Biochanin a and Daidzein Influence Meiotic Maturation of Pig Oocytes in a Different Manner

Abstract

Abstract The aim of the study was to determine the influence of different concentrations of phytoestrogens biochanin A (BIO A; 20, 40, 50μg ml-1) and daidzein (DAI; 10, 20, 40, 50μg ml-1) on the course of meiotic maturation of pig oocytes. After a 24-hour cultivation, a stage of nuclear maturation was achieved and the areas of cumulus-oocyte complexes (COCs), as an indicator of cumulus expansion, were evaluated. The effects of both contaminants on oocytes were mani - fested from the lowest concentration used. Nuclear maturation was inhibited in a dose-dependent manner in the case of BIO A. Effects of DAI reached a plateau at a concentration of 20μg ml-1.Possible relationship to limited solubility of DAI was excluded because limits of DAI solubility in culture medium were confirmed at 50 μg ml-1.The cumulus expansion was also influenced in a different manner - reduction of the COC’s area by BIO A was dose-dependent, whereas DAI had the strongest effect on CCs in the lowest and highest concentrations used. Both phytoestrogens negatively influence the meiotic maturation of porcine oocytes but there are significant differences in their concrete effects which could relate to the diverse mechanisms of their acting on target cells.