Devil's Claw (Harpagophytum procumbens): no evidence for anti-inflammatory activity in the treatment of arthritic disease.

Devil's Claw (Harpagophytum procumbens), an herbal product being marketed in Canada as a home remedy for the relief of arthritic disease, was screened for efficacy with standard preclinical screening methods. At doses 100 times or greater than the recommended daily dose for humans, Devil's Claw was completely ineffective in reducing edema of the rat hind foot induced by either lambda-carrageenan or Mycobacterium butyricum. At concentrations of up to 1 x 10(5) microgram/ml, Devil's Claw was also ineffective as an in-vitro inhibitor of prostaglandin synthetase. These results indicate that Devil's Claw lacks the anti-inflammatory properties possessed by all antiarthritic drugs of the nonsteroidal, anti-inflammatory analgesic type.