Devil's Claw and rheumatic inflammation
Devil's Claw (Harpagophytum procumbens) is native to South Africa, lives in dry soils, and produces large underground tubers that are a source of both food and medicine.
The tubers are rich in flavonoids, phytosterols, and a particular type of bitter iridoids (one of which, extensively researched, is known as harpagoside and usually serves as the 'marker compound'). It is traditionally used as a tonic for the digestion, helping to improve appetite and assimilation while also being very nourishing. It has also served as a general depurative and diuretic.
More recently interest has focused on its analgesic and anti-inflammatory qualities, with a range of human trials in the literature that expand on lots of pharmacological data (Doloteffin, the standardized aqueous extract of the whole tuber used in many trials, yields about 50mg of harpagoside per dose). Seems best for back pain, osteoarthitis, and muscular pain -- or generally, most chronic conditions involving structural inflammation.
A new study for the first time looks at Devil's Claw in chronic inflammation of autoimmune origin. It's not placebo-controlled, but rather focuses on qualitative impressions from the clinicians and the patients regarding long-term rheumatic inflammation of the knee, hip, and various other joints. Over 200 people were included in the study, though folks taking H2 and proton-pump inhibitors (two varieties of heartburn drugs) were turned away because of the potential for herb-drug interactions. Patients were followed for 8 weeks (with a mid-course checkup at week 4) and, with an eye to safety, were also evaluated through a blood analysis that looked at comprehensive blood counts and liver enzyme levels.
Bottom line: the only adverse events reported weer occasional mild GI upset. Over 50% of participants rated the results as "good" or "excellent", with assessment criteria showing a reduction in pain and stiffness, and improved joint function across the board. Additionally, no changes were seen in any blood values, showing that Devil's Claw is well-tolerated, has no liver toxicity, and works quite well for rheumatic joint pain.
A final note: the authors recorded that a majority of NSAID (aspirin, ibuprofen) users scaled back or eliminated the use of these painkillers during the study, because they no longer were necessary. They go on to point out that, since rheumatic complaints are chronic but have 'flare-ups', the Devil's Claw could be used for long-term management and the NSAIDs added only as needed. This would reduce the chance of side-effects from the medication, and improve patient well-being overall.