Botanie en chemie
De zaagtandpalm groeit in de moerasachtige gebieden langs de zuidoostkust van de Verenigde Staten. De plant heeft een karakteristieke wortelstok, die aan een zijde uit de grond oprijst en een korte stam vormt waaruit groen-wittige, gelobde/gezaagde bladeren ontspruiten. De zaagtandpalm produceert donkerpaars tot zwarte, in groepen groeiende bessen die tussen oktober en december rijpen. Deze rijpe, gedeeltelijk gedroogde bessen vor-men het uitgangsmateriaal voor de bereiding van de medicinaal gebruikte extracten. De bessen zijn rijk aan vrije vetzuren (oliezuur, laurinezuur, myristinezuur, palmitinezuur, linolzuur, capronzuur, caprylzuur, capri-nezuur, stearinezuur en linoleenzuur) en hun esters (ethylesters en triglyceriden). Plantensterolen zoals β-sitosterol, stigmasterol en daucosterol worden ook als belangrijke inhoudsstoffen beschouwd. Verder zijn in de bessen nog polysacchariden, flavonoïden, vluchtige oliën en anthranilzuur geïdentificeerd.
Traditioneel gebruik
De indianen gebruikten de bessen van de zaagtandpalm al voor urogenitale aandoeningen. Zij schreven aan de bessen een positief effect toe op het functioneren van de testis en bij irritaties van het slijmvlies. De eerste kolo-nisten gebruikten sabal als veevoer en merkten dat hetvee hiervan een glan-zende vacht kreeg en dikker werd. Rond 1870 werd voor het eerst onderzoek ver-richt naar de medici-nale eigenschappen van sabal. Een zeer divers aantal effecten werd gerapporteerd, waaronder het sti-muleren van de eet-lust, het vergroten van de melkafgifte door borstklierweef-sel, het verminderen van menstruatieklachten en irrita-ties aan de baarmoeder en eierstokken alsmede het ver-lichten van klachten ten gevolge van prostaatvergroting en ontstekingen aan de penis. De bessen van de zaag-tandpalm werden in 1906 opgenomen als geneesmiddel in de United States Pharmacopoeia en in 1926 in de National Formulary. Deze officiële status werd sabal echter weer ontnomen omdat de actieve bestanddelen niet konden worden geïsoleerd en fytotherapeutica in het algemeen in onbruik raakten na de opkomst van synthetische geneesmiddelen [3]. De laatste jaren wordt echter een hernieuwde belangstelling voor het gebruik van sabal gezien en zijn ook meerdere klinische studies uitgevoerd.
Effectiviteit en veiligheid
De (gedeeltelijk) gedroogde sabalbessen, in hun geheel of in verpulverde vorm, worden tot commercieel ver-krijgbare fytotherapeutica verwerkt en in de vorm van theebereidingen, tincturen, capsules en droogextracten op de markt gebracht [4; 5]. Liposterolische olie-extracten - verkregen met n-hexaan, 90-96% alcohol of superkritische kooldioxide en gestandaardiseerd op een gehalte aan vrije vetzuren van 70-95% [4; 5] - zijn veel-vuldig klinisch getest op effectiviteit bij de behandeling van mictiestoornissen en milde tot matige klachten als gevolg van BPH.
In de meeste klinische studies werd een dagelijkse dose-ring van 320 mg extract (in een eenmalige dosis of tweemaal daags 160 mg) vergeleken met een placebo, in enkele gevallen ook met een actieve controle (onder andere met de 5-α reductaseremmer finasteride en selectieveα1-receptorblokkers zoals alfuzosine en tam-sulosine). Deze studies waren over het algemeen van korte duur, variërend van een tot drie maanden, maar soms ook langduriger (zes maanden tot twee jaar). Uit meta-analyses [6; 7; 8] blijkt dat behandeling met sabal ten opzichte van placebobehandeling leidt tot een alge-mene verbetering van de symptomen, zowel wanneer de plasklachten werden gekwantificeerd met de International Prostate Symptom Score (IPSS) als ook wanneer de (subjectieve) rapportage door patiënten en behandelend arts in ogenschouw werd genomen. Sabal gaf tevens een significante verbetering te zien van ver-schillende urodynamische parameters – maximale uri-nestroom, gemiddelde stroomsnelheid en rest-volume van de urine in de blaas – en het aantal keren dat ’s nachts geplast moest worden. In een aantal studies werd ook een gunstige invloed op de kwaliteit van leven waargenomen. Behandeling met sabal heeft echter geen invloed op de grootte van de prostaat. Ten opzichte van regulier toegepaste geneesmiddelen blijkt sabal vergelijkbaar in werkzaamheid.
Hoewel de effectiviteit van liposterolische olie-extracten van sabal ter verlichting van mictiestoornissen in een groot aantal klinische studies is aangetoond, is het exacte werkingsmechanisme nog niet eenduidig opgehelderd. Momenteel wordt echter vrij algemeen aangenomen dat sabalextracten op drie manieren de fysiologie van de lagere urinewegen beïnvloeden: door middel van een anti-androgene werking, een ontstekingsremmende activiteit en door een direct effect op de groei van het prostaatweefsel.
Wat betreft de anti-androgene werking is aangetoond dat sabal de omzetting remt van testosteron in dihydro-testosteron door het enzym 5-α reductase in de pro-staat. In dit opzicht vertoont sabal overeenkomst met regulier toegepaste geneesmiddelen voor BPH zoals finasteride. Het remmende effect op 5-α reductase is gerelateerd aan de aanwezigheid van vrije vetzuren in sabal - met name laurinezuur, linol(een)zuur en myristi-nezuur - en lijkt het gevolg van morfologische en bio-chemische veranderingen in prostaatcellen; vooral de waargenomen verstoring van de membraan rond de cel-kern en de daaruit voortvloeiende inactivatie van het hieraan gebonden enzym lijkt hierbij een rol te spelen. Behalve een remming van de 5-α reductase-activiteit, beïnvloedt sabal nog andere hormonale processen in de prostaat.
Ten slotte is voor sabalextracten aangetoond dat ze de groei van epitheelcellen in de prostaat verminderen. Deze groeiremming vindt enerzijds plaats door een inductie van apoptose (geprogrammeerde celdood). Anderzijds wordt de proliferatie van prostaatcellen onder invloed van groeihormonen geblokkeerd. Vooral de groeibevorderende werking van basic fibroblast growth factor wordt door sabal tenietgedaan, in mindere mate ook de werking van epidermal growth factor.
Saw palmetto (Serenoa repens, Serenoa serrulata) is used popularly in Europe to treat symptoms of enlarged prostate. Although it is not considered the standard of care in the United States, it is the most popular herbal treatment for this condition. More than two million American men use saw palmetto for enlarged prostate, and it is commonly recommended as an alternative treatment by the U.S. Food and Drug Administration (FDA).
Many studies report that saw palmetto may be as effective as the hormonal agent finasteride (Proscar®) and may cause fewer side effects when used to treat bladder problems. Most research has focused on the saw palmetto product Permixon®. However, results are still mixed, and further research is needed.
Saw palmetto has also been used for low sperm count, low sex drive, hair loss, bronchitis, diabetes, inflammation, migraine, and prostate cancer, although there is limited evidence supporting its effectiveness for these conditions.
Uses
These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
Enlarged prostate
Saw palmetto has been long been used to treat enlarged prostate. According to a report, more than two million American men use saw palmetto for enlarged prostate, and it is often recommended as an alternative therapy by the U.S. Food and Drug Administration (FDA). Many studies report that saw palmetto may be as effective as the hormonal agent finasteride (Proscar®) and may cause fewer side effects when used to treat bladder problems. Most studies used the saw palmetto product Permixon®. Although more recent research failed to find significant benefits of saw palmetto, the available evidence suggests that it may be an effective treatment for enlarged prostate.
A
Hair loss
Saw palmetto may block some hormonal effects and may be an effective treatment for hair loss, with benefits similar to the agent finasteride (Propecia®), when applied to the scalp. Early research suggests that saw palmetto may improve hair density, but evidence is limited at this time. Further research is needed before conclusions can be made.
C
Preparation for surgery (prostate surgery)
Saw palmetto may help the recovery process in patients undergoing prostate surgery. Early research suggests that saw palmetto may improve the effectiveness of surgery, as well as reduce bleeding and duration of catheter use. However, results are conflicting, and more research is needed in this area.
C
Prostate cancer
Saw palmetto is commonly used for many types of prostate problems, including prostate cancer. Research suggests that saw palmetto may block the growth of cancer cells. However, there is limited human research on the effectiveness of saw palmetto for this condition. Evidence is lacking in support of PC-SPES®, a discontinued product that contains saw palmetto, for prostate cancer. The U.S. Food and Drug Administration (FDA) has issued a warning not to use PC-SPES® because it may contain warfarin and alprazolam, which may cause bleeding.
C
Prostate inflammation
There is conflicting evidence on the use of saw palmetto in treating prostate inflammation. Although some studies report that saw palmetto may improve symptoms, obvious benefit over standard drugs is lacking. Much of the research has focused on saw palmetto as part of a combination therapy. Further research is needed to understand the potential effects of saw palmetto alone.
C
Urination
There is limited evidence on the use of saw palmetto to treat underactive bladder. Available studies are low-quality or use saw palmetto in combination with other therapies. More research is needed in this area.
C
*Key to grades:A: Strong scientific evidence for this use; B: Good scientific evidence for this use; C: Unclear scientific evidence for this use; D: Fair scientific evidence against this use (it may not work); F: Strong scientific evidence against this use (it likely does not work).
Tradition/Theory
The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious and should be evaluated by a qualified health care professional
Acne, asthma, athletic performance enhancement, bacterial infections, bladder inflammation, breast milk stimulant, breast augmentation, breast reduction, bronchitis, clear sinuses, cough, cystitis, diabetes, diarrhea, diuretic, dysentery, Epstein-Barr virus, hair growth (excess), high blood pressure, hormone imbalances (estrogen or testosterone), immune stimulation, impotence, indigestion, inflammation, laryngitis, menstrual pain, migraine headache, muscle or intestinal spasms, ovarian cysts, pain, pelvic congestive syndrome, pelvic inflammatory disease, polycystic ovarian syndrome, postnasal drip, reproductive organ problems, sedation, sexual dysfunction, sore throat, sperm production, testicular atrophy, upper respiratory tract infection, urethritis, urinary antiseptic, urinary tract disorders, uterine disorders, vaginal disorders.
Dosing
The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.
Adults (18 years and older)
Saw palmetto has been taken as sterol and fatty acid extracts (such as LSESR), berries (ground, dried, whole, or pulp), tincture, fluid extract, or tea. Teas prepared from saw palmetto berries may be ineffective because the purported active constituents are water-insoluble.
For enlarged prostate (benign prostatic hypertrophy), a range of 100-960 milligrams of sabal or Serenoa repens extract has been taken by mouth daily for up to 18 months. A dose of 320 milligrams of saw palmetto extract (e.g., Permixon®, Serendar, Talso®), in one dose or two divided doses (80-90% liposterolic content), by mouth daily for up to six months, has been taken in numerous studies. Dosing regimens of 160 milligrams of saw palmetto twice daily for eight weeks (PA109), nine weeks, and 12 weeks (Prostaserene®) have been taken by mouth. Reports suggest that 160 milligrams once daily by mouth may be as effective as twice daily by mouth. Libeprosta® has been taken as two 80 milligram tablets twice or three times daily by mouth. A dose of 640 milligrams of saw palmetto has also been taken by mouth daily for an unknown length of time. A dose of 640 milligrams of saw palmetto extract has been applied to the rectum once daily for 12 weeks.
In preparation for surgery, pretreatment with 320 milligrams of Serenoa repens (Permixon®) has been taken by mouth daily for at least eight weeks before surgery.
To treat prostate inflammation, 320 milligrams of prostamol (Sabal serrulata plant extract) has been taken by mouth. Also, 320 milligrams of Serenoa repens has been taken by mouth daily for eight weeks.
Children (younger than 18 years)
There is no proven safe or effective dose for saw palmetto in children.
Safety
The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.
Allergies
Few allergic symptoms have been reported with saw palmetto. A study of people taking the combination product PC-SPES® (no longer commercially available), which includes saw palmetto and seven other herbs, reports that three out of 70 people developed allergic reactions. In one case, the reaction included throat swelling and difficulty breathing.
Avoid in people who are allergic or sensitive to saw palmetto, any of its parts, or other members of the Arecaceae or Palmae family.
Side Effects and Warnings
Few severe side effects of saw palmetto are noted in the published scientific literature. A study found that there may be a lack of herb-drug interactions associated with saw palmetto. Overall, there appear to be few safety concerns with short-term use of saw palmetto. Saw palmetto appears to be well tolerated by most people for up to 3-5 years. LSESR, a particular extract of Serenoa repens, may be better tolerated, although this claim has not been confirmed.
The most common complaints involve the stomach and intestines, and include stomach pain, nausea, vomiting, bad breath, constipation, diarrhea, gas, heartburn, and indigestion. Stomach upset caused by saw palmetto may be reduced by taking it with food.
Some reports describe ulcers, liver damage, liver inflammation, and jaundice (yellowing of the skin), but the role of saw palmetto is not clear in these cases. Similarly, reports of headache, dizziness, insomnia, depression, chest pain, abnormal heart rhythm, heart attack, heart disease, heart failure, high or low blood pressure, respiratory tract problems (including breathing difficulties), and muscle pain have been reported but may not be clearly caused by saw palmetto.
Saw palmetto may also cause or induce bloody urine, breast tenderness or enlargement, changes in blood chemistry, eye problems, flu-like symptoms, genital or urinary problems, hot flashes, inflammation of the pancreas, low energy, menstruation, mouth or teeth problems, physical injury, sexual dysfunction (such as ejaculation problems, erectile dysfunction, impotence, or low sex drive), skeletal muscle breakdown, skin reactions, and testicular pain.
Use cautiously in people scheduled to undergo some surgeries or dental work, who have bleeding disorders, or who are taking drugs that may increase the risk of bleeding. Dosing adjustments may be necessary.
Use cautiously in people who have high blood pressure, or those taking drugs or herbs and supplements that may affect blood pressure.
Use cautiously in people who have liver disorders or those taking drugs for liver disorders.
Use cautiously in patients with hormone-sensitive conditions or in those taking hormonal agents, due to possible hormonal effects of saw palmetto.
Use cautiously in people who have stomach disorders.
Use cautiously in combination with agents that may affect hemoglobin levels. Saw palmetto may reduce levels of hemoglobin, hematocrit, red blood cells, and platelets.
Avoid saw palmetto in women who are or may potentially be pregnant, due to the risk of developmental problems in the baby and hormonal effects.
Avoid saw palmetto when breastfeeding, due to a lack of available information.
Avoid saw palmetto in children, due to a lack of available information.
Avoid in people who are allergic or sensitive to saw palmetto, any of its parts, or other members of the Arecaceae or Palmae family.
In theory, prostate-specific antigen (PSA) levels may be artificially lowered by saw palmetto, based on a proposed mechanism of action of saw palmetto (inhibition of 5-alpha-reductase). Therefore, there may be a delay in diagnosis of prostate cancer or interference with following PSA levels during treatment or monitoring in men with known prostate cancer.
The combination product PC-SPES®, which contains saw palmetto and seven other herbs, has been found to contain prescription drugs including warfarin, a blood thinner. The U.S. Food and Drug Administration (FDA) has issued a warning not to use PC-SPES® for this reason, and it is no longer commercially available.
Pregnancy and Breastfeeding
Due to limited safety data, possible hormonal activity, and the risk of developmental problems in the baby, saw palmetto extract is not recommended for women who are or may potentially be pregnant, or women who are breastfeeding. Many tinctures contain high levels of alcohol and should be avoided during pregnancy.
Interactions
Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.
Interactions with Drugs
Saw palmetto may increase the risk of bleeding when taken with drugs that increase the risk of bleeding. Some examples include aspirin, anticoagulants (blood thinners) such as warfarin (Coumadin®) or heparin, antiplatelet drugs such as clopidogrel (Plavix®), and nonsteroidal anti-inflammatory drugs such as ibuprofen (Motrin®, Advil®) or naproxen (Naprosyn®, Aleve®). Some batches of the discontinued combination herbal preparation PC-SPES®, which contains saw palmetto and seven other herbs, has been found to contain several medications including the blood thinner warfarin.
Saw palmetto may affect blood pressure. Caution is advised in people taking drugs that may affect blood pressure.
Early research found that saw palmetto lacks effect on cytochrome P450 1A2, 3A4, 2E1, or 2D6 activity.
Saw palmetto may also interact with agents that may affect hemoglobin levels, agents that may affect the immune system, agents that may affect the liver, agents that may lower seizure threshold, agents that may regulate heart rate, agents that may treat genitourinary tract disorders, agents that may treat impotence, agents that may treat stomach disorders, antibiotics, anticancer agents, anti-inflammatories, disulfiram (Antabuse®), and hormonal agents (such as androgens or antiandrogens).
Interactions with Herbs and Dietary Supplements
Saw palmetto may increase the risk of bleeding when taken with herbs and supplements that are believed to increase the risk of bleeding. Multiple cases of bleeding have been reported with the use of Ginkgo biloba, and fewer cases with garlic. Numerous other agents may theoretically increase the risk of bleeding, although this has not been proven in most cases.
Saw palmetto may affect blood pressure. Caution is advised in people taking herbs or supplements that affect blood pressure.
Early research found that saw palmetto lacks effect on cytochrome P450 1A2, 3A4, 2E1, or 2D6 activity.
Tannins in saw palmetto may prevent iron absorption.
Saw palmetto may also interact with antibacterials, anticancer herbs and supplements, anti-inflammatories, cat's claw, echinacea, herbs and supplements that may affect hemoglobin levels, herbs and supplements that may affect the immune system, herbs and supplements that may lower seizure threshold, herbs and supplements that may regulate heart rate, herbs and supplements that may treat genitourinary tract disorders, herbs and supplements that may treat impotence, herbs and supplements that may affect the liver, herbs and supplements that may treat stomach disorders, hormonal herbs and supplements (such as androgens, antiandrogens, or phytoestrogens), Pinus pinaster, and Urtica dioica.
This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).
References
Anceschi R, Bisi M, Ghidini N, et al. Serenoa repens (Permixon(R)) reduces intra- and postoperative complications of surgical treatments of benign prostatic hyperplasia. Minerva Urol.Nefrol. 2010;62(3):219-223. View Abstract
Barry MJ, Meleth S, Lee JY, et al. Effect of increasing doses of saw palmetto extract on lower urinary tract symptoms: a randomized trial. JAMA 9-28-2011;306(12):1344-1351. View Abstract
Bercovich E and Saccomanni M. Analysis of the results obtained with a new phytotherapeutic association for LUTS versus control. [corrected]. Urologia. 2010;77(3):180-186. View Abstract
Bertaccini A, Giampaoli M, Cividini R, et al. Observational database serenoa repens (DOSSER): overview, analysis and results. A multicentric SIUrO (Italian Society of Oncological Urology) project. Arch.Ital.Urol.Androl 2012;84(3):117-122. View Abstract
Giulianelli R, Pecoraro S, Sepe G, et al. Multicentre study on the efficacy and tolerability of an extract of Serenoa repens in patients with chronic benign prostate conditions associated with inflammation. Arch.Ital.Urol.Androl 2012;84(2):94-98. View Abstract
Kul'chavenia EV, Breusov AA, Brizhatiuk EV, et al. [Approaches to raising efficacy of treatment of patients with chronic prostatitis associated with intracellular infections]. Urologiia. 2010;(6):55-58. View Abstract
Lapi F, Gallo E, Giocaliere E, et al. Acute liver damage due to Serenoa repens: a case report. Br.J.Clin.Pharmacol. 2010;69(5):558-560. View Abstract
Lee JY, Foster HE, McVary KT, et al. Recruitment of participants to a clinical trial of botanical therapy for benign prostatic hyperplasia. J.Altern.Complement Med. 2011;17(5):469-472. View Abstract
MacDonald R, Tacklind JW, Rutks I, et al. Serenoa repens monotherapy for benign prostatic hyperplasia (BPH): an updated Cochrane systematic review. BJU.Int. 2012;109(12):1756-1761. View Abstract
Mantovani F. Serenoa repens in benign prostatic hypertrophy: analysis of 2 Italian studies. Minerva Urol.Nefrol. 2010;62(4):335-340. View Abstract
Miroddi M, Carni A, Mannucci C, et al. Hot flashes in a young girl: a wake-up call concerning Serenoa repens use in children. Pediatrics 2012;130(5):e1374-e1376. View Abstract
Morgia G, Mucciardi G, Gali A, et al. Treatment of chronic prostatitis/chronic pelvic pain syndrome category IIIA with Serenoa repens plus selenium and lycopene (Profluss) versus S. repens alone: an Italian randomized multicenter-controlled study. Urol.Int. 2010;84(4):400-406. View Abstract
Scaglione F, Lucini V, Pannacci M, et al. Comparison of the potency of 10 different brands of Serenoa repens extracts. Eur.Rev.Med.Pharmacol.Sci. 2012;16(5):569-574. View Abstract
Villanueva S and Gonzalez J. Coagulopathy induced by saw palmetto: a case report. Bol.Asoc.Med.P.R. 2009;101(3):48-50. View Abstract
Wargo KA, Allman E, and Ibrahim F. A possible case of saw palmetto-induced pancreatitis. South.Med.J. 2010;103(7):683-685. View Abstract
Weblinks Serenoa repens
http://www.nlm.nih.gov/medlineplus/druginfo/natural/patient-sawpalmetto.html
http://www.stevenfoster.com/education/monograph/sawpalmetto.html
Referenties over Serenoa: integrale wetenschappelijke artikels
American palm ethnomedicine: a meta-analysis.Sosnowska J, Balslev H.J Ethnobiol Ethnomed. 2009 Dec 24;5:43. Review.
Serenoa Repens: Does It have Any Role in the Management of Androgenetic Alopecia?Murugusundram S.J Cutan Aesthet Surg. 2009 Jan;2(1):31-2.
An open label, dose response study to determine the effect of a dietary supplement on dihydrotestosterone, testosterone and estradiol levels in healthy males.Angwafor F 3rd, Anderson ML.J Int Soc Sports Nutr. 2008 Aug 12;5:12.
A detailed safety assessment of a saw palmetto extract.Avins AL, Bent S, Staccone S, Badua E, Padula A, Goldberg H, Neuhaus J, Hudes E, Shinohara K, Kane C.Complement Ther Med. 2008 Jun;16(3):147-54. Epub 2008 Feb 20.
Analysis of the interactions of botanical extract combinations against the viability of prostate cancer cell lines.Adams LS, Seeram NP, Hardy ML, Carpenter C, Heber D.Evid Based Complement Alternat Med. 2006 Mar;3(1):117-24.
A double-blind trial of an extract of the plant Serenoa repens in benign prostatic hyperplasia.Champault G, Patel JC, Bonnard AMBr J Clin Pharmacol. 1984 Sep;18(3):461-2. No abstract available.