title: Estimation of the relative antiinflammatory efficacies of six commercial preparations of Harpagophytum procumbens (Devil's Claw).
abstract: The current work compared the relative efficacies of six commercial formulations of H. procumbens. Each formulation was assayed for the content of harpagoside (1), harpagide (2), verbascoside (3) and 8-O-p-coumaroyl harpagide (4) and, based on the recommended dosages, the total daily amounts were determined and used to establish anti-/proinflammatory (A/P) factors. The formulations were compared using ex vivo porcine skin for their activities towards COX-2 by Western blotting. The results showed great variation in the amounts of compounds 1-4 within the six formulations examined. The relative proportions of 1-4 also varied widely between the products and this inconsistency was reflected in the A/P factors, which correlated with the COX-2 expression (R(2) = 0.9496). Although the data support the beneficial antiinflammatory effects from the use of some of the brands tested, others would appear potentially to exacerbate inflammation. To conclude, a ratio based upon the amount and relative proportions of anti- and proinflammatory compounds can be used to predict relative antiinflammatory properties. Also, with access to a diversity of ostensibly similar commercial products, the patient may experience varying therapeutic responses. Finally, current pharmacopoeia monographs, which are generally concerned with a minimum harpagoside content, are inadequate for ensuring the quality of products based on H. procumbens.
authors.affiliation: Welsh School of Pharmacy, Cardiff University, Cardiff CF10 3XF, Wales, UK.
authors.forename: Nassima Abdelouahab
authors.initials: NA
authors.lastname: Ouitas
authors.forename: Charles
authors.initials: C
authors.lastname: Heard
mesh_terms: D000279:Administration, Cutaneous; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000494:pharmacology*; D051546:Cyclooxygenase 2 / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005960:Glucosides / Q000494:pharmacology; D006027:Glycosides / Q000494:pharmacology; D031684:Harpagophytum / Q000737:chemistry*; D066298:In Vitro Techniques; D057889:Iridoid Glycosides; D010636:Phenols / Q000494:pharmacology; D008517:Phytotherapy; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology*; D011714:Pyrans / Q000494:pharmacology; D012867:Skin / Q000187:drug effects*; D012869:Skin Absorption; D013552:Swine; D059808:Polyphenols
chemical_list: D000893:Anti-Inflammatory Agents; D051546:Cyclooxygenase 2; D005960:Glucosides; D006027:Glycosides; D057889:Iridoid Glycosides; D010636:Phenols; D010936:Plant Extracts; D011714:Pyrans; C058956:acteoside; D059808:Polyphenols; C033249:harpagoside; C033250:harpagide