Bis(bibenzyls) from Liverworts Inhibit Lipopolysaccharide-Induced Inducible NOS in RAW 264.7 Cells: A Study of Structure−Activity Relationships and Molecular Mechanism

The inhibition of lipopolysaccharide-induced NOS by 19 bis(bibenzyls) isolated from liverworts in RAW 264.7 macrophages was evaluated. The presence of phenolic hydroxyls and saturation at 7,8 and/or 7'/8' are required for inhibition of NO production. Among the compounds tested, marchantin A was the most potent, and its inhibitory activity was consistent with the inhibition of LPS-induced iNOS mRNA.