Synthesis and Biological Evaluation of Novel 5-Benzylidenethiazolidine-2,4-dione Derivatives for the Treatment of Inflammatory Diseases

Twenty-two compounds based on thiazolidine-2,4-dione moiety were synthesized and evaluated for the inhibitory potency on the production of nitric oxide (NO), inducible nitric oxide synthase (iNOS) activity, and the generation of prostaglandin E2 (PEG2). (Z)-N-(3-Chlorophenyl)-2-(4-((2,4-dioxothiazolidin-5-ylidene) methyl) phenoxy) acetamide (3I), superior to the commercial anti-inflammatory drug indomethacin, significantly inhibited iNOS activity (IC50 = 8.66 μM), iNOS-mediated NO, and cyclooxygenase (COX)-2-derived PGE2 production (IC50 = 4.16 and 23.55 μM, respectively) on lipopolysaccharide (LPS)-induced RAW 264.7 cells. Docking study revealed that 3I was perfectly docking into the active site of murine iNOS and suppressed the expression of iNOS protein as evidenced by Western blot analysis. At the dose of 50 mg/kg, oral administration of 3I possessed protective properties in both carrageenan-induced paw edema and adjuvant-induced arthritis rat models.