Saw Palmetto May Relieve BPH Symptoms

SHIZUOKA, Japan—A study at the University of Shizuoka showed saw palmetto extract (SPE) (as SABALSELECT® from Indena) may relieve irritation and obstructive symptoms in men suffering from benign prostatic hyperplasia (BPH). For four weeks, rats received a vehicle or SPE (0.06 to 60 mg/kg/d) orally, and the alpha 1-adrenergic muscarinic receptor binding in tissues were measured. SPE inhibited specific binding of [3H]prazosin and [N-methyl-3H]scopolamine methyl chloride (NMS) but not alpha, beta-methylene adenosine triphosphate [2,8-3H]tetrasodium salt in the rat prostate and bladder. The binding activity of SPE for muscarinic receptors was four times greater than that for alpha 1-adrenergic receptors. Scatchard analysis revealed that SPE significantly reduced the maximal number of binding sites (Bmax) for each radioligand in the prostate and bladder under in vitro condition. Repeated oral administration of SPE to rats brought about significant alteration in Bmax for prostatic [3H]prazosin binding and for bladder [3H]NMS binding. The alteration by SPE was selective to the receptors in the lower urinary tract. The study (Urology 2007;69(6):1216-20) concluded SPE exerts significant binding activity on autonomic receptors in the lower urinary tract under in vitro and in vivo conditions.