Calma pessoal
não é bem assim.Pinçar um estudo que fala mal não é a forma mais adequda de criticar algo.
ocorre que por desmotivação da indústria farmacêutica existem poucos estudos comparativos entre SP e fina mas não podemos afirmar em nossa vasat ignoância que ele não vale PN....
cito abaixo outros ensaios entre centenas que existem a vossa disposição:
How can saw palmetto be used to treat baldness
Several reports indicate saw palmetto is effective in treating benign prostatic hyperplasia. Animal models show that Permixon will inhibit prostate gland enlargement when rats are given estrogens and testosterone. In comparison, control rats receiving hormones but no Permixon had significant prostate enlargement. Other animal studies reveal that the Permixon is being preferentially taken up and retained in the prostate gland. Other tissues such as the seminal vesicles or liver showed far lower uptake of saw palmetto extract.
Human treatment using saw palmetto is much more widely practiced in treatment of human prostatic hyperplasia typically involves oral ingestion of 160mg saw palmetto extract twice a day. This dosage has been associated with significant improvement for individuals with prostatic hyperplasia problems. Some investigators report that the results are even comparable to using finasteride (Propecia) to treat benign prostatic hyperplasia.
Some research suggests that saw palmetto extract works at the site of androgen receptors on steroid sensitive cells. Research shows that saw palmetto does not have an effect on the plasma concentration of testosterone, dihydrotestosterone, or other hormones so systemic production of testosterone is maintained when taking saw palmetto. In contrast finasteride has been shown effective in reducing serum concentration of dihydrotestosterone. Saw palmetto seems to work locally at the actual site of hormone binding to receptors on cells. It apparently stops or at least reduces the receptor binding of androgens. It also locally inhibits 5 alpha reductase and 3 ketosteroid reductase and these enzymes are involved in converting testosterone to the more potent dihydrotestosterone (DHT). Saw palmetto extract may also act to reduce inflammation that is associated with benign prostatic hyperplasia by reducing immune cell production of stimulating cytokine chemicals.
These reports suggest that saw palmetto may be effective in treating androgenetic alopecia, however, no direct clinical trails have been conducted to define just how effective saw palmetto may be in treating pattern baldness.
Can saw palmetto be used for female pattern baldness
Saw palmetto berry extracts contain inhibitors of 5 alpha reductase. Research has not been conducted to identify the biological effects of Saw palmetto on women. However, evidence from research on related products may suggest that Saw palmetto may not be directly dangerous to the idnividual woman but could have serious adverse effects for any male embryo in a woman taking Saw palmetto.
Propecia is a pharmaceutical drug that acts as a type II 5 alpha reductase inhibitor. Inhibition of 5 alpha reductase has significant consequences for the development of a male embryo. 5 alpha reductase is important in the development of male genital organs. Without 5 alpha reductase, male embryos develop without male genital organs.
The vast majority of people taking Saw palmetto have no apparent adverse side effects. It is tolerated very well and this has been confirmed during clinical investigations using Saw palmetto to treat begign prostate hyperplasia. Minor side effects can include stomach irritation and feelings of indigestion. In part, these side effects can be avoided by not taking Saw palmetto on an empty stomach.
1: Int J Cancer. 2005 Mar 20;114(2):190-4.Click here to read Links
Serenoa repens (Permixon) inhibits the 5alpha-reductase activity of human prostate cancer cell lines without interfering with PSA expression.
Habib FK, Ross M, Ho CK, Lyons V, Chapman K.
Prostate Research Group, University of Edinburgh, School of Molecular and Clinical Medicine, 2nd Floor Main Outpatient Building, Western General Hospital, Edinburgh EH2 2XU, Scotland, UK.
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. (c) 2004 Wiley-Liss, Inc.
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.
Di Silverio F, Monti S, Sciarra A, Varasano PA, Martini C, Lanzara S, D'Eramo G, Di Nicola S, Toscano V.
Department of Urology, University of Rome La Sapienza, Italy.
BACKGROUND: The n-hexane lipido-sterol extract of Serenoa repens (LSESr, Permixon, Pierre Fabre Medicament, Castres, France), a phytotherapeutic agent used in the treatment of benign prostatic hyperplasia (BPH), has a multisite mechanism of action including inhibition of types 1 and 2 5alpha-reductase and competitive binding to androgen receptors in prostatic cells. Here, the response of testosterone (T), dihydrotestosterone (DHT), and epidermal growth factor (EGF) in BPH tissue of patients treated with LSESr (320 mg/day for 3 months) is analyzed. METHODS: BPH samples were sectioned in periurethral, subcapsular, and intermediate regions: in each region T, DHT, and EGF were determined by radioimmunoassay after purification on celite columns or Sep-pak C18 cartridges. RESULTS: In the untreated group, T, DHT, and EGF presented the highest concentrations in the periurethral region (615 +/- 62 (SE) pg/g tissue, 7,317 +/- 551 pg/g tissue, and 20.9 +/- 3.3 ng/g tissue, respectively) with respect to the peripheral subcapsular region (425 +/- 45 pg/g tissue, 4,215 +/- 561 pg/g tissue, and 10.8 +/- 1.4 ng/g tissue, respectively). In the LSESr-treated group, a statistically significant reduction was observed, mainly in the periurethral region of DHT (2,363 +/- 553 pg/g tissue, P < 0.001) and EGF (6.98 +/- 2.48 ng/g tissue, P < 0.01), with increased T values (1,023 +/- 101 pg/g tissue, P < 0.001). CONCLUSIONS: The decrease of DHT and the rise of T in BPH tissue of patients treated with Permixon confirms the capacity of this drug to inhibit in vivo 5alpha-reductase in human pathological prostate. A marked decrease of EGF, associated with DHT reduction, was also observed. These biochemical effects, similar to those obtained with finasteride, are particularly evident in the periurethral region, whose enlargement is responsible for urinary obstruction, with respect to the subcapsular region. A possible speculation is that the preferential reduction of DHT and EGF content in the periurethral region is involved in the clinical improvement of the obstructive symptoms in BPH during LSESr therapy
Pharmacological effects of the lipidosterolic extract of Serenoa repens (Permixon) on rat prostate hyperplasia induced by hyperprolactinemia: comparison with finasteride.
Van Coppenolle F, Le Bourhis X, Carpentier F, Delaby G, Cousse H, Raynaud JP, Dupouy JP, Prevarskaya N.
Laboratoire de Physiologie Cellulaire, USTL, INSERM EPI 9938, Villeneuve d'Ascq, France.
fvancopp@pop.univ-lille1.fr
BACKGROUND: The growth of the prostate gland is mainly dependent on androgens. Other hormones, like prolactin (PRL), also influence prostate development. Our purpose was to analyze and compare the effects of two drugs (5alpha-reductase inhibitor) used in the therapy of benign prostatic hyperplasia: lipidosterolic extract of Serenoa repens (LSESR), and finasteride in an in vivo model of rat prostate hyperplasia induced by hyperprolactinemia. METHODS: Hyperprolactinemia was induced by 30 daily injections of sulpiride. Wistar rats received daily gavages of LSESR or finasteride. We used the following groups: control, castrated, castrated with a substitute testosterone (T), or 5alpha-dihydrotestosterone (DHT) implant. RESULTS: Hyperprolactinemia increases the wet weight and induces hyperplasia in the lateral prostate (LP). Unlike finasteride, LSESR significantly reduced LP growth and hyperplasia in castrated, DHT-implanted, and sulpiride-treated rats. CONCLUSIONS: Finasteride was only capable of inhibiting the effect of androgens on rat prostate enlargement. LSESR inhibited not only the androgenic but also the trophic effect of PRL in rat LP hyperplasia. Copyright 2000 Wiley-Liss, Inc.
Tissue effects of saw palmetto and finasteride: use of biopsy cores for in situ quantification of prostatic androgens.
Marks LS, Hess DL, Dorey FJ, Luz Macairan M, Cruz Santos PB, Tyler VE.
Urological Sciences Research Foundation, Culver City, California, USA.
OBJECTIVES: To determine the effects of a saw palmetto herbal blend (SPHB) compared with finasteride on prostatic tissue androgen levels and to evaluate needle biopsies as a source of tissue for such determinations. METHODS: Prostate levels of testosterone and dihydrotestosterone (DHT) were measured on 5 to 10-mg biopsy specimens (18-gauge needle cores) in three groups of men with symptomatic benign prostatic hyperplasia: 15 men receiving chronic finasteride therapy versus 7 untreated controls; 4 men undergoing prostate adenomectomy to determine sampling variability (10 specimens each); and 40 men participating in a 6-month randomized trial of SPHB versus placebo, before and after treatment. RESULTS: Prostatic tissue DHT levels were found to be several times higher than the levels of testosterone (5.01 versus 1.51 ng/g), that ratio becoming reversed (1.05 versus 3.63 ng/g) with chronic finasteride therapy. The finasteride effect was statistically significant for both androgens (P <0.01), and little overlap of individual values between finasteride-treated and control patients was seen. In the randomized trial, tissue DHT levels were reduced by 32% from 6.49 to 4.40 ng/g in the SPHB group (P <0.005), with no significant change in the placebo group. CONCLUSIONS: For control versus finasteride-treated men, the tissue androgen values obtained with needle biopsy specimens were similar-both for absolute values and the percentage of change-to those previously reported using surgically excised volumes of prostatic tissue. The quantification of prostatic androgens by assay of needle biopsies is thus feasible and offers the possibility of serial studies in individual patients. The SPHB-induced suppression of prostatic DHT levels, modest but significant in a randomized trial, lends an element of support to the hypothesis that inhibition of the enzyme 5-alpha reductase is a mechanism of action of this substance.
Serenoa repens (Permixon): a 5alpha-reductase types I and II inhibitor-new evidence in a coculture model of BPH.
Bayne CW, Donnelly F, Ross M, Habib FK.
Prostate Research Group, University Department of Oncology, Western General Hospital, Edinburgh, Scotland.
BACKGROUND: The aim of this study was to determine the effect of the phytotherapeutic agent, Permixon, on a novel coculture model of benign prostatic hyperplasia (BPH) in an effort to better understand the mode of action of the drug in vivo. METHODS: The effect of Permixon, at the calculated therapeutic concentration, on the activity of 5alpha-reductase isoenzymes was evaluated utilizing a pH-specific assay. Prostate-specific antigen (PSA) secretions into the medium were measured in the presence and absence of Permixon and quantified by an ELISA assay. The morphological patterns before and following Permixon treatment were also examined by electron microscopy. All results were compared to controls. RESULTS: Permixon at a concentration of 10 micrograms/ml (calculated plasma concentration in patient receiving recommended therapeutic dosage) was shown to be an effective inhibitor of both 5alpha-reductase types I and II isoenzymes without influencing the secretion of PSA by the epithelial cells, even after stimulation with testosterone. The morphology of Permixon-treated cells was found to be markedly different from that of untreated controls. Cells which had been treated with the drug demonstrated extensive accumulation of lipids in the cytoplasm and widespread damage of intracellular membranes, including mitochondrial and nuclear membranes. CONCLUSIONS: Permixon is an effective dual inhibitor of 5alpha-reductase isoenzyme activities in the prostate. Unlike other 5alpha-reductase inhibitors, Permixon induces this effect without interfering with the cells' capacity to secrete PSA, thus permitting the continued use of PSA measurements for prostate cancer screening. Copyright 1999 Wiley-Liss, Inc.
