Synthesis of 1-(4-(dimethylamino)phenyl)-3,4-diphenyl-1H-pyrrole-2,5-dione analogues and their anti-inflammatory activities in lipopolysaccharide-induced BV2 cells.

A series of thalidomide analogues, where the fused benzene ring in the phthalimide moiety was converted into two separated diphenyl rings in maleimide moiety and N-aminoglutarimide moiety was replaced by substituted phenyl moiety, were synthesized and evaluated for their NO inhibitory activities on BV2 cells stimulated with lipopolysaccharide (LPS). Among the synthesized compounds, the dimethylaminophenyl analogue 1s (IC50 = 7.1 µM) showed significantly higher inhibitory activity than the glutarimide analogue 1a (IC50 > 50 µM) and suppressed NO production dose-dependently without cytotoxicity. In addition, 1s inhibited the production of pro-inflammatory cytokines and the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) by blocking nuclear factor-kappa B (NF-κB) and p38 MAPK pathways. These results demonstrated that 1s showed good anti-inflammatory activity and could become a leading compound for the treatment of neuroinflammatory diseases.