AUSTIN, Texas, Jul 05, 2005 (BUSINESS WIRE) -- A new clinical trial supports the efficacy of an herbal combination in treating urinary tract difficulties in older men(a). The randomized, double-blind, placebo-controlled trial was conducted by researchers at the Institute of Urology in Moscow on 257 men. The herbal preparation combines saw palmetto and nettle root extracts, which have previously demonstrated beneficial effects on lower urinary tract symptoms (LUTS) due to the occurrence of benign prostatic hyperplasia (BPH), a non-cancerous swelling of the prostate and the resulting urinary difficulties that affect many men over 50.
Each capsule of the herbal combination consists of 160 mg of WS(R) 1473, an extract of saw palmetto berry, and 120 mg of WS(R) 1031, an extract of nettle root. The therapeutic efficacy of this combination has been confirmed in another recent trial(b). The product, called Prostagutt(R) forte (also known as PRO 160/120) in Germany, is manufactured under strict pharmaceutical standards by Willmar Schwabe Pharmaceuticals in Karlsruhe, Germany. It is imported into the United States and sold in health food stores as both ProstActive(R) Plus and Prostol(TM) by Nature's Way of Springville, Utah.
In the trial the subjects were randomized to receive either the herb combination (129 men) or placebo (128). In the unconventional design, all men in both groups received the placebo on a single-blind basis (i.e., the researchers knew that all men were receiving a placebo, but the men did not), followed by a 24-week double-blind period in which the patients received 2 capsules per day of the herb combination or the placebo. This double-blind period was then followed by a 24-week open-control period during which all patients were administered PRO 160/120. The trial design also included an optional 48-week follow-up period after the control period, creating a total observation period of 96 weeks.
To determine the treatment efficacy of the herbal combination, researchers recorded patient assessment of LUTS by using the International Prostate Symptom Score (I-PSS) test, a self-rating questionnaire, as well as a quality of life index. Objectively measurable outcome measures for efficacy include the maximum urinary flow rate, average urinary flow rate, urinary output, duration of urination and flow increase (all determined by means of an electronic uroflow recorder), residual urinary volume and size of prostate (both determined by ultrasound) as well as uroflow and sonographic parameters.
Using the I-PSS, patients treated with PRO 160/120 exhibited a substantially higher total score reduction after 24 weeks of double-blind treatment than patients of the placebo group (6 points vs. 4 points; P=0.003) with a tendency in the same direction after 16 weeks. This applied to men who experienced symptoms of urinary obstruction as well as to irritation and to patients who exhibited moderate or severe symptoms of BPH at the outset of the trial. Patients in the placebo group showed a marked improvement in LUTS (as measured by the I-PSS) after being switched to PRO 160/120 during the open control period (P=0.01, compared to those who had been treated with PRO 160/120 in the double-blind phase).
As with previous trials on saw palmetto and nettle root, the outcomes show a high degree of safety for the herb combination. The incidence of adverse effects for the men in the herb group was the same as those in taking the placebo. The tolerability of PRO 160/120 was comparable to the placebo.
"The clinical literature confirming the efficacy of saw palmetto is extensive and the evidence for nettle root's benefits keep growing," said Mark Blumenthal, founder and executive director of the nonprofit American Botanical Council, an independent herbal education organization. "Although the safety and efficacy of an herb or herbal product cannot be determined by the results of only one clinical trial, in the case of the saw palmetto and nettle root preparation, the combination of the literature on each ingredient, plus the new trials on the combined formulation, demonstrate that this phytomedicinal product is both safe and effective for treating many symptoms of BPH."
Don Brown, N.D., a naturopathic physician and author in Seattle, stated, "Evidence continues to grow for the proprietary herbal combination used in this trial." Dr. Brown, who has published extensively on herbs used for BPH, continued, "Not only has the combination of saw palmetto and nettle root been found to be safe and effective in long-term clinical trials in men with BPH, in some trials it has also been shown to be as effective as standard drug therapy, such as the widely used pharmaceutical finasteride (Proscar(R))."
Saw palmetto (Serenoa repens) preparations are made from the fruit of a small palm tree which is native to Florida and was a former staple food of Seminole Indians. Meta-analyses of 18 (c) and 21 (d) clinical trials have confirmed the safety and efficacy of saw palmetto preparations in treating symptoms of BPH.
Nettle root (Urtica dioica) is derived from the root of the nettle plant, also know as stinging nettle. Research on nettle root shows that, like saw palmetto, nettle root inhibits the enzyme involved with the conversion of testosterone to dihydrotestosterone, a principal mechanism in the development of BPH.
Both saw palmetto and stinging nettle root are approved by the Commission E of the German Federal Institute for Drugs and Medical Devices (analogous to the U.S. Food and Drug Administration) as nonprescriptions medications to treat symptoms of BPH(e).
About the American Botanical Council
The American Botanical Council is the nation's leading nonprofit organization addressing research and educational issues regarding herbs and medicinal plants. The 16-year-old organization occupies a 2.5 acre site in Austin, Texas, where it publishes HerbalGram, a peer-reviewed journal. ABC is also the publisher of The ABC Clinical Guide to Herbs, a continuing education and reference book, which contains extensive monographs on the safety and efficacy of 29 popular herbs, including saw palmetto. More details on saw palmetto, nettle root, and other herbal research on BPH is available on ABC's extensive website, www.herbalgram.org.
(a) Lopatkin N, Sivkov A, Walther C, Schlafke S, Medvedev A, Avdeichuk J, Golubev G, Melnik K, Elenberger N, Engelmann U. Long-term efficacy and safety of a combination of sabal and urtica extract for lower urinary tract symptoms: a placebo-controlled, double-blind, multicenter trial. World J Urol. 2005 Jun 1; (Epub ahead of print).
(b) Bondarenko B, Walther C, Funk P, Schlafke S, Engelmann U. Long-term efficacy and safety of PRO 160/120 (a combination of Sabal and Urtica extract) in patients with lower urinary tract symptoms (LUTS). Phytomedicine. 2003;10(Supp IV):53-55.
(c) Wilt TJ, Ishani A, Stark G, MacDonald R, Lau J, Mulrow C. Saw palmetto extracts for treatment of benign prostatic hyperplasia: a systematic review. JAMA. 1998; 280(18):1604-1609.
(d) Wilt T, Ishani A, Mac Donald R. Serenoa repens for benign prostatic hyperplasia. The Cochrane Library 2004, Issue 2.
(e) Blumenthal M, Busse WR, Goldberg A, Hall T, Riggins CW, Rister RS. (eds.). Klein S, Rister RS (trans.). The Complete German Commission E Monographs. Boston: Integrative Medicine Communications, 1998.