenyl-4,5-dihydro-1H-pyrazol-1-yl}methanone (16) showed significant COX-2 inhibition (IC50 =0.05±0.01 µM), and antiproliferative activity (IC50 =5.46±4.71 µM). Molecular docking studies showed that new pyrazoline-based compounds interact via multiple hydrophobic and hydrogen-bond interactions with key binding site residues of the COX-2 enzyme.