title: Anti-arthritic effects and toxicity of the essential oils of turmeric (Curcuma longa L.).
abstract: Turmeric (Curcuma longa L., Zingiberaceae) rhizomes contain two classes of secondary metabolites, curcuminoids and the less well-studied essential oils. Having previously identified potent anti-arthritic effects of the curcuminoids in turmeric extracts in an animal model of rheumatoid arthritis (RA), studies were undertaken to determine whether the turmeric essential oils (TEO) were also joint protective using the same experimental model. Crude or refined TEO extracts dramatically inhibited joint swelling (90-100% inhibition) in female rats with streptococcal cell wall (SCW)-induced arthritis when extracts were administered via intraperitoneal injection to maximize uniform delivery. However, this anti-arthritic effect was accompanied by significant morbidity and mortality. Oral administration of a 20-fold higher dose TEO was nontoxic, but only mildly joint-protective (20% inhibition). These results do not support the isolated use of TEO for arthritis treatment but, instead, identify potential safety concerns in vertebrates exposed to TEO.
authors.affiliation: Department of Medicine, University of Arizona, Tucson, Arizona 85724, USA. jfunk@u.arizona.edu
authors.forename: Janet L
authors.initials: JL
authors.lastname: Funk
authors.forename: Jennifer B
authors.initials: JB
authors.lastname: Frye
authors.forename: Janice N
authors.initials: JN
authors.lastname: Oyarzo
authors.forename: Huaping
authors.initials: H
authors.lastname: Zhang
authors.forename: Barbara N
authors.initials: BN
authors.lastname: Timmermann
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000009:adverse effects / Q000737:chemistry; D001172:Arthritis, Rheumatoid / Q000188:drug therapy* / Q000401:mortality; D030024:Curcuma / Q000009:adverse effects / Q000737:chemistry*; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D009822:Oils, Volatile / Q000008:administration & dosage* / Q000009:adverse effects* / Q000737:chemistry; D010936:Plant Extracts / Q000008:administration & dosage* / Q000009:adverse effects* / Q000737:chemistry; D051381:Rats; D011917:Rats, Inbred Lew
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D009822:Oils, Volatile; D010936:Plant Extracts; C012596:turmeric extract