In vitro inducible nitric oxide synthesis inhibitory active constituents from Fraxinus rhynchophylla

Bioassay-guided fractionation of an H2O extract of the barks of Fraxinus rh ynchophylla has furnished two inducible nitric oxide synthase (iNOS) inhibi tory compounds, ferulaldehyde (1) and scopoletin (3) together with a coumar in, fraxidin (2). Compounds 1 and 3 showed inhibition of nitric oxide (NO) synthesis in a dose-dependent manner by murine macrophage-like RAW 264.7 ce lls stimulated with interferon-gamma (IFN-gamma) plus lipopolysaccharide (L PS). The inhibition of NO synthesis of I was reflected in the decreased amo unt of iNOS protein, as determined by Western blotting.