Male Wistars

Extract of saw palmetto fruit (several hypercritical CO₂ extracts)

Rat model of prostate hyperplasia due to androgen stimulation: in castrated prepubescent rats, administration of testosterone (15 μg/d, subcutaneously, for 10 d) stimulated prostate hyperplasia

Oral administration of an extract of saw palmetto fruit inhibited testosterone-induced increase in prostate weight by 38% (150 mg extract/d) or 76% (300 mg extract/d); two other extracts were less effective (Cristoni et al., 1997)

Male Wistars

Extract of saw palmetto fruit (50 mg/kg body weight/d, oral gavage, for 90 d; control was 2.5% ethanol vehicle)

Castrated on day 0, hormone implants (estradiol implanted on day 7; testosterone implanted on day 21)

Rat model of prostate hyperplasia due to androgen stimulation: in castrated rats, administration of estradiol plus testosterone (over 3 mo following castration) stimulated prostate hyperplasia (maximal effect at 30 d)

Oral administration of extract of saw palmetto fruit (50 mg/kg body weight/d) inhibited hormone-induced increase in prostate weight (maximal effect at 60 d and 90 d for the dorsal and lateral regions of the rat prostate; maximal effect at 30 d and 60 d for ventral region) (Paubert-Braquet et al., 1998)

Males

Extract of saw palmetto fruit

Rat model of prostate hyperplasia due to androgen stimulation: in castrated rats, administration of testosterone stimulated prostate hyperplasia

Oral administration of an extract of saw palmetto fruit (200 mg/d, for 6 d) inhibited hormone-induced increase in prostate weight (Plosker and Brogden, 1996; Stenger et al., 1982)

Immature males

Extract of saw palmetto fruit (180 or 1,800 mg/d, in methyl cellulose in water, by gavage, BID), finasteride (0.1 or 10 mg/d, oral, BID) or cottonseed oil (2 ml, 5% ethanol, by gavage, control)

Castrated; treatment was started on the day following castration and continued for 7 d: testosterone propionate (10 μg/d, subcutaneously), dihydrotestosterone (DHT) propionate (20 μg/d, subcutaneously), or

Rat model of prostate hyperplasia due to androgen stimulation: in castrated rats, administration of testosterone or DHT stimulated prostate hyperplasia; coadministration of finasteride inhibited testosterone-stimulated prostate growth

Coadministration of an extract of saw palmetto fruit did not inhibit testosterone-stimulated prostate growth

Coadministration of finasteride or extracts of saw palmetto fruit did not inhibit DHT-stimulated prostate growth (Rhodes et al., 1993)