Assessment of the analgesic dipyrone as a possible (anti)androgenic endocrine disruptor.

Mild analgesics have been associated with antiandrogenic effects, but there are no such studies on dipyrone, despite its high prevalence of use in many countries. We examined the production of steroid hormones in human H295R cells after exposure to dipyrone and two metabolites, 4-Methylaminoantipyrine (MAA) and 4-Aminoantipyrine (AA), as well as fetal testicular testosterone production in rats following maternal dipyrone exposure. Androgen agonistic/antagonistic effects were examined in vitro for dipyrone and its metabolites in the Yeast Androgen Screen (YAS) assay and in vivo for dipyrone through the Hershberger assay. In vitro we tested dipyrone, MAA, and AA (0.1-1000 µM) while in vivo we used dipyrone (50, 100, 200 mg/kg/day). In the H295R assay, dipyrone, MAA and AA reduced the production of androgens and corticosteroids. Testosterone was reduced at concentrations 4-13 times higher than the maximum plasma concentrations reported in humans for MAA and AA. No effects were observed in the fetal testosterone production assay. In the YAS and Hershberger assays, no androgen agonistic/antagonistic activities were observed. These results indicate that dipyrone and its metabolites do not interact with the androgen receptor, but have the potential to inhibit steroidogenesis, however only at concentrations that are not relevant under normal medical use.

Effect of estrogenic binary mixtures in the yeast estrogen screen (YES).

Endocrine disrupting compounds (EDCs) of natural or synthetic origin can interfere with the balance of the hormonal system, either by altering hormone production, secretion, transport, or their binding and consequently lead to an adverse outcome in intact animals. An important aspect is the prediction of effects of combined exposure to two or more EDCs at the same time. The yeast estrogen assay (YES) is a broadly used method to assess estrogenic potential of chemicals. Besides exhibiting good predictivity to identify compounds which interfere with the estrogen receptor, it is easy to handle, rapid and therefore allows screening of a large number of single compounds and varying mixtures. Herein, we applied the YES assay to determine the potential combination effects of binary mixtures of two estrogenic compounds, bisphenol A and genistein, as well as one classical androgen that in vitro also exhibits estrogenic activity, trenbolone. In addition to generating data from combined exposure, we fitted these to a four-parametric logistic dose-response model. As all compounds tested share the same mode of action dose additivity was expected. To assess this, the Loewe model was utilized. Deviations between the Loewe additivity model and the observed responses were always small and global tests based on the whole dose-response data set indicated in general a good fit of the Loewe additivity model. At low concentrations concentration additivity was observed, while at high concentrations, the observed effect was lower than additivity, most likely reflecting receptor saturation. In conclusion, our results suggest that binary combinations of genistein, bisphenol A and trenbolone in the YES assay do not deviate from expected additivity.