Effect of the major glycosides of Harpagophytum procumbens (Devil's Claw) on epidermal cyclooxygenase-2 (COX-2) in vitro.

Abstract

Harpagophytum procumbens, commonly known as Devil's Claw, is indigenous to southern Africa, and extracts of the tubers have been used for centuries in the treatment of a variety of inflammatory disorders. Its major active components, harpagoside (1), harpagide (2), 8-coumaroylharpagide (3), and verbascoside (4), are believed to interact either synergistically or antagonistically in modulating the enzymes responsible for inducing inflammation, although this has not been probed hitherto. In the current work, the ability of these compounds to inhibit the expression of COX-2 following administration to freshly excised porcine skin has been investigated. An ethanol-soluble extract of H. procumbens tubers and two of the pure compounds tested showed promising activity in Western blotting and immunocytochemical assays, with harpagoside (1) and 8-coumaroylharpagide (3) exhibiting greater reductions in COX-2 expression than verbascoside (4). Harpagide (2) caused a significant increase in the levels of COX-2 expression after 6 h of topical application. The data suggest that the efficacy of H. procumbens is dependent upon the ratios of compounds 1-4 present, which is inconsistent with some current official monograph specifications based solely on harpagoside (1) content.

• Authors: Nassima Abdelouahab, Charles Heard
• Journal: Journal of natural products (J Nat Prod) Vol. 71 Issue 5 Pg. 746-9 (May 2008) ISSN: 0163-3864 [Print] United States
• PMID: 18412394 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• 8-O-p-coumaroylharpagide
• Anti-Inflammatory Agents, Non-Steroidal
• Coumaric Acids
• Cyclooxygenase 2 Inhibitors
• Glucosides
• Glycosides
• Iridoid Glycosides
• Phenols
• Pyrans
• acteoside
• harpagoside
• harpagide

Topics

• Animals
• Anti-Inflammatory Agents, Non-Steroidal (chemistry, isolation & purification, pharmacology)
• Coumaric Acids (chemistry, isolation & purification, pharmacology)
• Cyclooxygenase 2 Inhibitors (chemistry, isolation & purification, pharmacology)
• Epidermis (drug effects, enzymology)
• Glucosides (chemistry, isolation & purification, pharmacology)
• Glycosides (chemistry, isolation & purification, pharmacology)
• Harpagophytum (chemistry)
• Inflammation (metabolism)
• Iridoid Glycosides
• Molecular Structure
• Phenols (chemistry, isolation & purification, pharmacology)
• Plants, Medicinal (chemistry)
• Pyrans (chemistry, isolation & purification, pharmacology)
• Swine