Devil's Claw to suppress appetite--ghrelin receptor modulation potential of a Harpagophytum procumbens root extract

PLoS One. 2014 Jul 28;9(7):e103118. doi: 10.1371/journal.pone.0103118. eCollection 2014.


Ghrelin is a stomach-derived peptide that has been identified as the only circulating hunger hormone that exerts a potent orexigenic effect via activation of its receptor, the growth hormone secretagogue receptor (GHS-R1a). Hence, the ghrelinergic system represents a promising target to treat obesity and obesity-related diseases. In this study we analysed the GHS-R1a receptor activating potential of Harpagophytum procumbens, popularly known as Devil's Claw, and its effect on food intake in vivo. H. procumbens is an important traditional medicinal plant from Southern Africa with potent anti-inflammatory and analgesic effects. This plant has been also used as an appetite modulator but most evidences are anecdotal and to our knowledge, no clear scientific studies relating to appetite modulation have been done to this date. The ghrelin receptor activation potential of an extract derived from the dried tuberous roots of H. procumbens was analysed by calcium mobilization and receptor internalization assays in human embryonic kidney cells (Hek) stably expressing the GHS-R1a receptor. Food intake was investigated in male C57BL/6 mice following intraperitoneal administration of H. procumbens root extract in ad libitum and food restricted conditions. Exposure to H. procumbens extract demonstrated a significant increased cellular calcium influx but did not induce subsequent GHS-R1a receptor internalization, which is a characteristic for full receptor activation. A significant anorexigenic effect was observed in male C57BL/6 mice following peripheral administration of H. procumbens extract. We conclude that H. procumbens root extract is a potential novel source for potent anti-obesity bioactives. These results reinforce the promising potential of natural bioactives to be developed into functional foods with weight-loss and weight maintenance benefits.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Appetite / drug effects*
  • Calcium / metabolism
  • Calcium Signaling / drug effects
  • HEK293 Cells
  • Harpagophytum / chemistry*
  • Humans
  • Male
  • Mice
  • Plant Extracts / chemistry
  • Plant Extracts / pharmacology*
  • Plant Roots / chemistry*
  • Receptors, Ghrelin / agonists
  • Receptors, Ghrelin / metabolism*


  • Plant Extracts
  • Receptors, Ghrelin
  • Calcium

Grants and funding

This work was supported by Enterprise Ireland under Grant Number CC20080001. JFC and TGD are also supported in part by Science Foundation Ireland (SFI) in the form of a centre grant (Alimentary Pharmabiotic Centre) through the Irish Government's National Development Plan. The authors and their work were supported by SFI (grant nos. 02/CE/B124 and 07/CE/B1368). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.