Benzimidazole scaffold based hybrid molecules for various inflammatory targets: Synthesis and evaluation

Abstract

Designing of hybrid drugs with specific multitarget profile is a promising line of attack against inflammation. In light of this, a series of benzimidazole scaffold based hybrid molecules were designed by integrating benzimidazoles (containing pharmacophoric elements for COXs and LOXs inhibitors) with phthalimide subunit of thalidomide (pharmacophore element for TNF-α inhibitor) under one construct via molecular hybridization strategy. The designed molecules were synthesized and evaluated for their inhibitory activity against COXs (COX-1, COX-2), LOXs (5-LOX, 15-LOX) enzymes as well as TNF-α inhibitory effect. The results revealed that, compounds (3a-l) obtained showed inhibition in submicromolar range against COXs and LOXs targets whereas milder inhibitory activity was obtained against lipopolysaccharides (LPS)-induced TNF-α secretion by murine macrophage-like cells (RAW264.7). Within this class of compounds, 3j emerged as having alluring multiple inhibitory effects on set of COX-1/2 and 5-/15-LOX enzymes (COX-1 IC₅₀ = 9.85 µM; COX-2 IC₅₀ = 1.00 µM; SI = 9.85; 5-LOX IC₅₀ = 0.32 µM; 15-LOX IC₅₀ = 1.02 µM) in conjunction with a good anti-inflammatory and analgesic activities. Additionally, compound 3j showed gastrointestinal safety with reduced lipid peroxidation. Docking results of compound 3j with COX-2 and 5-LOX were also consistent with the in vivo anti-inflammatory results.

Keywords: Anti-inflammatory; Benzimidazole scaffold; COXs; Hybrid drugs; LOXs; Multitarget profile; TNF-α.