Isolation and pharmacological characterization of fatty acids from saw palmetto extract.
Saw palmetto extract (SPE) has been widely used for the treatment of lower urinary-tract symptoms secondary to benign prostatic hyperplasia. The mechanisms of pharmacological effects of SPE include the inhibition of 5alpha-reductase, anti-androgenic effects, anti-proliferative effects, and anti-inflammatory effects. Previously, we showed that SPE bound actively to alpha(1)-adrenergic, muscarinic and 1,4-dihydropyridine calcium channel (1,4-DHP) receptors in the prostate and bladder of rats, whereas its active constituents have not been fully clarified. The present investigation is aimed to identify the main active components contained in hexane and diethyl ether extracts of SPE with the use of column chromatography and preparative HPLC. Based on the binding activity with alpha(1)-adrenergic, muscarinic, and 1,4-DHP receptors, both isolated oleic and lauric acids were deduced to be active components. Authentic samples of oleic and lauric acids also exhibited similar binding activities to these receptors as the fatty acids isolated from SPE, consistent with our findings. In addition, oleic and lauric acids inhibited 5alpha-reductase, possibly leading to therapeutic effects against benign prostatic hyperplasia and related lower urinary-tract symptoms.
Department of Pharmacokinetics and Pharmacodynamics, and Global Center of Excellence Program, School of Pharmaceutical Sciences, University of Shizuoka, Suruga, Shizuoka 422-8526, Japan.
Masayuki
M
Abe
Yoshihiko
Y
Ito
Asahi
A
Suzuki
Satomi
S
Onoue
Hiroshi
H
Noguchi
Shizuo
S
Yamada
D000818:Animals; D015220:Calcium Channels / Q000378:metabolism; D042944:Cholestenone 5 alpha-Reductase / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D004095:Dihydropyridines / Q000378:metabolism; D005227:Fatty Acids / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology* / Q000627:therapeutic use; D008297:Male; D010936:Plant Extracts / Q000737:chemistry*; D011470:Prostatic Hyperplasia / Q000188:drug therapy / Q000378:metabolism; D051381:Rats; D018340:Receptors, Adrenergic, alpha-1 / Q000378:metabolism; D011976:Receptors, Muscarinic / Q000378:metabolism; D028024:Serenoa; D014570:Urologic Diseases / Q000188:drug therapy / Q000378:metabolism
D015220:Calcium Channels; D004095:Dihydropyridines; D005227:Fatty Acids; D010936:Plant Extracts; D018340:Receptors, Adrenergic, alpha-1; D011976:Receptors, Muscarinic; C038806:1,4-dihydropyridine; D042944:Cholestenone 5 alpha-Reductase; C040972:saw palmetto extract