Effects of novel 17-azolyl compounds on androgen synthesis in vitro and in vivo.
17-Azolyl steroids were synthesized and evaluated as inhibitors of androgen synthesis in vitro and in vivo. Several of the novel compounds exhibit potent noncompetitive inhibition of human 17alpha-hydroxylase/C17,20-lyase with IC50 values ranging from 7 to 90 nM, and Ki values from 1.2 to 41 nM. VN/85-1 and VN/108-1 were the most potent inhibitors against this enzyme with IC50 value of 8 nM (Ki of 1.2 nM) and 7 nM (Ki of 1.9 nM), respectively. VN/107-1, VN/108-1 and VN/109-1 also showed moderate inhibition of 5alpha-reductase in human prostatic microsomes. Normal adult male rats were treated with these novel 17-azolyl steroidal compounds at a dose level of 50 mg/kg, s.c., for 14 consecutive days, sacrificed 1-2 h after the last administered dose and blood, prostate and other tissues were collected. The organs were weighed and tissue concentrations of testosterone (T) and dihydrotestosterone (DHT) were measured. Tissue T levels were significantly (p<0.05) lower in rats treated with the novel 17-azolyl steroids by more than 50% compared to the control group. Similarly, the concentration of DHT in the serum and prostates was significantly (p<0.05) diminished in rats treated with the 17-azolyl steroids by 39-80% compared to the control group. Furthermore, the wet weights of the prostates and seminal vesicles were significantly (p<0.05) reduced by several of the novel steroids. Although only one dose was evaluated in these studies, VN/85-1 was the most effective compound and reduced prostatic androgen levels by more than 80% and the wet weights of the prostate and seminal vesicles in rats by about 50%. These findings suggest that these novel compounds may provide useful leads for the research and development of suitable agents for the treatment of androgen dependent prostate cancer.
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Department of Pharmacology and Experimental Therapeutics, University of Maryland School of Medicine, Baltimore 21201, USA.
Njar
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Liu
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Lu
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Brodie
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D000728:Androgens / Q000096:biosynthesis*; D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology; D001393:Azoles / Q000737:chemistry / Q000494:pharmacology*; D013196:Dihydrotestosterone / Q000097:blood / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology; D005837:Genitalia, Male / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D011467:Prostate / Q000187:drug effects / Q000378:metabolism; D011471:Prostatic Neoplasms / Q000188:drug therapy; D051381:Rats; D017207:Rats, Sprague-Dawley; D013254:Steroid 17-alpha-Hydroxylase / Q000037:antagonists & inhibitors; D013256:Steroids / Q000737:chemistry / Q000494:pharmacology*; D013737:Testis / Q000187:drug effects / Q000378:metabolism; D013739:Testosterone / Q000097:blood / Q000378:metabolism
D000728:Androgens; D000970:Antineoplastic Agents; D001393:Azoles; D004791:Enzyme Inhibitors; D013256:Steroids; D013196:Dihydrotestosterone; D013739:Testosterone; D013254:Steroid 17-alpha-Hydroxylase