Genistein and daidzein decrease food intake and body weight gain in mice, and alter LXR signaling<i>in vivo</i>and<i>in vitro</i>

Abstract

The study is designed to determine whether consumption of the soy isoflavones, genistein and daidzein, differentially influence metabolic syndrome, and to further investigate the involvement of Liver X Receptor (LXR) regulation. C57BL/6J mice were fed diets as follows: low fat diet (LF), western-style diet (WD), and WD containing 0.16% (w/w) of genistein (WD + G) or daidzein (WD + D) for 10 weeks. Intake of WD + G and WD + D produced a robust decrease in body weight gain by 40% and 19%, respectively (p < 0.05). Genistein reduced energy intake by 26%, and daidzein decreased energy intake by 8% (p < 0.05). A glucose tolerance test indicated that genistein consumption significantly decreased the incremental areas under the curve (AUC) from 60-120 min, compared to WD-fed mice. Gene array profiling of hepatic mRNA, and cell studies utilizing transiently-transfected HepG2 cells and mouse embryonic fibroblast cells devoid of or expressing LXRα, indicate that genistein and daidzein induce LXR-mediated pathways. In summary, addition of genistein, compared to daidzein, to a western-style diet, more profoundly decreased food intake, body weight gain, while both appear to regulate LXR-mediated pathways.