Saw Palmetto

 

Saw Palmetto Introduction

Serenoa repens is the plant commonly referred to as saw palmetto. It is a member of the Palmaceae, or Palm family. [1] The fruit of the saw palmetto is quite unique. It appears deep purple to almost black, and is an ovate (some 3 cm long), 1-seeded berry with a hard but fragile pericarp that covers a pale brown, spongy pulp. [2] These berries are the part of the plant used for various medicinal applications. Preparations of saw palmetto are generally characterized as tasting sweet and ‘soapy.’

Saw palmetto is native to the southern United States, growing from South Carolina to Florida, and parts of southern California as well. [3] It is also cultivated on a mass scale in Mexico.

The main constituents in saw palmetto are the lipid-soluble compounds. The purified fat-soluble extract is considered the most medicinally active component, and contains between 85 and 95% fatty acids and sterols. The fruity-smelling oil contains both saturated and unsaturated fatty acids, and sterols. About 63% of this oil is composed of free fatty acids including; capric, caprylic, caproic, lauric, palmitic, and oleic acids. Beta-sitosterol and its glucoside are also important components. Saw palmetto contains carotenes, lipase, tannins, and sugars, as well. [4-6]

Pharmacologic activity of saw palmetto is primarily attributed to inhibition of the intraprostatic conversion of testosterone to dihydrotestosterone (DHT); via blocking 5-alpha reductase, inhibition of its intracellular binding and transport, and contraction of epithelial cells. [7, 8] However, more recent research has suggested additional mechanisms of action, including increased molecular markers involved in the apoptotic process, i.e. the Bax-to-Bcl-2 expression ratio and caspase-3 activity. [9]

A six month study of treatment with a saw palmetto herbal blend appeared to alter the DNA chromatin structure and organization in prostate epithelial cells, suggesting a possible molecular basis for tissue changes and therapeutic effect of the compound. [10] Other mechanisms of action may include an anti-inflammatory effect, and an anti-proliferative influence through the inhibition of growth factors. [11]

Medicinal actions ascribed to saw palmetto include; anti-androgenic, anti-exudative, anti-inflammatory, endocrine agent, and spasmolytic. [5, 12] Traditionally, it has been used for respiratory complaints (especially if accompanied by chronic catarrh), genitourinary complaints (such as to reduce irritation), prostatic and uterine hypertrophy, atrophy of the breasts, inflammation or atrophy of the ovaries and testes, and as an aphrodisiac. Saw palmetto was considered to be a tissue building plant. [13, 14]

Saw Palmetto Uses

The main application of saw palmetto is for the treatment of lower urinary tracts symptoms (LUTS) associated with benign prostatic hyperplasia (BPH), a common disorder in elderly men. Over the years, there have been numerous trials with conflicting results; some showing no effect and some showing profound effects. [15-18] A review of clinical trials published in 2004 focused on trials that examined the benefit to risk ratio of lipido- sterolic extracts of S. repens in the treatment of BPH. [19] Researchers found that S. repens extract significantly reduces the symptoms of BPH, increases urinary flow, improves the quality of life, and is generally well tolerated.

A meta-analysis conducted of 14 randomized clinical trials and three open-label trials involving the saw palmetto extract, Permixon, for treating men with BPH also showed a significant improvement in peak flow rate and reduction in nocturia above placebo; a 5-point reduction in the International Prostate Symptom Score (IPSS) was also noted. [20]

Furthermore, a review published in American Family Physician in 2003 summarized that saw palmetto was comparable in efficacy to finasteride, the conventional therapy for BPH, but it is better tolerated and far less expensive. [21] An updated Cochrane review in 2002 had a similar conclusion stating that S. repens provides mild to moderate improvement in urinary symptoms and flow measures, produces similar improvement compared to finasteride, and is associated with fewer adverse treatment events. [22]

Saw palmetto may also be of benefit in the treatment of patients undergoing transurethral resection of prostate (TURP). A study of lipo-sterolic extract of Serenoa repens (Permixon) was conducted by Italian researchers in 2004 to determine whether pre-treatments would significantly reduce bleeding that occurs with this surgical procedure. [23] 108 patients were randomized into the experimental group or the control.

The pretreatment consisted of 320 milligrams per day of Permixon for 8 weeks prior to the TURP procedure. The results showed that perioperative bleeding was significantly lower in the experimental group than individuals in the control category (respectively 124 vs 287 milliliters); paralleled with a remarkable decrease for need of transfusion. The researchers also discovered that the duration of postoperative catheterization and hematological parameters in the experimental group (red cells 4.5 vs 4 million, hemoglobin 13.4 vs 11.9 g, hematocrit 40% vs 35%) were significantly lower when compared to control.

Saw palmetto has also demonstrated effectiveness in treating androgenetic alopecia (AGA). AGA has been shown to be responsive to drugs and agents used to treat BPH; the authors theorized that botanicals used to treat BPH may also address this disorder. A double-blind, placebo-controlled pilot study of men with mild to moderate AGA showed that 60% of the study subjects dosed with a lipo-sterolic S. repens extract and beta-sitosterol were rated as improved at the final visit. [24]

Finally, Saw palmetto may be useful for patients with non-infectious prostatitis, edema, and inflammatory disorders. [5]

Saw Palmetto Dosages

A lipo-sterolic saw palmetto extract at a dose of 160mg twice daily is the dose most commonly employed in study. The extract Permixon received the greatest attention; this particular extract is an 8:1 - 10:1 concentrate of dried, saw palmetto berries. A high ethanolic tincture of a strength consisting of 1:2, could also provide an effective dose if given in amounts ranging from 2 to 4ml daily. [5]

A six month double-blind, randomized, parallel-group study compared two dose regimens of Libeprosta, the lipidosterolic extract of Serenoa repens, in 100 male outpatients with lower urinary tract symptoms suggestive of BPH. [25] The results showed that both doses (80 mg twice daily and 80 mg three times daily) resulted in no significant differences in efficacy, showing improvements of statistical significance after 3 months. As well, no treatment-related complications or clinical adverse events occurred in either dose regimen.

A study in 2004 examined the variation in 14 different commercial brands of Serenoa repens extracts currently available. [26] The researchers discovered significantly different proportional content of free fatty acids, methyl and ethyl esters, long-chain esters, and glycerides; this finding suggests that the inconsistencies in nutrient content may impact the clinical efficacy and safety of such products. Additionally, researchers also suggested that only extracts with demonstrable pharmacological activity and proven clinical efficacy should be considered for the treatment of patients with benign prostatic hypertrophy.

Saw Palmetto Toxicities and Contraindications

There are no known drug interactions with saw palmetto, and reported side effects are quite rare. [21] High concentrations of S. repens have shown inhibition of sperm motility in vitro, at periods of 24 and 48 hours. [27] However, specific cases of gastrointestinal problems have been reported, including symptoms of nausea. [12]

Saw palmetto is contraindicated in pregnancy. [1]

References

1. Tilgner S. Herbal Medicine from the Heart of the Earth. Wise Acres Press, Inc. Creswell, OR, 1999:105.

2. Botanical Medicine Class Notes. Bastyr University, Kenmore, WA. 2002.

3. PDR for Herbal Medicines, 2nd ed. Medical Economics Company, Montvale, New Jersey 2000:665

4. Pizzorno JE, Murray MT (eds.) Textbook of Natural Medicine, 2nd ed. Vol I. Churchill Livingstone, Edinburgh, 1999:943-4

5. Mills S and Bone K. Principles and Practice of Phytotherapy. Churchill Livingstone, Edinburgh, UK 2000:523-533.

6. Lininger et al. Healthnotes: Clinical Essentials, Herb Monographs. Prima Publishing, Rocklin, CA, 2001

7. Marks LS et al. Tissue effects of saw palmetto and finasteride: use of biopsy cores for in situ quantification of prostatic androgens. Urology. 2001;57(5):999-1005.

8. Marks LS et al. Effects of a saw palmetto herbal blend in men with symptomatic benign prostatic hyperplasia. J Urol. 2000;163(5):1451-6.

9. Vela-Navarrete R et al. Serenoa repens treatment modifies bax/bcl-2 index expression and caspase-3 activity in prostatic tissue from patients with benign prostatic hyperplasia. J Urol. 2005;173(2):507-10.

10. Veltri RW et al. Saw palmetto alters nuclear measurements reflecting DNA content in men with symptomatic BPH: evidence for a possible molecular mechanism. Urology. 2002;60(4):617-22.

11. Buck AC. Is there a scientific basis for the therapeutic effects of serenoa repens in benign prostatic hyperplasia? Mechanisms of action. J Urol. 2004;172(5 Pt 1):1792-9.

12. Blumenthal M et al (eds.). The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. American Botanical Council, Austin, Texas, 1998:201

13. Grieve M. A Modern Herbal: The Medicinal, Culinary, Cosmetic and Economic Properties, Cultivation, and Folklore of Herbs, Grasses, Fungi Shrubs &Trees with Their Modern Scientific Uses, Vol. II. Dover Publications, Inc, New York, 1971:720

14. Felter HW and Lloyd JU. King’s American Dispensatory, 18th ed., 3rd revision, Vol. II. Eclectic Medical Publications, Portland, 1983:1750-2.

15. 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(1):284-8.

16. Pytel YA et al. Long-term clinical and biologic effects of the lipidosterolic extract of Serenoa repens in patients with symptomatic benign prostatic hyperplasia. Adv Ther. 2002;19(6):297-306.

17. Preuss HG et al. Randomized trial of a combination of natural products (cernitin, saw palmetto, B-sitosterol, vitamin E) on symptoms of benign prostatic hyperplasia (BPH). Int Urol Nephrol. 2001;33(2):217-25.

18. Gerber GS et al. Urology. Randomized, double-blind, placebo-controlled trial of saw palmetto in men with lower urinary tract symptoms. 2001;58(6):960-4; discussion 964-5.

19. Gerber GS, Fitzpatrick JM. The role of a lipido-sterolic extract of Serenoa repens in the management of lower urinary tract symptoms associated with benign prostatic hyperplasia. BJU Int. 2004;94(3):338-44.

20. Boyle P et al. Updated meta-analysis of clinical trials of Serenoa repens extract in the treatment of symptomatic benign prostatic hyperplasia. BJU Int. 2004;93(6):751-6.

21. Gordon AE, Shaughnessy AF. Saw palmetto for prostate disorders. Am Fam Physician. 2003;67(6):1281-3.

22. Wilt T, Ishani A, Mac Donald R. Serenoa repens for benign prostatic hyperplasia. Cochrane Database Syst Rev. 2002;(3):CD001423.

23. Pecoraro S et al. [Efficacy of pretreatment with Serenoa repens on bleeding associated with transurethral resection of prostate]. Minerva Urol Nefrol. 2004;56(1):73-8.

24. Prager N et al. A randomized, double-blind, placebo-controlled trial to determine the effectiveness of botanically derived inhibitors of 5-alpha-reductase in the treatment of androgenetic alopecia. J Altern Complement Med. 2002;8(2):143-52.

25. Giannakopoulos X et al. The lipidosterolic extract of Serenoa repens in the treatment of benign prostatic hyperplasia: a comparison of two dosage regimens. Adv Ther. 2002;19(6):285-96.

26. 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(3):195-200.

27. Ondrizek RR et al. Inhibition of human sperm motility by specific herbs used in alternative medicine. J Assist Reprod Genet. 1999;16(2):87-91.

 
 


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