Abstract
Objectives. To determine the effects of a saw palmetto herbal blend (SPHB) compared
with finasteride on prostatic tissue androgen levels and to evaluate needle biopsies
as a source of tissue for such determinations.
Methods. Prostate levels of testosterone and dihydrotestosterone (DHT) were measured
on 5 to 10-mg biopsy specimens (18-gauge needle cores) in three groups of men with
symptomatic benign prostatic hyperplasia: 15 men receiving chronic finasteride therapy
versus 7 untreated controls; 4 men undergoing prostate adenomectomy to determine sampling
variability (10 specimens each); and 40 men participating in a 6-month randomized
trial of SPHB versus placebo, before and after treatment.
Results. Prostatic tissue DHT levels were found to be several times higher than the
levels of testosterone (5.01 versus 1.51 ng/g), that ratio becoming reversed (1.05
versus 3.63 ng/g) with chronic finasteride therapy. The finasteride effect was statistically
significant for both androgens (P <0.01), and little overlap of individual values between finasteride-treated and control
patients was seen. In the randomized trial, tissue DHT levels were reduced by 32%
from 6.49 to 4.40 ng/g in the SPHB group (P <0.005), with no significant change in the placebo group.
Conclusions. For control versus finasteride-treated men, the tissue androgen values
obtained with needle biopsy specimens were similar—both for absolute values and the
percentage of change—to those previously reported using surgically excised volumes
of prostatic tissue. The quantification of prostatic androgens by assay of needle
biopsies is thus feasible and offers the possibility of serial studies in individual
patients. The SPHB-induced suppression of prostatic DHT levels, modest but significant
in a randomized trial, lends an element of support to the hypothesis that inhibition
of the enzyme 5-alpha reductase is a mechanism of action of this substance.
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Article info
Publication history
Accepted:
November 1,
2000
Received in revised form:
November 1,
2000
Received:
July 27,
2000
Footnotes
☆This study was supported in part by NIH grants RR00163 and HD18185 and by the Nutrilite Division of Amway Corporation.
Identification
Copyright
© 2001 Elsevier Science Inc. Published by Elsevier Inc. All rights reserved.
