||Devil's Claw Root
Harpagophytum procumbens (Botanical)
Harpagophyti radix (Pharmacopeial)
Harpagophytum procumbens and a closely related plant, Harpagophytum
zeyheri, are native to southern Africa and Madagascar. They are the only two
species in Harpagophytum, a genus in the sesame family. Both species have
comparable anti-inflammatory and pain-reducing activity, and both are used as a
source of Harpagophyti radix.
According to traditional folklore, the Khoisan of the Kalahari used the dried
root in remedies to treat pain, pregnancy complications, and skin disorders.
Devil's claw has appetite stimulating and mildly analgesic pharmacological
actions. Today, this bitter-tasting plant is sold in Europe and Canada as a
digestive aid and appetite stimulant.
Devil's claw is collected from the savannas and outskirts of the Kalahari
Desert in South Africa and Namibia. The drug is made from dried, secondary
tubers. The root tubers are always sliced or pulverized before they are dried
because they are nearly impossible to cut once they have dried.
Devil's claw is a leafy perennial with a branched root system and branched
shoots. The fruit consists of large woody grapples that are pointed and barbed.
The secondary tuber roots grow out of the main and lateral roots. The root
tubers (also called peripheral tubers) can reach a size of 20 cm long and 3 cm
thick. The crude drug is made from the dried, yellowish-gray to bright pink
- Roots (rhizome)
- Dried secondary tubers
Monoterpenes include mainly harpagoside (0.5% to 1.6%; extremely bitter
iridoid glycoside), harpagide, procumbide; phenylethanol derivatives include
acteoside (verbascoside), isoaceteoside; oligosaccharides; harpagoquinones;
other compounds (carbohydrates, amino acids, flavonoids).
Dried powder capsules and fluid extract preparations are made from dried
Traditional herbal actions: antirheumatic, analgesic, sedative, diuretic,
antipyretic, anti-inflammatory; Newall painful arthroses, tendinitis, dyspepsia,
liver and gallbladder problems, loss of appetite (anorexia); supportive
treatment for degenerative musculoskelatal conditions (disorders of locomotive
Clinical applications: Rheumatic and joint disorders such as rheumatoid
arthritis, osteoarthritis, and gout. Conditions involving inflammation of
connective tissues such as fibromyalgia, fibrositis, tendinitis, adhesions due
to scar tissue. Liver, kidney, and bladder disorders; allergies;
arteriosclerosis; lumbago; gastrointestinal problems; menstrual symptoms;
neuralgia; headache; heartburn; nicotine poisoning
Several in vitro and in vivo investigations confirm that aqueous extracts of
devil's claw and its primary active principle, harpagoside, have
anti-inflammatory and anti-exudative effects. In one study, devil's claw
exhibited anti-inflammatory effects comparable to those of the antiarthritic
drug, phenylbutazone. Anti-inflammatory effects have been strongest in
semi-chronic rather than in acute inflammatory animal models. In another
investigation, however, devil's claw failed to show anti-inflammatory properties
when compared to aspirin and indomethacin. Other studies have not unequivocally
shown that devil's claw reduces inflammation in either animals or humans.
Inconsistent findings on efficacy may be due to different modes of administering
the drug. Gastric juices apparently inactivate some of the active constituents.
Therapeutic effects may be difficult to demonstrate in animal models unless
devil's root extracts are protected from gastric enzymes.
In an in vitro experiment, indomethacin and aspirin caused a 5% inhibition of
prostaglandin synthetase activity, but devil's claw did not produce a
significant reduction in enzyme activity. In vitro research also shows that
harpagoside diminished the contractile response of smooth muscle in isolated
muscle preparations. Harpagoside and other active principles presumably are able
to alter the contractile response by disrupting calcium influx. In addition,
devil's claw extracts have weak antifungal properties.
Devil's claw extracts are cardioactive and have protective activity against
ventricular arrhythmias. However, the cardioactive effects are not entirely due
to harpagoside. Instead, cardioprotecive properties are attributed to a synergy
between hapagoside and other active constituents in the crude extract.
The biochemical action of devil's claw on arachidonic acid metabolism
apparently differs from the mechanisms of action found in NSAIDs. The
therapeutic effects are perhaps explained by in vivo conversion (via enzymatic
hydrolysis) of either harpagoside or harpagide into harpagogenin.
In a double-blind, placebo-controlled clinical study, 89 patients with
rheumatoid symptoms were given 2 g of powdered devil's claw daily for two
months. The treatment group had significant improvements compared to the placebo
group in sensitivity to pain and in flexibility measured by fingertip-floor
|Dosage Ranges and Duration of
- Dried tuber: Take 0.1 to 0.25 g tid, encapsulated or as decoction.
- Fluid extract (1:1 in 25% alcohol): Take 0.1 to 0.25 ml tid.
- Tincture (1:5 in 25% alcohol): Take 0.5 to 1.0 ml tid.
Most experts consider devil's claw nontoxic and safe.
No side effects have been reported for devil's claw root when it is
administered in recommended therapeutic doses. However, this herb should not be
used in excess because information on toxicology is limited. Cardioactivity
makes it potentially risky for individuals with certain medical conditions
because devil's claw stimulates gastric secretions. Individuals with gastric
and/or duodenal ulcers, and/or gallstones should not take devil's claw without
the advice of a physician or other qualified health care provider. Cinnamylic
acid and terpene in devil's claw may trigger allergic effects. Despite a common
misconception that devil's claw is an abortifacient, pharmacological research
suggests that this plant does not induce abortion. However, digestive stimulants
such as devil's claw should not be used in pregnancy because of the reflexive
action on uterine muscle.
Devil's claw and warfarin may interact, resulting in purpurea (Shaw et al.
1991). The mechanism for this interaction is unclear and there is no data
available regarding effects from rechallenge. Patients taking devil's claw with
anticoagulants should be monitored closely for clinical signs of
over-coagulation or bleeding disorders.
|Regulatory and Compendial
The U.S. FDA classifies devil's claw as a dietary supplement. The plant is
accepted in France for specified indications. It is approved by the German
Commision E. Devil's claw is not included on the General Sale List in Britain.
Baghdikian B, Lanhers M, Fleurentin J, et al. An analytical study,
anti-inflammatory and analgesic effects of Harpagophytum procumbens and
Harpagophytum zeyheri. Planta Med. 1997;63:171-176.
Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic
Guide to Herbal Medicines. Boston, Mass: Integrative Medicine
Bradley P, ed. British Herbal Compendium. Dorset, England: British
Herbal Medicine Association; 1992;1:96-98.
British Herbal Pharmacopoeia. 4th ed. Dorset, England: British Herbal
Medicine Association; 1996.
Costa de Pasquale R, Busa G, Circosta C, et al. A drug used in traditional
medicine: Harpagophytum procumbens DC. III. Effects on hyperkinetic
ventricular arrhythmias by reperfusion. J Ethnopharmacology.
Grahame R, Robinson B. Devil's claw (Harpagophytum procumbens):
pharmacological and clinical studies. Ann Rheum Dis. 1981;40:632.
Guyader M. 1984. Les plantes antirhumatismales. Etude historique et
pharmacologique, et etude clinique du nebulisat d'Harpagophytum
procumbens DC chez 50 patients arthrosiques sivis en service hospitalier.
Paris: Universite Pierre et Marie Curie.
Lanhers MC, Fleurentin J, Mortier F, Vinche A, Younos C. Anti-inflammatory
and analgesic effects of an aqueous extract of Harpagophytum procumbens.
Planta Med. 1992;58:117-123.
Mabberley DJ. The Plant-Book: A Portable Dictionary of the Higher Plants.
Cambridge, England: Cambridge University Press; 1987.
McLeod D, et al. Investigations of Harpagophytum procumbens (Devil's
Claw) in the treatment of experimental inflammation and arthritis in the rat.
Br J Pharmacol. 1979;66:140P.
Moussard C, Alber D, Toubin M, Thevenon N, Henry JC. A drug used in
traditional medicine, Harpagophytum procumbens: no evidence for
NSAID-like effect on whole blood eicosanoid production in human.
Prostaglandins Leukot Essent Fatty Acids. 1992;46:283-286.
Newall C, Anderson L, Phillipson J. Herbal Medicines: A Guide for
Health-care Professionals. London: Pharmaceutical Press; 1996.
Occhiuto F, Circosta C, Ragusa S, Ficarra P, Costa De Pasquale R. A drug used
in traditional medicine: Harpagophytum procumbens DC. IV. Effects on some
isolated muscle preparations. J Ethnopharmacol. 1985;13:201-208.
Schulz V, Hänsel R, Tyler VE. Rational Phytotherapy: A Physicians' Guide
to Herbal Medicine. 3rd ed. Berlin: Springer-Verlag; 1998.
Shaw D, Leon C, Kolev S, Murray V. Traditional remedies and food supplements:
A 5-year toxicological study (1991-1995). Drug Safety.
Tyler VE. The Honest Herbal: A Sensible Guide to the Use of Herbs and
Related Remedies. 3rd ed. Binghamton, NY: Pharmaceutical Products Press;
Whitehouse L, et al. Devil's Claw (Harpagophytum procumbens): no
evidence for anti-inflammatory activity in the treatment of arthritic disease.
Can Med Assoc J. 1983;129:249-251.
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