Clinical use of saw palmetto
- Robert B Saper, MD, MPH
Robert B Saper, MD, MPH
- Associate Professor of Family Medicine
- Boston University School of Medicine
Extracts of the fruit from saw palmetto (Serenoa repens), the American dwarf palm tree (picture 1), are commonly used to treat benign prostatic hypertrophy (BPH). The first evidence of saw palmetto use for urinary symptoms in men is from Egypt in the 15th century BC . Native Americans in Florida in the early 1700s utilized saw palmetto to treat prostate gland swelling and inflammation, testicular atrophy, and erectile dysfunction [2,3].
In the 1870s, eclectic medical practitioners used the plant for urologic conditions. Saw palmetto berries were officially listed in the United States Pharmacopoeia in the first half of the 20th century . Saw palmetto use is common in Europe and somewhat less popular in the United States .
A number of studies and meta-analyses have evaluated extracts of the saw palmetto berry for its safety and efficacy in the treatment of BPH; these are reviewed here. Detailed discussions of the treatment of BPH and the use of saw palmetto in the combination herbal product PC-SPES for the treatment of prostate cancer are discussed separately. (See "Secondary endocrine therapies for castration resistant prostate cancer" and "Medical treatment of benign prostatic hyperplasia", section on 'Herbal therapies'.)
MECHANISM OF ACTION
The saw palmetto berry contains over 100 known compounds. The active ingredients in saw palmetto appear to be contained in the purified lipid soluble extract of the saw palmetto berry. This has been found to contain 85 to 95 percent fatty acids (predominantly lauric, caprylic, and caproic), long-chain alcohols, and sterols (including beta-sitosterol, stigmasterol, cycloartenol, lupeol, lupenone, and methylcycloartenol) .
The exact mechanisms of action of saw palmetto are unknown . Proposed mechanisms include antiandrogenic effects [6,7]; inhibition of type 1 and type 2 isoenzymes of 5-alpha-reductase [8-10]; inhibition of growth factors such as the insulin-like growth factor-I ; relaxation of lower urinary tract smooth muscle through antagonism of muscarinic receptors ; antiinflammatory effects through inhibition of lipoxygenase, cyclooxygenase , and leukotrienes ; alteration of cholesterol metabolism; antiestrogenic effects; and a decrease in available sex hormone-binding globulin [6,15-18].
- Wilt TJ, Ishani A, Stark G, et al. Saw palmetto extracts for treatment of benign prostatic hyperplasia: a systematic review. JAMA 1998; 280:1604.
- Lowe FC, Ku JC. Phytotherapy in treatment of benign prostatic hyperplasia: a critical review. Urology 1996; 48:12.
- Bennett B, et al. Uses of saw palmetto (Serenoa repens, Arecaceae) in Florida. Econ Bot 1998; 52:381.
- DerMarderosian, A. Saw palmetto in the review of natural products. Facts and Comparisons, St. Louis 2000.
- Blumenthal M, Gruenwald J, Hall T, et al. German Commission E monographs: therapeutic monographs on medicinal plants, American Botanical Council, Austin 1998.
- Barrette EP. Use of saw palmetto extract for benign prostatic hyperplasia. Alternative Medicine Alert 1998; 1:1.
- Di Silverio F, Monti S, Sciarra A, et al. Effects of long-term treatment with Serenoa repens (Permixon) on the concentrations and regional distribution of androgens and epidermal growth factor in benign prostatic hyperplasia. Prostate 1998; 37:77.
- Marks LS, Hess DL, Dorey FJ, et al. Tissue effects of saw palmetto and finasteride: use of biopsy cores for in situ quantification of prostatic androgens. Urology 2001; 57:999.
- Goepel M, Hecker U, Krege S, et al. Saw palmetto extracts potently and noncompetitively inhibit human alpha1-adrenoceptors in vitro. Prostate 1999; 38:208.
- Strauch G, Perles P, Vergult G, et al. Comparison of finasteride (Proscar) and Serenoa repens (Permixon) in the inhibition of 5-alpha reductase in healthy male volunteers. Eur Urol 1994; 26:247.
- Wadsworth TL, Carroll JM, Mallinson RA, et al. Saw palmetto extract suppresses insulin-like growth factor-I signaling and induces stress-activated protein kinase/c-Jun N-terminal kinase phosphorylation in human prostate epithelial cells. Endocrinology 2004; 145:3205.
- Suzuki M, Oki T, Sugiyama T, et al. Muscarinic and alpha 1-adrenergic receptor binding characteristics of saw palmetto extract in rat lower urinary tract. Urology 2007; 69:1216.
- Levin RM, Das AK. A scientific basis for the therapeutic effects of Pygeum africanum and Serenoa repens. Urol Res 2000; 28:201.
- Paubert-Braquet M, Mencia Huerta JM, Cousse H, Braquet P. Effect of the lipidic lipidosterolic extract of Serenoa repens (Permixon) on the ionophore A23187-stimulated production of leukotriene B4 (LTB4) from human polymorphonuclear neutrophils. Prostaglandins Leukot Essent Fatty Acids 1997; 57:299.
- Dreikorn K, Richter R. Conservative nonhormonal treatment of patients with benign prostatic hyperplasia. In: New Developments in Biosciences 5, Prostatic Hyperplasia, Ackerman R, Schroeder FH (Eds), Walter de Gruyter and Co, Berlin 1989. p.109.
- Marwick C. Growing use of medicinal botanicals forces assessment by drug regulators. JAMA 1995; 273:607.
- McGuire E. Detrusor response to obstruction. Department of Health and Human Services, Bethesda, MD 1987.
- Di Silverio F, D'Eramo G, Lubrano C, et al. Evidence that Serenoa repens extract displays an antiestrogenic activity in prostatic tissue of benign prostatic hypertrophy patients. Eur Urol 1992; 21:309.
- Veltri RW, Marks LS, Miller MC, et al. Saw palmetto alters nuclear measurements reflecting DNA content in men with symptomatic BPH: evidence for a possible molecular mechanism. Urology 2002; 60:617.
- Tacklind J, Macdonald R, Rutks I, et al. Serenoa repens for benign prostatic hyperplasia. Cochrane Database Syst Rev 2012; 12:CD001423.
- Shoskes DA. Phytotherapy in chronic prostatitis. Urology 2002; 60:35.
- Kaplan SA, Volpe MA, Te AE. A prospective, 1-year trial using saw palmetto versus finasteride in the treatment of category III prostatitis/chronic pelvic pain syndrome. J Urol 2004; 171:284.
- Boon H, Westlake K, Stewart M, et al. Use of complementary/alternative medicine by men diagnosed with prostate cancer: prevalence and characteristics. Urology 2003; 62:849.
- Carraro JC, Raynaud JP, Koch G, et al. Comparison of phytotherapy (Permixon) with finasteride in the treatment of benign prostate hyperplasia: a randomized international study of 1,098 patients. Prostate 1996; 29:231.
- Gerber GS, Zagaja GP, Bales GT, et al. Saw palmetto (Serenoa repens) in men with lower urinary tract symptoms: effects on urodynamic parameters and voiding symptoms. Urology 1998; 51:1003.
- Braeckman J, et al. Efficacy and safety of the extract of Serenoa repens in the treatment of BPH: therapeutic equivalence between twice and once daily dosage forms. Phytotherapy Res 1997; 11:558.
- Braeckman J. The extract of Serenoa repens in the treatment of BPH: A multicenter open study. Curr Ther Res 1994; 55:776.
- Hamid S, Rojter S, Vierling J. Protracted cholestatic hepatitis after the use of prostata. Ann Intern Med 1997; 127:169.
- Wargo KA, Allman E, Ibrahim F. A possible case of saw palmetto-induced pancreatitis. South Med J 2010; 103:683.
- Jibrin I, Erinle A, Saidi A, Aliyu ZY. Saw palmetto-induced pancreatitis. South Med J 2006; 99:611.
- Cheema P, El-Mefty O, Jazieh AR. Intraoperative haemorrhage associated with the use of extract of Saw Palmetto herb: a case report and review of literature. J Intern Med 2001; 250:167.
- Newall CA, Anderson LA, Phillipson JD. Herbal medicines: A guide for health-care professionals, The Pharmaceutical Press, London 1996.
- Ang-Lee MK, Moss J, Yuan CS. Herbal medicines and perioperative care. JAMA 2001; 286:208.
- Gurley BJ, Gardner SF, Hubbard MA, et al. In vivo assessment of botanical supplementation on human cytochrome P450 phenotypes: Citrus aurantium, Echinacea purpurea, milk thistle, and saw palmetto. Clin Pharmacol Ther 2004; 76:428.
- Markowitz JS, Donovan JL, Devane CL, et al. Multiple doses of saw palmetto (Serenoa repens) did not alter cytochrome P450 2D6 and 3A4 activity in normal volunteers. Clin Pharmacol Ther 2003; 74:536.
- Feifer AH, Fleshner NE, Klotz L. Analytical accuracy and reliability of commonly used nutritional supplements in prostate disease. J Urol 2002; 168:150.
- Habib FK, Wyllie MG. Not all brands are created equal: a comparison of selected components of different brands of Serenoa repens extract. Prostate Cancer Prostatic Dis 2004; 7:195.
- Scaglione F, Lucini V, Pannacci M, et al. Comparison of the potency of different brands of Serenoa repens extract on 5alpha-reductase types I and II in prostatic co-cultured epithelial and fibroblast cells. Pharmacology 2008; 82:270.
- www.fda.gov/bbs/topcs/NEWS/2007/NEW01657.html (Accessed on October 09, 2007).