A detailed safety assessment of a saw palmetto extract.
BACKGROUND: Saw palmetto is commonly used by men for lower-urinary tract symptoms. Despite its widespread use, very little is known about the potential toxicity of this dietary supplement. METHODS: The Saw palmetto for Treatment of Enlarged Prostates (STEP) study was a randomized clinical trial performed among 225 men with moderate-to-severe symptoms of benign prostatic hyperplasia, comparing a standardized extract of the saw palmetto berry (160 mg twice daily) with a placebo over a 1-year period. As part of this study, detailed data were collected on serious and non-serious adverse events, sexual functioning, and laboratory tests of blood and urine. Between-group differences were assessed with mixed-effects regression models. RESULTS: There were no significant differences observed between the saw palmetto and placebo-allocated participants in the risk of suffering at least one serious adverse event (5.4% vs. 9.7%, respectively; p=0.31) or non-serious symptomatic adverse event (34.8% vs. 30.1%, p=0.48). There were few significant between-group differences in sexual functioning or for most laboratory analyses, with only small differences observed in changes over time in total bilirubin (p=0.001), potassium (p=0.03), and the incidence of glycosuria (0% in the saw palmetto group vs. 3.7% in the placebo group, p=0.05). CONCLUSIONS: Despite careful assessment, no evidence for serious toxicity of saw palmetto was observed in this clinical trial. Given the sample size and length of this study, however, these data do not rule out potential rare adverse effects associated with the use of saw palmetto.
Complement Ther Med. 2008 Jun;16(3):147-54
Saw Palmetto induces growth arrest and apoptosis of androgen-dependent prostate cancer LNCaP cells via inactivation of STAT 3 and androgen receptor signaling.
PC-SPES is an eight-herb mixture that has an activity against prostate cancer. Recently, we purified Saw Palmetto (Serenoa repens) from PC-SPES and found that Saw Palmetto induced growth arrest of prostate cancer LNCaP, DU145, and PC3 cells with ED50s of approximately 2.0, 2.6, and 3.3 microl/ml, respectively, as measured by mitochondrial-dependent conversion of the the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Saw Palmetto induced apoptosis of LNCaP cells in a time- and dose-dependent manner as measured by TUNEL assays. Also, Saw Palmetto increased the expression of p21waf1 and p53 protein in LNCaP cells. In addition, we found that Saw Palmetto down-regulated DHT- or IL-6-induced expression of prostate specific antigen in conjunction with down-regulation of the level of androgen receptor in the nucleus as measured by Western blot analysis. Moreover, Saw Palmetto down-regulated the IL-6-induced level of the phosphorylated form of STAT 3 in LNCaP cells. Furthermore, Saw Palmetto inhibited the growth of LNCaP cells present as tumor xenografts in BALB/c nude mice without adverse effect. These results indicate that Saw Palmetto might be useful for the treatment of individuals with prostate cancer.
Int J Oncol. 2007 Sep;31(3):593-600
Effects of dietary saw palmetto on the prostate of transgenic adenocarcinoma of the mouse prostate model (TRAMP).
BACKGROUND: Several of the proposed mechanisms for the actions of the liposterolic extract of saw palmetto (SPE) are exerted on known risk factors for prostate cancer (CaP). This study investigated whether SPE could prevent the progression of CaP in a transgenic adenocarcinoma of the mouse prostate (TRAMP) model. METHODS: Two different doses of SPE designed to deliver 50 mg/kg/day SPE and 300 mg/kg/day SPE were administered in a custom diet to TRAMP mice for 12 or 24 weeks. Body and organ weights were used to evaluate toxicity, and radioimmunoassay was used to measure plasma and tissue androgen levels to monitor effects of SPE on 5alpha reductase activity. Prostate tissues were evaluated histologically to determine the effect of treatment on tumor grade, cell proliferation, and apoptosis. RESULTS: Treatment with 300 mg/kg/day SPE from 4 to 24 weeks of age significantly reduced the concentration of 5alpha-dihydrotestosterone (DHT) in the prostate and resulted in a significant increase in apoptosis and significant decrease in pathological tumor grade and frank tumor incidence. CONCLUSIONS: Dietary supplementation with SPE may be effective in controlling CaP tumorigenesis. SPE suppression of prostatic DHT levels lends support to the hypothesis that inhibition of the enzyme 5alpha-reductase is a mechanism of action of this substance.
Prostate. 2007 May 1;67(6):661-73
A preliminary investigation of the enzymatic inhibition of 5alpha-reduction and growth of prostatic carcinoma cell line LNCap-FGC by natural astaxanthin and Saw Palmetto lipid extract in vitro.
Inhibition of 5alpha-reductase has been reported to decrease the symptoms of benign prostate hyperplasia (BPH) and possibly inhibit or help treat prostate cancer. Saw Palmetto berry lipid extract (SPLE) is reported to inhibit 5alpha-reductase and decrease the clinical symptoms of BPH. Epidemiologic studies report that carotenoids such as lycopene may inhibit prostate cancer. In this investigation the effect of the carotenoid astaxanthin, and SPLE were examined for their effect on 5alpha-reductase inhibition as well as the growth of prostatic carcinoma cells in vitro. These studies support patent #6,277,417 B1. The results show astaxanthin demonstrated 98% inhibition of 5alpha-reductase at 300 microg/mL in vitro. Alphastat, the combination of astaxanthin and SPLE, showed a 20% greater inhibition of 5alpha-reductase than SPLE alone n vitro. A nine day treatment of prostatic carcinoma cells with astaxanthin in vitro produced a 24% decrease in growth at 0.1 mcg/mL and a 38% decrease at 0.01 mcg/mL. SPLE showed a 34% decrease at 0.1 mcg/mL. CONCLUSIONS: Low levels of carotenoid astaxanthin inhibit 5alpha-reductase and decrease the growth of human prostatic cancer cells in vitro. Astaxanthin added to SPLE shows greater inhibition of 5alpha-reductase than SPLE alone in vitro.
J Herb Pharmacother. 2005;5(1):17-26
Saw palmetto for the treatment of men with lower urinary tract symptoms.
PURPOSE: A comprehensive review of the literature on the use of saw palmetto in men with lower urinary tract symptoms is provided. MATERIALS AND METHODS: A literature search of studies that have assessed the mechanism of action and clinical results of saw palmetto in men with benign prostatic hyperplasia was performed. RESULTS: A variety of potential mechanisms of action of saw palmetto have been demonstrated through in vitro studies, including 5-alpha reductase inhibition, adrenergic receptor antagonism and intraprostatic androgen receptor blockade. Clinical evidence of the relevance of these effects is largely unavailable. The use of saw palmetto in men with benign prostatic hyperplasia is safe with no recognized adverse effects. No effect on serum prostate specific antigen has been noted. Placebo controlled trials and meta-analyses have suggested that saw palmetto leads to subjective and objective improvement in men with lower urinary tract symptoms. However, most studies are significantly limited by methodological flaws, small patient numbers and brief treatment intervals. CONCLUSIONS: Evidence suggests that saw palmetto may have a significant effect on urinary flow rates and symptom scores compared to placebo in men with lower urinary tract symptoms. However, large scale, placebo controlled trials are needed to assess the efficacy of saw palmetto.
J Urol. 2000 May;163(5):1408-12
Phytotherapy for benign prostatic hyperplasia.
OBJECTIVE: To systematically review the existing evidence regarding the efficacy and safety of phytotherapeutic compounds used to treat men with symptomatic benign prostatic hyperplasia (BPH). DESIGN: Randomized trials were identified searching MEDLINE (1966--1997), EMBASE, Phytodok, the Cochrane Library, bibliographies of identified trials and review articles, and contact with relevant authors and drug companies. The studies were included if men had symptomatic benign prostatic hyperplasia, the intervention was a phytotherapeutic preparation alone or combined, a control group received placebo or other pharmacologic therapies for BPH, and the treatment duration was at least 30 days. Key data were extracted independently by two investigators. RESULTS: A total of 44 studies of six phytotherapeutic agents (Serenoa repens, Hypoxis rooperi, Secale cereale, Pygeum africanum, Urtica dioica, Curcubita pepo) met inclusion criteria and were reviewed. Many studies did not report results in a method allowing meta-analysis. Serenoa repens, extracted from the saw palmetto, is the most widely used phytotherapeutic agent for BPH. A total of 18 trials involving 2939 men were reviewed. Compared with men receiving placebo, men taking Serenoa repens reported greater improvement of urinary tract symptoms and flow measures. Serenoa repens decreased nocturia (weighted mean difference (WMD) = -0.76 times per evening; 95% CI = -1.22 to -0.32; n = 10 studies) and improved peak urine flow (WMD = 1.93 ml s(-1); 95% CI = 0.72 to 3.14, n = 8 studies). Men treated with Serenoa repens rated greater improvement of their urinary tract symptoms versus men taking placebo (risk ratio of improvement = 1.72; 95% CI = 1.21 to 2.44, n = 8 studies). Improvement in symptoms of BPH was comparable to men receiving the finasteride. Hypoxis rooperi (n = 4 studies, 519 men) was also demonstrated to be effective in improving symptom scores and flow measures compared with placebo. For the two studies reporting the International Prostate Symptom Score, the WMD was -4.9 IPSS points (95% CI = -6.3 to -3.5, n = 2 studies) and the WMD for peak urine flow was 3.91 ml s(-1) (95% CI = 0.91 to 6.90, n = 4 studies). Secale cereale (n = 4 studies, 444 men) was found to modestly improve overall urological symptoms. Pygeum africanum (n = 17 studies, 900 men) may be a useful treatment option for BPH. However, review of the literature has found inadequate reporting of outcomes which currently limit the ability to estimate its safety and efficacy. The studies involving Urtica dioica and Curcubita pepo are limited although these agents may be effective combined with other plant extracts such as Serenoa and Pygeum. Adverse events due to phytotherapies were reported to be generally mild and infrequent. CONCLUSIONS: Randomized studies of Serenoa repens, alone or in combination with other plant extracts, have provided the strongest evidence for efficacy and tolerability in treatment of BPH in comparison with other phytotherapies. Serenoa repens appears to be a useful option for improving lower urinary tract symptoms and flow measures. Hypoxis rooperi and Secale cereale also appear to improve BPH symptoms although the evidence is less strong for these products. Pygeum africanum has been studied extensively but inadequate reporting of outcomes limits the ability to conclusively recommend it. There is no convincing evidence supporting the use of Urtica dioica or Curcubita pepo alone for treatment of BPH. Overall, phytotherapies are less costly, well tolerated and adverse events are generally mild and infrequent. Future randomized controlled trials using standardized preparations of phytotherapeutic agents with longer study durations are needed to determine their long-term effectiveness in the treatment of BPH.
Public Health Nutr. 2000 Dec;3(4A):459-72
Role of phytotherapy in men with lower urinary tract symptoms.
PURPOSE OF REVIEW: Serenoa repens extract is a popular phytotherapeutic agent in men with lower urinary tract symptoms. Although the exact mechanism of action is unknown, the agent is generally well accepted for its easy availability and good tolerability. This paper reviews the evidence of its efficacy in comparison with placebo, 5-alpha reductase inhibitor and alpha-1 adrenoreceptor antagonist. RECENT FINDINGS: Serenoa repens extract is comparable with 5-alpha reductase (finasteride) and alpha-1 antagonist in the treatment of benign prostatic hyperplasia in terms of symptom score and peak urinary flow rate improvement, but has a lower incidence of associated sexual dysfunction. Furthermore, long-term usage (36 months) of Serenoa repens decreases the progression rate of the condition as compared with watchful waiting. In addition, the efficacies of Serenoa repens are proven in several placebo-controlled trials. SUMMARY: Serenoa repens has proven its role in the management of benign prostatic hyperplasia and will remain as a viable first-line treatment option.
Curr Opin Urol. 2005 Jan;15(1):45-8
Efficacy and safety of a combination of sabal and urtica extract in lower urinary tract symptoms. A randomized, double-blind study versus tamsulosin.
The aim of this prospective, randomized, double-blind, double-dummy, multicenter clinical trial was to investigate the efficacy and safety of PRO 160/120 (Prostagutt forte), a fixed combination preparation of 160 mg Sabal fruit extract WS 1473 and 120 mg Urtica root extract WS 1031 per capsule, in comparison to the alpha1-adrenoceptor antagonist tamsulosin (CAS 106463-17-6) in lower urinary tract symptoms (LUTS) caused by benign prostatic hyperplasia (BPH). 140 elderly out-patients suffering from LUTS caused by BPH, with an initial score > or = 13 points in the International Prostate Symptom Score (I-PSS), received 2 x 1 capsule/d PRO 160/120 or 1 x 0.4 mg/d tamsulosin and were treated for 60 weeks with interim visits at weeks 8, 16, 24, 36, and 48. The primary outcome measure for efficacy was the change in I-PSS total score, the percentage of patients with an I-PSS score < or = 7 points at endpoint (‘responders’) was analyzed as well. During 60 weeks of randomized treatment the I-PSS total score was reduced by a median of 9 points in both groups. In total, 32.4 % of the patients in the PRO 160/120 group and 27.9% in the tamsulosin group were responders (test for non-inferiority of PRO 160/120: p = 0.034; non-inferiority margin 10%). Both drugs were well tolerated, with one adverse event in 1514 treatment days for PRO 160/120 and one event in 1164 days for tamsulosin. The study supports non-inferiority of PRO 160/120 in comparison to tamsulosin in the treatment of LUTS caused by BPH.
Serenoa repens (Permixon) inhibits the 5alpha-reductase activity of human prostate cancer cell lines without interfering with PSA expression.
The phytotherapeutic agent Serenoa repens is an effective dual inhibitor of 5alpha-reductase isoenzyme activity in the prostate. Unlike other 5alpha-reductase inhibitors, Serenoa repens induces its effects without interfering with the cellular capacity to secrete PSA. Here, we focussed on the possible pathways that might differentiate the action of Permixon from that of synthetic 5alpha-reductase inhibitors. We demonstrate that Serenoa repens, unlike other 5alpha-reductase inhibitors, does not inhibit binding between activated AR and the steroid receptor-binding consensus in the promoter region of the PSA gene. This was shown by a combination of techniques: assessment of the effect of Permixon on androgen action in the LNCaP prostate cancer cell line revealed no suppression of AR and maintenance of PSA protein expression at control levels. This was consistent with reporter gene experiments showing that Permixon failed to interfere with AR-mediated transcriptional activation of PSA and that both testosterone and DHT were equally effective at maintaining this activity. Our results demonstrate that despite Serenoa repens effective inhibition of 5alpha-reductase activity in the prostate, it did not suppress PSA secretion. Therefore, we confirm the therapeutic advantage of Serenoa repens over other 5alpha-reductase inhibitors as treatment with the phytotherapeutic agent will permit the continuous use of PSA measurements as a useful biomarker for prostate cancer screening and for evaluating tumour progression.
Int J Cancer. 2005 Mar 20;114(2):190-4
Serenoa repens extract targets mitochondria and activates the intrinsic apoptotic pathway in human prostate cancer cells.
OBJECTIVE: To investigate the effects of Serenoa repens extract (Sr) in human PC3 and LNCaP prostate cancer and MCF7 breast cancer cells, with specific emphasis on the role of the mitochondrial apoptotic pathway, as the molecular pathway through which Sr, a natural product of plant origin, induces death of prostate cancer cells in culture is still unknown. MATERIAL AND METHODS: Cellular and mitochondrial structure and function, and the cell cycle, were analysed using light, electron and fluorescence microscopy, spectrophotometry and flow cytometry. Apoptosis was evaluated using biochemical and cytohistochemical methods. RESULTS: Cells treated with Sr underwent massive vacuolization and cytosolic condensation, followed by cell death only in the prostate lines. Within minutes of adding Sr to prostate cells, it caused opening of the permeability transition pore (PTP), which led to complete mitochondrial depolarization within 2 h, and to the appearance of small, pycnotic mitochondria. Release of cytochrome c and SMAC/Diablo to the cytosol was detectable after 4 h of treatment, while caspase 9 activation and poly(ADP-ribose) polymerase 1 cleavage occurred at 16 h, followed by appearance of a sub-G1 peak and apoptosis at 24 h. CONCLUSION: Sr selectively induces apoptotic cell death of prostate cancer cells through the intrinsic pathway, and activation of the mitochondrial PTP might play a central role in this process.
BJU Int. 2009 May;103(9):1275-83
Feeding tomato and broccoli powders enriched with bioactives improves bioactivity markers in rats.
Many studies have evaluated the cancer -preventive potential of individual bioactives from tomatoes and broccoli, but few have examined them within the context of a whole food. Male Copenhagen rats were fed diets containing 10% standard tomato powder, tomato enriched with lycopene or total carotenoids, standard broccoli floret, broccoli sprouts, or broccoli enriched with indole glucosinolates or selenium for 7 days. All broccoli diets increased the activity of colon quinone reductase (NQO1). Indole glucosinolate-enriched broccoli and selenium-enriched broccoli increased hepatic NQO1 and cytochrome P450 1A activity (P < 0.05). Standard broccoli and lycopene-enriched tomato diets down-regulated prostatic glutathione S-transferase P1 mRNA expression. Different tomato diets resulted in altered hepatic accumulation of lycopene, phytofluene, and phytoene. These results demonstrate that the bioactive content of vegetables affects both tissue content of bioactives and activity of detoxification enzymes. Enhancing bioactive content of tomatoes and broccoli may enhance efficacy in the prevention of prostate cancer.
J Agric Food Chem. 2009 Aug 3
Economic evaluation of medical treatment of benign prostatic hyperplasia (BPH) in the specialised care setting in Spain. Application to the cost-effectiveness of two drugs frequently used in its treatment.
OBJECTIVES: To develop a pharmacoeconomic study in order to know the average cost of BPH diagnosis and follow-up in Spain in the Urology Department setting from the perspective of the public health system, considering two frequently used drugs in the Spanish Healthcare environment, an alpha-blocker (tamsulosin) and the lipido-sterolic extract of Serenoa repens (Permixon). MATERIAL AND METHODS: Direct healthcare costs of BPH diagnosis and treatment were determined for each clinical stage according to the International Prostate Symptom Score (IPSS): mild, moderate and severe. Data on the usage and unit costs of healthcare resources were obtained from a semi-structured interview with clinical experts. The clinical efficacy of the medical treatments was obtained from the PERMAL clinical study, where therapeutic equivalence between the two studied drugs was observed. RESULTS: For patients treated in the Urology Department setting, the average annual cost of diagnostic tests and medical visits related to mild, moderate or severe BPH symptoms were, respectively, Euro 124, Euro 207, and Euro 286. The average annual cost of the drugs, including adverse effects treatment, was Euro 211 for Permixon and Euro 346 for tamsulosin. DISCUSSION: Costs of medical care of BPH increases with symptom intensity. Pharmacological treatment makes up a significant part of the disease’s cost. According to the model used, treatment with Permixon is considerably more cost-effective than with tamsulosin, offering average yearly savings of Euro 135 per patient.
Actas Urol Esp. 2008 Oct;32(9):916-25