Study supports efficacy of Saw Palmetto - Stinging Nettle combo (Prostactive Plus, by Nature's Way)for Prostate Symptoms.

Article by Arnie Gitomer

Special Saw Palmetto and Stinging Nettle Root Combination as Effective as Tamsulosin for Prostate Problems

Englemann U, Walther C, Bondarenko B, Funk P, Schlafke S. Efficacy and safety of a combination of sabal and urtica extract in lower urinary tract symptoms. Arzneim Forsch/Drug Res. 2006;56(3):222-229.

More than 60% of males in the second half of life show evidence of benign prostatic hyperplasia (BPH) on histological examination. BPH may result in obstruction and irritation of the lower urinary tract with symptoms such as incomplete voiding, nighttime urination, and decreased urinary flow. Two types of conventional pharmaceutical drugs have demonstrated efficacy in the treatment of these lower urinary tract symptoms (LUTS), although the etiology of BPH has not been fully elucidated. The 5-alpha-reductase inhibitors, such as finasteride (Proscar®, Merck), block the conversion of testosterone to dihydrotestosterone, which is believed to be responsible for some of the swelling of the prostate. The selective alpha1-adrenoceptor antagonists block post-synaptic alpha1-adrenergic receptors, resulting in relaxation of smooth muscle in the bladder neck and prostatic urethra. Drugs that act selectively on specific alpha-1 subtypes cause fewer unwanted side effects (e.g., sexual dysfunction) than 5-AR inhibitors.

In placebo-controlled studies, the selective alpha1A- adrenoreceptor antagonist tamsulosin (Flomax®, Boehringer-Ingelheim), has been shown to effectively reduce subjective LUTS symptoms within 2 weeks of initiating treatment. Improvement in peak urinary flow rate and residual urinary volume reached statistical significance after 4 weeks of treatment and reached maximum benefit after 12-14 weeks.

Plant extracts are also extensively used in many European countries in the management of BPH and they are becoming more popular in the United States. Saw palmetto (Serenoa repens) fruit (berry) extract and stinging nettle (Urtica dioica) root extract are the most commonly used herbal preparations in Germany, where 61.6% of men with LUTS are treated with plant extracts. In randomized, double-blind clinical trials, both of these extracts have demonstrated effectiveness in treating LUTS symptoms. (See HC 120133.253) A product that combines both extracts — PRO 160/120 (a fixed combination of 160 mg saw palmetto fruit extract, WS® 1473, and 120 mg stinging nettle root extract, WS® 1031 (both made by Dr. Willmar Schwabe GmbH & Co; Karlsruhe, Germany.) — has been shown in published clinical trials to improve peak urinary flow and improve subjective symptom scores on the International Prostate Symptom Score (IPSS) better than placebo and comparable to the drug finasteride.1 The IPSS is a self -rating questionnaire regarding lower urinary tract symptoms, including frequency, urgency, nocturia, weak stream and incomplete emptying.

In the current study, researchers compared the efficacy and tolerability of PRO 160/120 to tamsulosin in patients with LUTS. The study was a prospective, randomized, double-blind, double-dummy, multicenter trial that utilized PRO 160/120. Tamsulosin in 0.4 mg slow-release capsules was purchased from the domestic market. (In a double-dummy design, both treatment groups receive an active treatment as well as a placebo, as explained below.)

The trial enrolled 149 subjects who were recruited from outpatients in 23 private urological practices and outpatient clinics in Germany. Study subjects were suffering from BPH not requiring surgery. Inclusion criteria included age greater than/equal to 50 years, maximum urinary flow rate less than/equal to 12 ml/s at a urinary volume greater than/equal to 150 ml, and initial IPSS total score greater than/equal to 13. During a 2-week placebo run-in phase, 140 subjects were randomized to receive either 1 capsule/day 2 times daily of PRO 160/120 plus 1 capsule tamsulosin placebo per day (n = 71) or 1 capsule per day