Native to the Kalahari desert, Namibian steppes, Madagascar, and other parts of southern Africa, devil's claw is named for the hooks that cover its fruit. Medicinal preparations made from the secondary storage tubers of the tree have been used in the folk medicine traditions of tribal Africa for the bitter, analgesic, and antipyretic actions of devil's claw root (Schulz et al., 1998). Europeans and Canadians use it, mostly for relief of arthritic symptoms (Der Marderosian, 1999). Apart from its applications as a bitter and fever-reducing agent, devil's claw administered externally to the skin is said to heal sores, boils, and other skin lesions. The conditions that benefit from use of devil's claw include dyspepsia, blood disease, headache, allergy, gout, neuralgia, arthritis, rheumatism, and lower back pain (Leung and Foster, 1996).
Today devil's claw is used as an anti-inflammatory agent for rheumatic or arthritic conditions, and is approved by Commission E to restore appetite and relieve heartburn. Tests demonstrate both anti-inflammatory and anti-exudative activity (Schulz et al., 1998). The constituents most likely responsible for devil's claw root's anti-inflammatory effects are its iridoids, particularly harpagoside (Newall et al., 1996). In animal models, harpagoside is not only anti-inflammatory, but it also lowers blood pressure and heart rate (Der Marderosian, 1999).
Both in vitro and in vivo tests have resulted in conflicting evidence of devil's claw root's therapeutic activity. Pain-reducing and anti-inflammatory properties were observed in guinea pigs, particularly in chronic pain conditions, but when devil's claw root's effects on rats were compared to those of aspirin and indomethacin, significant efficacy was not found (Newall et al., 1996). When iridoids were isolated and tested, these, too, produced conflicting results. In humans, oral doses of extract of devil's claw root were ineffective compared to indomethacin, according to reports from 13 participants followed in a six week study (Newall et al., 1996). On the other hand, intraperitoneal administration of 100 mg devil's claw root extract/kg was equal to 2.5 mg/kg indomethacin in anti-inflammatory effects (Leung and Foster, 1996). A German study in 1976 found devil's claw root's effects to be comparable to the anti-arthritic drug phenylbutazone (Tyler, 1993).
Most clinical studies of devil's claw root have not been double-blinded and placebo-controlled in design. One that was, however, showed that for a significant number of the study's participants, powdered devil's claw root reduced arthritis pain (Schulz et al., 1998). In another, patients with lower back pain felt significant relief following four weeks of devil's claw root treatment (two 400 mg tablets of extract, three times daily, total of 2400 mg per day), demonstrated by reduction of use of analgesics (Chrubasik et al., 1996).
Description
Devil's claw root is the dried, secondary tubers of Harpagophytum procumbens (Burchell) de Candolle [Fam. Pedaliaceae] and their preparations in effective dosage. The commercial product contains bitter substances.
Chemistry and Pharmacology
Constituents include the iridoid glucosides (0.5-3%) harpagoside, harpagide, and procumbide; stachyose and simple sugars; free and glycosylated phytosterols, including b-sitosterol; oleanolic acid; flavonoids kaempferol and luteolin; phenolic acids; and the glycosidic phenylpropanoic esters verbascoside and isoacteoside (Bradley, 1992; Bruneton, 1995). The iridoids are thought to be responsible for the anti-inflammatory activity (Bruneton, 1995; Newall et al., 1996).
The Commission E reported appetite-stimulating, choleretic, antiphlogistic, and mild analgesic properties. Infusions and decoctions of the herb have been used for benign rheumatic disorders (Bruneton, 1995). In vitro experiments have shown a significant, dose-dependent, protective action against arrhythmias induced by calcium chloride and epinephrine-chloroform on isolated rabbit heart (ESCOP, 1997). In vivo experiments with devil's claw root have determined that anti-inflammatory properties differ by dosage method (ESCOP, 1997). Intraperitoneal and intraduodenal administration reduced carrageenan-induced edema. Oral administration had no effect, regardless of the dose used (ESCOP, 1997).
Uses
The Commission E approved the use of devil's claw root for loss of appetite, dyspepsia, and degenerative disorders of the locomotor system. Devil's claw root has been used to treat painful arthroses, tendonitis, indigestion, blood diseases, headache, allergies, rheumatism, arthritis, lumbago, neuralgia, and fever, and externally for sores, ulcer, boils, and skin lesions (Bradley, 1992; Leung and Foster, 1996). It has also been used as an anti-inflammatory and analgesic (Bradley, 1992; Wichtl and Bisset, 1994).
Devil's claw root, when administered in aqueous extract containing 2.5% iridoid glucosides at a daily dosage of 3-9 g, divided into three doses, improved the states of 42% to 85% of the 630 patients suffering from arthrosis. A double-blind study of 89 ambulant volunteers established that a dosage of 335 mg (2 capsules three times daily for two months) of powdered devil's claw root with an iridoid glucoside content of 3% decreased the intensity of pain in a significant number of patients (ESCOP, 1997).
Contraindications
Gastric and duodenal ulcers. With gallstones, consult a physician before use.
Side Effects
None known.
Use During Pregnancy and Lactation
No restrictions known.
Interactions with Other Drugs
None known.
Dosage and Administration
Unless otherwise prescribed: For loss of appetite: 1.5 g per day of cut tuber or preparations of equivalent bitter value for teas and other preparations for internal use. Otherwise: 4.5 g per day of cut tuber; equivalent preparations.
For loss of appetite:
Decoction: 0.5 g in 150 ml water, three times daily.
Fluidextract 1:1 (g/ml): 0.5 ml, three times daily.
Other conditions:
Infusion: 4.5 g in 300 ml boiled water, steep at room temperature for 8 hours, strain and drink in three portions daily.
Decoction: 1.5 g in 150 ml water, three times daily.
Fluidextract 1:1 (g/ml): 1.5 ml, three times daily.
References
Bradley, P.R. (ed.). 1992. British Herbal Compendium, Vol. 1. Bournemouth: British Herbal Medicine Association.
Bruneton, J. 1995. Pharmacognosy, Phytochemistry, Medicinal Plants. Paris: Lavoisier Publishing.
Chrubasik, S. et al. 1996. Effectiveness of Harpagophytum procumbens in treatment of acute low back pain. Phytomedicine 3(1):1-10.
Der Marderosian, A. (ed.). 1999. The Review of Natural Products. St. Louis: Facts and Comparisons.
ESCOP. 1997. 'Harpagophyti radix.' Monographs on the Medicinal Uses of Plant Drugs. Exeter, U.K.: European Scientific Cooperative on Phytotherapy.
Leung, A.Y. and S. Foster. 1996. Encyclopedia of Common Natural Ingredients Used in Food, Drugs, and Cosmetics, 2nd ed. New York: John Wiley & Sons, Inc.
Newall, C.A., L.A. Anderson, J.D. Phillipson. 1996. Herbal Medicines: A Guide for Health-Care Professionals. London: The Pharmaceutical Press.
Schulz, V., R. Hänsel, V.E. Tyler. 1998. Rational Phytotherapy: A Physicians' Guide to Herbal Medicine. New York: Springer.
Tyler, V.E. 1993. The Honest Herbal: A Sensible Guide to the Use of Herbs and Related Remedies, 3rd ed. New York: Pharmaceutical Products Press.
Wichtl, M. and N.G. Bisset (eds.). 1994. Herbal Drugs and Phytopharmaceuticals. Stuttgart: Medpharm Scientific Publishers.
Additional Resources
Baghdikian, B. et al. 1997. An analytical study, anti-inflammatory and analgesic effects of Harpagophytum procumbens and Harpagophytum zeyheri. Planta Med 63(2):171-176.
Circost, C. et al. 1984. A drug used in traditional medicine: Harpagophytum procumbens DC. II. Cardiovascular activity. J Ethnopharmacol 11(3):259-274.
Costa de Pasquale, R. et al. 1985. A drug used in traditional medicine: Harpagophytum procumbens DC. III. Effects on hyperkinetic ventricular arrhythmias by reperfusion. J Ethnopharmacol 13(2):193-199.
Erdos, A., R. Fontaine, H. Friehe, R. Durand, T. Poppinghaus. 1978. [Contribution to the pharmacology and toxicology of different extracts as well as the harpagoside from Harpagophytum procumbens DC] [In German]. Planta Med 34(1):97-108.
Grahame, R. and B.V. Robinson. 1981. Devil's claw (Harpagophytum procumbens): pharmacological and clinical studies. Ann Rheum Dis 40(6):632.
Lanhers, M.C., J. Fleurentin, F. Mortier, A. Vinche, C. Younos. 1992. Anti-inflammatory and analgesic effects of an aqueous extract of Harpagophytum procumbens.Planta Med 58(2):117-123.
Mestdagh, O. and M. Torck. 1995. [Quality evaluation of Harpagophyton capsules] [In French]. Ann Pharm Fr 53(3):135-137.
Moussard, C., D. Alber, M.M. Toubin, N. Thevenon, J.C. Henry. 1992. 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 46(4):283-286.
Occhiuto, F., C. Circosta, S. Ragusa, P. Ficarra, R. Costa de Pasquale. 1985. A drug used in traditional medicine: Harpagophytum procumbens DC. IV. Effects on some isolated muscle preparations. J Ethnopharmacol 13(2):201-208.
Soulimani, R., C. Younos, F. Mortier, C. Derrieu. 1994. The role of stomachal digestion on the pharmacological activity of plant extracts, using as an example extracts of Harpagophytum procumbens. Can J Physiol Pharmacol 72(12):1532-1536.
Whitehouse, L.W., M. Znamirowska, C.J. Paul. 1983. Devil's Claw (Harpagophytum procumbens): no evidence for anti-inflammatory activity in the treatment of arthritic disease. Can Med Assoc J 129(3):249-251.
This material was adapted from The Complete German Commission E Monographs—Therapeutic Guide to Herbal Medicines. M. Blumenthal, W.R. Busse, A. Goldberg, J. Gruenwald, T. Hall, C.W. Riggins, R.S. Rister (eds.) S. Klein and R.S. Rister (trans.). 1998. Austin: American Botanical Council; Boston: Integrative Medicine Communications.
1) The Overview section is new information.
2) Description, Chemistry and Pharmacology, Uses, Contraindications, Side Effects, Interactions with Other Drugs, and Dosage sections have been drawn from the original work. Additional information has been added in some or all of these sections, as noted with references.
3) The dosage for equivalent preparations (tea infusion, fluidextract, and tincture) have been provided based on the following example:
Unless otherwise prescribed: 2 g per day of [powdered, crushed, cut or whole] [plant part]
Infusion: 2 g in 150 ml of water
Fluidextract 1:1 (g/ml): 2 ml
Tincture 1:5 (g/ml): 10 ml
4) The References and Additional Resources sections are new sections. Additional Resources are not cited in the monograph but are included for research purposes.
This monograph, published by the Commission E in 1994, was modified based on new scientific research. It contains more extensive pharmacological and therapeutic information taken directly from the Commission E.
Excerpt from Herbal Medicine: Expanded Commission E Monographs Copyright 2000 American Botanical Council Published by Integrative Medicine Communications Available from the American Botanical Council.