Epidemiological studies comparing typical Western and traditional Eastern lifestyles indicate that dietary intake of soyderived phytoestrogens, including genistein, daidzein, and equol, may have significant health protective effects on
hormone-dependent cancers, osteoporosis and cardiovascular diseases. Phytoestrogens have been demonstrated to exert varying effects depending on tissue, endogenous hormone concentrations, and receptor types. Thus, a detailed understanding of the biodistribution and bioavailability of specific phytoestrogens is required in order to predict the subsequent biologic activities. In this study we aimed to investigate the cellular uptake of these soy-derived
phytoestrogens in different cell types, including the mammary MCF-7/6 and MDAB-MB 231 cell lines, the ovarian
Ishikawa Var-I cell lines and in murine adipocyte clusters. Furthermore, the biodistribution between serum and cell
fraction was also investigated in human whole blood. Equol generally shows a higher cellular uptake when compared
with genistein and daidzein. Therefore, equol may be more potent with respect to its relative bioactivity, which is
corroborated by the observations of specific health effects associated with the equol-producer phenotype
