Enzyme activities in tissue of human benign prostatic hyperplasia after three months' treatment with the Sabal serrulata extract IDS 89 (Strogen) or placebo

Abstract

Objective: The mechanism of action of plant extracts used for the medical treatment of human benign prostatic hyperplasia (BPH) is still unknown. In this prospective, randomized, double-blind trial, we investigated the possible influence of the Sabal serrulata extract IDS 89 (Strogen) on epithelial and stromal enzyme activities of BPH tissue.

Methods: 18 patients with BPH were randomly assigned to receive 3 x 2 capsules Strogen uno (320 mg/capsule) (n = 8) or placebo (n = 10) daily for 3 months. The activity (Vmax and Km) of 5 alpha-reductase. 3 alpha-HSORred, 3 beta-HSORred, and creatine kinase was determined in mechanically separated epithelium and stroma of human BPH.

Results: The multivariate correlation analysis revealed a positive correlation between therapy and the following enzyme alterations: (1) In epithelium, the substrate affinity of the 5 alpha-reductase decreased slightly (increase of Km value). (2) In stroma, the Vmax value of the 3 alpha-HSORred increased statistically distinctly, leading to a moderate increase of Vmax/Km. (3) In stroma, the Vmax value of the 3 beta-HSORred increased moderately, but not statistically significant. (4) In stroma, the Vmax value of creatine kinase increased significantly, leading to a statistically distinct increase of Vmax/Km.

Conclusion: This double-blind, placebo-controlled clinical trial with the S. serrulata extract IDS 89 revealed significant biochemical changes at the cellular level of BPH tissue. However, the alterations are merely moderate, their biochemical causes and consequences regarding the pathophysiology of BPH rather uncertain. Therefore, more studies are needed before plant extracts like IDS 89 become valid candidates likewise synthetic substances already used for medical treatment of human BPH.