Harpagophytum procumbens, also called grapple plant, wood spider and most commonly Devil's Claw, is a plant of the sesame family, native to South Africa. It got its name from 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.
H. procumbens are mainly found in the eastern and south eastern parts of Namibia, Southern Botswana and the Kalahari region of the Northern Cape, South Africa. H. Zeyheri is found in the northern parts of Namibia (Ovamboland) and southern Angola. The active ingredient is harpagoside with values ranging in both species from 1.0% to 3.3%.
Devil's Claw is also claimed to be beneficial for treating diseases of the liver, kidneys, gallbladder and bladder, arthritis and rheumatism. It is said to help alleviate problems with and improve the vitality of the joints, as well as stimulating appetite and aid digestion, increase cholesterol and fatty acids in the blood. Devil's Claw has been recommended for treating diabetes, hardening of the arteries, lumbago, gastrointestinal disturbances, menstrual difficulties, neuralgia, headache, heartburn and gout.
Several studies have been performed using Doloteffin, a standardized preparation of Devil's Claw. A series of small-scale studies completed in Germany found that H. procumbens was indistinguishable from Vioxx in the treatment of chronic low back pain, and was well-tolerated after more than four years of treatment of 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 can also be used externally to treat sores, ulcers, boils and skin lesions.