Volatile Composition of Juniperus pingii var. wilsonii and Its Inhibitory Effect on Nitric Oxide Production of Macrophage Cells

The leaves and twigs of Juniperus pingii var. wilsonii (Cupressaceae) smell aromatic and are traditionally used as the Tibetan medicine Xuba. Their essential oil obtained by ultrasonic-assisted hydrodistillation and volatiles collected by GC headspace technique were analyzed and compared by GC-MS. The analyses revealed the presence of thirty-nine components in the essential oil, representing 95.8% in content of the total oil, mainly including sabinene (22.6%), elemol (15.5%) and (-)-terpinen-4-ol (9.6%). Thirty-eight components accounting for 99.4% of the headspace volatiles were identified, mainly including sabinene (32.5%), β-pinene (21.9%) and α-thujene (10.3%). The compositions of the oil and headspace volatiles were quite similar, and twenty-five compounds identified were in common, which was 91.3% of the oil and 96.0% of the headspace volatiles in content. The essential oil could obviously inhibit Nitric oxide production in LPS-stimulated RAW 264.7 cells with no significant effect on cell viability, indicating its good anti-inflammatory activity.