title: Devil's Claw to suppress appetite--ghrelin receptor modulation potential of a Harpagophytum procumbens root extract.
abstract: 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.
authors: Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland.
authors: Cristina
authors: C
authors: Torres-Fuentes
authors: Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland.
authors: Wessel F
authors: WF
authors: Theeuwes
authors: Life Force Research, Ljungskile, Sweden; School of Biosciences, University of Westminster, London, United Kingdom.
authors: Michael K
authors: MK
authors: McMullen
authors: Life Force Research, Ljungskile, Sweden.
authors: Anna K
authors: AK
authors: McMullen
authors: Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland; Dept of Psychiatry, University College Cork, Cork, Ireland.
authors: Timothy G
authors: TG
authors: Dinan
authors: Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland.
authors: John F
authors: JF
authors: Cryan
authors: Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland.
authors: Harriët
authors: H
authors: Schellekens
mesh_terms: D000818:Animals; D001066:Appetite / Q000187:drug effects*; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects; D057809:HEK293 Cells; D031684:Harpagophytum / Q000737:chemistry*; D006801:Humans; D008297:Male; D051379:Mice; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D018517:Plant Roots / Q000737:chemistry*; D054440:Receptors, Ghrelin / Q000819:agonists / Q000378:metabolism*
chemical_list: D010936:Plant Extracts; D054440:Receptors, Ghrelin; D002118:Calcium