Comparison of the potency of 10 different brands of Serenoa repens extracts

BACKGROUND: The extract of Serenoa repens is the phytopharmaceutical product most often used for the treatment of urological symptoms associated with benign prostatic hyperplasia (BPH). Several extracts are commercially available but extraction processes vary between manufacturers and thus not all these products are equivalent in terms of active ingredient content and composition of preparations. AIM: As there is a paucity of comparative studies, we compared the activity of different extracts of Serenoa repens widely available on the world market. MATERIALS AND METHODS: Beltrax Uno, Permicaps, Permixon, Prostadyn, Prostagutt, Prostamen, Prostamol Uno, ProstaX, Urocaps and Urogutt were assayed for 5-alpha-reductase activity on 10 day fibroblasts and epithelial cells cocultures. Human fibroblast growth factor (hFGF)-induced-proliferation inhibition was also assayed. RESULTS: As to extract activity, differences were observed between the tested extracts, but all were able to inhibit 5-a-reductase types I and II isoenzymes (5alphaR-I and 5alphaR-II) as well as fibroblast proliferation. CONCLUSIONS: Extract potency differs between products and so does proliferation inhibition potency. Quantitative and qualitative variations in the active ingredient are likely to account for these differences.