Effect of a soybean methanolic fraction containing isoflavones on beta/delta peroxisome proliferator-activated receptors (PPAR)
The effects of the methanolic fraction of soy isoflavones from seeds and bark on PPARβ/δ, PPARα, and PPARγ receptors were investigated. The bark was obtained as a residue from industrial-oil extraction of the seeds. Analysis of transgenia did not detect the presence of genetically modified material containing the gene  CP4 EPSPS. The concentrations of isoflavones in seeds as obtained by HPLC analyses  (mg of isoflavones/100g) for daidzin, glycitin, genistin, malonyldaidzin, malonylglycitin, malonylgenistin, daidzein, glycitein, genistein, and total isoflavones were: 145.67±3.14, 45.69±1.86, 147.54±5.54, 276.54±4.21, 105.73±1.17, 466.54±7.37, 57.73±1.26, 22.61±0.36, 75.04±1.61, and 1345.09, respectively. In addition, the concentrations of isoflavones in the bark (mg of isoflavones/100g) for daidzin, glycitin, genistin, malonyldaidzin, malonylglycitin, malonylgenistin, daidzein, glycitein, genistein, and total isoflavones were 393.78±5.39, 149.41±1.52, 296.14±4.14, 152.29±3.38, 89.11±3.94, 161.80±2.82, 86.64±0.93, 33.92±1.08, 55.84±0.82, and 1418.93, respectively. The data also indicated that the methanolic fraction, rich in conjugated soy isoflavones, was capable of activating PPARα and PPARβ/δ gene expression. In contrast, the methanolic fraction from seeds or bark did not activate PPARγ gene expression. The results showing activation of PPARα are consistent with in vitro  and clinical  studies regarding soy isoflavones as a lipid lowering agent. However, future studies will be necessary to clarify the physiological significance of the activation of PPARβ/δ.
Acknowledgement: Support through grants from the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and CAPES.
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