Authors
C. Cederroth, M. Vinciguerra, F. Kühne, R. Madani, D. Doerge.
Lab
University of Geneva, Department of Genetic Medicine and Development and National Center for Competence in Research - Frontiers in Genetics, Geneva, Switzerland.
Journal
Environ Health Perspect.
Abstract
Background: Obesity is an increasingly prevalent health problem, and natural effective therapeutic approaches are required to prevent its occurrence. Phytoestrogens are plant-derived compounds with estrogenic activities; they can bind to both estrogen receptors _ and _ and mimic the action of estrogens on target organs. Objectives: The purpose of this study was to examine the influence of soy-derived phytoestrogens on energy balance and metabolism. Methods: Male outbred mice (CD-1) were allowed ad libitum access to either a high soy-containing diet or a soy-free diet from conception to adulthood. We measured circulating serum isoflavone levels using reverse-phase solid-phase extraction for subsequent liquid chromatography electrospray tandem mass spectrometry analysis. Adult animals were analyzed for body composition by dual-energy X-ray absorptiometry, locomotor activity by running-wheel experiments, respiratory exchange rate by indirect calorimetry, and food intake using metabolic cages. Quantitative reverse transcriptase-polymerase chain reaction was performed to determine the expression of hypothalamic neuropeptide genes. Results: We found that adult mice fed a soy-rich diet had reduced body weight, adiposity, and resistance to cold. This lean phenotype was associated with an increase in lipid oxidation due to a preferential use of lipids as fuel source and an increase in locomotor activity. The modulation of energy balance was associated with a central effect of phytoestrogens on the expression of hypothalamic neuropeptides, including agouti-related protein. Conclusion: The data suggest that dietary soy could have beneficial effects on obesity, but they also emphasize the importance of monitoring the phytoestrogen content of diets as a parameter of variability in animal experiments.
BIOSEB Instruments Used:
Infrared Actimeter (LE8815)