The novel progestin drospirenone and its natural counterpart progesterone: biochemical profile and antiandrogenic potential.

ABSTRACT

PIP: In various research laboratories in Germany, researchers conducted receptor binding studies and transactivation assays in vitro and studied antiandrogenic activity in juvenile castrated male rats of the new progestin drospirenone and of the natural hormone progesterone. Drospirenone exhibited high affinity to the progesterone receptor (PR) and the mineralocorticoid receptor (MR), while it exhibited low affinity to the androgen receptor (AR). Progesterone also had low affinity to AR. Neither the new progestin nor progesterone bound to the estrogen receptor (ER). Neither drospirenone nor progesterone displayed androgenic activity. On the other hand, they thwarted AR-mediated transcription in a dose-dependent manner, therefore displaying antiandrogenic activity. The in vivo studies confirmed the antiandrogenic activity of drospirenone and progesterone. In fact, these studies revealed that drospirenone had an antiandrogenic potency 5-10 times greater than progesterone. Unlike progesterone, drospirenone exhibited no glucocorticoid activity, but both drospirenone and progesterone exhibited antiglucocorticoid activity. They also displayed strong antimineralocorticoid activity and weak mineralocorticoid activity.