Dual COX-2/5-LOX Inhibition by Novel Thymol Derivatives: From Molecular Modeling to In Vitro Validation

Dual cyclooxygenase-2/5-lipoxygenase (COX-2/5-LOX) inhibitors constitute safer alternatives to classical nonsteroidal anti-inflammatory drugs, widely used to effectively manage inflammation. In this article, molecular docking and molecular dynamics simulations guide the synthesis of novel thymol derivatives that interact with both COX-2 and 5-LOX active sites. Ligands are designed with the aim of improving thymol bioactivity, selectivity, stability, as well as pharmacokinetic properties. Therefore, -Br, -F, and -CF₃ inclusion on thymol is here evaluated, screening COX-2 and 5-LOX interactions with thymol (T), 4-fluorothymol (FT), 4-bromothymol (BT), isopropyl thymyl succinate (T1), 1,1,1,3,3,3-hexafluoroisopropyl thymyl succinate (T2), and 1',1',1',3',3',3'-hexafluoroisopropyl 4-(4''-thymyl)-4-oxobutanoate (T3). Molecular modeling reveals that the estimated ligands can establish favorable interactions with both COX-2 and 5-LOX active pockets, highlighting T1-T3 as the most promising compounds. In vitro assays identify T3 as the most active COX-2 inhibitor, while T2 results as the most effective ligand for 5-LOX. Interestingly, cavity analysis of the COX-2 entry site reveals that T3 insertion is favored over T1 and T2 due to its greater polarity, conferred by the presence of a free phenolic group (OH) able to establish H-bonds with surrounding residues.