Harpagophyti radix

Harpagophyti radix, the devil's claw root, is used as a drug in herbal medicines. The parent plant is the South African devil's claw. Harpagophyti radix is a preparation made from the roots of the devil's claw. The roots are crushed after harvesting and then air-dried in the sun for about 3 days. Harpagophyti radix has a high bitter value of 5,000 to 12,000, making it a bitter drug.

The quality is specified in the European Pharmacopoeia (Ph. Eur.):

HMPC monograph: Traditional-use: Mild aches and pains, improvement of digestive disorders (e.g. flatulence, bloating), intermittent loss of appetite

ESCOP monograph: pain treatment, osteoarthritis, back pain; loss of appetite, dyspeptic complaints.
Commission e-monograph: loss of appetite, dyspeptic complaints; supportive therapy: degenerative diseases of the musculoskeletal system

Empirical medicine: painful arthrosis, chronic inflammatory polyarthritis, painful spondylosis, soft tissue rheumatism, neuralgia, headache

The active ingredients of the root are iridoid glycosides (bitter substances). These include the glycoside harpagoside as the main ingredient, the aglycone harpagide (see iridoids below) and procumbide. Other ingredients are free cinnamic acid, flavonoids, including kaemperol; in addition, up to 46% stachyose and monosaccharides.

In laboratory tests, extracts from devil's claw root show anti-inflammatory and pain-relieving effects. The exact ingredients responsible for this are not yet known. It is possible that harpagoside plays the decisive role (Ungerer G et al. 2020). Experimentally, an inhibition of the prostaglandin synthesis can be proven. Interleukin-2, matrix metalloproteinases and cholinesterase are further inhibited. Among the isolates, verbascosides (5, 6 and 8), which contain a caffeoyl and a 3,4-dihydroxyphenethyl group in their structure, showed effective AChE inhibitory activity. The results suggest that verbascoside derivatives may be partially related to the anti-Alzheimer effect of this medicinal plant (Bae YH et al. 2014).

According to Commission E, the following indications are monographed:

Loss of appetite

Soft tissue rheumatism

Chronic inflammatory polyarthritis: Whether the root really helps is not scientifically proven. Human studies come to contradictory results and there is a lack of conclusive high quality research. Nevertheless, many people report that their joint pain eases when they take devil's claw (Menghini L et al 2019).

Dyspeptic complaints: The bitter substances contained in the root stimulate digestion and increase appetite. Devil's claw is therefore traditionally used for flatulence, bloating and lack of appetite.

Furthermore, harpagoside is attributed a neuroprotective effect (Ungerer G et al. 2020).

In case of hypersensitivity to the ingredients and in case of gastric and duodenal ulcers, application is not recommended. If a gallstone disease exists, a medical consultation is necessary.

In case of loss of appetite the daily dose is 1.5g; otherwise 4.5g/day.

For internal use as tea, the medicinal drug is poured over hot water and left to stand for about 8 hours. The usual daily dose is about 4.5 g of the drug (about a teaspoon). Liquid preparations taste unpleasantly bitter (bitter drug).

Most suitable are ready-to-use drugs with standardised aqueous or ethanolic-aqueous dry extracts; dosages: 0.8g-2.4g dry extract/day.

In rare cases, the following undesirable effects may occur: digestive problems such as heartburn, flatulence, diarrhoea, nausea and vomiting. Other: headache, dizziness and allergic skin reactions.

Allergy to one of the ingredients, gastric or duodenal ulcers, children and adolescents under 18 years of age in the absence of data, breastfeeding and pregnancy.

Caution with gallstone disease!

It is believed that the devil's claw extract interacts with P-glycoprotein and CYP450. Interactions with drugs can therefore not be excluded.

Ceftex® effervescent tablets 2x1 BT/day; Tetonal® 480FT, 2x1 Tbl/day, Allya® 2x2Tbl/day. Doloteffin® 3x1Drg /day

The potential effects of Harpagophytum procumbens root extracts only occur protractedly after several weeks. The analgesic effect is only weakly pronounced (Schilher 2015) The plant is not suitable for acute pain. In addition, the studies that have come to positive results show that a high dosage is necessary for any effect to be noticeable. In this respect, devil's claw preparations should be taken as finished medicines.

Tea preparations contain too small amounts of the potentially active substances to be effective for joint pain. Tea preparations are suitable for digestive complaints such as flatulence or bloating.

1. Bae YH et al (2014) Cholinesterase inhibitors from the roots of Harpagophytum procumbens. Arch Pharm Res 37:1124-1129.
2. Bae YH et al. (2014) Cholinesterase inhibitors from the roots of Harpagophytum procumbens . Arch Pharm Res 37: 1124-1129.
3. Brien S et al.(2006) Devil's Claw (Harpagophytum procumbens) as a treatment for osteoarthritis: a review of efficacy and safety. J Altern Complement Med 12:981-993.
4. Clarkson C et al (2006) Identification of major and minor constituents of Harpagophytum procumbens (Devil's claw) using HPLC-SPE-NMR and HPLC-ESIMS/APCIMS. J Nat Prod 69:1280-1288.
5. Dragos D et al (2017) Phytomedicine in joint disorders. Nutrients 9:70.
6. Hostanska K et al. (2014) Alteration of anti-inflammatory activity of Harpagophytum procumbens (devil's claw) extract after external metabolic activation with S9 mix. J Pharm Pharmacol 66:1606-1614.
7. Menghini L et al. (2019) Devil's claw (Harpagophytum procumbens) and chronic inflammatory diseases: A concise overview on preclinical and clinical data. Phytother Res 33:2152-2162.
8. Moré M et al. (2017) A Rosa canina - Urtica dioica -Harpagophytum procumbens/zeyheri Combination Significantly Reduces Gonarthritis Symptoms in a Randomized, Placebo-Controlled Double-Blind Study. Planta Med 83:1384-1391.
9. Schilcher H Plant profiles In: Leitfaden Phytotherapie. Urban and Fischer Publishers Munich. S 317-318
10. Torres-Fuentes C et al. (2014) Devil's Claw to suppress appetite--ghrelin receptor modulation potential of a Harpagophytum procumbens root extract. PLoS One 28:e103118.
11. Ungerer G et al. (2020) Harpagophytum procumbens Extract Ameliorates Allodynia and Modulates Oxidative and Antioxidant Stress Pathways in a Rat Model of Spinal Cord Injury. Neuromolecular Med 22:278-292.
12. https://arzneipflanzenlexikon.info/devil's-claw.php.
13. https://www.ema.europa.eu/en/documents/herbal-monograph/final-european-union-herbal-monograph-harpagophytum-procumbens-dc/harpagophytum-zeyheri-decne-radix_en.pdf
14. Wenigmann M.(2017) Phytotherapy medicinal drugs phytopharmaceuticals application. Urban & Fischer: 5.108 Rockweed (Meliloti herba) pp 204-205.