Safety and Efficacy of a Combination of Saw Palmetto (Sabal serrulata) and Stinging Nettle (Urtica dioica) for the Treatment of Urinary Tract Disorders

  • Benign Prostatic Hyperplasia (BPH)
  • Saw Palmetto (Sabal serrulata)
  • Stinging Nettle (Urtica dioica)
  • Date: August 15, 2005 HC# 070151-286

    Re: Safety and Efficacy of a Combination of Saw Palmetto (Sabal serrulata) and Stinging Nettle (Urtica dioica) for the Treatment of Urinary Tract Disorders

    Lopatkin N, Sivkov A, Walther C, et al. 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 Journal of Urology. 2005 Jun;23(2):139-146.

    Lower urinary tract symptoms (LUTS), such as incomplete emptying of the bladder and decreased urinary, are a common occurrence in older men and are primarily caused by benign prostatic hyperplasia (BPH). Although the pathophysiological mechanisms responsible for BPH are not clear, the main etiological factors are sexual steroids, and alpha-1-adrenoreceptor antagonists are commonly used to manage BPH. Alternatively, in Europe, fruit extracts of saw palmetto (Sabal serrulata or S. repens) and the root extracts of stinging nettle (Urtica dioica) are popular treatments. The clinical efficacy of both plant extracts in improving urinary tract symptoms related to BPH has been shown. A combination of both extracts, because of their synergistic effects, shows promise as an effective treatment of BPH. The objective of this study was to investigate the safety and efficacy of a combination of saw palmetto and stinging nettle extracts in alleviating LUTS in elderly men with BPH.

    Elderly men (age equal to or greater than 50 years) with LUTS caused by stage I or II BPH were enrolled in this prospective, double-blind, multicenter, randomized clinical trial. Two hundred fifty-seven subjects were randomly assigned to 1 of 2 groups. The experimental group (n = 129) received daily a 2 capsules of PRO 160/120 (Dr. Willmar Schwabe Pharmaceuticals, Karlsruhe, Germany), which consisted of a combination of 160 mg sabal fruit extract (WS 1473) and 120 mg urtica root extract (WS 1031), and the control group (n = 128) received placebo for 24 weeks. 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. The primary outcome measure of efficacy was the subject’s perception of LUTS, which was assessed with the use of the International Prostate Symptom Score (I-PSS) self-rating questionnaire; secondary measures included urinary output, duration of urination and flow increase, residual urinary volume, prostate size, and quality of life. Safety was evaluated on the basis of a physical examination.

    Outcome measures were not significantly different (P > 0.05) between groups at baseline. After 24 weeks of treatment, the I-PSS score decreased significantly (P = 0.003) more in the PRO 160/120 group than in the placebo group: decreases of 6 (35.3%) and 4 points (23.5%), respectively, from a median score of 17 points in both groups. The largest improvements in irritative symptoms in the PRO 160/120 group were observed for urgency, nycturia (nighttime urination), intermittency, and hesitancy. A change in the degree of symptom severity, from a more severe to a milder group, occurred in 55 of 127 subjects (43.3%) in the PRO 160/120 group compared with 36 of 122 subjects (29.5%) in the placebo group. The difference in efficacy between the 2 groups was "slightly more pronounced" in the subjects with moderate LUTS than in those with severe LUTS at baseline. The maximum urinary flow rate increased from baseline in both groups, but the difference was not significantly different between groups (P = 0.59); the rate of improvement was greatest in both groups during the initial weeks of the double-blind phase. The tolerability of PRO 160/120 was comparable with that of the placebo; the most commonly reported symptoms were respiratory system disorders.

    In conclusion, "PRO 160/120 was clearly superior to the placebo for the amelioration of LUTS as measured by the I-PSS." The herbal preparation effectively reduced both obstructive and irritative LUTS of BPH in subjects with moderate or severe complaints at baseline. This finding agrees with those of other studies of PRO 160/120. Furthermore, treatment with PRO 160/120 was not associated with a greater risk of adverse effects than was treatment with placebo.

    —Brenda Milot, ELS

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