Devil’s claw (Harpagophytum procumbens) is a plant native to the desert regions of southern Africa, known for its anti-inflammatory and analgesic properties. The tuberous roots of the plant contain the main active ingredients, including harpagoside, iridoids and other bioactive compounds, which confer the medicinal properties. In the past, it was not very widespread; for about 20 years now, it has been very common to come across commercial preparations, which rheumatologists recommend to their patients to manage their rheumatic diseases in a complementary way to diet or drug therapy. In these preparations, it is quite easy to find the presence of devil’s claw extracts at dosages between 50 and 150 mg of active dry extract. Devil’s claw-based preparations are available in different forms:
- Titrated dry extracts: Capsules or tablets containing a standardized amount of harpagoside (generally 2-5%).
- Liquid extracts: Mother tincture or fluid extracts for oral use.
- Ointments or gels: Topical formulations for local applications.
- Herbal teas: Dried root for infusions.
ACTIVE INGREDIENTS:
Iridoid glycosides: harpagoside, harpagide, procumbide, harprocumbide A and B, 8-cinnamoyl-myoporoside.
Phytosterols: oleanolic acid, beta-sitosterol, ursolic acid and their methyl esters.
Aromatics: caffeic acid, chlorogenic acid, cinnamic acid, harpagoquinone.
Carbohydrates: glucose, fructose, raffinose (trisaccharide), stachyose (tetrasaccharide).
Flavonoids: kaempferol, fisetin, luteolin.
Various: glucoquinin (also present in onion).
Plant properties: anti-inflammatory, analgesic, antipyretic (against fever), hypocholesterolemic, spasmolytic, hypouricemic, choleretic (bile draining) and liver depurative, hypoglycemic.
Rheumatological indications: degenerative rheumatism, acute arthritis, cervicarthrosis with muscle-tension headache, hip arthrosis with sciatica, lumbar arthrosis.
Extra-rheumatological indications: hyperuricemia (high uric acid), type 2 diabetes, enteritis with diverticula, dysmenorrhea (irregular/painful period).
Biological actions of the extract
Glucoiridoids such as harpagide, harpagoside and 8-p-coumaroyl-harpagide, as well as the phenolic glycoside acteoside, were found to be the main bioactive constituents that inhibit inflammation and relieve pain by inhibiting the synthesis of prostaglandins (from COX-2) and leukotrienes (from 5-LOX) in cases of rheumatism and painful menstruation. Their potency is equal to phenylbutazone, but without its toxicity. Part of the direct analgesic action of the extract is still attributable to the iridoids. The anti-inflammatory action is also contributed by triterpenes (oleanolic and ursolic acid), which can inhibit the activation of the NF-kB transcription factor, necessary for white blood cells to produce inflammatory cytokines (IL-1, Il-6, TNF-alpha and others). There are some studies by an italian group (Mariano et al.) that would indicate how the total extract is able to stimulate cannabinoid cellular signaling through the CB2R receptor.
The action is not attributed individually to the iridoids or beta-caryophyllene or polyphenols, but rather to the complex as a whole, since the individual components have not been found to be so effective in their actions on pain in experimental models. Aside from the action on pain and inflammation, devil’s claw extract has other biological actions that are less known to the public, but reported anyway. Iridoids together with organic acids are stomachic (stimulate appetite and digestion), choleretic (promote the exit of bile from the liver) and liver purifiers. Phenolic acids (caffeic, chlorogenic) are direct anti-inflammatories and antioxidants; they are also inhibitors of XOS (lower uric acid levels) and PTP1B (improve type 2 diabetes and insulin sensitivity). Chlorogenic acid also regulates the enzyme HMG-CoA reductase, limiting the synthesis of cholesterol by the liver during the night (similar action to statins).
This effect can be useful in inflammatory conditions where reflex hypercholesterolemia has been found (such as rheumatoid arthritis, peripheral vascular disease, type 2 diabetes, to name a few).
- edited by Dr. Gianfrancesco Cormaci, PhD, specialist in Clinical Biochemistry.
Scientific references
Hong JY, Kim H et al. Oxid Med Cell Longev. 2022; 2022:3472443.
Gxaba N, Manganyi MC. Molecules. 2022 Jun 6; 27(11):3637.
Mariano A, Bigioni I et al. Pharmaceuticals (Basel). 2022; 15(4):457.
Mariano A, Di Sotto A et al. Nutrients. 2020 Aug 23; 12(9):2545.
Moré M, Gruenwald J et al. Planta Med. 2017; 83(18):1384-91.
Mncwangi N, Chen W et al. J Ethnopharmacol. 2012; 143(3):755.
Warnock M, McBean D et al. Phytother Res. 2007; 21(12):1228.
Altman RD, Marcussen KC. Arthritis Rheum. 2001; 44(11):2531.
Chrubasik S, Zimpfer C et al. Phytomedicine. 1996; 3(1):1-10.
