Synthesis and Investigation of Anti-Inflammatory Activity of New Thiourea Derivatives of Naproxen.

The aim of the study was a synthesis and investigation of the dose-dependent anti-inflammatory effect of new thiourea derivatives of naproxen with selected aromatic amines and esters of aromatic amino acids. The results of the in vivo study indicate that derivatives of -anisidine () and -methyl tryptophan methyl ester () showed the most potent anti-inflammatory activity four hours after injection of carrageenan, with the percentage of inhibition of 54.01% and 54.12%, respectively. In vitro assays of COX-2 inhibition demonstrated that none of the tested compounds achieved 50% inhibition at concentrations lower than 100 µM. On the other hand, the aromatic amine derivatives (-) accomplished significant inhibition of 5-LOX, and the lowest IC value was observed for compound (0.30 μM). High anti-edematous activity of compound in the rat paw edema model, together with potent inhibition of 5-LOX, highlight this compound as a promising anti-inflammatory agent.