Critical Role of Peroxisome Proliferator Activated Receptor-δ on Body Fat Reduction in C57BL/6J and Human Apolipoprotein E2 Transgenic Mice Fed Delipidated Soybean

The consumption of soy protein and fiber reduces body fat accumulation, however, the mechanism of this effect has not been clearly understood We investigated the antiobesogenic effect of soy protein and fiber m two different mouse models Normolipidemic nonobese C57BL/6J and hyperlipidemic obese human apolipoprotein E2 transgenic mice were fed either delipidated soybean (DLSB) containing soy protein and fiber or a control diet The DLSB-fed mice showed a significant reduction in body weight gain and adiposity compared with controls, in both C57BL/6J and apoE2 mice All metabolic parameters were significantly Improved in the DLSB group compared with controls total cholesterol, low-density lipoprotein cholesterol, insulin, and leptin levels were significantly reduced Adiponectin concentrations were significantly elevated, and glucose tolerance was improved In both types of DLSB-fed mice, the specific induction of PPAR-delta protein expression was' evident in muscle and adipose tissues The expression of PPAR-delta target genes in the DLSB-fed mice was also significantly altered Acetyl-CoA carboxylase-1 and fatty acid synthase levels, in adipose tissue were downregulated, and uncoupling protein-2 in muscle was upregulated Intestinal expression of fatty acid transport protein-4, cluster of differentiation-36 and acyl-CoA synthetase were significantly downregulated We propose that marked activation of PPAR-delta is the primary mechanism mediating the antiobesogenic effect of soybean and that PPAR-delta has multiple actions induction of thermogenesis in muscle, reduction of fatty acid synthesis in adipose tissue, and reduction of fatty acid uptake in intestinal tissue