COX-2 Active Site Research Articles

A Novel Quinazoline-4-one Derivatives as a Promising Cytokine Inhibitors: Synthesis, Molecular Docking, and Structure-activity Relationship.

Quinazolines are a common class of nitrogen-containing heterocyclic scaffolds, which exhibit a broad spectrum of pharmacological activities. In the present study, quinazoline and quinazolin-4-one derivatives were prepared, characterized, and evaluated for their biological activity, which may pave the way for possible therapeutic applications. New derivatives of quinazoline and quinazolin-4-one were prepared and tested for antiulcerogenic, anti-inflammatory and hepatoprotective activities. The synthesized compounds were characterized by elemental analysis and spectral data. Also, the median lethal doses (LD50s) of compounds 1-3 in rats were 1125, 835 and 1785 mg/kg b.w., respectively. IC50 values of compounds (1-3) as measured by ABTS•+ radical method were 0.8, 0.92 and 0.08 mg/mL, respectively. Antiulcerogenic activity at dose 1/20 LD50 in albino rats was observed at 47.94, 24.60 and 56.45%, respectively. Anti-inflammatory effect at dose 1/20 LD50 of compounds (1-3) was observed in the induced edema model after 120 min. The prepared compounds were found to possess hepato gastric mucosa protective activity against ibuprofen-induced ulceration and LPS-induced liver toxicity, respectively, in rats etc. normalization of oxidative stress biomarkers, and inflammatory mediators were inhibited in peritoneal macrophage cells at a concentration of 100 μg/L. Molecular docking suggested that the most active compounds 1 and 2 could be positioned within the active sites of COX-2 at Arg121 and Tyr356, similarly to ibuprofen (Arg-120, Glu-524, and Tyr-355). The compound 3-COX-2 complex generated by docking revealed intricate interactions with a COX-2 channel. These findings suggest that compounds 1-3 exhibited good antioxidant, antiulcer, and anti-inflammatory activities, and were safe on liver enzymes in rats.

Molecular docking-guided synthesis of NSAID-glucosamine bioconjugates and their evaluation as COX-1/COX-2 inhibitors with potentially reduced gastric toxicity.

Non-steroidal anti-inflammatory drugs (NSAIDs) are a powerful class of inhibitors targeting two isoforms of the family of cyclooxygenase enzymes (COX-1 and COX-2). While NSAIDs are widely used in the management of pain, in particular as a treatment for osteo- and rheumatoid arthritis, their long-term use has been associated with numerous on- and off-target effects. As the carboxylic acid moiety present in common NSAIDs is responsible for some of their adverse effects, but is not required for their anti-inflammatory activity, we sought to mask this group through direct coupling to glucosamine, which is thought to prevent cartilage degradation. We report herein the conjugation of commonly prescribed NSAIDs to glucosamine hydrochloride and the use of molecular docking to show that addition of the carbohydrate moiety to the parent NSAID can enhance binding in the active site of COX-2. In a preliminary, in vitro screening assay, the diclofenac-glucosamine bioconjugate exhibited 10-fold greater activity toward COX-2, making it an ideal candidate for future in vivo studies. Furthermore, in an intriguing result, we observed that the mefenamic acid-glucosamine bioconjugate displayed enhanced activity toward COX-1 rather than COX-2.

Design, synthesis of new anti-inflammatory agents with a pyrazole core: COX-1/COX-2 inhibition assays, anti-inflammatory, ulcerogenic, histopathological, molecular Modeling, and ADME studies

Novel anti-inflammatory pyrazole derivatives (4a,b, 5a,b, 6a,b, 7a,b, 8a,b, 11a-c, 12a-c, 13a-c and 14a-c) were designed as coxib analogues, synthesized and evaluated for both in vitro and in vivo inhibitory activity. Compounds 4a, 4b, 5a, 6a, 6b, 13a-c and 14a-c were the most COX-2 selective compounds (Selectivity Index) = 242.52, 235.32, 234.50, 462.91 and 334.25, 277.18, 229.07, 243.83, 287.51, 237.03, 236.22 respectively) in comparison with the COX-2 selective reference drug celecoxib (Selectivity Index) = 313.12). Also, compounds 6a and 6b (possess SO2NH2 as selective COX-2 pharmacophore) presented the highest anti-inflammatory activity (ED50 = 136 and 126 µMol/kg, sequentially) in addition, they have the lowest ulcerogenic liability (Ulcer Index = 1.25 and 1.00, respectively) reflecting their expected safe GI profiles. Moreover, the different binding mode of interactions between the synthesized compounds and COX-2 active site were elucidated through molecular docking analysis.

Study of the structure-bioactivity of fleximers: synthesis, crystal structure, Hirshfeld surface analysis, and anti-inflammatory assays

Synthesized and natural pyridones/pyridines derivatives exhibiting diverse biological activities. 2-pyridone has lactam-lactim tautomerization like thymine and uracil bases. In this study, COX-2 target based series of pyridone/pyridine linked fleximers were designed, synthesized and studied. All analogues binding affinity with COX-2 active site were studied through molecular docking, and anti-inflammatory activity studied by in vivo analysis. Weak interactions were studied to find binding sites among analogues through crystal packing, Hirshfeld surface analysis and in silico analysis. All the analogues exhibited anti-inflammatory activity, while compound (3) is the most active analogue among the series. In contrast, since compound (3) is a pyridine-phthalimide ring-containing analogue, the presence of a phthalimide group probably favors anti-inflammatory activity over other types of rings. The results suggested further investigations on compounds as anti-inflammatory prodrugs.

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 invitro as dual COXs/15-LOX inhibitors. The new triazine-quinoline hybrids (8a-n) exhibited potent COX-2 inhibitory profiles (IC50=0.047-0.32μM, SI∼20.6-265.9) compared to celecoxib (IC50=0.045μM, SI∼326). Moreover, they revealed potent inhibitory activities against 15-LOX enzyme compared to reference quercetin (IC50=1.81-3.60 vs. 3.34μM). Hybrid 8e was the most potent and selective dual COX-2/15-LOX inhibitor (COX-2 IC50=0.047μM, SI=265.9, 15-LOX IC50=1.81μM). 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 1.02μM (11-fold more potent than that of celecoxib, IC50=11.75μM) and 0.17μM (about 43 times more potent than celecoxib, IC50=7.46μM), respectively. Hybrid 8h exhibited an outstanding TNF-α inhibition with IC50 value of 0.40μM which was about 25 times more potent than that of celecoxib and diclofenac (IC50=10.69 and 10.27μM, 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 Selective COX-2 Inhibition and In Silico Study of Kuwanon Derivatives Isolated from Morus alba.

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

Local anesthetic Ropivacaine protects rats from myocardial ischemia/reperfusion injury by inhibition of COX-2

IntroductionMyocardial ischaemia/reperfusion (I/R) injury is the leading cause of morbidity and mortality worldwide. Despite novel advances in therapeutics, the management of myocardial I/R is still an unmet medical need. Therefore, in the present study, we have demonstrated the protective effect of ropivacaine (RPC) on the myocardial infarction in rats and its underlying mechanism.Material and methodsInitially, the effect of RPC was determined on the infarct size and histopathology of cardiac tissues. The effect of RPC was also determined on the levels of various cardiac biomarkers such as creatine kinase (CK), creatine kinase MB (CK-MB), alanine aminotransferase (ALT), asparganine aminotransferase (AST), and lactate dehydrogenase (LDH), and biomarkers of oxidative stress (MDA, SOD, and GSH) and inflammation (tumour necrosis factor-α (TNF-α), interleukin 1β (IL-1β), and IL-6). RPC effect was also quantified on cellular apoptosis and COX-2 and iNOS expression via western blot analysis. The RPC was further docked into the active site of COX-2.ResultsIt has been found that RPC reduces the improves haemodynamics of (LVSP and ± dp/dtmax, and LVEDP), infarct percentage and architecture of cardiac tissues of rats. It also reduces the level of studies cardiac injury biomarkers together with a reduction of oxidative stress (MDA, SOD, and GSH) and inflammation (TNF-α, IL-1β, and IL-6). Upon administration of RPC, the rate of cellular apoptosis was found to be greatly reduced, with a reduction in COX-2 and iNOS expression. In docking analysis, RPC creates van der Waals forces and pi-interactions with Tyr381, Arg106, Val102, Leu345, Val509, Ser339, Leu338, Val335, Ala513, His75, and Leu517 at the catalytic site of COX-2.ConclusionsCollectively, our results demonstrated that ropivacaine showed significant benefit against myocardial ischaemic injury.

Protective effect of Ellipticine in ovalbumin (OVA)-induced murine model of allergic rhinitis via dual inhibition of COX-2 and NF-κB

Abstract Allergic rhinitis (AR) is a serious health concern across the globe. Despite its non-fatal character, it accounts for affecting millions of people across the world and is deemed responsible to affect their quality of life and put a significant economic burden. In the current study, we aimed to assess the anti-allergic and anti-inflammatory effects and the underlying molecular mechanisms of ellipticine (ETC) against AR using ovalbumin (OVA)-induced murine model of allergic rhinitis. The ETC was administered to mice via intra-peritoneal route after suspending in 5% CMC after sensitization by OVA. Results of the study suggested that ETC causes a significant reduction the nose rubs as compared to disease control. A significant reduction in the serum level of histamine, IgG1, TNF-α, IL-1β, MIP-2, and IL-6 was found in ETC treated group in a dose-dependent manner as compared to OVA challenged mice. It also reduces eosinophils in BALF of AR mice. In western blot analysis, the expression of aberrantly activated COX-2 and NF-ĸB found significantly reduced in ETC treated group due to inhibition of TLR-4 and caspase-1 as compared to disease-control mice. ETC showed significant interaction with residues of the active site of COX-2 and NF-ĸB. Collectively, our results indicated that ETC can be used to improve present therapeutic strategies against AR.

Anti-inflammatory scalarane-type sesterterpenes, erectascalaranes A–B, from the marine sponge Hyrtios erectus attenuate pro-inflammatory cyclooxygenase-2 and 5-lipoxygenase

Chemical investigation of demosponge Hyrtios erectus (family Thorectidae) resulted in the identification of two scalarane-type sesterterpenes, erectascalaranes A–B, which were characterized as 3-((but-35-enyloxy)methyl)-icosahydro-11-hydroxy-4,4,8,10,13-pentamethyl-20-oxochryseno[2,1-c]furan-12-yl acetate (erectascalarane A) and 3-((but-35-enyloxy)methyl)-hexadecahydro-11-hydroxy-4,4,8,10,13-pentamethylchryseno[2,1-c]furan-20(5bH)-one (erectascalarane B) using detailed spectroscopic experiments. Erectascalarane A exhibited significantly greater attenuation property against pro-inflammatory cyclooxygenase-2 (IC50 0.80 mM) than that displayed by erectascalarane B (IC50 ~ 1 mM). Erectascalarane A was found to be a potential inhibitor against 5-lipoxygenase (IC50 1.21 mM), and its activity was significantly higher than that displayed by standard anti-inflammatory agent ibuprofen (IC50 4.50 mM, p 1.5 mM). Lesser docking parameters obtained for erectascalarane A at the active site of COX-2 and greater electronic factors acquired from structure–activity analyses (topological polar surface area 82.06) were also in agreement with greater anti-inflammatory activity. Lesser steric bulk and greater electronic properties combined with lower binding energy with cyclooxygenase-2 further reinforced the significant anti-inflammatory potential of erectascalarane A.

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-1β 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.

New Naproxen Analogs: Synthesis, Docking and Anti-Inflammatory Evaluation

Naproxen is a well-known nonsteroidal anti-inflammatory drug belonging to aryl propanoic acid family; it nonselectively inhibits major cyclo-oxygenase (COX) isoforms causing GIT irritation as a side effect. A series of Naproxen analogs with modifiable carboxylic acid functionality (2–14) have been synthesized aiming to retain anti-inflammatory activity with reduced ulcerogenic effect. Docking studies of the new compounds into cyclo-oxygenase-2 complexes with its bound inhibitor SC-558 (1CX2) were performed in order to predict the binding affinities and orientations of these compounds at the active site. Best fit Naproxen analogs, 3, 5b, 9, 10f, 14 to COX-2 active site were screened for their anti-inflammatory activity by carrageenan-induced rat paw edema test method. The target compound, 3 showed higher inhibition rate (74.71%) than the reference standard, Naproxen (71.11%), compound 10f showed comparable inhibition rate (68.94%) to Naproxen, while the other targets 5b, 9, 14 elicited moderate anti-inflammatory activities (47.98–40.27%). All the test compounds were devoid of ulcerogenicity effect compared to Naproxen. Detailed synthesis, spectroscopic, and pharmacological data are disclosed. ICM values of compounds 3 and 10f are –87.69 and –105.57 kcal/mol respectively and the number of hydrogen bonding to COX-2 prove their affinity and showed good agreement with their remarkable pharmacological data.

Synthesis, Molecular Docking, Biological Potentials and Structure Activity Relationship of New Quinazoline and Quinazoline-4-one Derivatives

In this work, a new derivative of ethyl 5-chloro-2-(3-(4-hydroxyphenyl)propanamido)benzoate (1) was synthesized by reacting the amino group of 3-(4-hydroxyphenyl)propanoic acid (0.01 mol) and methyl 2-amino-5-chlorobenzoate in presence of PCl3. Cyclcondensation of 1 with hydrazine hydrate afforded the corresponding 2-(4-hydroxyphenethyl)-3-amino-6-chloroquinazolin-4(3H)-one (2). Also, new Schiff base 3 was prepared via reaction of 2-(4-hydroxyphenethyl)-3-amino-6-chloroquinazolin- 4(3H)-one (2) with 4-hydroxy-3-methoxybenzaldehyde. The synthesized compounds were characterized by elemental analysis, IR, 1H NMR and mass spectral data. Also, the median lethal doses (LD50s) of compounds 1-3 in rats were 1125, 835 and 1785 mg/kg b.w., respectively. IC50 values of compounds (1, 3) as measured by DPPH• method was 136.47 and 73.54 μg/mL, respectively. IC50 values of compounds (1-3) as measured by ABTS•+ radical method was 0.8, 0.92 and 0.08 mg/mL, respectively. Antiulcerogenic activity at dose 1/20 LD50 in albino rats was 47.94, 24.60 and 56.45%, respectively. However, the anti-inflammatory effect at dose 1/20 LD50 of compounds (1-3) induced edema model after 120 min were 74.19, 69.93 and 59.03%, respectively. The synthesized compounds also possess hepatocytes and gastric mucosa protective activity against ibuprofen induced ulceration and LPS-induced liver toxicity, respectively in rats via normalization of oxidative stress biomarkers and inflammatory mediators (Na+/K+-ATPase, ALT, AST, LDH, TNF-α, NO, TBARS, GPx, CAT and SOD). Also, TNF-α, NO, PGE2 and COX-2 were inhibited in peritoneal macrophage cells at a concentration of 100 μg/L. Molecular docking suggested that the most active compounds 1 and 2 can be positioned within the active sites of COX-2 at Arg121 & Tyr356 similarly to ibuprofen (Arg-120, Glu-524 and Tyr-355). The compound 3–COX-2 complex generated by docking, revealed intricate interactions with a COX-2 channel, including hydrogen bonds with key residues Arg121 and phe519. These findings suggest that compounds 1-3 exhibited good antioxidant, antiulcer, anti-inflammatory activity and safe on liver enzymes in rats.

Challenging inflammatory process at molecular, cellular and in vivo levels via some new pyrazolyl thiazolones

The work reported herein describes the synthesis of a new series of anti-inflammatory pyrazolyl thiazolones. In addition to COX-2/15-LOX inhibition, these hybrids exerted their anti-inflammatory actions through novel mechanisms. The most active compounds possessed COX-2 inhibitory activities comparable to celecoxib (IC50 values of 0.09–0.14 µM) with significant 15-LOX inhibitory activities (IC50s 1.96 to 3.52 µM). Upon investigation of their in vivo anti-inflammatory activities and ulcerogenic profiles, these compounds showed activity patterns equivalent or more superior to diclofenac and/or celecoxib. Intriguingly, the most active compounds were more effective than diclofenac in suppressing monocyte-to-macrophage differentiation and inflammatory cytokine production by activated macrophages, as well as their ability to induce macrophage apoptosis. The latter finding potentially adds a new dimension to the previously reported anti-inflammatory mechanisms of similar compounds. These compounds were effectively docked into COX-2 and 15-LOX active sites. Also, in silico predictions confirmed the appropriateness of these compounds as drug-like candidates.

Design, Synthesis and Comprehensive Investigations of Pyrrolo[3,4-d]pyridazinone-Based 1,3,4-Oxadiazole as New Class of Selective COX-2 Inhibitors.

The long-term use of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) in treatment of different chronic inflammatory disorders is strongly restricted by their serious gastrointestinal adverse effects. Therefore, there is still an urgent need to search for new, safe, and efficient anti-inflammatory agents. Previously, we have reported the Mannich base-type derivatives of pyrrolo[3,4-d]pyridazinone which strongly inhibit cyclooxygenase, have better affinity to COX-2 isoenzyme and exert promising anti-oxidant activity. These findings encouraged us to perform further optimization of that structure. Herein, we present the design, synthesis, molecular docking, spectroscopic, and biological studies of novel pyrrolo[3,4-d]pyridazinone derivatives bearing 4-aryl-1-(1-oxoethyl)piperazine pharmacophore 5a,b–6a,b. The new compounds were obtained via convenient, efficient, one-pot synthesis. According to in vitro evaluations, novel molecules exert no cytotoxicity and act as selective COX-2 inhibitors. These findings stay in good correlation with molecular modeling results, which additionally showed that investigated compounds take a position in the active site of COX-2 very similar to Meloxicam. Moreover, all derivatives reduce the increased level of reactive oxygen and nitrogen species and prevent DNA strand breaks caused by oxidative stress. Finally, performed spectroscopic and molecular docking studies demonstrated that new compound interactions with bovine serum albumin (BSA) are moderate, formation of complexes is in one-to-one ratio, and binding site II (subdomain IIIA) is favorable.

Design and synthesis of pyrimidine-5-carbonitrile hybrids as COX-2 inhibitors: Anti-inflammatory activity, ulcerogenic liability, histopathological and docking studies

Two new series of 1,3,4-oxadiazole and coumarin derivatives based on pyrimidine-5-carbonitrile scaffold have been synthesized and evaluated for their COX-1/COX-2 inhibitory activity. Compounds 10c, 10e, 10h-j, 14e-f, 14i and 16 were found to be the most potent and selective inhibitors of COX-2 (IC50 0.041–0.081 μM, SI 139.74–321.95). Eight compounds were further investigated for their in vivo anti-inflammatory activity. The most active derivatives 10c, 10j and 14e displayed superior in vivo anti-inflammatory activity (% edema inhibition 39.3–48.3, 1 h; 58.4–60.5, 2 h; 70.8–83.2, 3 h; 78.9–89.5, 4 h) to the reference drug celecoxib (% edema inhibition 38.0, 1 h; 48.8, 2 h; 58.4, 3 h; 65.4, 4 h). These derivatives were also tested for their ulcerogenic liability, compound 10j showed better safety profile with reference to celecoxib while 10c and 14e exhibited mild lesions. Molecular docking studies of 10c, 10j, and 14e in the COX-2 active site revealed similar orientation and binding interactions as selective COX-2 inhibitors with a higher liability to access the selectivity side pocket.

New indomethacin analogs as selective COX-2 inhibitors: Synthesis, COX-1/2 inhibitory activity, anti-inflammatory, ulcerogenicity, histopathological, and docking studies.

New indomethacin analogs 4a-g, 5, 6, 8a, and 8b were synthesized to overcome the nonselectivity and ulcer liability of indomethacin. All newly synthesized compounds were more potent against cyclooxygenase 2 (COX-2; IC50 value range: 0.09-0.4 μМ) ascompared with celecoxib (IC50 = 0.89 μМ). Compounds 4a, 4b, 4d, 5, and 6 showed the highest COX-2 selectivity index (SI range = 4.07-6.33) as compared with indomethacin (SI = 1.14) and celecoxib (SI = 3.52). Additionally, 4a, 4b, 4d, 5, and 7 showed good anti-inflammatory activity with edema inhibition (79.36-88.8%), relative to celecoxib (78.96%) and indomethacin (90.43%), after 5 h. Also, ulcerogenic effects and histopathological examination were assessed for the most potent analogs,4b, 4d, 5, and 6, to determine their safety. The results can shed light on indomethacin analog5 as a remarkable anti-inflammatory lead compound with a good safety profile (ulcer index = 10.62) close to the nonulcerogenic drug celecoxib (ulcer index = 10.53) and better than indomethacin (ulcer index = 18.50). Docking studies were performed in the COX-2 active site for the most active compounds, to test their selectivity and to confirm their mechanism of action.

Design, Synthesis and Pharmacological Evaluation of Gastro- Protective Anti-inflammatory Analgesic Agents based on Dual Oxidative Stress / Cyclooxygenase Inhibition.

Non-steroidal anti-inflammatory drugs (NSAIDs) derived local generation of reactive oxygen species (ROS) plays a crucial role in the formation of gastric ulceration. Therefore, anti-inflammatory analgesics with potent antioxidant activity could be a potential therapeutic strategy for the treatment of pain and inflammatory disorders without gastrointestinal (GI) side effects. In an effort to develop gastroprotective analgesic and anti-inflammatory agents, a series of 2-methylamino-substituted-1H-benzo[d] imidazol-1-yl) (phenyl) methanone derivatives were synthesized and evaluated in vitro for cyclooxygenase (COX) inhibition as well as anti-oxidant potential by the FRAP assay. The compounds with significant in vitro COX-1/COX-2 inhibitory activity and antioxidant activity were further screened in vivo for their anti-inflammatory and analgesic activities. Moreover, the ulcerogenic potential of test compounds was also studied. To gain insight into the plausible mode of interaction of compounds within the active sites of COX-1 and COX-2, molecular docking simulations were performed. Among the various synthesized molecules, most of the compounds showed good cyclooxygenase inhibitory activity and efficient antioxidant activity in FRAP assay. After preliminary and indicative in vitro assays, three compounds exhibited most significant antiinflammatory and analgesic activity with better gastric tolerability during their in vivo evaluation. Ligand interaction studies indicated highest dock score -43.05 of 1,2- disubstituted benzimidazole derivatives in comparison to the reference ligand -30.70. Overall studies provided us (2-((4-methoxyphenylamino) methyl) -1h-benzo [d] imidazol- 1-yl) (phenyl) methanone as a lead with potent gastro-protective anti-inflammatory and analgesic activities that can be used for future research. From the above results, it can be concluded that designing of multifunctional molecules with COX-1/COX-2 inhibitory and anti-oxidant activities could hold a great promise for further development of GI-safer NSAIDs.

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

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

Hyrtioscalaranes A and B, two new scalarane-type sesterterpenes from Hyrtios erectus with anti-inflammatory and antioxidant effects

Two new scalarane-type sesterterpenes, hyrtioscalaranes A and B, were isolated from the organic extract of the Demosponge Hyrtios erectus through extensive chromatographic purification. Hyrtioscalarane A exhibited significantly greater attenuation property against cyclooxygense-2 (IC50 0.83 mM) than that displayed by hyrtioscalarane B (IC50 0.98 mM). The greater selectivity index of hyrtioscalaranes (> 1) than that exhibited by the commercial anti-inflammatory agent ibuprofen (0.43) further supported the higher selectivity of the former towards pro-inflammatory cyclooxygenase-2. Hyrtioscalarane A exhibited greater antioxidant activities as determined by 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (IC50 0.77 mM) and 2,2-diphenyl-1-picrylhydrazyl (IC50 0.81 mM) free radical quenching properties than those displayed by hyrtioscalarane B (IC50 > 0.83 mM) and the antioxidative agent α-tocopherol (IC50 1.51 mM). The greater binding energy (–14.32 kcal/mol) and docking score (15.22 kcal/mol) of hyrtioscalarane A at the active site of cyclooxygenase-2 along with the higher electronic parameters and balanced hydrophobicity could attribute its potential anti-inflammatory activity.

Calcarea carbonica treatment rescues lipopolysaccharide-induced inflammatory response in human mononuclear cells via downregulation of inducible cyclooxygenase pathway

ObjectiveProlonged use of nonsteroidal anti-inflammatory drugs is associated with severe side effects and toxicity. Therefore, we studied the anti-inflammatory role of Calcarea carbonica which had minimal toxicity at the low doses. MethodsTHP-1 human mononuclear cells were treated with C. carbonica to evaluate the 50% cytotoxicity concentration (CC50) and 50% effective concentration (EC50). Cell survival was evaluated in lipopolysaccharide-stimulated C. carbonica-treated cells. Nitric oxide (NO) and tumor necrosis factor-α (TNF-α) were measured to evaluate the anti-inflammatory activity of C. carbonica. Cyclooxygenase-2 (COX-2) protein expression was determined by Western blotting analysis, and the interaction of C. carbonica with the COX-2 protein was evaluated using molecular docking simulation. ResultsThe CC50 and EC50 of C. carbonica were found to be 43.26 and 11.99 µg/mL, respectively. The cell survival assay showed a 1.192-fold (P = 0.0129), 1.443-fold (P = 0.0009) and 1.605-fold (P = 0.0004) increase in cell survival at 24, 48 and 72 h after initiating C. carbonica treatment, respectively. C. carbonica-treated cells showed a reduction in NO levels by 2.355 folds (P = 0.0001), 2.181 folds (P = 0.0001) and 2.071 folds (P = 0.0001) at 24, 48 and 72 h, respectively. The treated cells also showed a reduction in TNF-α levels by 1.395 folds (P = 0.0013), 1.541 folds (P = 0.0005) and 1.550 folds (P = 0.0005) at 24, 48 and 72 h, respectively. In addition, a 1.193-fold reduction (P = 0.0126) in COX-2 protein expression was found in C. carbonica-treated cells. The molecular docking showed interaction of C. carbonica with the phenylalanine 367 residue present in active site of Cox-2. ConclusionC. carbonica exhibited anti-inflammatory properties in lipopolysaccharide-stimulated cells by significantly reducing NO production and TNF-α level through downregulation of the COX-2 protein. This effect is probably mediated through interaction of C. carbonica with the phenylalanine 367 residue present in active site of Cox-2.