Chemical Composition and Anti-inflammation Activity of Essential Oils from Citrus unshiu Flower

Though many essential oils from citrus peels are claimed to have several medicinal functions, the chemical composition and biological activities of the essential oils of Citrus flowers have not been well described. Therefore, this study intended to investigate the chemical composition and anti-inflammatory potential of essential oils from C. unshiu flower (CEO) to support its purported beneficial health effects. The chemical constituents of the CEO, analyzed by gas chromatography-mass spectrometry (GC-MS), included gamma-terpinene (24.7%), 2-beta-pinene (16.6%), 1-methyl-2-isopropylbenzene (11.5%), L-limonene (5.7%), beta-ocimene (5.6%), and alpha-pinene (4.7%). The effects of the CEO on nitric oxide (NO) and prostaglandin E-2 (PGE(2)) production in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages were also examined. The results indicate that the CEO is an effective inhibitor of LPS-induced NO and PGE(2) production in RAW 264.7 cells. Additionally, CEO was shown to suppress the production of inflammatory cytokines including interleukin (IL)-1 beta, tumor necrosis factor (INF)-alpha, and IL-6. Based on these results, CEO may be considered a potential anti-inflammatory candidate with human health benefits.