Isolation and Pharmacological Characterization of Fatty Acids from Saw Palmetto Extract

Abstract

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 5a-reductase, antiandrogenic effects, anti-proliferative effects, and anti-inflammatory effects. Previously, we showed that SPE bound actively to a1-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 a1-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 5a-reductase, possibly leading to therapeutic effects against benign prostatic hyperplasia and related lower urinary-tract symptoms.

Modern extraction techniques and their impact on the pharmacological profile of Serenoa repens extracts for the treatment of lower urinary tract symptoms

“…Consistent with these results, Raynaud et al reported that palmitic acid was inactive in the inhibition of 5α-reductase [25]. The inhibitory effect on 5α-reductase activity by each fatty acid was roughly similar to their affinity for pharmacologically relevant receptors [26,27]. In a recent research, the effect on rat prostate gland contractility of this extract was evaluated after fractioning.…”

Fatty Acid and Phytosterol Content of Commercial Saw Palmetto Supplements

“…Several studies suggest that the fatty acids in saw palmetto extracts are responsible for its ability to inhibit 5α-reductase [21,22,23,24,25,26], but which fatty acid(s) is/are responsible for the inhibition varies. Some research suggests that saw palmetto phytosterols (β-sitosterol, campesterol, stigmasterol), inhibit 5α-reductase, prostate cancer cell/tumor growth, and/or BPH symptoms [27,28,29,30,31]; however, these phytosterols are not unique to saw palmetto extracts [32].…”

An overview of herbal alternatives in androgenetic alopecia

“…It is extracted from palm tree berries belonging to the Arecaceae family inherent to the West Indies, Atlantic coast of North America (from South Carolina to Florida). The extract or oil obtained from the berries of saw palmetto is found to be rich in fatty acids (85%‐90%), other constituents include sterols rich in carotenoids, lipases, tannin, sugars and beta sitosterol, anthranilic acid, capric acid, caproic acid, caprylic acid, ‐carotene, ferulic acid, mannitol, ‐sitosterol, ‐sitosterol‐ d ‐glucoside, linoleic acid, myristic acid, lauric acid, oleic acid, palmitic acid, 1‐monolaurin, and 1‐monomyristin …”