Effect of the essential oil from the flowers of Magnolia sieboldii on the lipopolysaccharide-induced production of nitric oxide and prostaglandin E2 by rat peritoneal macrophages.

The essential oil from the flowers of Magnolia sieboldii was tested for its effects on lipopolysaccharide (LPS)-induced production of nitric oxide (NO) and prostaglandin E(2) (PGE(2)) by rat peritoneal macrophages. It was shown to induce the production of NO and PGE 2 in a concentration-dependent manner (3 - 30 microg/ml). Gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS) led to the identification of sixty compounds, of which beta-elemene (18.0 %), alpha-terpinene (14.83 %) and beta-myrcene (12.72 %) were the major constituents. Among these three compounds, alpha-terpinene was found to be the most effective one with inhibitory activity on NO and PGE(2) production by LPS-stimulated rat peritoneal macrophages.