Steroids with modified ring A or B: Screening for potential antiandrogenic and synandrogenic activity

A series of 14 steroids with modified ring A or B (A-homosteroids, B-homosteroids and 3,6-cyclo-A-nor-3,5-seco-6β-androstanes) were tested for potential antiandrogenic activity by binding assays, using prostate cytosol receptor or sex hormone binding globulin as binder, and by the inhibition of 5α-reductase. The results of in vitro screening were compared with in vivo bioassay. The antiandrogenic or synandrogenic activity of these compounds seemed to have an integrated effect on steroid binding to the cytosol receptors, displacement of the endogenous androgens from the binding to sex hormone binding globulin and influence the transformation of testosterone into 5α-dihydrotestosterone.