Benign prostatic hyperplasia (BPH), a nonmalignant enlargement of the prostate, can lead to obstructive and irritative lower urinary tract symptoms (LUTS). The pharmacologic use of plants and herbs (phytotherapy) for the treatment of LUTS associated with BPH is common. The extract of the berry of the American saw palmetto, or dwarf palm plant, Serenoa repens (also known by its botanical name of Sabal serrulatum), is one of several phytotherapeutic agents available for the treatment of BPH.
This systematic review aimed to assess the effects of Serenoa repens in the treatment of LUTS consistent with BPH.
Trials were searched in computerized general and specialized databases (MEDLINE, EMBASE, and The Cochrane Library), by checking bibliographies, and by handsearching the relevant literature.
Trials were eligible if they (1) randomized men with symptomatic BPH to receive preparations of Serenoa repens (alone or in combination) for at least four weeks in comparison with placebo or other interventions, and (2) included clinical outcomes such as urologic symptom scales, symptoms, and urodynamic measurements. Eligibility was assessed by at least two independent observers.
Data collection and analysis
Information on patients, interventions, and outcomes was extracted by at least two independent reviewers using a standard form. The main outcome measure for comparing the effectiveness of Serenoa repens with placebo or other interventions was the change in urologic symptom-scale scores. Secondary outcomes included changes in nocturia and urodynamic measures. The main outcome measure for side effects or adverse events was the number of men reporting side effects.
In this update 9 new trials involving 2053 additional men (a 64.8% increase) have been included. For the main comparison - Serenoa repens versus placebo - 3 trials were added with 419 subjects and 3 endpoints (IPSS, peak urine flow, prostate size). Overall, 5222 subjects from 30 randomized trials lasting from 4 to 60 weeks were assessed. Twenty-six trials were double blinded and treatment allocation concealment was adequate in eighteen studies.
Serenoa repens was not superior to placebo in improving IPSS urinary symptom scores, (WMD (weighted mean difference) −0.77 points, 95% CI −2.88 to 1.34, P > 0.05; 2 trials), finasteride (MD (mean difference) 0.40 points, 95% CI −0.57 to 1.37, P > 0.05; 1 trial), or tamsulosin (WMD −0.52 points, 95% CI −1.91 to 0.88, P > 0.05; 2 trials).
For nocturia, Serenoa repens was significantly better than placebo (WMD −0.78 nocturnal visits, 95% CI −1.34 to −0.22, P < 0.05; 9 trials), but with the caveat of significant heterogeneity (I2 = 66%). A sensitivity analysis, utilizing higher quality, larger trials (≥ 40 subjects), demonstrated no significant difference (WMD −0.31 nocturnal visits, 95% CI −0.70 to 0.08, P > 0.05; 5 trials) (I2 = 11%). Serenoa repens was not superior to finasteride (MD −0.05 nocturnal visits, 95% CI −0.49 to 0.39, P > 0.05; 1 trial), or to tamsulosin (per cent improvement) (RR) (risk ratio) 0.91, 95% CI 0.66 to 1.27, P > 0.05; 1 trial).
Comparing peak urine flow, Serenoa repens was not superior to placebo at trial endpoint (WMD 1.02 mL/s, 95% CI −0.14 to 2.19, P > 0.05; 10 trials), or by comparing mean change (WMD 0.31 mL/s, 95% CI −0.56 to 1.17, P > 0.05; 2 trials).
Comparing prostate size at endpoint, there was no significant difference between Serenoa repens and placebo (MD −1.05 cc, 95% CI −8.84 to 6.75, P > 0.05; 2 trials), or by comparing mean change (MD −1.22 cc, 95% CI −3.91 to 1.47, P > 0.05; 1 trial).
Serenoa repens was not more effective than placebo for treatment of urinary symptoms consistent with BPH.