Saw palmetto extract SPEan extract from the ripe berries of the American dwarf palm, has been widely used as a therapeutic remedy for urinary dysfunction due to benign prostatic hyperplasia BPH in Europe. Thus, SPE at clinically relevant doses may exert a direct effect on the pharmacological receptors in the lower urinary tract, thereby improving urinary dysfunction in patients with BPH and Kürbissamen aus Prostatitis overactive bladder.
SPE does not have interactions with co-administered drugs or serious adverse events in blood biochemical parameters, suggestive of its relative safety, even with long-term intake.
The prevalence of histopathologic BPH is age dependent, with initial development usually occurring after 40 years of age 1. Similar to histological evidence, the prevalence of Kürbissamen aus Prostatitis symptoms also increases with age. In addition to these medications, the ripe berries of the American dwarf palm Serenoa repenssaw palmetto have been traditionally used to treat genitourinary problems; Kürbissamen aus Prostatitis enhance sperm production, breast size, or libido; and as a mild diuretic 3.
In Kürbissamen aus Prostatitis European countries, phytotherapeutic agents, including saw palmetto, are very popular. Kürbissamen aus Prostatitis palmetto is a dwarf palm tree of the family Arecaceae and is indigenous to the Kürbissamen aus Prostatitis parts of the United States. Saw palmetto berries have traditionally been used by American Indians to cure genitourinary disturbances, relieve mucous membrane irritations, increase testicular function, or increase breast size 56.
However, most of these pharmacological effects were observed at relatively high concentrations or large doses of SPE 910and it is uncertain whether the reported modes of action of SPE are therapeutically relevant 11 Thus, the effects of SPE on these receptors in the lower urinary tract might be pharmacologically relevant.
To date, more than 11 placebo-controlled trials and 4 active-controlled trials with SPE in men with BPH have been conducted. Most of these were reported in the s. Patient numbers were usually limited and the evaluation periods were relatively short, so it would be difficult to evaluate the effect of SPE and ascertain the Kürbissamen aus Prostatitis of SPE in BPH patients.
Herbal products, including SPE, are often used with other prescription medications, and most patients with BPH are aged men. Elderly individuals frequently take dietary supplements with prescription drugs, and such a tendency will continue to increase in the near future. In such cases, a major concern is adverse events caused by a large excess intake or interactions between dietary supplements and drugs. Thus, the safety, as well as the efficacy, of these natural products and of their active ingredients remains to be analyzed at a scientific level.
This review Kürbissamen aus Prostatitis newly revealed pharmacological actions of SPE, as well as some well-known mechanisms of action of SPE, and also summarizes clinical trials of SPE in comparison with currently used medicines. Milano, Italywas used for the animal experiments 1418 Indena SpA. Habib and Wyllie 20 reported that the contents of different brands of SPE were markedly different; for example, free fatty acids ranged from In the United States, herbal products are regulated under the Dietary Supplement Health and Education Act DSHEA ; however, approval for launching products onto the market is not required except in cases of a new dietary ingredient.
Therefore, herbal products that existed before October 15,can remain with different ingredients Levin and Das 22 issued a warning that each preparation must be considered individually because of differences in extraction techniques, preparation of products, composition, and biological activities.
Mechanisms of pharmacological action of saw palmetto extract SPE. The development and growth of the prostate gland depend on androgen stimulation 23 However, palmitic acid, stearic acid, esterified fatty acids, sterols, and alcohols were inactive against both Sultan et al 9 investigated the interaction of SPE with the intercellular androgen-receptor complex.
SPE inhibited [ 3 H]dihydrotestosterone from binding to its receptor. The affinity of SPE was higher for cytosol receptors than for nuclear receptors. Competitive interference with the binding of [ 3 H]methyltrienolone to cytosolic androgen receptors was also shown in rat prostate cells Inflammation was frequently observed in hormonally induced hypertrophied prostates of dogs 32 and in a study of human BPH Mahapokai et al 32 concluded that the development of hyperplasia preceded inflammatory infiltration.
An anti-inflammatory effect was indicated as one of the mechanisms of action of SPE. In fact, it is plausible that SPE affects several inflammatory mediators. SPE showed anti-inflammatory and anti-edematous effects in vivo Breu et al 34 demonstrated that acid lipophilic compounds of SPE inhibited the biosynthesis of cyclooxygenase Kürbissamen aus Prostatitis 5-lipoxygenase metabolites with the same intensity as SPE.
Thus, SPE was shown to exert an anti-inflammatory effect. Maintenance of a constant number of cells is one of the basic Kürbissamen aus Prostatitis of homeostasis. In normal adult prostate, the delicate balance between apoptosis and proliferation is well regulated and these indices are low. In contrast, Kürbissamen aus Prostatitis a prostate with BPH this equilibrium may not be maintained 373839 Claus et al 41 also indicated stromal growth in BPH due to cell proliferation in the absence of apoptosis.
Vacherot Kürbissamen aus Prostatitis al 40 revealed that proliferation exceeded apoptosis in the stroma and epithelium of human BPH tissues. Although the rate of apoptosis did not differ between normal prostate and BPH tissue, the proliferative index was significantly higher in BPH tissue than in Kürbissamen aus Prostatitis prostate in both the stroma and the epithelium. Thus, SPE might block prolactin-induced prostate growth by inhibiting several steps of prolactin receptor signal transduction.
We evaluated the in vitro and in vivo binding of SPE to autonomic receptors in the lower urinary tract 1418 Our recent study has shown that SPE competitively inhibited specific binding of [ 3 H]prasozin and Kürbissamen aus Prostatitis 3 H]NMS in human prostate and bladder Yamada et alunpublished data.
Vanilloids exert their activity through the transient receptor potential vanilloid subtype 1 TRPV1a nonselective cation channel. TRPV1 has been shown to be located in urinary bladder epithelial cells Thus, TRPV1 may play a significant role in the pathophysiology of bladder disease.
Suzuki et al 1819 examined the effects of oral administration of SPE on autonomic receptors in rats. Notably, such a reduction in the number of [ 3 H]NMS binding sites was observed at relatively low doses 0. The in vitro experiment showed that SPE exhibited little tissue selectivity in the binding of each receptor. Although there is no clear explanation for such selectivity, the most plausible reason may be the preferential distribution of receptor-binding constituents in the lower urinary tract after the systemic administration of SPE.
A systemic distribution study in rats administered [ 14 C]oleic acid or Kürbissamen aus Prostatitis 14 C]sitosterol-supplemented SPE has shown that these components are accumulated to a greater extent in the prostate than in other tissues Because the prostate is particularly rich in free fatty acids, it would be expected that greater amounts of lipophilic substances accumulate in the prostate than in other tissues.
Our previous study has shown that repeated treatment with testosterone for 4 weeks resulted in significantly increased 1. The reason why our data could not reproduce previous results might be the lower dosage and shorter treatment period. It may be concluded that SPE at a clinically relevant dose exerts a direct effect on the pharmacological receptors in the lower urinary tract, thereby improving urinary dysfunction in patients with BPH and overactive bladders OAB.
Although the usage of medical herbs has grown quickly as a complementary and alternative medicine, scientific knowledge of the efficacy and safety of herbs Kürbissamen aus Prostatitis still lacking. Furthermore, the potential for interactions between herbs and drugs should be a concern because all herbs contain a large number of constituents 505152 The proposed interactions would affect the pharmacokinetics and pharmacodynamics of drugs: absorption in the small intestine, metabolism in the intestine and liver, distribution to target organs, transport across cell membranes, and binding to specific receptors.
Among these interactions, induction and inhibition Kürbissamen aus Prostatitis hepatic drug-metabolizing enzymes by herbal medicines Kürbissamen aus Prostatitis dietary compounds have Kürbissamen aus Prostatitis investigated. Suzuki et al 18 have shown that repeated oral administration of SPE in rats had little significant influence on the content and activities of hepatic drug-metabolizing enzymes.
Therefore, it is unlikely that SPE at generally recommended doses alters the disposition of co-administered drugs. Also, repeated oral administration of SPE in rats had little effect on blood biochemical parameters, except for a slight increase in the albumin value, suggestive of relative Kürbissamen aus Prostatitis even with long-term intake There have been more than 11 placebo-controlled trials 817585960616263646566 and 4 active-controlled trials 111567 Most of them were reported in the s; the patient number was usually limited and the evaluation period was relatively short.
More recently, two new and relatively large-scale placebo-controlled trials were conducted. One was reported by Willetts et al 17 and the other by Bent et al 8. A double-blind placebo-controlled trial was held in Australia from January to March The treatment period was 12 weeks.
The IPSS score decreased over time in both treatment groups; however, there was no significant difference after 12 weeks of treatment Kürbissamen aus Prostatitis the groups. There were no significant differences between the two treatment groups in the quality of life QOL score, the maximal urinary flow rate, and the IIEF score. On the other hand, each treatment group showed a significant improvement between week 0 and week This trial was double-blind placebo-controlled, with high compliance and a low withdrawal rate; therefore, it could be regarded as a well-controlled trial.
However, some of the results were unexpected, especially for the IPSS score and urine flow rates. The Kürbissamen aus Prostatitis considered that it might be ascribable to a low IPSS at baseline, a small number of patients, and a relatively short trial period. The other clinical trial was held in the United States Kürbissamen aus Prostatitis July to May 8. It was a double-blind placebo-controlled trial lasting 14 months 2 months Kürbissamen aus Prostatitis, 12 months treatment.
Secondary outcomes were changes in prostate size, residual urinary volume after voiding, QOL, laboratory values, and the rate of reported adverse effects 8. The incidence of side effects was similar in the two groups. During the single-blind, placebo run-in period, there was a small but significant decrease in the AUASI score. Bent et al 8 considered the discrepancy between their results and results from previous trials and questioned the adequacy of blinding, whether certain attributes of participants were taken into account, and specification of the SPE preparations of the previous trials.
Just as the placebo-controlled trials, half of Kürbissamen aus Prostatitis trials Kürbissamen aus Prostatitis very limited numbers Kürbissamen aus Prostatitis patients and had very short evaluation periods.
Two active-controlled trials recruited enough patients and had relatively long treatment periods 6 and 12 months. SPE fared better than finasteride in a sexual function questionnaire and resulted in fewer complaints of decreased libido and impotence. Both treatments relieved the symptoms of BPH in about two thirds Kürbissamen aus Prostatitis the patients but, unlike finasteride, SPE had little effect on so-called androgen-dependent Kürbissamen aus Prostatitis.
This suggests that other pathways are also involved in the symptomatology of BPH. Eight hundred and eleven men Kürbissamen aus Prostatitis symptomatic BPH were recruited and patients were randomized to receive either tamsulosin 0.
At 12 months, IPSS decreased by 4. The increase in maximal urinary flow rate was similar in both treatment groups. The mean prostate volume decreased by 0. The tamsulosin group showed no significant changes in total PSA. The two compounds were well tolerated; however, evacuation disorders occurred more frequently in the tamsulosin group. Debruyne et al 69 conducted a subset analysis of the trial mentioned above. At 12 months, total IPSS decreased by 7. Kürbissamen aus Prostatitis superiority of SPE in reducing irritative symptoms appeared only 3 months into treatment and was maintained up to month