Design, synthesis and pharmacological evaluation of 4-[2-alkylthio-5（4）-（4- substitutedphenyl）imidazole-4（5）yl]benzenesulfonamides as selective COX-2 inhibitors

Aim： To design and synthesize a series of benzenesulfonamide derivatives, 4-[2- alkylthio-5 （4）-（4-substitutedphenyl）imidazole-4（5）-yl]benzenesul fonamides （4a-4j）, which are intended to act as cyclooxygenase-2 （COX-2） inhibitors with good COX-2 inhibitor activity, and which will exert anti-inflammatory activities in vivo. Methods： Benzenesulfonamide derivatives were designed and synthesized through multi-step chemical reactions. All the synthesized compounds were evaluated in an in vitro assay. The active compound 4a-4f was selected for further evaluation in a carrageenan-induced rat paw edema model. Results： Docking studies showed that compound 4 bind into the primary binding site of COX-2 with the sulfonamide SO2NH2 moiety interacting with the secondary pocket amino acid residues. In the in vitro assay, compound 4 inhibited COX-2 with an inhibition concentration IC50 value of 1.23-8 nmol/L, compared to celecoxib with IC50 value of 1.5 nmol/L. Compound 4b and 4c had good potency and selectivity in comparison to the celecoxib. In the in vivo model, compound 4a-4f exhibited a moderate potency to inhibit 50% carrageenan-induced paw edema with value of 1.58-4.3 mg/kg. In the latter experiment, compound 4c was the most active compound. Conclusion： The antiinflammatory effects obtained for compound 4a-4j could be due to the presence of fluorine or hydrogen substituents in the para position of the phenyl ring of these compounds.     

Ligand-based design, synthesis and primary in vivo screening of pyrrole derivatives as potential tricyclic anti-inflammatory agents

Twelve new compounds were designed as 5-aryl-1H-pyrrole analogs of celecoxib (CAS 169590-42-5) and were synthesized by Paal-Knorr cyclization in three series according to 1H-substitution: derivatives with salicylic acid, pyrazolone or isonicotinamide residues. The average physico-chemical and steric similarity between the prototype and the new analogs (completed with two previously synthesized related products) was assessed to be 82 % and therefore considered as a reliable prerequisite for spatial compatibility and effective binding to the cyclooxygenase (COX) enzymes. The anti-inflammatory effects were determined in acute inflammation model using the carrageenan-induced rat paw edema assay on male Wistar rats (180-200 g) at doses of 10, 20 and 40 mg/kg, i.p. Six of the new products showed higher percent of inhibition (up to 100 %) compared to the highly selective COX-2 inhibitor celecoxib and the nonselective indometacin (CAS 53-86-1) used as reference compounds. Ethyl 1-(1,5-di-methyl-3-oxo-2-phenyl-2,3-dihydro-1H-4-pyrazolyl)-2-methyl-5-phenyl-1H-3-pyrrolecarboxylate (2b), ethyl 5-(4-chlor-ophenyl)-2-methyl-1-[(4-pyridylcarbonyl) amino]-1H-3-pyrrolecarboxylate (3c) and 5-[3-acetyl-2-methyl-5-(4-methylphenyl)-1H-1-pyrrolyl] -2-hydroxybenzoic acid (4b) were pointed out as the most active representatives of each of the three tested sub-series.     

Synthesis, biological evaluation, and enzyme docking simulations of 1,5-diarylpyrrole-3-alkoxyethyl ethers as selective cyclooxygenase-2 inhibitors endowed with anti-inflammatory and antinociceptive activity

A series of substituted 1,5-diarylpyrrole-3-alkoxyethyl ethers (6, 7, and 8) has been synthesized with the aim to assess if in the previously reported 1,5-diarylpyrrole derivatives (5) the replacement of the acetic ester moiety with an alkoxyethyl group still led to new, highly selective and potent COX-2 inhibitors. In the in vitro cell culture assay, all the compounds proved to be potent and selective COX-2 inhibitors. In the human whole blood (HWB) assay, compound 8a had a comparable COX-2 selectivity to valdecoxib, while it was more selective than celecoxib but less selective than rofecoxib. The potential anti-inflammatory and antinociceptive activities of compounds 7a, 8a, and 8d were evaluated in vivo, where they showed a very good activity against both carrageenan-induced hyperalgesia and edema in the rat paw test. In the abdominal constriction test compound 7a, 8a, and 8d were able to reduce the number of writhes in a statistically significant manner. Furthermore, the affinity data of these compounds have been rationalized through enzyme docking simulations in terms of interactions with a crystallographic model of the COX-2 binding site by means of the software package Autodock 3.0.5, GRID 21, and MacroModel 8.5 using the complex between COX-2 and SC-558 (1b), refined at a 3 A resolution (Brookhaven Protein Data Bank entry: 6cox ).     

Synthesis and structure-activity relationship studies of urea-containing pyrazoles as dual inhibitors of cyclooxygenase-2 and soluble epoxide hydrolase

A series of dual inhibitors containing a 1,5-diarylpyrazole and a urea were designed, synthesized, and evaluated as novel COX-2/sEH dual inhibitors in vitro using recombinant enzyme assays and in vivo using a lipopolysaccharide (LPS) induced model of pain in rats. The best inhibition potencies and selectivity for sEH and COX-2 over COX-1 were obtained with compounds (21b, 21i, and 21j) in which both the 1,5-diaryl-pyrazole group and the urea group are linked with a three-methylene group. Compound 21i showed the best pharmacokinetic profiles in both mice and rats (higher AUC and longer half-life). Following subcutaneous administration at 10 mg/kg, compound 21i exhibited antiallodynic activity that is more effective than the same dose of either a COX-2 inhibitor (celecoxib) or a sEH inhibitor (t-AUCB) alone, as well as coadministration of both inhibitors. Thus, these novel dual inhibitors exhibited enhanced in vivo antiallodynic activity in a nociceptive behavioral assay.     

Inducible nitric oxide synthase and cyclooxygenase-2 participate in anti-inflammatory and analgesic effects of the natural marine compound lemnalol from Formosan soft coral Lemnalia cervicorni

Lemnalol (8-isopropyl-5-methyl-4-methylene-decahydro-1,5-cyclo-naphthalen-3-ol) is a natural compound isolated from the marine soft coral Lemnalia cervicorni. In the present study, the anti-inflammatory and anti-nociceptive properties of lemnalol were investigated in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and carrageenan-injected rats, respectively. Our results demonstrate that lemnalol significantly inhibited the expression of the pro-inflammatory proteins, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), in LPS-stimulated RAW 264.7 cells. An in vivo inflammation model was induced by intraplantar injection of carrageenan into rat hind paws. An intramuscular injection of lemnalol (15 mg/kg) 10 min before carrageenan injection resulted in significant inhibition of carrageenan-induced rat paw edema and thermal hyperalgesia behavior. Western blot experiments revealed that the carrageenan-induced expression of iNOS and COX-2 in paw tissue was significantly down-regulated by lemnalol. Moreover, post-intrathecal injection of lemnalol produced a dose-dependent anti-nociceptive effect in carrageenan-injected rats (1 and 5 microg). The present results indicate that the marine-derived compound lemnalol had anti-inflammatory and analgesic effects in LPS-stimulated RAW 264.7 cells and carrageenan-injected rats, respectively. In addition, inhibition of elevated iNOS and COX-2 protein expression as well as neurophil infiltration of carrageenan-injected paws may be involved in the beneficial effects of lemnalol.     

Synthesis and anti-inflammatory activity of alkyl/arylidene-2-aminobenzothiazoles and 1-benzothiazol-2-yl-3-chloro-4-substituted-azetidin-2-ones

Ten new derivatives of 1-benzothiazol-2-yl-3-chloro-4-substituted-azetidin-2-ones (3a-j) were synthesized using various Schiff bases (alkyl/arylidene-2-aminobenzothiazoles; 2a-j), which in turn were prepared starting from 2-aminobenzothiazole (1). All the synthesised compounds were characterised by elemental analyses and spectral (IR, 1H-NMR, 13C-NMR and EI-MS) data. The title compounds 2a-j and 3a-j were screened in vivo using carrageenan-induced rat paw edema model. All the test compounds showed anti-inflammatory activity when tested in vivo. In general, compounds 3a-j were found to be more potent compared to compounds 2a-j. Among the compounds tested, compound 2g in the alkyl/arylidene-2-aminobenzothiazoles series and compound 3 g in the 1-benzothiazol-2-yl-3-chloro-4-substituted-azetidin-2-ones series were found to be the most potent. All the test compounds were also evaluated to check the gastric ulcer incidence. In gastric ulceration studies, all the test compounds were generally found to be safe at the 100 mg/kg dose level. Furthermore the most potent compounds 2 g and 3 g from each series were screened in vitro for inhibition of both COX-2 and COX-1 catalysed prostaglandin biosynthesis (radiochemical assay). Like most of the commercially available non-steroidal anti-inflammatory drugs (NSAIDs), in the in vitro study, compounds 2 g and 3 g showed anti-inflammatory activity by blocking the metabolism of arachidonic acid to prostaglandin via the cyclooxygenase pathways. In general, in the vitro assay, test compounds 2 g and 3 g were found to be more active after 15 min pre-incubation with the enzyme. Compound 3 g was found to be more COX-2 selective, while compound 2 g was found to be equally COX-2 and COX-1 selective.     

Pharmacological profile of celecoxib, a specific cyclooxygenase-2 inhibitor

The pharmacological profile of celecoxib (CAS 169590-42-5, SC-58635), a specific cyclooxygenase-2 (COX-2) inhibitor, was investigated. Celecoxib inhibited COX-2-mediated prostaglandin E2 (PGE2) production in human dermal fibroblasts (IC50 = 91 nmol/l), whereas it was a weak inhibitor of COX-1-mediated PGE2 production in human lymphoma cells (IC50 = 2800 nmol/l). In in vivo studies, the effects of celecoxib were compared with those of nonsteroidal anti-inflammatory drugs (NSAIDs) in acute rat models of hyperalgesia and pyrexia. Celecoxib abrogated carrageenan-induced hyperalgesia in the hind paw accompanied by a decrease in PGE2 content in paw exudates and cerebrospinal fluid in a dose-related manner, with an ED30 = 0.81 mg/kg. Its analgesic potency was comparable to those of NSAIDs. In lipopolysaccharide-induced pyrexia, the anti-pyretic potency of celecoxib was equal to that of NSAIDs. On the other hand, in a gastric toxicity study in rats, single oral administration of celecoxib had no effect on gastric mucosa or mucosal PGE2 content at doses up to 200 mg/kg. Additionally, celecoxib did not inhibit thromboxane B2 production of calcium ionophore-stimulated peripheral blood of rats or arachidonic acid-induced aggregation of human platelets. These findings suggest that celecoxib might be a safe and effective alternative to NSAIDs for clinical use.     

Synthesis and biological evaluation of pyrazolone analogues as potential anti-inflammatory agents targeting cyclooxygenases and 5-lipoxygenase

New pyrazolone derivatives structurally related to celecoxib and FPL 62064 were synthesized and biologically evaluated for their inhibitory activity against cyclooxygenases (COXs) and 5-lipoxygenase (5-LOX) and their selectivity indices were calculated. The results showed that compounds 3f , 3h , 3l , and 3p have an excellent COX-2 selectivity index. Moreover, they showed potent 5-LOX inhibitory activity relative to celecoxib and zileuton, as positive controls. These promising candidates were further investigated for anti-inflammatory activity using the carrageenan-induced rat paw edema method and ulcerogenic liability. The results showed no ulceration, which implies their gastric safety profile. Moreover, these compounds were evaluated for prostaglandin (PGE2) production in rat serum. Molecular docking in the COX-2 and 5-LOX active sites was performed to rationalize their anti-inflammatory activities. Strong binding interactions and effective docking scores were identified. The results indicated that these derivatives are good leads for dual-acting COX-2/5-LOX inhibitors to be used as potent and safe anti-inflammatory agents.     

Analgesic and anti-inflammatory activity of amifostine, DRDE-07, and their analogs, in mice

Objectives:

To find out the analgesic and anti-inflammatory activity, if any, of Amifostine [S-2(3 amino propyl amino) ethyl phosphorothioate], DRDE-07 [S-2(3 amino ethyl amino) ethyl phenyl sulphide] and their analogs DRDE-30 and DRDE-35, the probable prophylactic agent for sulphur mustard (SM).

Materials and Methods:

In order to find out the analgesic activities of the compounds two methods were employed, namely, acetic acid-induced writhing test and formalin-induced paw licking. The persistent pain model of formalin-induced hind paw licking was carried out to test the effect of the compounds on neurogenic pain or early phase (0 to 5 minutes) and on the peripheral pain or the late phase (15 to 30 minutes). To test the effect of the compound in acute inflammation, carrageenan-induced hind paw edema was carried out. This model of inflammation involves a variety of mediators of inflammation.

Results:

DRDE-07 (81.7%) and DRDE-30 (79.4%) showed significant reduction in the acetic acid-induced writhing test. DRDE-07 (93.1%), DRDE-30 (82%), and DRDE-35 (61.3%) showed significant reduction in the second or late phase of formalin-induced paw licking. All the analogs (more than 60%) including amifostine (43.9%) showed significant reduction of paw edema in the carrageenan-induced paw edema in mice.

Conclusion:

The analgesic and anti-inflammatory activity of the antidotes were comparable with aspirin.     

Synthesis and biological evaluation of ester derivatives of indomethacin as selective COX-2 inhibitors

The ester derivatives of indomethacin were prepared by condensing indomethacin with an equimolar quantity of an appropriate alcoholic compound in anhydrous dichloromethane in the presence of DCC and DMAP. Spectral studies comprising of IR, ¹H NMR, mass, and microanalysis were performed in order to confirm their structures. In vivo anti-inflammatory studies were carried out using carrageenan rat paw edema method and in vivo ulcerogenic studies by ulcer index method for the panel of synthesized compounds. Out of eleven compounds, the compound IIc displayed moderate anti-inflammatory activity with no observable ulcerogenic effect when compared to indomethacin. Furthermore, compound IIc, indomethacin and celecoxib were tested at a concentration of 20?μM against COX-1 and COX-2 enzymes by colorimetric COX inhibitor screening assay. Compound IIc was found to be active against COX-2 and COX-1 enzymes exhibiting 62.0 and 12.9% inhibition, respectively.     

Design, synthesis, and evaluation of anti-inflammatory and ulcerogenicity of novel pyridazinone derivatives

A series of pyridazinone-containing compounds were designed and synthesized as congeners for diclofenac, the most potent and widely used NSAID. The target compounds were evaluated for their anti-inflammatory activity on rat paw edema inflammation model against diclofenac as a reference compound. Seven of the tested compounds demonstrated more than 50% inhibition of carrageenan-induced rat paw edema at a dose 10?mg/kg. The compounds, 6-(2-bromophenylamino)pyridazin-3(2H)-one 2a and 6-(2,6-dimethylphenylamino)pyridazin-3(2H)-one 2e, displayed 74 and 73.5% inflammation-inhibitory activity, respectively, which is comparable to diclofenac (78.3%) at the same dose level after 4?h. The most active compounds as anti-inflammatory agents, 2a, 2e, and 6a, displayed fewer number of ulcers and milder ulcer score than indomethacin in ulcerogenicity screening.     

Studies on the anti-inflammatory effects of<Emphasis Type="Italic">clerodendron trichotomum</Emphasis> thunberg leaves

Clerodendron trichotomum Thunberg Leaves (CTL) have been used for centuries in Chinese folk medicine for their anti-inflammatory properties. We have studied the anti-inflammatory effects of CTL extracts in rats, mice and in Raw 264.7 cells. 1 mg/kg solutions of the 30% and 60% methanol extracts of CTL were used and a 1 mg/kg of indomethacin was used as a positive anti-inflammatory standard; these were then administrated to rats. Carrageenan was injected subcutaneously to induce hind paw edema in rats. The result of carrageenan-induced rat paw oedema showed that a 1 mg/kg of the 30%, and 60% methanol fraction of CTL and 1 mg/kg of indomethacin inhibited the hind paw edema by 19.5%, 23.0%, and 20.5% respectively. The effect of CTL on inflammation in mice by a capillary permeability assay was examined by detecting Evans blue leakage from capillaries after the intraperitoneal injection of acetic acid, a potent inflammatory stimulus. The 60% methanol fraction of CTL inhibited Evans blue dye leakage by 47.0%, which was 10% higher than that of the inhibition of 1 mg/kg of indomethacin. Also, the 60% methanol fraction of CTL suppressed the prostaglandin E2 (PGE2) generation in RAW 264.7 macrophage cells after treatment with lipopolysaccharide (LPS) by as much as the inhibition of 1 mg/kg of indomethacin and this led to the synthesis of PGE2 by COX-2 induction. The inhibition of the carrageenan-induced rat paw oedema, vascular permeability and the PGE2 generation demonstrates that the 60% methanol fraction of CTL contains a potent anti-inflammatory activity.     

Anti-inflammatory and Analgesic Effects of Drypemolundein A,a Sesquiterpene Lactone from Drypetes molunduana

Previous pharmacological screening in our laboratory showed analgesic and anti-inflammatory effects of a crude stem bark extract of Drypetes molunduana. Phytochemical studies of this plant led to the isolation an structural elucidation of seven pentacylic triterpenes and one lignan, which were already known compounds, and a new furanosesquiterpene lactone, Drypemolundein A. The purpose of this study was to examine the anti-inflammatory and analgesic activities of drypemolundein A. The compound was studied against carrageenan-induced acute edema. At doses of 10 and 20 mg/kg, orally administered, it significantly reduced (57.57 and 66.66% inhibition at 1 h intervals, respectively) paw edema. At the same doses, this sesquiterpene lactone also exhibited significant analgesic action in force-induced pain in rat paw. These results indicate that drypemolundein A functions as an effective anti-inflammatory and analgesic agent.     

Evaluation of anti-inflammatory,analgesic activities,and side effects of some pyrazole derivatives

Background and purpose

Non-steroidal anti-inflammatory drugs are associated with several side effects, such as gastrointestinal mucosal damage, renal toxicity, and cardiovascular side effects. Aiming to find a novel analgesic/anti-inflammatory drug with minimal side effects, the present study was designed to screen and evaluate some newly synthesized pyrazole derivatives.

Method

Anti-inflammatory activity using carrageenan-induced rat paw edema and cotton-pellet-induced granuloma, COX-1/COX-2 selectivity using thin layer chromatography, and analgesic using hot plate and tail flick tests as well as ulcerogenic and renal side effects of the ten compounds were assessed.

Results and discussion

The results of the carrageenan-induced rat paw edema showed that the carboxyphenylhydrazone derivative (N9) was more potent than the chlorophenyl counterpart (N8) with a relative activity compared to celecoxib of 1.08 and ?0.13, respectively, after 1 h. Even though this is true, N9 caused significant increase in the ulcer index, creatinine, and Blood Urea Nitrogen levels. The cotton granuloma test showed that the carboxyphenylhydrazone derivative (N7) was also more potent than its chlorophenyl counterpart (N6) with a relative activity compared to celecoxib of 1.13 and 0.86, respectively. Moreover, adding an acetyl not only increased the anti-inflammatory activity from a relative activity compared to celecoxib of 0.57–1.17 for the compounds X4 and N5, respectively, in the granuloma test, but also increased the selectivity toward COX-2 from 0.197 to 47.979.

Conclusion

As a conclusion, from the ten compounds analyzed, N5 and N7 showed promising results as anti-inflammatory/analgesic agents with low ulcerogenicity and nephrotoxicity and thus should be further analyzed to determine the ED50 and other side effects.

     

Pharmacological screening for anti-inflammatory, analgesic activity of pyrazolyl derivatives along with molecular docking studies

The pyrazole derivatives were synthesized and pharmacologically evaluated for analgesic (tail flick) and anti-inflammatory (based on carrageenan-induced paw edema) activities. Compound 4k showed high potency as an anti-inflammatory agent after 3 and 4-h time intervals (P?<?0.001) equipotent to indomethacin. They were devoid of ulcerogenic potential when administered at a dose of 30?mg/kg. The compounds, which showed less ulcerogenic action, also showed reduced malondialdehyde content (MDA), which is one of the byproduct of lipid peroxidation. Further docking studies of titled compounds was done to understand key interactions responsible for observed inhibition of COX enzyme. The most active compound 4k was found to have ?11.192?kcal/mol, as the free energy of binding. Various other key interactions between the synthesized molecules and active site of COX-2 enzyme, responsible for the obtained pharmacological results were also reported. Most of the active compounds were docked well into the active sites of the receptor.     

Synthesis and biological evaluation of anti-inflammatory activity of 1,3 diphenyl propenone derivatives

A series of five chalcone derivatives were synthesized by Claisen–Schmidt condensation of acetophenone with appropriately substituted benzaldehyde in the presence of aqueous alkali. The synthesized compounds were characterized by their IR, NMR, and Mass spectral data. These compounds have been subjected to anti-inflammatory screening using the carrageenan-induced rat hind paw edema model. Chalcone derivatives at dose 25 mg/kg by oral route inhibited significantly the formation of edema. Chalcone posses a highly electrophilic α,β-unsaturated carbonyl moiety showed better anti-inflammatory activity.     

The effects of newly synthesized pyrazole derivatives on formaldehyde-, carrageenan-, and dextran-induced acute paw edema in rats

The antiinflammatory effects of 10 newly synthesized pyrazole derivatives on formaldehyde-induced rat paw edema were investigated. The most effective of them (K-3) was investigated again in dextran- and carrageenan-induced paw edema. In formaldehyde-induced paw edema, K-3 50, 100, and 200 mg/kg p.o. inhibited the edema by 48.9% (p<0.002), 68.7% (p<0.001), and 79.1% (p<0.001), respectively, 3 h after administration. In dextran-induced paw edema, the same dose of K-3 produced 27.1% (p<0.05), 46.8% (p<0.01), and 63.8% (p<0.002) inhibition, respectively. In the carrageenan-induced paw edema test, K-3 100 mg/kg decreased the inflammatory response by 52.0% after 4 h. Acute toxicity studies revealed that K-3 was nontoxic up to an oral dose of 2500 mg/kg.     

Anti-inflammatory and analgesic effect of LD-RT and some novel thiadiazole derivatives through COX-2 inhibition

Generally, highly selective COX-2 inhibitors cause cardiovascular side effects. Celecoxib is the highly marketed coxib, so there is still a need for the synthesis of COX-2 inhibitors with less adverse effects. Moreover, low-dose radiotherapy (LD-RT) is clinically used for the treatment of inflammatory diseases. The present study aimed to investigate the analgesic and anti-inflammatory activity of a novel series of 1,3,4-thiadiazole derivatives alone or combined with LD-RT with a single dose of 0.5 Gy. Initially, in vitro COX-1/COX-2 inhibition assays were performed, identifying the sulfonamide-containing compounds 5 – 10 as the most potent candidates, with IC₅₀ values in the range of 0.32–0.37 µM and the highest selectivity indices. These compounds and celecoxib were subjected to in vivo examination after their safety was assessed through the acute toxicity test. Treatment with compounds 5 – 10 inhibited carrageenan-induced edema by nearly 47–56%, which was nearly equivalent to celecoxib. Compounds 7 and 8 and celecoxib showed an analgesic activity of 64.15%, 49.05%, and 84.90%, respectively, whereas compounds 5 , 6 , 9 , and 10 did not show any analgesic activity unless combined with LD-RT. Ulcerogenic activity, histological paw examination, and docking studies were performed. Compounds 5 – 10 were nearly similar to celecoxib, showing normal histological features with no ulcerogenic activity.     

(-)-Nyasol (cis-hinokiresinol), a norneolignan from the rhizomes of <Emphasis Type="Italic">Anemarrhena asphodeloides</Emphasis>, is a broad spectrum inhibitor of eicosanoid and nitric oxide production

To assess the anti-inflammatory activity of constituents from the rhizomes of Anemarrhena asphodeloides, (-)-nyasol {cis-hinokiresinol, 4,4-[1Z,3R]-3-ethenyl-1-propene-1,3-diyl]bisphenol} was isolated and its anti-inflammatory activity was examined in lipopolysaccharide (LPS)-treated RAW 264.7 cells and A23187-treated RBL-1 cells. In vivo activity was measured using carrageenan-induced paw edema assay. At > 1 μM, (-)-nyasol significantly inhibited cyclooxygenase-2 (COX-2)-mediated PGE₂ production and inducible nitric oxide synthase (iNOS)-mediated NO production in LPS-treated RAW 264.7 cells, a mouse macrophage-like cell line, but did not affect the expression levels of COX-2 and iNOS. (-)-Nyasol also inhibited 5-lipoxygenase (5-LOX)-mediated leukotriene production in A23187-treated RBL-1 cells. Furthermore, (-)-nyasol potently inhibited carrageenan-induced paw edema in mice (28.6–77.1% inhibition at 24–120 mg/kg). Therefore, (-)-nyasol is a potential new lead compound and may contribute to the anti-inflammatory action of A. asphodeloides, possibly by inhibiting COX-2, iNOS and 5-LOX.     

Synthesis of some novel oxadiazole and oxadiazoline analogues for their antiinflammatory activity

The search for newer non-steroidal antiinflammatory drugs (NSAIDs) and the importance of oxadiazoles as antiinflammatory agents prompted us to undertake the synthesis of some novel oxadiazole and related analogues with unreported antiinflammatory activities. The antiinflammatory potential of the compounds was investigated using the carrageenan-induced rat paw edema method and cotton pellet-induced granuloma method. Some compounds demonstrated marked antiinflammatory activities. The antiinflammatory activity of oxadiazoles at doses of 100 mg/kg was shown by their ability to provide 28-55%, 21-36%, and 27-49% protection against carrageenan-induced rat paw edema, moist cotton pellet-induced, and dry cotton pellet-induced granuloma, respectively. On the other hand, the antiinflammatory properties of oxadiazolines at doses of 100 mg/kg was reflected by their ability to provide 15-47%, 22-39%, and 23-47% protection against carrageenan-induced rat paw edema, moist cotton pellet-induced, and dry cotton pellet-induced granuloma, respectively. Structure-activity relationships among synthesized compounds were also studied.