Anti-inflammatory activity of compounds from the rhizome of Cnidium officinale

Five new compounds, 9,3′-dimethoxyhierochin A (1), 6-oxo-trans-neocnidilide (2), (±)-(3E)-trans-6-hydroxy-7-methoxydihydroligustilide (3), (±)-cnidiumin (4), and 6-(1-oxopentyl)-salicylic acid methyl ester (5), together with twenty known compounds (6–25), were isolated from the rhizome of Cnidium officinale. The chemical structures of new compounds were established by NMR spectroscopic techniques, mass spectrometry, Mosher’s method, and CD spectrum. Their anti-inflammatory activities were evaluated against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in macrophage RAW 264.7 cells. Compounds 7, 13, and 14 showed inhibitory effects with IC₅₀ values of 5.1, 24.5, and 27.8 μM, respectively. In addition, compounds 7, 13, and 14 reduced LPS-induced inducible nitric oxide synthase (iNOS) expression and cyclooxygenase-2 (COX-2) protein in a concentration-dependent manner.