Harpagophytum procumbens – Traditional Anti-inflammatory Herbal Drug with Broad Therapeutic Potential

Abstract

Harpagophytum procumbens (Devil’s Claw) is a traditional African herbal drug used by the natives of the Kalahari and Savannah desert regions to treat a variety of ailments. In Europe, the anti-inflammatory properties of Harpagophytum procumbens extracts (Hp) have been the basis for its popular use in the treatment of inflammatory disorders of the musculoskeletal system and of low back pain. This is the subject of a draft monograph recently issued by the European drug authorities (EMEA). There is good clinical evidence for Hp’s use in treating painful osteoarthritis, but more evidence (such as from phase-III trials) is needed before Hp can be considered a standard treatment of osteoarthritis and other chronic inflammatory diseases. Here, the published evidence is reviewed that reveal the anti-inflammatory effects of Hp including inhibition of key mediators and promoters of inflammation. The relevance of these effects for the therapeutic use of Hp in osteoarthritis is discussed. The main constituents of Hp, glycosides of harpagoside and of acteoside, have been shown to act on molecular pathways that have become recognised as targets in the development of new anti-inflammatory drugs. The pharmacological profile of Hp is that of a modern anti-inflammatory agent. Today there is great interest in new anti-inflammatory drugs as toxicological doubts have arisen concerning standard drugs but also as it has become apparent that the therapeutic potential of novel anti-inflammatory drugs goes well beyond the treatment of recognised chronic inflammatory diseases. Inflammation is now seen as a primary process in osteoarthritis but also as a key pathophysiological factor in many common modern diseases (cardiovascular disease, diabetes, osteoporosis, neurodegenerative diseases, dementia and Alzheimer’s). The therapeutic potential of Hp, therefore, demands attention.