Androgen-independent Effects of Serenoa repens Extract (Prostasan®) on Prostatic Epithelial Cell Proliferation and Inflammation

The Therapeutic Potential of Saw Palmetto Extract in Urological Disorders

Saw palmetto extract (SPE) has been widely used as a therapeutic remedy for urinary dysfunction in western countries. Furthermore, as an herb drug, it can be used as an alternative therapy for benign prostatic hyperplasia (BPH) due to its safety and minimum adverse effects. Reportedly, SPE improves the urinary symptoms, which mainly depend on anti-androgenic effects and effects on autonomic receptors in the lower urinary tract. However, the mechanisms of action responsible for the therapeutic roles of SPE have not been fully elucidated. Relevant studies indicate that SPE has some positive effects on the treatment of urological diseases in animals, and clinical trials are ongoing. In this review, we summarize the pharmacological properties and discuss the possible therapeutic mechanisms of SPE in urological diseases, including anti-androgenic effects, effects on autonomic receptors in the lower urinary tract, anti-inflammatory activity, anti-proliferative and pro-apoptotic effects, and highlight a potential therapeutic approach in the clinical treatment of patients with BPH, prostate cancer, chronic prostatitis (CP) and erectile dysfunction (ED).

Phenolic Content and Antimicrobial and Anti-Inflammatory Effects of Solidago virga-aurea, Phyllanthus niruri, Epilobium angustifolium, Peumus boldus, and Ononis spinosa Extracts

Prostatitis is an inflammatory condition that is related to multiple infectious agents, including bacteria and fungi. Traditional herbal extracts proved efficacious in controlling clinical symptoms associated with prostatitis. In this context, the aim of the present study was to explore the efficacy of extracts from Solidago virga-aurea, Ononis spinosa, Peumus boldus, Epilobium angustifolium, and Phyllanthus niruri against bacterial (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus) and fungi strains (Candida albicans; C. tropicalis) involved in prostatitis. Additionally, anti-mycotic effects were tested against multiple species of dermatophytes (Trichophyton rubrum, T. tonsurans, T. erinacei, Arthroderma crocatum, A. quadrifidum, A. gypseum, A. currey, and A. insingulare). Antioxidant effects were also evaluated in isolated rat prostates challenged with lipopolysaccharide (LPS), and phytochemical analyses were conducted to identify and quantify selected phenolic compounds, in the extracts. Finally, a bioinformatics analysis was conducted to predict putative human and microbial enzymes targeted by extracts’ phytocompounds and underlying the observed bio-pharmacological effects. The phytochemical analysis highlighted that rutin levels could be crucial for explaining the highest antibacterial activity of P. boldus extract, especially against E. coli and B. cereus. On the other hand, in the E. angustifolium extract, catechin concentration could partially explain the highest efficacy of this extract in reducing lipid peroxidation, in isolated rat prostates stimulated with LPS. Concluding, the results of the present study showed moderate antimicrobial and anti-inflammatory effects induced by water extracts of S. virga-aurea, P. boldus, E. angustifolium, P. niruri, and O. spinosa that could be related, at least partially, to the phenolic composition of the phytocomplex.

Upregulated Interleukin 21 Receptor Enhances Proliferation and Epithelial-Mesenchymal Transition Process in Benign Prostatic Hyperplasia

Background: Interleukins (ILs) and related chronic inflammation have been found to contribute to the development of benign prostatic hyperplasia (BPH) in recent decades. As a late member of the ILs family, IL-21 receptor (IL-21R) can modulate cell proliferation, however, IL-21R activity in the prostate has not been examined. The current study aimed to elucidate a potential role of IL-21R in the development of BPH. Material and Methods: Human prostate tissues, cell lines and rats were used. QRT-PCR, Western blot, and immunohistochemistry, along with hematoxylin and eosin, Masson's trichrome, and immunofluorescent staining were performed. BPH-1 cells with IL-21R silenced were cultured or co-cultured with macrophages (active THP-1, AcTHP-1). Apoptosis and cell cycle phases were determined via flow cytometry. Epithelial-mesenchymal transition (EMT) processes were also examined. In vivo, rat prostatitis was induced with intraprostatic injected lipopolysaccharide (LPS). Results: IL-21R was highly expressed in human as well as rat prostate, mainly in the epithelial compartment. BPH concomitant with prostatitis significantly upregulated the expression of IL-21R. Knockdown of IL-21R induced cell apoptosis and cycle arrest at G0/G1 phase, and blocked the EMT process in BPH-1 cells. When IL-21R silenced BPH-1 cells were co-cultured with AcTHP-1 cells, these aforementioned processes and IL-21R change were completely reversed. Prostatic hyperplasia was observed with IL-21R upregulated in LPS induced prostatitis rats. More specifically, the expression of apoptosis, cyclin, and EMT proteins in this rat model are altered in a manner consistent with that seen in the cell line model. Conclusions: Our novel data demonstrates the expression and functional activities of IL-21R in the mechanism for development of BPH. IL-21R mainly localized in prostate epithelium and it was upregulated in hyperplastic prostate tissues. IL-21R enhanced proliferation of BPH-1 cells, via inhibiting cell apoptosis, and modulating cell cycles, as well as the EMT process, in response to inflammatory stimuli.

Graminex Pollen: Phenolic Pattern, Colorimetric Analysis and Protective Effects in Immortalized Prostate Cells (PC3) and Rat Prostate Challenged with LPS

Prostatitis, a general term describing prostate inflammation, is a common disease that could be sustained by bacterial or non-bacterial infectious agents. The efficacy of herbal extracts with antioxidant and anti-inflammatory effects for blunting the burden of inflammation and oxidative stress, with possible improvements in clinical symptoms, is under investigation. Pollen extracts have been previously reported as promising agents in managing clinical symptoms related to prostatitis. The aim of the present work was to evaluate the protective effects of Graminex pollen (Graminex^TM, Deshler, OH, USA), a commercially available product based on standardized pollen extracts, in rat prostate specimens, ex vivo. In this context, we studied the putative mechanism of action of pollen on multiple inflammatory pathways, including the reduction of prostaglandin E₂ (PGE₂), nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB), and malondialdehyde (MDA), whose activities were significantly increased by inflammatory stimuli. We characterized by means of chromatographic and colorimetric studies the composition of Graminex pollen to better correlate the activity of pollen on immortalized prostate cells (PC3), and in rat prostate specimens challenged with Escherichia coli lipopolysaccharide (LPS). We found that Graminex pollen was able to reduce radical oxygen species (ROS) production by PC3 cells and MDA, NFκB mRNA, and PGE₂ levels, in rat prostate specimens. According to our experimental evidence, Graminex pollen appears to be a promising natural product for the management of the inflammatory components in the prostate.

Toll-like receptor 5 agonist CBLB502 induces radioprotective effects in vitro

CBLB502 derived from Salmonella flagellin is a novel agonist of Toll-like receptor 5 (TLR5). It has been shown that CBLB502 can exert high radioprotective efficacy on mice and primates from both GI and hematopoietic syndromes during whole-body irradiation with low toxicity and immunogenicity. However, no effective system has been used to investigate the protective effect of CBLB502 against irradiation and the related mechanism in vitro. In this study, we investigated the radioprotective properties of CBLB502 in HEK293-N-T cells constitutively expressing human TLR5 and NF-κB-dependent luciferase. HEK293-N-T cells were treated with different doses of CBLB502 prior to 60Co-γ ray irradiation. After irradiation, cell viability was real-time measured for 4 days by using the real-time cell analysis system. We found that CBLB502 was capable of efficiently maintaining the survival rate of irradiated HEK293-N-T cells. Then apoptotic cell death and cell cycle were detected by flow cytometry. The results showed that CBLB502 pre-treatment could reduce the apoptosis and promote the recovery of irradiated HEK293-N-T cells from G2-phase arrest in a dose-dependent manner. Our data indicated that CBLB502 has a direct radioprotective effect in vitro via anti-apoptosis and promotes cell cycle recovery. The method developed here could be an effective in vitro system to screen other TLR5-target radioprotectants like CBLB502.

Intraurethral injection with LPS: an effective experimental model of prostatic inflammation

OBJECTIVE

Chronic inflammation has been recognized as having a prominent role pathogenesis of benign prostatic hyperplasia (BPH) and cancer. It is believed that chronic inflammation induces prostatic fibromuscular growth. This correlation has been clearly illustrated by both in vivo and in vitro studies; however, current experimental models of BPH require complex surgery or hormonal treatment. Therefore, the aim of the present study was to propose a new murine model of BPH/prostatitis induced by intraurethral injection of LPS.

METHODS

Male Swiss and C57Bl/6 mice were then sacrificed 3, 7, 10, and 14 days after intraurethral injection of LPS. The prostates were quickly dissected and fixed for morphological and immunohistochemical analyses.

RESULTS

The results showed that LPS played an important role in the cell proliferation of the prostate. Histological and ultrastructural analysis showed epithelial hyperplasia, clear stromal cells, little inflammatory infiltration, and heavy bleeding. Treatment with LPS also promoted the increase of growth factor (FGF-7 and TGF-β), α-actin, and proinflammatory cytokines (IL-1, IL-6, IL-17), both in the stroma and epithelium.

CONCLUSION

According to the present findings, it can be concluded that the intraurethral administration of LPS promotes tissue remodeling, as well as stimulating the pattern of pro-inflammatory cytokines, and therefore, constitutes an effective experimental model of BPH/inflammation.

Anti-inflammatory properties of Lipidosterolic extract of Serenoa repens (Permixon®) in a mouse model of prostate hyperplasia

BACKGROUND

Permixon®, the hexanic lipidosterolic extract of saw palmetto Serenoa repens (LSESr), has shown properties that highlight its benefit in the management of benign prostate hyperplasia (BPH). To address its actual anti-inflammatory potency, we used a unique pro-inflammatory mouse model of prostate hyperplasia involving prostate-specific over-expression of prolactin transgene (Pb-Prl).

METHODS

Six month-old Pb-Prl males were administered with Permixon® per os at the daily dose of 100 mg/kg for 28 days. Body and prostate weights were measured weekly and at sacrifice, respectively. Prostate histology was carefully assessed by a pathologist and detailed quantifications of epithelial and stromal compartments were performed using image analysis software. Luminal cell proliferation index was determined using Ki-67 immunostaining, and apoptosis using Bax/Bcl2 mRNA ratio. Tissue inflammation and fibrosis were assessed by histological analyses then quantified using CD45 immunostaining and picrosirius staining, respectively. Expression profiling of selected pro-inflammatory cytokines, chemokines, and chemokine receptors was performed by quantitative RT-PCR.

RESULTS

In this model, Permixon® significantly decreased tissue weight and proliferation index specifically in the ventral lobe. Although treatment had no noticeable effect on epithelial histology of any lobe, it markedly reduced the histological hallmarks of inflammation in all lobes. This was confirmed by the global down-regulation of prostate pro-inflammatory cytokine profile, with significant reduction of CCR7, CXCL6, IL-6, and IL-17 expression.

CONCLUSIONS

In this mouse model of prostate hyperplasia, Permixon® exerted potent anti-inflammatory properties in the whole prostate while anti-androgenic effects were lobe-specific, suggesting that distinct LSESr components may be involved in these effects. Our results support the beneficial role of Permixon® treatment for BPH. The relevance of CCR7, CXCL6, IL-6, and IL-17 as potential biomarkers to follow up BPH inflammatory status needs to be assessed.

Modern extraction techniques and their impact on the pharmacological profile of Serenoa repens extracts for the treatment of lower urinary tract symptoms

Background

Bioactive compounds from plants (i.e., Serenoa repens) are often used in medicine in the treatment of several pathologies, among which benign prostatic hyperplasia (BPH) associated to lower urinary tract symptoms (LUTS).

Discussion

There are different techniques of extraction, also used in combination, with the aim of enhancing the amount of the target molecules, gaining time and reducing waste of solvents. However, the qualitative and quantitative composition of the bioactives depends on the extractive process, and so the brands of the recovered products from the same plant are different in terms of clinical efficacy (no product interchangeability among different commercial brands).

Summary

In this review, we report on several and recent extraction techniques and their impact on the composition/biological activity of S. repens-based available products.

A phytochemical comparison of saw palmetto products using gas chromatography and (1) H nuclear magnetic resonance spectroscopy metabolomic profiling

Objectives

Preparations containing saw palmetto berries are used in the treatment of benign prostatic hyperplasia (BPH). There are many products on the market, and relatively little is known about their chemical variability and specifically the composition and quality of different saw palmetto products notwithstanding that in 2000, an international consultation paper from the major urological associations from the five continents on treatments for BPH demanded further research on this topic. Here, we compare two analytical approaches and characterise 57 different saw palmetto products.

Methods

An established method – gas chromatography – was used for the quantification of nine fatty acids, while a novel approach of metabolomic profiling using ¹H nuclear magnetic resonance (NMR) spectroscopy was used as a fingerprinting tool to assess the overall composition of the extracts.

Key findings

The phytochemical analysis determining the fatty acids showed a high level of heterogeneity of the different products in the total amount and of nine single fatty acids. A robust and reproducible ¹H NMR spectroscopy method was established, and the results showed that it was possible to statistically differentiate between saw palmetto products that had been extracted under different conditions but not between products that used a similar extraction method. Principal component analysis was able to determine those products that had significantly different metabolites.

Conclusions

The metabolomic approach developed offers novel opportunities for quality control along the value chain of saw palmetto and needs to be followed further, as with this method, the complexity of a herbal extract can be better assessed than with the analysis of a single group of constituents.

Improving BPH symptoms and sexual dysfunctions with a saw palmetto preparation? Results from a pilot trial

In elderly men, benign prostatic hyperplasia (BPH) is a major risk factor for sexual dysfunctions (SDys). Additionally, the standard treatments for BPH symptoms, alpha blockers and 5-alpha-reductase inhibitors, cause SDys themselves. Preparations from saw palmetto berries are an efficacious and well-tolerated symptomatic treatment for mild to moderate BPH and have traditionally been used to treat SDys. We conducted an open multicentric clinical pilot trial to investigate whether the saw palmetto berry preparation Prostasan® influenced BPH symptoms and SDys. Eighty-two patients participated in the 8-week trial, taking one capsule of 320 mg saw palmetto extract daily. At the end of the treatment, the International Prostate Symptom Score was reduced from 14.4 ± 4.7 to 6.9 ± 5.2 (p < 0.0001); SDys measured with the brief Sexual Function Inventory improved from 22.4 ± 7.2 to 31.4 ± 9.2 (p < 0.0001), and the Urolife BPH QoL-9 sex total improved from 137.3 ± 47.9 to 195.0 ± 56.3 (p < 0.0001). Investigators' and patients' assessments confirmed the good efficacy, and treatment was very well tolerated and accepted by the patients. Correlation analyses confirmed the relationship between improved BPH symptoms and reduced SDys. This was the first trial with saw palmetto to show improvement in BPH symptoms and SDys as well. [Corrections made here after initial online publication.]