Satiating properties of a grape seed proanthocyanidin extract

Identificador:  TDX:2650

Handle: https://hdl.handle.net/20.500.11797/TDX2650

Autors:  Serrano López, Joan

Resum:
Given the health problems associated with overweight, in this thesis we have investigated the possible use of a grape seed proanthocyanidin extract (GSPE) as a satiating agent, using rats as an experimental model. We have observed that under an adequate administration pattern, GSPE decreases intake both acutely and continuously along periods of 8 consecutive days. These satiating properties, added to a lipolytic effect, result in a significant decrease in body weight. In investigating the signaling pathways involved, we have observed that the administration of GSPE modifies the production and secretion of several gastrointestinal hormones that affect appetite, including GLP-1, with satiating effects, and the appetite-inducing hormone ghrelin. In studies with antagonists we have observed that the administration of GSPE increases the plasma concentration of GLP-1 and that the satiating effect of GSPE and one of its compounds, gallic acid, is directly mediated by the GLP-1 receptor. In studies of 8 consecutive days we have observed that the satiating effects of gallic acid are not maintained over time, reinforcing the importance of other compounds in the extract to maintain a continued effect. In these subchronic studies, GSPE administration leads to a large decrease in ghrelin synthesis, a fact that we have observed closely related to the increase in GLP-1 signaling in the hypothalamus, the satiety induction and the lipolytic effect of GSPE . We hope these studies will allow translational studies for the application of GSPE in humans.