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.

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.