Inhibition of 5 α-reductase and aromatase by PHL-00801 (Prostatonin®), a combination of PY102 (Pygeum africanum) and UR102 (Urtica dioica) extracts.

This study was undertaken to evaluate a possible effect of the extracts PY102 of Pygeum africanum (Hook), and UR 102 of Urtica dioica L. as well as their combination PHL-00801 (Prostatonin®) on the enzymes 5 α-reductase (5 α-RE) and aromatase (AR): Inhibition of 5 α-RE: Pygeum africanum extract PY 102, and Urtica dioica extract UR 102, inhibited the 5 α-RE activity in a concentration dependent manner. Whereas UR102 extract was only able to influence the enzyme activity at high concentrations (≥ 12mg/ml) and its ED(50) being calculated as 14.7mg/ml, the PY102 extract showed a much higher activity starting with low concentrations (0.1 mg/ml) its ED(50) being calculated as 0.78 mg/ml. When compared with the effects of UR 102, the combination of both extracts, PHL-00801 (Prostatonin®), led to a similar inhibition of the enzyme (ED(50) 14.15 mg/ml). Inhibition of AR: The PY 102 extract showed a concentration dependent and strong activity (ED(50) = 0.98 mg/ml). The activity of the UR 102 extract was also concentration dependent (ED(50) = 3.58 mg/ml). The combination of both extracts, PHL-00801 (Prostatonin®) showed a synergistic action and significantly (p = 0.05) increased the AR-inhibitory activity in concentrations as low as 0.1 mg/ml (ED(50) 0.24 mg/ml). These observations are an explanation for the beneficial effects of PHL-00801 (Prostatonin®) observed in the clinical studies on BPH.