Design, synthesis, analgesic, anti-inflammatory activity of novel pyrazolones possessing aminosulfonyl pharmacophore as inhibitors of COX-2/5-LOX enzymes: Histopathological and docking studies.

A series of newly synthesized 4-aryl-hydrazonopyrazolones were designed and their structures were confirmed by spectral and elemental analyses. All synthesized compounds were evaluated for their in vitro COXs, 5-LOX inhibition, in vivo analgesic and anti-inflammatory activities. Compounds 5d, 5f and 5i were found to be the most potent COX-2/5-LOX inhibitors with superior COX-2 selectivity index values (SI = 5.29-5.69) to reference standard celecoxib (SI = 3.52). Four compounds; 5b, 5c, 5d and 5f showed excellent anti-inflammatory activity (% edema inhibition = 72.72-54.54%) and perfect ED50 values (ED50 = 0.044-0.104 mmol/kg) relative to celecoxib (ED50 = 0.032 mmol/kg). To explore the most active compounds, ulcerogenic effect on stomach in comparison with indomethacin and celecoxib in addition to histopathological investigations were performed. Compound 5f showed better gastric profile (UI = 2.33) than celecoxib (UI = 3.00). Also, 5f caused 50% increase in thermal pain threshold close to reference drug indomethacin (53.13%). Docking study of all the target compounds into COX-2 and 5-LOX active sites was performed to rational their anti-inflammatory activities.

Non-acidic 1,3,4-trisubstituted-pyrazole derivatives as lonazolac analogs with promising COX-2 selectivity, anti-inflammatory activity and gastric safety profile.

Twelve new compounds of 1,3,4-trisubstituted-pyrazole derivatives possessing two cyclooxygenase-2 (COX-2) pharmacophoric moieties (SO2Me or/and SO2NH2) 11a-c, 12a-c, 13a-c and 14a-c were designed and synthesized to be evaluated for their COX inhibition, anti-inflammatory activity, ulcerogenic liability. All compounds were more selective for COX-2 isozyme and showed good in vivo anti-inflammatory activity. The bisaminosulphonyl derivatives (14a-c) were the most COX-2 selective compounds (S.I. = 9.87, 9.50 and 9.22 respectively) and showed good anti-inflammatory potency (ED50 = 15.06, 42.51 and 50.43 µmol/kg respectively) in comparison with celecoxib (COX-2 S.I. = 8.61, ED50 = 82.2 µmol/kg). Also, compounds 14a-c were less ulcerogenic (ulcer indexes = 2.72-3.72) than ibuprofen (ulcer index = 20.25) and comparable to celecoxib (ulcer index = 2.93). In addition, to explain the preferential (COX-2) inhibitory and selectivity, the designed compounds were subjected to molecular docking studies. It was found that compound 14c with the highest COX-2 activity and selectivity exhibited a binding pattern and interactions similar to that of celecoxib with formation of more hydrogen-bond features.

Synthesis, anti-inflammatory, cyclooxygenases inhibitions assays and histopathological study of poly-substituted 1,3,5-triazines: Confirmation of regiospecific pyrazole cyclization by HMBC.

Three novel triazines series were prepared. These series are pyrazolines (4a and 4b), pyrazoles (6a, 6b and 8a-d) and isoxazoles (7a and 7b). Such series were designed as COX-2 inhibitors. All compounds were characterized by using spectroscopic methods and elemental analysis. Regarding COX-2, compounds 5b, 4a and 3b were the most active with IC50 in the range of 0.55-0.87 µM. Most of synthesized compounds were relatively more potent to celecoxib (0.78 µM), diclofenac (2.94 µM) and indomethacin (7.24 µM). A molecular modeling study was performed for the most active compounds. Histopathological evaluation also was done to estimate the safety of compounds. Finally, structure elucidation of pyrazole 8 was studied by 2D NMR.

Novel N-substituted indole Schiff bases as dual inhibitors of cyclooxygenase-2 and 5-lipoxygenase enzymes: Synthesis, biological activities in vitro and docking study.

Two new series of N-substituted indole derivatives 4a-l and 5a-h were synthesized. Their chemical structures were confirmed using spectroscopic tools including IR, (1)H NMR, (13)C NMR mass spectroscopy and elemental analyses. The results showed no significant cytotoxic activity on either cancer or normal human cells. Anti-inflammatory activity for all target compounds was evaluated in vitro. Compounds 5a-h were found to have better anti-inflammatory activity than 4a-l. The inhibitory activity of COX-2 and 5-LOX were tested for 5a-h. Three compounds, 5c, 5d and 5f showed excellent COX-2 inhibitory activity with IC50 ranging from 0.98 to 1.23 µM compared to the reference celecoxib (1.54 µM). These compounds had a reasonable selectivity index between 7.03 and 8.05. Additionally, p-methylbenzoyl derivative 5g (IC50 = 5.78 µM) had superior 5-LOX inhibitory activity, higher than quercetin. 5e was close to quercetin in its LOX inhibitory activity. Compounds 5a-h were docked inside the active site of COX-2 and 5-LOX enzymes.

Synthesis, cyclooxygenase inhibition, anti-inflammatory evaluation and ulcerogenic liability of new 1,5-diarylpyrazole derivatives.

A new series of 1,5-diarylpyrazoles 10a-l was designed and synthesized for evaluation as COX inhibitors and as anti-inflammatory agents. All compounds were more selective for COX-2 isozyme and showed good in vivo anti-inflammatory activity. Compound 10e was the most COX-2 selective compound (S.I. = 10.67) and the most potent anti-inflammatory derivative (ED50 = 46 µmol/kg) which is approximately 11-folds more potent than ibuprofen (ED50 = 499 µmol/kg) and had 2/3 potency of celecoxib (ED50 = 31 µmol/kg). All compounds were less ulcerogenic (ulcer indexes = 1.20-4.61) than ibuprofen (ulcer index = 20.25) and comparable to celecoxib (ulcer index = 2.90).

Cyclooxygenase-2 and 15-lipoxygenase inhibition, synthesis, anti-inflammatory activity and ulcer liability of new celecoxib analogues: Determination of region-specific pyrazole ring formation by NOESY.

Two new series of 1,5-diaryl pyrazoline (3a-f) and 1,5-diaryl pyrazole (5a and 5b) were designed as both COX-2 and 15-LOX inhibitors. All the prepared compounds were fully characterized by all spectral and element analysis. Their anti-inflammatory activity and ulcer index were included. Pyrazoline 3f is the most effective with IC50=1.14 and 4.7µM against COX-2 and 15-LOX respectively, and more potent than celecoxib and meclofenamate references. In addition 3a, 3b, 5a, and 5b were safer with low ulcer index than celecoxib. Docking study was performed for the most active compounds such as 2b, 3a, and 3f on COX-2 and 15-LOX enzymes.