Effects of a saw palmetto herbal blend in men with symptomatic benign prostatic hyperplasia

Purpose: We tested the effects of a saw palmetto herbal blend in men with symptomatic benign prostatic hyperplasia (BPH) via a randomized, placebo controlled trial. Materials and Methods: We randomized 44 men 45 to 80 years old with symptomatic BPH into a trial of a saw palmetto herbal blend versus placebo. End points included routine clinical measures (symptom score, uroflowmetry and post-void residual urine volume), blood chemistry studies (prostate specific antigen, sex hormones and multiphasic analysis), prostate volumetrics by magnetic resonance imaging, and prostate biopsy for zonal tissue morphometry and semi-quantitative histology studies. Results: Saw palmetto herbal blend and placebo groups had improved clinical parameters with a slight advantage in the saw palmetto group (not statistically significant). Neither prostate specific antigen nor prostate volume changed from baseline. Prostate epithelial contraction was noted, especially in the transition zone, where percent epithelium decreased from 17.8% at baseline to 10.7% after 6 months of saw palmetto herbal blend (p < 0.01). Histological studies showed that the percent of atrophic glands increased from 25.2% to 40.9% after treatment with saw palmetto herbal blend (p < 0.01). The mechanism of action appeared to be nonhormonal but it was not identified by tissue studies of apoptosis, cellular proliferation, angiogenesis, growth factors or androgen receptor expression. We noted no adverse effects of saw palmetto herbal blend. When the study was no longer blinded, 41 men elected to continue therapy in an open label extension. Conclusions: Saw palmetto herbal blend appears to be a safe, highly desirable option for men with moderately symptomatic BPH. The secondary outcome measures of clinical effect in our study were only slightly better for saw palmetto herbal blend than placebo (not statistically significant). However, saw palmetto herbal blend therapy was associated with epithelial contraction, especially in the transition zone (p < 0.01), indicating a possible mechanism of action underlying the clinical significance detected in other studies.