Inhibitory effects of ginger (Zingiber officinale Roscoe) essential oil on leukocyte migration in vivo and in vitro

Zingiber officinale Roscoe, popular name ginger, is grown naturally in many parts of the world, including Brazil. Ginger is used in pharmaceutical, cosmetic, and food and beverage industries and the essential oil has been used in folk medicine for manifold conditions including as an analgesic, anti-inflammatory, and antirheumatic. The purpose of this study was to investigate the effects of ginger (Zingiber officinale Roscoe) essential oil (GEO) in an in vitro chemotaxis assay and on leukocyte-endothelial interactions in vivo. GEO was analyzed by GC-MS and the main components identified were ar-curcumene (59%), β-myrcene (14%), 1,8-cineol (8%), citral (7.5%), and zingiberene (7.5%). Oral administration of GEO (200-500 mg/kg) reduced the rolling and leukocyte adherence after 2 h of carrageenan injection (100 μg) into the scrotal chamber. The number of leukocytes migrated to the perivascular tissue 4 h after the irritant stimulus was also diminished. GEO in all doses tested (10(-4), 10(-3), or 10(-2) μL/mL) caused a significant reduction of leukocyte chemotaxis (35.89 ± 4.33, 30.67 ± 0.70, and 35.85 ± 3.83%, respectively) toward casein stimuli. The data presented showed direct and systemic effects of GEO on leukocyte migration as an important mechanism of the anti-inflammatory action of ginger.