Steroidal 5α-reductase inhibitors using 4-androstenedione as substrate

Biological activity of pyrazole and imidazole-dehydroepiandrosterone derivatives on the activity of 17β-hydroxysteroid dehydrogenase

The enzyme type 5 17β-hydroxysteroid dehydrogenase 5 (17β-HSD5) catalyzes the transformation of androstenedione (4-dione) to testosterone (T) in the prostate. This metabolic pathway remains active in cancer patients receiving androgen deprivation therapy. Since physicians seek to develop advantageous and better new treatments to increase the average survival of these patients, we synthesized several different dehydroepiandrosterone derivatives. These compounds have a pyrazole or imidazole function at C-17 and an ester moiety at C-3 and were studied as inhibitors of 17β-HSD5. The kinetic parameters of this enzyme were determined for use in inhibition assays. Their pharmacological effect was also determined on gonadectomized hamsters treated with Δ(4)-androstenedione (4-dione) or testosterone (T) and/or the novel compounds. The results indicated that the incorporation of a heterocycle at C-17 induced strong 17β-HSD5 inhibition. These derivatives decreased flank organ diameter and prostate weight in castrated hamsters treated with T or 4-dione. Inhibition of 17β-HSD5 by these compounds could have therapeutic potential for the treatment of prostate cancer and benign prostatic hyperplasia.

In vivo and in vitro effect of androstene derivatives as 5α-reductase type 1 enzyme inhibitors

The aim of these studies was to synthesize twelve ester derivatives of dehydroepiandrosterone with therapeutic potential. The effect of 1-12 was demonstrated in the flank organs of gonadectomized hamsters treated with testosterone and the synthesized steroids. In vitro studies were carried out determining the IC50 values for the inhibition of the activity of 5α-reductase type 1 and 2, which are present in rat liver and human prostate respectively. The binding of 1-12 to the androgen receptors (AR) was determined using rat's prostate cytosol. Steroids 1-12 containing different substituents in the phenyl group of the ester moiety in C-3 reduced the flank organs and inhibited the activity of 5α-R type 1; however only steroids 1 and 2 inhibited 5α-R type 2. 1-12 did not bind to the AR. The modification of one atom of the substituents in the phenyl group of the ester moiety in C-3 changed their biological potency (IC50).