title: Anti-Inflammatory Effects of the Essential Oils of Ginger (Zingiber officinaleRoscoe)in Experimental Rheumatoid Arthritis.
abstract: Ginger and its extracts have been used traditionally as anti-inflammatory remedies, with a particular focus on the medicinal properties of its phenolic secondary metabolites, the gingerols. Consistent with these uses, potent anti-arthritic effects of gingerol-containing extracts were previously demonstrated by our laboratory using an experimental model of rheumatoid arthritis, streptococcal cell wall (SCW)-induced arthritis. In this study, anti-inflammatory effects of ginger's other secondary metabolites, the essential oils (GEO), which contain terpenes with reported phytoestrogenic activity, were assessed in female Lewis rats with SCW-induced arthritis. GEO (28 mg/kg/d ip) prevented chronic joint inflammation, but altered neither the initial acute phase of joint swelling nor granuloma formation at sites of SCW deposition in liver. Pharmacologic doses of 17-β estradiol (200 or 600 μg/kg/d sc) elicited the same pattern of anti-inflammatory activity, suggesting that GEO could be acting as a phytoestrogen. However, contrary to this hypothesis, GEO had noin vivoeffect on classic estrogen target organs, such as uterus or bone. En toto, these results suggest that ginger's anti-inflammatory properties are not limited to the frequently studied phenolics, but may be attributable to the combined effects of both secondary metabolites, the pungent-tasting gingerols and as well as its aromatic essential oils.
authors.affiliation: Department of Medicine, The University of Arizona, Tucson, AZ, USA.
authors.forename: Janet L
authors.initials: JL
authors.lastname: Funk
authors.affiliation: Department of Medicine, The University of Arizona, Tucson, AZ, USA.
authors.forename: Jennifer B
authors.initials: JB
authors.lastname: Frye
authors.affiliation: Department of Medicine, The University of Arizona, Tucson, AZ, USA.
authors.forename: Janice N
authors.initials: JN
authors.lastname: Oyarzo
authors.affiliation: Department of Medicine, The University of Arizona, Tucson, AZ, USA.
authors.forename: Jianling
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Medicinal Chemistry, School of Pharmacy, The University of Kansas, Lawrence, KS, USA.
authors.forename: Huaping
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Medicinal Chemistry, School of Pharmacy, The University of Kansas, Lawrence, KS, USA.
authors.forename: Barbara N
authors.initials: BN
authors.lastname: Timmermann
keywords: arthritis; essential oil; estradiol; estrogen; ginger; gingerol; inflammation; mice; phytoestrogen; rats