Effects of New Saw Palmetto Extract on Urological Parameters, Bladder Contractility and Muscarinic Receptors in Rats.

To clarify the efficacy of saw palmetto extract (SPE) (Lalilab Incorporated, NC, USA), a phytotherapeutic agent, in rats, its pharmacological effects on urodynamic parameters, bladder contractility and autonomic receptors were investigated. The urodynamic parameters, bladder contractile responses, and muscarinic receptors were measured by a cystometric method, organ-bath methods, and specific binding of [N-methyl-3H]scopolamine chloride (pH]NMS), respectively. Orally administered SPE (160 mg/kg) in rats significantly increased the micturition interval and decreased the frequency of micturition. SPE (0.1 mg/mL) significantly attenuated the contraction of isolated rat bladder induced by electrical field stimulation (EFS) and acetylcholine. SPE (20-600 jxg/mL) inhibited specific [3H]NMS binding in the rat bladder in a concentration dependent manner. These results indicate that SPE improves the detrusor overactivity in rats by antagonizing bladder muscarinic receptors. Therefore, SPE may be a potential beneficial agent for improving lower urinary tract symptoms in subjects wi1h lower urinary tract symptoms (LUTS). [ABSTRACT FROM AUTHOR]