Comparison of finasteride (Proscar), a 5 alpha reductase inhibitor, and various commercial plant extracts in in vitro and in vivo 5 alpha reductase inhibition.
Rhodes L; Primka RL; Berman C; Vergult G; Gabriel M; Pierre-Malice M; Gibelin B
Department of Biochemistry, Merck Research Laboratories, Rahway, New Jersey 07065.
Prostate 1993; 22 (1): 43-51
LANGUAGE OF PUBLICATION
Human prostate was used as a source of 5 alpha reductase. Compounds were incubated with an enzyme preparation and [3H]testosterone. [3H]-dihydrotestosterone production was measured to calculate 5 alpha reductase activity. IC50 values (ng/ml) were finasteride = 1; Permixon = 5,600; Talso = 7,000; Strogen Forte = 31,000; Prostagutt = 40,000; and Tadenan = 63,000. Bazoton and Harzol had no activity at concentrations up to 500,000 ng/ml. In castrate rats stimulated with testosterone (T) or dihydrotestosterone (DHT), finasteride, but not Permixon or Bazoton, inhibited T stimulated prostate growth, while none of the three compounds inhibited DHT stimulated growth. These results demonstrate that finasteride inhibits 5 alpha reductase, while Permixon and Bazoton have neither anti-androgen nor 5 alpha reductase inhibitory activity. In addition, in a 7 day human clinical trial, finasteride, but not Permixon or placebo, decreased serum DHT in men, further confirming the lack of 5 alpha reductase inhibition by Permixon. Finasteride and the plant extracts listed above do not inhibit the binding of DHT to the rat prostatic androgen receptor (concentrations to 100 micrograms/ml). Based on these results, it is unlikely that these plant extracts would shrink the prostate by inhibiting androgen action or 5 alpha reductase. (AUTHOR)
MJTR: Androstenes PD. Azasteroids PD. Plant Extracts PD. Testosterone 5-alpha-Reductase AI.
MNTR: Animal. Comparative Study. Human. In Vitro. Male. Prostate DE. Prostate EN. Rats. Receptors, Androgen DE. Stanolone BL. Testosterone BL. CLINICAL TRIAL. CONTROLLED CLINICAL TRIAL. JOURNAL ARTICLE
RNUM: EC 184.108.40.206 (Testosterone 5-alpha-Reductase); 0 (Androstenes); 0 (Azasteroids); 0 (Permixon); 0 (Plant Extracts); 0 (Receptors, Androgen); 521-18-6 (Stanolone); 57-85-2 (Testosterone); 98319-26-7 (Finasteride)
GEOT: UNITED STATES
IDEN: ISSN: 0270-4137. JOURNAL-CODE: PB4. ENTRY-DATE: 930226. JOURNAL-SUBSET: M X. IM-DATE: 9305.