Objectives: 

In addition to energy restriction combined with adequate exercise, strategies for reducing obesity include drug-based measures, focusing on functional foods. Our aim was to assess in normal-weight rats the effect of two functional ingredients supplied by Biosearch Life S.A. on circulating insulin, leptin, ghrelin and PYY, whose concentrations in plasma are determinants of food intake and, thus, of body weight.

Materials: 

Thirty male Wistar rats (150±5 g body weight) were given free access to food and water. A Control group received AIN-93M rodent diet and two groups (E1 and E2) were fed modified AIN-93M diets added each one with a functional ingredient. After 7 days on these diets, experiments were conducted to determine the plasma concentrations of the above hormones in fasting conditions and 15, 30, 60 and 120 minutes postprandially. Analysis of hormones was performed by Luminex X-MAP technology.

Results: 

Insulin and leptin responses to food were similar and, for both hormones, values were greater in the control group compared with E1. As expected, plasma ghrelin decreased rapidly following food ingestion. However, neither ghrelin nor PYY was influenced by the experimental manipulation.

Conclusions: 

Addition of the functional ingredients to the diets of normal-weight rats affected only those peptides that act in the long-term regulation of food intake: leptin and insulin.

This research was funded by Biosearch S.A. within the context of PRONAOS, a project supported by the CITD (Programme INGENIO 2010).