Efficacy and tolerability of the hexanic extract of Serenoa repens compared to tamsulosin in moderate-severe LUTS-BPH patients

Construction of lncRNA- and circRNA-associated ceRNA networks in the prostatic urethra of rats after simulating transurethral laser prostatectomy (TULP)

Non-coding RNA appears to be involved in wound repair. Competing endogenous RNA (ceRNA) appears to be an important post-transcriptional mechanism, it means that long noncoding RNA (lncRNA) or circular RNA (circRNA) acts as a microRNA (miRNA) sponge to further regulate mRNA. However, ceRNA network related to wound repair after prostatectomy has yet been constructed. TULP is the main surgical method of prostatectomy, but there have been no reports of TULP rat models in the past. We simulated TULP on rats, and observed the whole process of wound injury and repair after operation through pathological examination of wound tissue. Next, we discovered 732 differentially expressed lncRNAs (DElncRNAs), 47 differentially expressed circRNAs (DEcircRNAs), 17 differentially expressed miRNAs (DEmiRNAs), and 1892 differentially expressed mRNAs (DEmRNAs) related to wound repair after TULP through full transcriptome microarray and bioinformatics methods, and confirmed the reliability of transcriptome data by quantitative Reverse Transcription PCR (qRT-PCR), and immunohistochemistry. Then, we constructed the lncRNA- and circRNA-associated ceRNA regulatory networks related to wound repair after TULP in rats. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses showed that molecules in these networks were mainly involved in inflammatory infiltration, cell differentiation, and intercellular interactions and involved signal pathways such as the PI3K-Akt signaling pathway. Thus, this study successfully established the TULP model in rats, revealed potentially important biomarkers and ceRNA networks after prostatectomy in rats, and provided theoretical support for the repair of post-prostatectomy wound.

[Alpha-blockers or hexanic extract of Serenoa repens for 6 months: sub-analysis of the PERSAT study]

OBJECTIVE

The objective of this sub-analysis of the PERSAT study was to evaluate the efficacy of hexanic extract of S. Repens (HESr) and alpha-blockers (AB), at 6 months in patients with moderate to severe LUTS/BPH.

METHODS

The PERSAT observational study was conducted in France by general practitioners on patients with BPH with an IPSS≥12 score. The primary endpoint was the percentage of responders (decrease in total IPSS score ≥ 3) at 6 months. Improvement in quality of life (IPSS-QoL) as well as patient satisfaction were also measured.

RESULTS

Of the 759 patients in the study, 324 treated with HESr and 309 with AB were reviewed at 6 months, with no change in treatment during follow-up. Characteristics at inclusion were globally similar with a mean IPSS of 18.2±4.9. The response rates at 6 months (IPSS-total decrease ≥ 3) were 93.7% and 94.8% for patients treated with HESr and AB, with a mean decrease in IPSS score of 10.1±5.6 points, which reached 13.6 and 14.8 points respectively, in severe patients (IPSS>19), without major difference between groups. More than 95% of HESr or AB patients reported a significant overall improvement in their LUTS/BPH. The most frequently reported adverse events with AB were ejaculation disorders (4.9%) and hypotension (4.2%) and with HESr digestive disorders (1.5%).

CONCLUSION

This sub-analysis of the PERSAT cohort reported the clinical efficacy of HESr and AB as a first-line treatment in the management of moderate or severe LUTS/BPH patients.

LEVEL OF EVIDENCE: 3

Lipid Profile and 5α-Reductase Inhibition Activity of Proprietary Ultrahigh-Pressure Supercritical Carbon Dioxide and Hexane Saw Palmetto Extracts

Inhibition of 5α-reductase (5αR), which blocks the conversion of testosterone to its active metabolite, dihydrotestosterone, has been shown to impact further prostate enlargement (benign prostatic hyperplasia, or BPH). Clinical trials of standardized lipidosterolic extracts of Serenoa repens (LSESr), also known as standardized extracts of saw palmetto, have demonstrated improvement in lower urinary tract symptoms (LUTS) and delayed progression of BPH. The aim of this preclinical study was to compare two standardized LSESr, a proprietary ultrahigh-pressure supercritical carbon dioxide extract of S. repens (UHP-sCESr) and the well-established hexanic extract of S. repens (HESr), for both 5αR inhibition activity and lipid profiles. UHP-sCESr and HESr had nearly identical inhibition curves and comparable IC50 values for 5αR-1 (9.25 ± 0.87 and 9.86 ± 0.11 μg/mL, respectively; p = 0.43) and 5αR-2 (7.47 ± 0.07 and 7.72 ± 0.05 μg/mL, respectively; p = 0.0544). UHP-sCESr and HESr also had comparable lipid profiles based on similar total fatty acid levels (87.7% and 91.5%, respectively), weight/weight comparisons of individual fatty acids, and individual fatty acid ratios to lauric acid. In addition, UHP-sCESr meets the standard set by the United States Pharmacopeia (USP) monograph for authenticity and purity for a supercritical carbon dioxide (SCCO2) extract of saw palmetto, whereas HESr meets the standard set by the European Medicines Agency (EMA) for a well-established medicinal product. In conclusion, based on enzyme inhibition curves and IC50 values, a standardized lipid profile is important to achieve comparable mechanisms of action for lipidosterolic extracts of saw palmetto. UHP-sCESr offers a comparable, standardized LSESr for men with LUTS/BPH in regions where the proprietary HESr is not available.

The Role of Combination Therapy with α-Blockers and Hexanic Extract of Serenoa repens in the Treatment of LUTS/BPH

The hexanic extract of Serenoa repens (HESr) has been in use for decades as an effective, safe and well-tolerated therapy for relieving bothersome lower urinary tract symptoms (LUTS) associated with benign prostate hyperplasia (BPH). This manuscript gives an overview of HESr as monotherapy for LUTS/BPH treatment and focuses on the currently available literature investigating the possible clinical benefits of HESr combination therapy with α-blockers. Combination therapy of HESr with α-blockers has been gaining significant interest in recent years, as an increasing body of evidence shows the beneficial pharmacological effects that HESr treatment can add to standard first-line treatment with α-blockers. By reducing persistent Prostatic Inflammatory Status (PIS), commonly present in LUTS/BPH patients, HESr complements the relaxation of prostate smooth muscle induced by α-blockers, thus providing additional symptom relief. Data suggest that patients harbouring PIS and having a specific clinical profile might especially benefit from the combination therapy. Future therapeutic efforts may take advantage of more personalised strategies for LUTS/BPH management.

Permixon®, hexane-extracted Serenoa repens, inhibits human prostate and bladder smooth muscle contraction and exerts growth-related functions in human prostate stromal cells

AIMS

Recently, the European Association of Urology recommended hexane-extracted fruit of Serenoa repens (HESr) in their guidelines on management of non-neurogenic male lower urinary tracts symptoms (LUTS). Despite previously lacking recommendations, Permixon® is the most investigated HESr in clinical trials, where it proved effective for male LUTS. In contrast, underlying mechanisms were rarely addressed and are only marginally understood. We therefore investigated effects of Permixon® on human prostate and detrusor smooth muscle contraction and on growth-related functions in prostate stromal cells.

MAIN METHODS

Permixon® capsules were dissolved using n-hexane. Contractions of human prostate and detrusor tissues were induced in organ bath. Proliferation (EdU assay), growth (colony formation), apoptosis and cell death (flow cytometry), viability (CCK-8) and actin organization (phalloidin staining) were studied in cultured human prostate stromal cells (WPMY-1).

KEY FINDINGS

Permixon® inhibited α₁-adrenergic and thromboxane-induced contractions in prostate tissues, and methacholine-and thromboxane-induced contractions in detrusor tissues. Endothelin-1-induced contractions were not inhibited. Neurogenic contractions were inhibited in both tissues in a concentration-dependent manner. In WPMY-1 cells, Permixon® caused concentration-dependent breakdown of actin polymerization, inhibited colony formation, reduced cell viability, and proliferation, without showing cytotoxic or pro-apoptotic effects.

SIGNIFICANCE

Our results provide a novel basis that allows, for the first time, to fully explain the ubiquitous beneficial effects of HESr in clinical trials. HESr may inhibit at least neurogenic, α₁-adrenergic and thromboxane-induced smooth muscle contraction in the prostate and detrusor, and in parallel, prostate stromal cell growth. Together, this may explain symptom improvements by Permixon® in previous clinical trials.

Efficacy and Tolerability of 6-Month Treatment with Tamsulosin Plus the Hexanic Extract of Serenoa repens versus Tamsulosin Plus 5-Alpha-Reductase Inhibitors for Moderate-to-Severe LUTS-BPH Patients: Results of a Paired Matched Clinical Study

The objective of this subset analysis was to evaluate and compare the efficacy and tolerability of two combination treatments for men with moderate-to-severe lower urinary tract symptoms associated with benign prostatic hyperplasia (LUTS/BPH). Data were from a real-world, open-label, prospective, and multicenter study performed in outpatient urology clinics. Men with moderate-to-severe LUTS/BPH received 6-month treatment with tamsulosin (TAM) in combination with either the hexanic extract of S. repens (HESr) or a 5-alpha-reductase inhibitor (5ARI). Changes in urinary symptoms and quality of life were measured using the IPSS and BII questionnaires, respectively. Treatment tolerability was assessed by recording adverse effects (AEs). Patients in the two study groups were matched using iterative and propensity score matching approaches. After iterative matching, data were available from 136 patients (n = 68 treated with TAM + 5ARI, n = 68 with TAM + HESr). After 6 months of treatment, mean (SD) IPSS total score improved by 7.7 (6.3) and 6.7 (5.0) points in the TAM + 5ARI and TAM + HESr groups, respectively (p = 0.272); mean BII total scores improved by 3.1 (2.9) and 2.9 (2.4) points (p = 0.751), respectively. AEs were reported by 26.5% and 10.3% of patients in the same groups, mostly affecting sexual function (p < 0.027). When used in a real-world setting to treat patients with moderate-severe LUTS/BPH, 6-month treatment with TAM + HESr was as effective as TAM + 5ARI, but with better tolerability.

Hexanic Extract of Serenoa repens (Permixon®): A Review in Symptomatic Benign Prostatic Hyperplasia

The hexanic extract (HE) of Serenoa repens (Permixon^®) is indicated for the symptomatic treatment of benign prostatic hyperplasia (BPH). The drug is the n-hexane lipidosterolic extract of the American dwarf palm tree (also known as saw palmetto). The anti-inflammatory activity of HE S.repens has been demonstrated in vitro, in vivo and in men with prostatic inflammation. In randomized clinical trials, the efficacy of HE S. repens was similar to that of an α-blocker in terms of improving voiding and storage symptoms, increasing urinary flow rate and reducing prostate volume in men with BPH. HE S. repens was also as effective as 5α-reductase inhibitors and/or α-blockers at improving lower urinary tract symptoms (LUTS) and quality of life (QOL) in real-world observational studies. HE S. repens was generally well tolerated, with a lesser impact on male sexual function compared with other available therapies. Thus, HE S. repens is a useful option for the treatment of symptomatic BPH.

BPH (enlargement of the prostate gland) compresses the urethra, leading to uncomfortable LUTS such as difficulty starting a urine stream, weak flow, incomplete bladder emptying, frequent urination, urgency, and waking at night to urinate. To avoid side effects often associated with other available treatments such as 5α-reductase inhibitors and α-blockers, plant extracts like HE Serenoa repens (Permixon^®) are commonly used to treat the symptoms of BPH. HE S. repens is derived from a small palm tree native to America and has been shown to have anti-inflammatory effects in prostate inflammation. In clinical studies, HE S. repens was as effective as an α-blocker at improving urinary symptoms, increasing urinary flow rate and reducing prostate volume in men with BPH. In real-world studies, HE S. repens was as effective as 5α-reductase inhibitors and/or α-blockers at improving LUTS and QOL. European guidelines recommend HE S. repens as a treatment option for men with LUTS who want to avoid any potential side effects, especially those related to sexual function. HE S. repens was generally well tolerated, and is a useful option for the treatment of symptomatic BPH.

Efficacy and Safety of the Hexanic Extract of Serenoa repens vs. Watchful Waiting in Men with Moderate to Severe LUTS-BPH: Results of a Paired Matched Clinical Study

We investigated changes in symptoms and quality of life (QoL) in men with moderate-to-severe lower urinary tract symptoms associated with benign prostatic hyperplasia (LUTS/BPH) receiving the hexanic extract of Serenoa repens (HESr) and compared results with a matched group on watchful waiting (WW). Data was from a real-world, open-label, prospective, multicenter study. This sub-group analysis included patients with moderate-to-severe symptoms receiving either the HESr 320 mg/daily for six months (HESr) or who remained untreated for LUTS/BPH (WW). Changes in urinary symptoms and QoL were measured by IPSS and BII questionnaires. Two statistical approaches (iterative matching and propensity score pairing) were used to maximize between-group comparability at baseline. Tolerability was assessed in the HESr group. After iterative matching, data for analysis was available for 783 patients (102 WW, 681 HESr). IPSS scores improved by a mean (SD) of 3.8 (4.4) points in the HESr group and by 2.2 (4.5) points in the WW group (p = 0.002). Changes in BII score were 1.8 (2.4) points and 1.0 (2.2) points, respectively (p < 0.001). Three patients (0.9%) treated with the HESr reported mild adverse effects. Moderate-severe LUTS/BPH patients treated for six months with the HESr showed greater improvements in symptoms and QoL than matched patients on WW, with a very low rate of adverse effects.

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).