DC. ex Meisn.
Harpagophytum, also called grapple plant, wood spider and most commonly devil's claw, is a genus of plants in the sesame family, native to southern Africa. It owes to common name devil's claw to the peculiar appearance of its hooked fruit. The plant's large tuberous roots are used medicinally to reduce pain and fever, and to stimulate digestion. European colonists brought devil's claw home where it was used to treat arthritis.
Harpagophytum procumbens is mainly found in the eastern and south eastern parts of Namibia, Southern Botswana and the Kalahari region of the Northern Cape, South Africa. Harpagophytum zeyheri is found in the northern parts of Namibia (Ovamboland) and southern Angola. The active ingredient is harpagoside (structure at PubChem ) with values ranging in both species from 1.0% to 3.3%.
Potential medical uses
The constituents thought to be responsible for the anti-inflammatory effects of Devil's Claw (dried secondary tubers) are iridoid glycosides, particularly harpagoside (trans-cinnamoyl harpagide) including small amounts of trans-coumaroyl harpagide, procumbide and plant sterols. The British Herbal Pharmacopoeia recognises Devil's Claw as having analgesic, sedative and diuretic properties. Most studies involve chronic use, rather than acute treatment of pain. This herbal drug is also official in the European Pharmacopoeia and a component of a number of OTC preparations and dietary supplements for its claimed anti-rheumatic effects.
Several studies have been performed using Doloteffin, a standardized preparation of Devil's Claw. Due to the natural variability of herbal extracts, the results of studies using different products and preparations are difficult to compare. A series of small-scale studies completed in Germany found that H. procumbens was comparable to Vioxx in the treatment of chronic low back pain, and was well-tolerated after more than four years of treatment with H. procumbens alone. H. procumbens also seems efficacious in the treatment of arthritis-caused hip and knee pain. An author involved in several studies on Devil's Claw and pain relief had the general conclusion that a minimum 50 mg per dose standardized extract was an alternative to synthetic analgesics with a low risk of adverse events. A separate 2006 systematic review of herbal medications for low back pain reached the conclusion that a standardized daily dose between 50 and 100 mg of harpagoside performed better than a placebo, and an unspecified dose of harpagoside demonstrated relative equivalence to 12.5 mg per day of Vioxx.
Devil's claw may interfere with the action of ticlopidine and warfarin, and patients should consult with a physician before combining Devil's claw with these medications. In addition, Devil's Claw promotes the secretion of stomach acid, leading to difficulties in those with peptic ulcers, gastritis or excess stomach acid. Care should also be taken for individuals with gallstones.
- Wichtl Max (Ed.) 2004. Herbal Drugs and Phytopharmaceuticals. medpharm Scientific Publishers/CRC Press. pp 272-274 ISBN 0-8493-1961-7
- Chrubasik S, Model A, Black A, Pollak S (January 2003). "A randomized double-blind pilot study comparing Doloteffin and Vioxx in the treatment of low back pain". Rheumatology (Oxford) 42 (1): 141–8. doi:10.1093/rheumatology/keg053. PMID 12509627.
- Chrubasik S, Künzel O, Thanner J, Conradt C, Black A (January 2005). "A 1-year follow-up after a pilot study with Doloteffin for low back pain". Phytomedicine 12 (1–2): 1–9. doi:10.1016/j.phymed.2004.01.005. PMID 15693701.
- Chrubasik S (July 2004). "[Devil's claw extract as an example of the effectiveness of herbal analgesics]". Orthopade (in German) 33 (7): 804–8. doi:10.1007/s00132-004-0675-7. PMID 15150687.
- Gagnier JJ, van Tulder M, Berman B, Bombardier C (2006). "Herbal medicine for low back pain". In Gagnier, Joel J. Cochrane Database Syst Rev (2): CD004504. doi:10.1002/14651858.CD004504.pub3. PMID 16625605.