Novel drug targets for the pharmacotherapy of benign prostatic hyperplasia (BPH)

Future aspects of plant derived bioactive metabolites as therapeutics to combat benign prostatic hyperplasia

ETHNOPHARMACOLOGICAL RELEVANCE

Benign prostatic hyperplasia (BPH), characterized by prostate enlargement due to cell proliferation, is a common urinary disorder in men over 50, manifesting as lower urinary tract symptoms (LUTS). Currently, several therapeutic options are accessible for treating BPH, including medication therapy, surgery and watchful waiting. Conventional drugs such as finasteride and dutasteride are used as 5α-reductase inhibitors for the treatment of BPH. However long-term use of these drugs is restricted due to their unpleasant side effects. Despite the range of available medical therapies, the effective treatment against BPH is still inadequate. Certain therapeutic plants and their phytochemicals have the aforementioned goals and work by regulating this enzyme.

AIM OF THE STUDY

This review aims to provide a comprehensive insight to advancements in diagnosis of BPH, modern treatment methods and the significance of ethnobotanically relevant medicinal plants as alternative therapeutics for managing BPH.

MATERIAL AND METHODS

A thorough and systematic literature search was performed using electronic databases and search engines such as PubMed, Web of Science, NCBI and SciFinder till October 2023. Specific keywords such as "benign prostatic hyperplasia", "medicinal plants", "phytochemicals", "pharmacology", "synergy", "ethnobotany", "5-alpha reductase", "alpha blocker" and "toxicology". By include these keywords, a thorough investigation of pertinent papers was assured, and important data about the many facets of BPH could be retrieved.

RESULTS

After conducting the above investigation, 104 herbal remedies were found to inhibit Phosphodiesterase-5 (PDE-5) inhibition, alpha-blockers, or 5α -reductase inhibition effects which are supported by in vitro, in vivo and clinical trial studies evidence. Of these, 89 plants have ethnobotanical significance as alpha-blockers, alpha-reductase inhibition, or PDE-5 inhibition, and the other fifteen plants were chosen based on their ability to reduce BPH risk factors. Several phytocompounds, including, rutaecarpine, vaccarin, rutin, kaempferol, β-sitosterol, quercetin, dicaffeoylquinic acid, rutaevin, and phytosterol-F have been reported to be useful for the management of BPH. The use of combination therapy offers a strong approach to treating long-term conditions compare to single plant extract drugs. Furthermore, several botanical combinations such as lycopene and curcumin, pumpkin seed oil and saw palmetto oil, combinations of extracts from Funtumia africana (Benth.) Stapf and Abutilon mauritianum (Jacq.) Medik., and Hypselodelphys poggeana (K.Schum.) Milne-Redh. and Spermacoce radiata (DC.) Sieber ex Hiern are also supported through in vitro and in vivo studies for managing BPH through recuperation in patients with chronic long-term illnesses, as measured by the International Prostate Symptom Score.

CONCLUSION

The review proposes and endorses careful utilization of conventional medications that may be investigated further to discover possible PDE-5, 5 alpha-reductase, an alpha-blocker inhibitor for managing BPH. Even though most conventional formulations, such as 5 alpha-reductase, are readily available, systemic assessment of the effectiveness and mechanism of action of the herbal constituents is still necessary to identify novel chemical moieties that can be further developed for maximum efficacy. However, there exist abundant botanicals and medicinal plants across several regions of Africa, Asia, and the Americas, which can be further studied and developed for utilization as a potential phytotherapeutic for the management of BPH.

Effects of the CB1 receptor antagonists AM6545 and AM4113 on metabolic syndrome-induced prostatic hyperplasia in rats

Metabolic syndrome (MetS) is a combination of metabolic disorders that can predispose individuals to benign prostatic hyperplasia (BPH). The inhibition of the cannabinoid 1 (CB1) receptor has been used to treat metabolic disorders in animal models. This study reports the use of a peripherally restricted CB1 antagonist (AM6545) and a neutral CB1 antagonist (AM4113) to improve MetS-related BPH in rats. Animals were divided into three control groups to receive either a normal rodent diet, AM6545, or AM4113. MetS was induced in the fourth, fifth, and sixth groups using a concentrated fructose solution and high-salt diet delivered as food pellets for eight weeks. The fifth and sixth groups were further given AM6545 or AM4113 for additional four weeks. Body and prostate weights were measured and prostate sections were stained with hematoxylin eosin. Cyclin D1, markers of oxidative stress and inflammation, and levels of the endocannabinoids were recorded. BPH in rats with MetS was confirmed through increased prostate weight and index, as well as histopathology. Treatment with either AM6545 or AM4113 significantly decreased prostate weight, improved prostate histology, and reduced cyclin D1 expression compared with the MetS group. Groups treated with CB1 antagonists experienced reduced lipid peroxidation, recovered glutathione depletion, restored catalase activity, and had lower inflammatory markers interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α). MetS rats treated with either AM6545 or AM4113 showed reduced concentrations of anandamide (AEA) and 2-arachidonoylglycerol (2-AG) in the prostate compared with the MetS group. In conclusion, the CB1 antagonists AM6545 and AM4113 protect against MetS-induced BPH through their anti-proliferative, antioxidant, and anti-inflammatory effects.

Analysis of genetic biomarkers, polymorphisms in ADME-related genes and their impact on pharmacotherapy for prostate cancer

Prostate cancer (PCa) is a non-cutaneous malignancy in males with wide variation in incidence rates across the globe. It is the second most reported cause of cancer death. Its etiology may have been linked to genetic polymorphisms, which are not only dominating cause of malignancy casualties but also exerts significant effects on pharmacotherapy outcomes. Although many therapeutic options are available, but suitable candidates identified by useful biomarkers can exhibit maximum therapeutic efficacy. The single-nucleotide polymorphisms (SNPs) reported in androgen receptor signaling genes influence the effectiveness of androgen receptor pathway inhibitors and androgen deprivation therapy. Furthermore, SNPs located in genes involved in transport, drug metabolism, and efflux pumps also influence the efficacy of pharmacotherapy. Hence, SNPs biomarkers provide the basis for individualized pharmacotherapy. The pharmacotherapeutic options for PCa include hormonal therapy, chemotherapy (Docetaxel, Mitoxantrone, Cabazitaxel, and Estramustine, etc.), and radiotherapy. Here, we overview the impact of SNPs reported in various genes on the pharmacotherapy for PCa and evaluate current genetic biomarkers with an emphasis on early diagnosis and individualized treatment strategy in PCa.

Traditional Chinese Medicine Danzhi qing'e decoction inhibits inflammation-associated prostatic hyperplasia via inactivation of ERK1/2 signal pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Inflammation plays a critical role during benign prostatic hyperplasia (BPH) development. Danzhi qing'e (DZQE) decoction is a traditional Chinese medicine that has been widely used for estrogen and androgen-related diseases. However, its effect on inflammation-related BPH remains unclear.

AIM OF THE STUDY

To investigate the effect of DZQE on inhibition of inflammation-related BPH, and further identify the possible mechanism involved.

METHODS AND MATERIALS

Experimental autoimmune prostatitis (EAP)-induced BPH was established and then 2.7 g/kg of DZQE was administrated orally for 4 weeks. The prostate sizes, weights and prostate index (PI) values were recorded. Hematoxylin and eosin (H&E) was performed for pathological analyses. Macrophage infiltrate was evaluated by Immunohistochemical (IHC). The inflammatory cytokine levels were measured by Rt-PCR and ELISA methods. The phosphorylation of ERK1/2 was examined by Western blot. The expression differences of mRNA expressions between EAP-induced and oestrogen/testosterone (E2/T)-induced BPH was investigated by RNA sequencing analyses. In vitro, human prostatic epithelial BPH-1 cells were stimulated with the conditioned medium from monocyte THP-1-derived M2 macrophages (M2CM), followed by treatment of Tanshinone IIA (Tan IIA), Bakuchiol (Ba), ERK1/2 antagonist PD98059 or ERK1/2 agonist C6-Ceramide. The ERK1/2 phosphorylation and cell proliferation were then detected by Western blotting and CCK8 assay.

RESULTS

DZQE significantly inhibited the prostate enlargement and decreased PI value in EAP rats. Pathological analysis showed that DZQE alleviated prostate acinar epithelial cell proliferation by decreasing and reduction of CD68⁺ and CD206⁺ macrophage infiltration in the prostate. The levels of cytokines TNF-α, IL-1β, IL-17, MCP-1, TGF-β, and IgG in EAP rats' prostate or serum were significantly suppressed by DZQE as well. Moreover, mRNA sequencing data showed that the expressions of inflammation-related genes were elevated in EAP-induced BPH but not in E2/T-induced BPH. ERK1/2-related genes expression has been found in both E2/T and EAP-induced BPH. ERK1/2 is one of the core signal pathways involved in EAP-induced BPH, which was activated in EAP group but inactivated in DZQE group. In vitro, two active components of DZQE Tan IIA and Ba inhibited M2CM-induced BPH-1 cell proliferation, similarly to ERK1/2 inhibitor PD98059 did. Meanwhile, Tan IIA and Ba inhibited M2CM-induced ERK1/2 signal activation in BPH-1 cells. When re-activated the ERK1/2 by its activator C6-Ceramide, the inhibitory effects of Tan IIA and Ba on BPH-1 cell proliferation were blocked.

CONCLUSION

DZQE suppressed inflammation-associated BPH via regulation of ERK1/2 signal by Tan IIA and Ba.

In-vivo and in-silico studies revealed the molecular mechanisms of Colocasia esculenta phenolics as novel chemotherapy against benign prostatic hyperplasia via inhibition of 5α-reductase and α1-adrenoceptor

Benign Prostatic Hyperplasia (BPH) is a major cause of lower urinary tract infections and erectile dysfunction thus a major contributor to lowering the quality of life among older men. In this study, we investigated the molecular mechanism of Colocasia esculenta (CE) as a novel agent for BPH chemotherapy. In vivo, we assigned 45 male Wistar albino rats about 6 weeks old into 9 experimental groups (n = 5). BPH was induced in groups 2-9 with 3 mg/kg of Testosterone Propionate (TP) subcutaneously. Group 2 (BPH) was not treated. Group 3 was treated with 5 mg/kg Finasteride (standard drug). Group 4-9 were treated each with 200 mg/kg body weight (b.w) of CE crude tuber extracts/fractions (ethanol, hexane, dichloromethane, ethyl acetate, butanol, aqueous). At the end of treatment, we sampled the rats' serum to check the level of PSA. In silico, we conducted a molecular docking of the crude extract of CE phenolics (CyP) previously reported, targeting 5α-Reductase and α1-Adrenoceptor linked to the BPH progressions. We adopted the standard inhibitors/antagonists (5α-reductase: finasteride; α1-adrenoceptor: tamsulosin) of the target proteins as controls. Furthermore, the pharmacological properties of the lead molecules were studied in terms of ADMET using swissadme and pKCSM resources, respectively. Results showed that administration of TP in male Wistar albino rats significantly (p < 0.05) elevated serum PSA levels whereas CE crude extracts/fractions significantly (p < 0.05) lowered the serum PSA level. Also, fourteen of the CyPs bind to at least one or two of the target proteins with their binding affinity of between - 9.3 to - 5.6 kcal/mol and - 6.9 to - 4.2 kcal/mol, respectively. The CyPs possess better pharmacological properties compared to the standard drugs. Therefore, they have the potentials to be enlisted for clinical trials towards the management of BPH.

Graphical Abstract

Application of Box-Behnken Design in the Preparation, Optimization, and In-Vivo Pharmacokinetic Evaluation of Oral Tadalafil-Loaded Niosomal Film

Benign prostatic hyperplasia (BPH) affects about 90% of men whose ages are over 65. Tadalafil, a selective PDE-5 inhibitor, was approved by FDA for BPH, however, its poor aqueous solubility and bioavailability are considered major drawbacks. This work intended to develop and evaluate oral fast dissolving film containing tadalafil-loaded niosomes for those who cannot receive the oral dosage form. Niosomes were statistically optimized by Box-Behnken experimental design and loaded into a polymeric oral film. Niosomes were assessed for their vesicular size, uniformity, and zeta potential. The thickness, content uniformity, folding endurance, tensile strength, disintegration time, and surface morphology were evaluated for the prepared polymeric film. The optimized niosomes revealed high entrapment efficiency (99.78 ± 2.132%) and the film was smooth with good flexibility and convenient thickness (110 ± 10 µm). A fast release of tadalafil was achieved within 5 min significantly faster than the niosomes-free drug film. The in-vivo bioavailability in rats established that the optimized niosomal film enhanced tadalafil systemic absorption, with higher peak concentration (C_max = 0.63 ± 0.03 µg/mL), shorter T_max value (0.66-fold), and relative bioavailability of 118.4% compared to the marketed tablet. These results propose that the oral film of tadalafil-loaded niosomes is a suitable therapeutic application that can be passed with ease to geriatric patients who suffer from BPH.

The Effect Of Continuously Dutasteride Monotherapy on The Expression Of Protein Kinase C-Alpha Enzyme In BPH Model Of Wistar Strain Rattus Novergicus Rat

Background

Benign prostate hyperplasia (BPH) is frequently found in the elderly and significantly impacts the quality of life. One of the risk factors that induce BPH is the androgen hormone. One of the effective medications in reducing the severity of Lower Urinary Tract Symptoms caused by BPH is the α-adrenergic receptor 5α-reductase inhibitor.

Objective

The study aims to see the effect of long-term dutasteride on the expression of the PKC-α enzyme in prostatic stromal tissue in the BPH Model of Wistar strain Rattus norvegicus rats.

Method

This study was an experimental, post-test-only, control group design that used randomization in sample selection. The objective is to measure the expression of PKC-α enzyme from prostate tissue of an adult male Wistar Strain of Rattus Novergicus rat that was given testosterone to induce BPH and given dutasteride in 1,3 and 6 days continuously. Data is shown in mean±SD, and all of the data were analyzed using the software SPSS 21st version with the One Way ANOVA Statistical method after fulfilling the normality test and variant homogeneity test. Data analysis with confidence rate 95% and a=0,05.

Results

There was a decrease of PKC-α enzyme and prostate weight in dutasteride monotherapy in 1,3,6 days compared to the positive control, and the lowest value was on the sixth day (SD ± 2876.8). There was a constant decrease of PKC-α enzyme from the first day until the sixth day.

Conclusion

In conclusion, long-term dutasteride monotherapy could significantly decrease the level of PKC-α enzyme. There was no upregulation of the PKC-α enzyme in the long term of dutasteride monotherapy.

Cleistanthins A and B Ameliorate Testosterone-Induced Benign Prostatic Hyperplasia in Castrated Rats by Regulating Apoptosis and Cell Differentiation

Background The aging male population is at higher risk for benign prostatic hyperplasia (BPH) wherein increased proliferation of stromal and epithelial cells of the prostate is observed. In this study, we investigated the effect of cleistanthins A and B on the inhibition of testosterone-induced BPH in castrated rats. Methodology Male Wistar rats were divided into eight groups (n = 6) and surgical castration was performed. BPH was induced by the administration of testosterone propionate in corn oil at 5 mg/kg for four weeks. The control group received corn oil, and the model group received testosterone propionate. The standard treatment group received finasteride orally along with testosterone. Cleistanthins A and B at 0.3, 1, and 3 mg/kg were administered by oral gavage along with testosterone. After four weeks, rats were sacrificed, and prostates were weighed and assessed for histomorphological, inflammatory, apoptotic, and proliferative markers. Results Cleistanthins A and B decreased prostatic enlargement and histopathological abnormalities. Elevated serum dihydrotestosterone levels were lowered significantly in both the cleistanthin A and cleistanthin B groups compared to the BPH model group. Cleistanthins A and B significantly lowered the serum interleukin (IL)-1β and tumor necrosis factor-alpha inflammatory markers in the test groups. Western blot analysis revealed cleistanthin A downregulated the IL-6, signal transducer and activator of transcription 3/cyclin D1 signaling pathway. Both cleistanthins A and B upregulated the apoptotic markers caspase-3 and cleaved caspase-3, whereas the cell proliferation markers cyclin D1 and proliferating cell nuclear antigen were found to be downregulated. Conclusions Both cleistanthins A and B inhibited BPH in a rat model by apoptotic induction and impeded cell proliferation.

Cordycepin Attenuates Testosterone-Induced Benign Prostatic Hyperplasia in Rats via Modulation of AMPK and AKT Activation

Benign prostatic hyperplasia (BPH) is a disease that commonly affects elderly men. Cordycepin is an adenosine analog with a wide range of pharmacological activities including antiproliferative and prostatic smooth muscle relaxant effects. This study was designed to assess the actions of cordycepin in testosterone-induced BPH in rats. Animals were divided into six treatment groups: control, cordycepin-alone (10 mg/kg), testosterone-alone (3 mg/kg), cordycepin (5 mg/kg) + testosterone, cordycepin (10 mg/kg) + testosterone, and finasteride (0.5 mg/kg) + testosterone. Treatments were continued daily, 5 days a week, for 4 weeks. Cordycepin significantly prevented the increase in prostate weight and prostate index induced by testosterone. This was confirmed by histopathological examinations. Cordycepin antiproliferative activity was further defined by its ability to inhibit cyclin-D1 and proliferating cell nuclear antigen (PCNA) expression. In addition, cordycepin exhibited significant antioxidant properties as proven by the prevention of lipid peroxidation, reduced glutathione diminution, and superoxide dismutase exhaustion. This was paralleled by anti-inflammatory activity as shown by the inhibition of interleukin-6, tumor necrosis factor-α, and nuclear factor-κB expression in prostatic tissues. It also enhanced apoptosis as demonstrated by its ability to enhance and inhibit mRNA expression of Bax and Bcl2, respectively. Western blot analysis indicated that cordycepin augmented phospho-AMP-activated protein kinase (p-AMPK) and inhibited p-AKT expression. Collectively, cordycepin has the ability to prevent testosterone-induced BPH in rats. This is mediated, at least partially, by its antiproliferative, antioxidant, anti-inflammatory, and pro-apoptotic actions in addition to its modulation of AMPK and AKT activation.

Aqueous extracts of Urtica dioica (stinging nettle) leaf contain a P2-purinoceptor antagonist—Implications for male fertility

Stinging nettle root and leaf extracts were tested for their effect on prostatic smooth muscle contractility. Root extract did not affect electrical field stimulation induced-nerve mediated contractions of isolated rat prostates. On the other hand, leaf extract attenuated electrical field stimulation-induced contractions at all frequencies. Similarly, contractions elicited by exogenous administration of ATP and αβ-methylene ATP were inhibited by leaf extract, whereas contractions elicited by exogenous administration of noradrenaline or acetylcholine were unaffected. The active component was present within the aqueous phase of the leaf extract. In mouse mating studies, stinging nettle leaf extract (50 mg p.o. daily) reduced male fertility by 53% compared to vehicle-treated male mice. Cardiovascular parameters were unaffected by administration of stinging nettle leaf extract (p ≥ 0.057). Treated mice exhibited normal mating behaviour. Bladder and testes weighed less in stinging nettle leaf extract treated mice. All other organs and total body weight were unaffected. It is concluded that stinging nettle leaf extract reduces contractility of genitourinary smooth muscle by acting as an antagonist at postjunctional P2X1-purinoceptors. These data indicates that blocking sperm transport through pharmacological blockade of P2X1-purinoceptors via oral administration is consistent with an effective and convenient biological strategy male contraception.

Computational analysis of protein-protein interaction network of differentially expressed genes in benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is a commonly occurring disease in aging men. It involves cellular proliferation of stromal and glandular tissues leading to prostate enlargement. Current drug therapies show several adverse effects such as sexual dysfunctions and cardiovascular side effects. Therefore, there is a need to develop more effective medical treatment for BPH. In this regard, we aimed to identify genes which play a critical role in BPH. We have obtained the dataset of differentially expressed genes (DEGs) of BPH from NCBI GEO. DEGs were investigated in the context of their protein-protein interactions (PPI). Hub genes i.e. genes associated with BPH were scrutinized based on the topological parameters of the PPI network. These were analyzed for functional annotations, pathway enrichment analysis and transcriptional regulation. In total, 38 hub genes were identified. Hub genes such as transcription factor activator protein-1 and adiponectin were found to play key roles in cellular proliferation and inflammation. Another gene peroxisome proliferator activated receptor gamma was suggested to cause obesity, a common comorbidity of BPH. Moreover, our results indicated an important role of transforming growth factor-beta (TGF-β) signaling and smooth muscle cell proliferation which may be responsible for prostate overgrowth and associated lower urinary tract symptoms frequently encountered in BPH patients. Zinc finger protein Snai1 was the most prominent transcription factor regulating the expression of hub genes that participate in TGF-β signaling. Overall, our study has revealed significant hub genes that can be employed as drug targets to develop potential therapeutic interventions to treat BPH.

Curcumin attenuates prostatic hyperplasia caused by inflammation via up-regulation of bone morphogenetic protein and activin membrane-bound inhibitor

CONTEXT

Inflammation and epithelial-mesenchymal transition (EMT) play important roles in the occurrence and development of benign prostatic hyperplasia (BPH); curcumin exerts anti-proliferative, anti-inflammatory, and anti-EMT effects.

OBJECTIVE

To explore the anti-inflammatory and anti-EMT mechanisms of curcumin in BPH.

MATERIALS AND METHODS

Ten-week-old male C57BL/6 mice were administered lipopolysaccharide (LPS, 100 µg/kg) in the prostate lobules to establish an inflammatory BPH model (LPS group), and curcumin (120 mg/kg) was administered into the abdominal cavity for 2 weeks (three times a week, curcumin-treated group). A group of healthy mice served as the control group. The expression of Toll-like receptor 4 (TLR4), bone morphogenetic protein and activin membrane-bound inhibitor (BAMBI), EMT markers, inflammatory cytokines, and transforming growth factor β1 (TGF-β1) was detected by PCR and western blotting. TGF-β1 (0.1 ng/mL) and LPS (100 ng/mL) were used to induce EMT in benign prostatic hyperplasia epithelial cells (BPH-1).

RESULTS

In vivo, curcumin reduced the size of the prostate, suppressed the expression of vimentin and TLR4, and increased the expression of E-cadherin and BAMBI in the LPS-induced BPH mouse model. Moreover, curcumin decreased the levels of IL-6 and TNF-α by 44.52 and 46.17%, respectively. In vitro, curcumin attenuated cell proliferation, suppressed the expression of vimentin and TLR4, and increased the expression of E-cadherin and BAMBI in BPH-1 cells. Furthermore, BAMBI knockdown reversed the expression of vimentin and E-cadherin induced by curcumin.

DISCUSSION AND CONCLUSION

This study demonstrated that curcumin alleviated hyperplasia, EMT, and inflammation in vivo. Furthermore, curcumin suppressed EMT by targeting BAMBI via the TLR4/BAMBI/TGF-β1 signalling pathway in vitro, demonstrating its potential utility in BPH treatment.

Lenalidomide and pomalidomide inhibit growth of prostate stromal cells and human prostate smooth muscle contraction

AIMS

Medical treatment for lower urinary tract symptoms secondary to benign prostatic hyperplasia is characterized by an unfavorable balance between limited efficacy and pronounced side effects. We recently reported, that thalidomide reduces prostate smooth muscle contraction and inhibits cell growth. Like thalidomide, its analogs lenalidomide and pomalidomide are also in clinical use. Therefore, we investigated the effects of lenalidomide and pomalidomide on human prostate smooth muscle contraction, cytoskeletal organization, and growth-related functions in stromal cells.

MATERIALS AND METHODS

Proliferation was assessed by EdU assay and colony formation, cytoskeletal organization by phalloidin staining, cell viability by CCK8, and apoptosis and cell death by flow cytometry in cultured prostate stromal cells (WPMY-1). Contractions of human prostate tissues from radical prostatectomy were induced by methoxamine, noradrenaline, phenylephrine, endothelin-1, U46619, or electric field stimulation (EFS) in an organ bath.

KEY FINDINGS

Proliferation of WPMY-1 cells was significantly reduced by lenalidomide (5-200 μM) and pomalidomide (2.5-5 μM). In parallel, organization of actin filaments collapsed after treatment with lenalidomide and pomalidomide. Lenalidomide and pomalidomide inhibited both adrenergic contractions and non-adrenergic contractions as well as neurogenic contractions induced by EFS. Neither reduction in viability, nor increase in cell death or apoptosis was observed in WPMY-1 cells.

SIGNIFICANCE

Thalidomide-derivatives impair growth of human prostate stromal cells, without showing a decrease in cell viability and, in parallel, inhibit adrenergic, neurogenic, and non-adrenergic contractions by breakdown of the actin cytoskeleton. Urodynamic effects in vivo appear possible.

Inhibition of human prostate stromal cell growth and smooth muscle contraction by thalidomide: A novel remedy in LUTS?

BACKGROUND

Medical treatment in benign prostatic hyperplasia targets prostate size to prevent disease progression, complications, and surgery, and prostate smooth muscle tone for rapid relief of lower urinary tract symptoms. Combination therapies are still required to target both at once. However, current medications are insufficient, due to an unfavorable balance between side effects and efficacy. The limited efficacy of α₁ -blockers may be due to nonadrenergic mediators like endothelin-1 and thromboxane A₂ (TXA₂ ), which keep up prostate smooth muscle contraction even in the presence of α₁ -blockers. Consequently, future options with higher efficacy need to target α₁ -adrenergic and nonadrenergic contractions as well as stromal cell growth at once. Thalidomide has been approved as an oral medication for various diseases, including the treatment of prostate cancer. Therefore, we investigated the effect of thalidomide on cellular functions of prostate stromal cells and human prostate smooth muscle contraction.

METHODS

Cytoskeletal organization was visualized by phalloidin staining, cell growth was assessed by 5-ethynyl-2'-deoxyuridine assay, cell viability by cell counting kit-8, and apoptosis and cell death by flow cytometry in cultured prostate stromal cells (WPMY-1). Contractions of human prostate tissues from radical prostatectomy were studied in an organ bath, where they were induced by the α₁ -adrenoceptor agonists methoxamine, noradrenaline, phenylephrine, and the nonadrenergic agonists endothelin-1, TXA₂ analog U46619, or electric field stimulation (EFS).

RESULTS

Thalidomide significantly reduced the proliferation of WPMY-1 cells, which was time- and concentration-dependent (10-300 µM). In parallel, organization of actin filaments collapsed after treatment with thalidomide. Thalidomide (30-100 µM) inhibited noradrenaline-, phenylephrine-, and methoxamine-induced contractions, as well as nonadrenergic contractions induced by endothelin-1 and U46619, and neurogenic contractions induced by EFS. No reduction in viability and no increases in apoptosis or in cell death were observed in WPMY-1 cells.

CONCLUSIONS

Thalidomide impairs the growth of human prostate stromal cells, without showing a decrease in cell viability. In parallel, thalidomide inhibits adrenergic, neurogenic, and nonadrenergic contractions. This may be explained by a breakdown of the actin cytoskeleton. In vivo, urodynamic effects of thalidomide appear possible and may even exceed those of α₁ -blockers or combination therapies.

An inhibitory effect of Berberine from herbal Coptis chinensis Franch on rat detrusor contraction in benign prostatic hyperplasia associated with lower urinary tract symptoms

ETHNOPHARMACOLOGICAL RELEVANCE

Coptis chinensis Franch (CCF), also known as Huang Lian in China, is a traditional Chinese medicine that commonly used for more than 2000 years. Clinically, CCF often used as anti-inflammatory, immune regulation and other effects. It has been reported that the decoction containing CCF can be used for the treatment of benign prostatic hyperplasia (BPH) or lower urinary tract symptoms (LUTS).

AIM OF THE STUDY

This research aims to investigate the effect of CCF on inhibition of BPH development in vivo and in vitro, and further identify the active compound (s) and the possible mechanism involved in BPH-related bladder dysfunction.

MATERIALS AND METHODS

Oestrodial/testosterone-induced BPH rat model was established as the in vivo model. The prostate index (PI) was calculated, the pathogenesis was analyzed and the micturition parameters were determined in the shamed-operated, BPH model and BPH + CCF groups after 4-week administration. The tension in detrusor strips was then assessed upon KCl or ACh stimulation with or without incubation of CCF or active compounds. To further investigate the signaling involved, rat detrusor cells were cultured as the in vitro models, the instantaneous calcium influx was measured and the ROCK-1 expression was detected.

RESULTS

Increased PI value and the aggravated prostatic pathology were observed with voiding dysfunction in BPH rats, which were significantly blocked by oral CCF taken. ACh or KCl-induced contractile responses in detrusor strips were significantly inhibited and the micturition parameters were improved when incubation with CCF or its active compounds such as berberine. Both CCF and berberine suppressed the cellular calcium influx and ROCK-1 expression upon ACh stimulation, demonstrating that berberine was one of the active compounds that contributed to CCF-improved micturition symptoms and function.

CONCLUSIONS

Taken together, our findings give evidence that CCF and its active compound berberine inhibited BPH and bladder dysfunction via Ca²⁺ and ROCK signaling, supporting their clinical use for BPH and BPH-related LUTS treatment.

Light-controlled calcium signalling in prostate cancer and benign prostatic hyperplasia

Background

Identifying ways to reduce the burden of prostate cancer (Pca) or benign prostatic hyperplasia (BPH) is a top research priority. It is a typical entanglement seen in men which is portrayed by trouble in micturition. It stands as a significant problem in our society. Different molecular biomarker has high potential to treat Pca or BPH but also causes serious side effects during treatment.

Main text

The role of calcium signalling in the alteration of different biomarkers of Pca or BPH is important. Therefore, the photoswitch drugs may hold the potential to rebalance the altered calcium signaling cascade and the biomarker levels. Thereby play a significant role in the management of Pca and BPH. Online literature searches such as PubMed, Web of Science, Scopus, and Google Scholar were carried out. The search terms used for this review were photo-pharmacology, photo-switch drug, photodynamic therapy, calcium signalling, etc. Present treatment of Pca or BPH shows absence of selectivity and explicitness which may additionally result in side effects. The new condition of the calcium flagging may offer promising outcomes in restoring the present issues related with prostate malignancy and BPH treatment.

Conclusion

The light-switching calcium channel blockers aim to solve this issue by incorporating photo-switchable calcium channel blockers that may control the signalling pathway related to proliferation and metastasis in prostate cancer without any side effects.

Graphical abstract

Schematic diagram explaining the proposed role of photo-switch therapy in curbing the side effects of active drugs in Pca (prostate cancer) and BPH (benign prostatic hyperplasia). a) Delivery of medication by ordinary strategies and irreversible phototherapy causes side effects during treatment. Utilization of photo-switch drug to control the dynamic and inert condition of the medication can cause the medication impacts as we required in prostate cancer and BPH. b) Support of harmony between the calcium signaling is essential to guarantee ordinary physiology. Increment or abatement in the dimensions of calcium signaling can result in changed physiology. c) Major factors involved in the pathogenesis of BPH; downregulation of vitamin D receptor (VDR) and histone deacetylase (HDAC) can prevent BPH. Similarly, downregulation of α-1 adrenoceptor can reduce muscle contraction, while overexpression of β-3 adrenoceptor in BPH can promote further muscle relaxation in BPH treatment therapy. Inhibition of overexpressed biomarkers in BPH TRPM2-1: transient receptor potential cation channel subfamily M member 1; TRPM2-2: transient receptor potential cation channel subfamily M member 2; Androgens; CXCL5: C-X-C motif chemokine ligand 5; TGFβ-1: transforming growth factor β-1; TXA2; thromboxane-2; NMDA: N-methyl-d-aspartate can be the potential target in BPH therapy.

Inhibition of neurogenic and thromboxane A2 -induced human prostate smooth muscle contraction by the integrin α2β1 inhibitor BTT-3033 and the integrin-linked kinase inhibitor Cpd22

INTRODUCTION

Prostate smooth muscle contraction is critical for etiology and treatment of lower urinary tract symptoms in benign prostatic hyperplasia (BPH). Integrins connect the cytoskeleton to membranes and cells to extracellular matrix, what is essential for force generation in smooth muscle contraction. Integrins are composed of different subunits and may cooperate with integrin-linked kinase (ILK). Here, we examined effects of inhibitors for different integrin heterodimers and ILK on contraction of human prostate tissues.

METHODS

Prostate tissues were obtained from radical prostatectomy. Integrins and ILK were detected by Western blot, real-time polymerase chain reaction (RT-PCR), and double fluorescence staining. Smooth muscle contractions of prostate strips were studied in an organ bath. Contractions were compared after application of solvent (controls), the ILK inhibitor Cpd22 (N-methyl-3-(1-(4-(piperazin-1-yl)phenyl)-5-(4'-(trifluoromethyl)-[1,1'-biphenyl]-4-yl)-1H-pyrazol-3-yl)propanamide), the integrin α2β1 inhibitor BTT-3033 (1-(4-fluorophenyl)-N-methyl-N-[4[[(phenylamino)carbonyl]amino]phenyl]-1H-pyrazole-4-sulfonamide), or the integrin α4β1/α9β1 inhibitor BOP (N-(benzenesulfonyl)- l-prolyl- l-O-(1-pyrrolidinylcarbonyl)tyrosine sodium salt).

RESULTS

Western blot analyses of prostate tissues using antibodies raised against integrins α2b, α4, α9, β1, and ILK revealed bands matching the expected sizes of corresponding antigens. Expression of integrins and ILK was confirmed by RT-PCR. Individual variations of expression levels occurred independently from divergent degree of BPH, reflected by different contents of prostate-specific antigen. Double fluorescence staining of prostate sections using antibodies raised against integrins α2 and β1, or against ILK resulted in immunoreactivity colocalizing with calponin, suggesting localization in prostate smooth muscle cells. Electric field stimulation (EFS) induced frequency-dependent contractions, which were inhibited by Cpd22 (3 µM) and BTT-3033 (1 µM) (inhibition around 37% by Cpd22 and 46% by BTT-3033 at 32 Hz). The thromboxane A₂ analog U46619-induced concentration-dependent contractions, which were inhibited by Cpd22 and BTT-3033 (around 67% by Cpd22 and 39% by BTT-3033 at 30 µM U46619). Endothelin-1 induced concentration-dependent contractions, which were not affected by Cpd22 or BTT-3033. Noradrenaline and the α₁ -adrenergic agonists methoxamine and phenylephrine-induced concentration-dependent contractions, which were not or very slightly inhibited by Cpd22 and BTT-3033. BOP did not change EFS- or agonist-induced contraction.

CONCLUSIONS

Integrin α2β1 and ILK inhibitors inhibit neurogenic and thromboxane A₂ -induced prostate smooth muscle contraction in human BPH. A role for these targets for prostate smooth muscle contraction may appear possible.

A NAV2729-sensitive mechanism promotes adrenergic smooth muscle contraction and growth of stromal cells in the human prostate

Voiding symptoms in benign prostatic hyperplasia (BPH) are driven by prostate smooth muscle contraction and prostate growth. Smooth muscle contraction in the prostate and other organs critically depends on activation of the small monomeric GTPase RhoA and probably Rac1. A role of another GTPase, ADP-ribosylation factor 6 (ARF6), for smooth muscle contraction has been recently suggested by indirect evidence but remains to be proven for any organ. Here, we report effects of NAV2729, an inhibitor with assumed specificity for ARF6, in human prostate tissues and cultured prostate stromal cells (WPMY-1). NAV2729 (5 μm) inhibited neurogenic and α₁-adrenergic contractions of human prostate tissues. Contractions induced by endothelin-1, by the thromboxane A₂ agonist U46619, or by high molar KCl were not inhibited. Correlation analyses suggested up-regulation of prostatic ARF6 expression with increasing degree of BPH, as ARF6 expression increased with the content of prostate-specific antigen (PSA) of prostate tissues. NAV2729 inhibited ARF6 activity but not other GTPases (ARF1, RhoA, Rac1) in prostate tissues and in WPMY-1 cells. Proliferation of WPMY-1 cells was inhibited concentration-dependently by NAV2726, as reflected by decreased viability, 5-ethynyl-2'-deoxyuridine (EdU) assay, colony formation assay, and expression of Ki-67. Silencing of ARF6 expression mimicked effects of NAV2729 on viability and in the EdU assay. Effects of NAV2729 on viability and proliferation were attenuated in cells with silenced ARF6 expression. Our findings suggest that a NAV2729-sensitive mechanism promotes adrenergic contraction and stromal cell growth in the human prostate, which is probably ARF6-mediated. Similar actions in other organs and urodynamic effects of NAV2729 appear possible.

New strategies for inhibition of non-adrenergic prostate smooth muscle contraction by pharmacologic intervention

BACKGROUND

Inhibition of prostate smooth muscle contraction by α₁ -adrenoceptor antagonists (α₁ -blockers) is a first-line medical treatment of lower urinary tract symptoms suggestive of benign prostatic hyperplasia. Increased smooth muscle tone in the hyperplastic prostate may drive urethral obstruction, resulting in bladder outlet obstruction and voiding symptoms. However, efficacy of α₁ -blockers is limited, as non-adrenergic mediators including endothelin-1 and thromboxane A₂ (TXA₂ ) increase prostate smooth muscle tension in parallel to α₁ -adrenoceptors. This may maintain urethral obstruction despite therapy with α₁ -blockers. Consequently, future treatment options with higher efficacy need to target α₁ -adrenergic and non-adrenergic contractions simultaneouly. Recently, several compounds were reported to inhibit adrenergic or neurogenic prostate contractions, however, their effects on non-adrenergic contraction are unknown. Here, we examined effects of inhibitors for Rac-GTPase, Src family kinases (SFKs), and p21-activated kinases (PAKs) on non-adrenergic prostate contractions.

METHODS

Prostate tissues were obtained from radical prostatectomy. Contractions were studied in an organ bath. Viability of cultured stromal cells was assessed by CCK-8 assay.

RESULTS

Inhibition of α₁ -adrenergic contractions by Rac inhibitors EHT1864 (100 μM) and NSC23766 (100 μM), and SFK inhibitors AZM475721 (10 μM) and PP2 (10 μM) was confirmed by inhibition of methoxamine-induced contractions. No effects of the PAK inhibitors FRAX486 (30 μM) and IPA3 (300 μM) on α₁ -adrenergic contraction were confirmed by absent effects on methoxamine-inuced contractions. EHT1864 caused inhibition of endothelin-1- and U46619-induced contractions. EHT1864 reduced the viability of stromal cells concentration- and time-dependently. EHT1864 attenuated KCl-induced contractions of prostate strips only slightly, so that toxic effects may not account alone for inhibition of agonist-induced contractions. NSC23766 inhibited U46619-induced contractions, but not endothelin-1-induced contractions. AZM475271 had no effects on endothelin-1- or U46619-induced contractions, while PP2 inhibited U46619- but not endothelin-1-induced contractions. FRAX486 caused inhibition of U46619-induced contractions. IPA3 inhibited U46619-, but not endothelin-1-induced contractions.

CONCLUSIONS

Of all six inhibitors, EHT1864 seems to be most promising from a translational point of view, as it inhibited TXA₂ - and endothelin-1-induced besides α₁ -adrenergic prostate contractions. This reflects divergent pharmacologic profiles of EHT1864 and NSC23766, although both are Rac-GTPase inhibitors. In vivo, urodynamic effects of EHT1864 and possibly of FRAX486 may exceed those of α₁ -blockers.

What makes the α1A -adrenoceptor gene product assume an α1L -adrenoceptor phenotype?

The α_1A -adrenoceptor is abundantly expressed in the lower urinary tract and is the principal therapeutic target for the symptomatic treatment of lower urinary tract symptoms in men. Prazosin has a lower affinity for the lower urinary tract α_1A -adrenoceptor than α_1A -adrenoceptors found in other parts of the body. This has led to the lower urinary tract α_1A -adrenoceptor being subclassified as an α_1L -adrenoceptor. It was demonstrated that this pharmacologically distinct α_1L -adrenoceptor is a product of the α_1A -adrenoceptor gene, but the mechanism by which this altered phenotype is achieved remains a mystery. Hypotheses for this altered pharmacology include the presence of an interacting protein such as cysteine-rich with EGF-like domain (CRELD) 1 or other GPCRs such as the CXCR2 chemokine or 5-HT_1B receptor. Alternatively, the influence of breast cancer resistance protein (BCRP) efflux transporters on the pharmacology of α_1A -adrenoceptors has also been investigated. These and other hypotheses will be described and discussed in this review. LINKED ARTICLES: This article is part of a themed section on Adrenoceptors-New Roles for Old Players. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.14/issuetoc.

Over-the-counter medication availability could augment self-management of male lower urinary tract symptoms

In this review, we focus on current trends in the management of male lower urinary tract symptoms (LUTS), defined here as LUTS, namely, storage, voiding, and post-micturition symptoms presumed secondary to benign prostatic hyperplasia (BPH), and discuss possible novel approaches toward better care. According to results of a PubMed database search covering the last 10 years and using keywords pertaining to male LUTS, this condition continues to be globally undiagnosed or diagnosed late, partly because of men's hesitation to seek help for perceived embarrassing problems or problems considered a normal part of aging. In addition, the prevalence of male LUTS is continually increasing because of a constantly aging population. Male LUTS can be bothersome and affect the quality of life (QoL) and sexual function. Additional effective alternatives for managing this condition need to be identified and incorporated into the current care model. Considering that most male LUTS such as frequency, hesitancy, urgency, and intermittency are easy to self-identify, a self-management approach toward male LUTS is proposed. Limited evidence supports the efficacy of phytotherapies and herbals as self-management options for male LUTS. However, introducing over-the-counter (OTC) medication with proven efficacy, accompanied by lifestyle and behavioral modifications, may be a promising approach that will encourage more men to treat their symptoms in a timely manner. Formal guidelines, along with appropriate education programs for patients and support from the healthcare community, will be needed to ensure that the promise of this approach is fully materialized.

Inhibition of Prostate Smooth Muscle Contraction by Inhibitors of Polo-Like Kinases

Background: Prostate smooth muscle contraction plays an important role for pathophysiology and treatment of male lower urinary tract symptoms (LUTS) but is incompletely understood. Because the efficacy of available medication is limited, novel options and improved understanding of prostate smooth muscle contraction are of high demand. Recently, a possible role of polo-like kinase 1 (PLK1) has been suggested for smooth muscle contraction outside the lower urinary tract. Here, we examined effects of PLK inhibitors on contraction of human prostate tissue.

Methods: Prostate tissues were obtained from radical prostatectomy. RT-PCR, Western blot and immunofluorescence were performed to detect PLK expression and phosphorylated PLK. Smooth muscle contractions were induced by electric field stimulation (EFS), α₁-agonists, endothelin-1, or the thromboxane A₂ analog U46619 in organ bath.

Results: RT-PCR, Western blot, and immunofluorescence suggested expression of PLK1 in the human prostate, which may be located and active in smooth muscle cells. EFS-induced contractions of prostate strips were reduced by SBE 13 (1 μM), cyclapolin 9 (3 μM), TAK 960 (100 nM), and Ro 3280 (100 nM). SBE 13 and cyclapolin 9 inhibited contractions by the α₁-agonists methoxamine, phenylephrine, and noradrenaline. In contrast, no effects of SBE 13 or cyclapolin 9 on endothelin-1- or U46619-induced contractions were observed.

Conclusion: Alpha1-adrenergic smooth muscle contraction in the human prostate can be inhibited by PLK inhibitors. PLK-dependent signaling may be a new pathway, which promotes α₁-adrenergic contraction of prostate smooth muscle cells. As contractions by endothelin and U46619 are not susceptible to PLK inhibition, this reflects divergent regulation of adrenergic and non-adrenergic prostate smooth muscle contraction.

Inhibition of human prostate smooth muscle contraction by the LIM kinase inhibitors, SR7826 and LIMKi3

BACKGROUND AND PURPOSE

In men with benign prostatic hyperplasia, increased smooth muscle tone in the prostate may lead to bladder outlet obstruction and subsequent lower urinary tract symptoms. Consequently, medical treatment aims to inhibit prostate smooth muscle contraction. However, the efficacy of the treatment options available is limited, and improved understanding of mechanisms of prostate smooth muscle contraction and identification of new targets for medical intervention are mandatory. Several studies suggest that LIM kinases (LIMKs) promote smooth muscle contraction; however, this has not yet been examined. Here, we studied effects of the LIMK inhibitors on prostate smooth muscle contraction.

EXPERIMENTAL APPROACH

Human prostate tissues were obtained from radical prostatectomy. Phosphorylation of cofilin, a LIMK substrate, was examined using a phospho-specific antibody. Smooth muscle contractions were studied in organ bath experiments.

KEY RESULTS

Real-time PCR, Western blot and immunofluorescence suggested LIMKs are expressed in smooth muscle cells of prostate tissues. Two different LIMK inhibitors, SR7826 (1 μM) and LIMKi3 (1 μM), inhibited contractions of prostate strips, which were induced by electrical field stimulation, α₁ -adrenoceptor agonists phenylephrine and methoxamine and the TXA₂ analogue, U46619. LIMK inhibition in prostate tissues and cultured stromal cells (WPMY-1) was confirmed by cofilin phosphorylation, which was reduced by SR7826 and LIMKi3. In WPMY-1 cells, SR7826 and LIMKi3 caused breakdown of actin filaments and reduced viability.

CONCLUSIONS AND IMPLICATIONS

Smooth muscle tone in the hyperplastic human prostate may underlie the effects of LIMKs, which promote contraction. Contraction of prostate strips can be inhibited by small molecule LIMK inhibitors.

Changes in autonomic nervous system activity after treatment with alpha-blocker in men with lower urinary tract symptoms

Purpose

To determine changes in autonomic nervous system activity after treatment in men with lower urinary tract symptoms (LUTS), we evaluated changes in patients' symptoms, uroflowmetry, and heart rate variability (HRV) after treatment with alpha-blockers for 12 weeks.

Materials and Methods

Ninety-five men who had LUTS (International Prostate Symptom Score [IPSS] ≥8) were included in this study. We divided them into two groups on the basis of a low frequency/high frequency (LF/HF) ratio of 1.6. After treatment with Xatral XL (Handok Inc., Korea) 10 mg for 3 months, we rechecked their IPSS, uroflowmetry, HRV and compared these with the baseline measurements.

Results

Fifty-four men were assigned to the low LF/HF group (group A: LF/HF ≤1.6) and 41 men to the high LF/HF group (group B: LF/HF >1.6). At baseline and 12 weeks, none of the parameters differed significantly between the groups except for HF, which is one of the parameters of HRV. IPSS, the IPSS-voiding subscore, and the IPSS-storage subscore decreased and maximal uroflow increased significantly after 12 weeks of treatment. Whereas the baseline LF/HF ratio increased from 0.89±0.407 to 1.80±1.804 after treatment in group A, it decreased from 3.93±5.471 to 1.79±1.153 in group B.

Conclusions

The efficacies of Xatral XL were clear in both groups. We found that the LF/HF ratio in the two groups merged to a value of approximately 1.79 after treatment. We suggest that this could be a clue to the importance of balance in autonomic nervous system activity in men with LUTS.

Inhibition of smooth muscle contraction and ARF6 activity by the inhibitor for cytohesin GEFs, secinH3, in the human prostate

Prostate smooth muscle contraction is critical for etiology and treatment of male lower urinary tract symptoms (LUTS) and is promoted by small monomeric GTPases (RhoA and Rac). GTPases may be activated by guanosine nucleotide exchange factors (GEFs). GEFs of the cytohesin family may indirectly activate Rac, or ADP ribosylation factor (ARF) GTPases directly. Here we investigated the expression of cytohesin family GEFs and effects of the cytohesin inhibitor Sec7 inhibitor H3 (secinH3) on smooth muscle contraction and GTPase activities in human prostate tissues. Of all four cytohesin isoforms, cytohesin-1 and -2 showed the highest expression in real-time PCR. Western blot and fluorescence staining suggested that cytohesin-2 may be the predominant isoform in prostate smooth muscle cells. Contractions induced by norepinephrine, the α₁-adrenoceptor agonist phenylephrine, the thromboxane A₂ analog U-46619 , and endothelin-1 and -3, as well as neurogenic contractions induced by electric field stimulation (EFS), were reduced by secinH3 (30 µM). Inhibition of EFS-induced contractions appeared to have efficacy similar to that of inhibition by the α₁-adrenoceptor antagonist tamsulosin (300 nM). Combined application of secinH3 plus tamsulosin caused larger inhibition of EFS-induced contractions than tamsulosin alone. Pull-down assays demonstrated inhibition of the small monomeric GTPase ARF6 by secinH3, but no inhibition of RhoA or Rac1. In conclusion, we suggest that a cytohesin-ARF6 pathway takes part in smooth muscle contraction. This may open attractive new possibilities in medical treatment of male LUTS.

Associations of SRD5A2/CYP17/CYP19/VDR gene polymorphisms with the development and clinical progression of benign prostatic hyperplasia: a case-control study in northern Chinese population

This study aims to explore the effect of gene polymorphisms of 5a-reduction enzyme (SRD5A2), steroidogenic cytochrome P-450 17alpha-hydroxylase (CYP17), aromatase cytochrome P450 family 19 (CYP19) and vita-min D receptor (VDR) on benign prostatic hyperplasia (BPH) susceptibility and clinical progress. A total of 452 BHP patients and 501 healthy individuals were selected in Harbin Medical University Daqing School from October 2014 and December 2015 as the case and control groups. All BPH patients received drug treatment and were subsequently divided into the progression and non-progression groups based on their therapeutic efficacy. PCR-RFLP was applied to detect the genotype distributions of SRD5A2/CYP17/CYP19/VDR, which were further tested with Hardy-Weinberg (H-W) equilibrium. Logistic regression analysis was applied to determine the risk factors for BPH progression. Compared with subjects carrying VV genotype and V allele at SRD5A2 V89L, those with LL genotype and L allele at SRD5A2 V89L may have reduced risk of BPH susceptibility or progression (all P < 0.05). Compared with subjects carrying TT genotype and T allele at CYP17 -34T>C, those with CC genotype and C allele at CYP17 -34T>C may have increased risk of BPH susceptibility or progression (all P < 0.05). Compared with individuals carrying FF genotype and F allele at VDRVDR Fok I, those with ff genotype and f allele at VDRVDR Fok I may have increased susceptibility to BPH (all P < 0.05). Logistic regression analysis showed that SRD5A2 V89L and CYP17 -34T>C polymorphisms and CYP17 -34T>C (TC + CC)/SRD5A2 V89L (VV) combined genotypes were significantly related with the clinical progression of BHP. These results revealed that SRD5A2 V89L and CYP17 -34T>C polymorphisms were associated with the risk of BPH and its clinical progression.

Crystal structures, absolute configurations and molecular docking studies of naftopidil enantiomers as α1D-adrenoceptor antagonists

Chiral drug naftopidil (NAF), a specific α_1D-adrenoceptor (AR) antagonist for the treatment of benign prostatic hyperplasia, was used in racemic form for several decades. Our recent work declared that NAF enantiomers showed the same antagonistic effects on the α_1D-AR, but the binding mechanism of these two stereochemical NAF isomers to the α_1D receptor remained unclear. Herein, we reported the crystallographic structures of optically pure NAF stereoisomers for the first time and unambiguously determined their absolute configurations. The crystal data of R and S enantiomers matched satisfactorily the pharmacophore model for α_1D-selective antagonists. Based on the constructed α_1D homology model, molecular docking studies shed light on the molecular mechanism of NAF enantiomers binding to α_1D-AR. The results indicated that NAF enantiomers exhibited the very similar binding poses and occupied the same binding pocket.

Factors influencing biased agonism in recombinant cells expressing the human α1A -adrenoceptor

BACKGROUND AND PURPOSE

Agonists acting at GPCRs promote biased signalling via Gα or Gβγ subunits, GPCR kinases and β-arrestins. Since the demonstration of biased agonism has implications for drug discovery, it is essential to consider confounding factors contributing to bias. We have examined bias at human α_1A -adrenoceptors stably expressed at low levels in CHO-K1 cells, identifying off-target effects at endogenous receptors that contribute to ERK1/2 phosphorylation in response to the agonist oxymetazoline.

EXPERIMENTAL APPROACH

Intracellular Ca²⁺ mobilization was monitored in a Flexstation® using Fluo 4-AM. The accumulation of cAMP and ERK1/2 phosphorylation were measured using AlphaScreen® proximity assays, and mRNA expression was measured by RT-qPCR. Ligand bias was determined using the operational model of agonism.

KEY RESULTS

Noradrenaline, phenylephrine, methoxamine and A61603 increased Ca²⁺ mobilization, cAMP accumulation and ERK1/2 phosphorylation. However, oxymetazoline showed low efficacy for Ca⁺² mobilization, no effect on cAMP generation and high efficacy for ERK1/2 phosphorylation. The apparent functional selectivity of oxymetazoline towards ERK1/2 was related to off-target effects at 5-HT_1B receptors endogenously expressed in CHO-K1 cells. Phenylephrine and methoxamine showed genuine bias towards ERK1/2 phosphorylation compared to Ca²⁺ and cAMP pathways, whereas A61603 displayed bias towards cAMP accumulation compared to ERK1/2 phosphorylation.

CONCLUSION AND IMPLICATIONS

We have shown that while adrenergic agonists display bias at human α_1A -adrenoceptors, the marked bias of oxymetazoline for ERK1/2 phosphorylation originates from off-target effects. Commonly used cell lines express a repertoire of endogenous GPCRs that may confound studies on biased agonism at recombinant receptors.

Autoantibodies Directed Against the Endothelin A Receptor in Patients With Benign Prostatic Hyperplasia

BACKGROUND

Over-stimulation of G-protein coupled receptors (GPCRs) such as α1-adrenergic, muscarinic, endothelin, and AT1 receptors is considered to drive benign prostatic hyperplasia (BHP) which is often associated with lower urinary tract syndrome (LUTS). However, in addition to physiologic GPCR ligands, there is a new class of autoantibodies called functional autoantibodies that target the same GPCRs (GPCR-AABs) for over-stimulation, thus, presenting pathogenic potency. We hypothesize that patients with BPH/LUTS could carry GPCR-AABs representing potential targets for treatment.

METHODS

GPCR-AABs were identified, quantified, and characterized in the serum from 20 patients (aged 55-82 years, median 71 years) with BPH using the bioassay of spontaneously beating cultured neonatal rat cardiomyocytes.

RESULTS

A sum of 60% of the patients were positive for agonistic autoantibodies directed against the endothelin A receptor (ETA-AABs). ETA-AABs were associated with the IgG 1 subclass, targeted an epitope located on the second extracellular receptor loop and their agonistic activity could be neutralized by the aptamer BC007.

CONCLUSIONS

Agonistic ETA-AABs could-via uncontrolled over-boarding endothelin A receptor stimulation-contribute to the pathogenesis of BPH/LUTS. The in vitro demonstrated ETA-AAB neutralization by the aptamer BC007 could open the door for a new treatment strategy in patients with BPH/LUTS. Prostate 77:458-465, 2017. © 2016 Wiley Periodicals, Inc.

Combination treatment with naftopidil increases the efficacy of radiotherapy in PC-3 human prostate cancer cells

PURPOSE

Clinically, radiotherapy (RT) often leads to the development of prostate cancer (PCa) resistance because of protective responses in cancer cells. One of the mechanisms includes the upregulation of RT-induced antioxidant enzymes. Thus, combination therapy with RT and certain pharmaceutical drugs targeting antioxidant enzymes may be ideal for increasing the efficacy of RT with minimum side effects. Naftopidil is a subtype-selective α_1D-adrenoceptor antagonist used for the treatment of benign prostatic hyperplasia (BPH). In our drug repositioning study, naftopidil showed not only unique growth-inhibitory effects but also AKT phosphorylation-inhibitory effects in PC-3 human PCa cells. Here, we examined the efficacy of additive naftopidil treatment in combination with RT in PC-3 cells.

METHODS

The effects of combination therapy with RT plus naftopidil were analyzed using an animal model of PC-3 xenografts in BALB/c nude mice. The expression of the antioxidant enzyme manganese superoxide dismutase (MnSOD) was evaluated by western blotting.

RESULTS

Combination therapy with RT plus naftopidil induced a more efficacious delay in PC-3 xenograft tumor growth as compared with monotherapy with naftopidil or RT. In PC-3 tumors, combination therapy with RT plus naftopidil suppressed the upregulation of RT-induced MnSOD expression. In vitro, neither AKT inhibitor IV nor naftopidil directly altered MnSOD expression. Upregulation of RT-induced MnSOD expression was markedly suppressed by combination treatment with RT plus AKT inhibitor IV or naftopidil.

CONCLUSIONS

These results suggest that additive naftopidil treatment in combination with RT may increase the efficacy of RT for the treatment of PCa.

The treatment effects of flaxseed-derived secoisolariciresinol diglycoside and its metabolite enterolactone on benign prostatic hyperplasia involve the G protein-coupled estrogen receptor 1

Secoisolariciresinol diglucoside (SDG), a lignan extracted from flaxseed, has been shown to suppress benign prostatic hyperplasia (BPH). However, little is known about the mechanistic basis for its anti-BPH activity. The present study showed that enterolactone (ENL), the mammalian metabolite of SDG, shared the similar binding site of G1 on a new type of membranous estrogen receptor, G-protein-coupled estrogen eceptor 1 (GPER), by docking simulations method. ENL and G1 (the specific agonist of GPER) inhibited the proliferation of human prostate stromal cell line WPMY-1 as shown by MTT assay and arrested cell cycle at the G0/G1 phase, which was displayed by propidium iodide staining following flow cytometer examination. Silencing GPER by short interfering RNA attenuated the inhibitory effect of ENL on WPMY-1 cells. The therapeutic potential of SDG in the treatment of BPH was confirmed in a testosterone propionate-induced BPH rat model. SDG significantly reduced the enlargement of the rat prostate and the number of papillary projections of prostatic alveolus and thickness of the pseudostratified epithelial and stromal cells when comparing with the model group. Mechanistic studies showed that SDG and ENL increased the expression of GPER both in vitro and in vivo. Furthermore, ENL-induced cell cycle arrest may be mediated by the activation of GPER/ERK pathway and subsequent upregulation of p53 and p21 and downregulation of cyclin D1. This work, in tandem with previous studies, will enhance our knowledge regarding the mechanism(s) of dietary phytochemicals on BPH prevention and ultimately expand the scope of adopting alternative approaches in BPH treatment.

Smooth muscle contraction and growth of stromal cells in the human prostate are both inhibited by the Src family kinase inhibitors, AZM475271 and PP2

BACKGROUND AND PURPOSE

In benign prostatic hyperplasia, increased prostate smooth muscle tone and prostate volume may contribute alone or together to urethral obstruction and voiding symptoms. Consequently, it is assumed there is a connection between smooth muscle tone and growth in the prostate, but any molecular basis for this is poorly understood. Here, we examined effects of Src family kinase (SFK) inhibitors on prostate contraction and growth of stromal cells.

EXPERIMENTAL APPROACH

SFK inhibitors, AZM475271 and PP2, were applied to human prostate tissues to assess effects on smooth muscle contraction, and to cultured stromal (WPMY-1) and c-Src-deficient cells to examine effects on proliferation, actin organization and viability.

KEY RESULTS

SFKs were detected by real time PCR, western blot and immunofluorescence in human prostate tissues, some being located to smooth muscle cells. AZM475271 (10 μM) and PP2 (10 μM) inhibited SFK in prostate tissues and WPMY-1 cells. Both inhibitors reduced α₁ -adrenoceptor-mediated and neurogenic contraction of prostate strips. This may result from cytoskeletal deorganization, which was observed in response to AZM475271 and PP2 in WPMY-1 cells by staining of actin filaments with phalloidin. This was paralleled by reduced proliferation of wildtype but not of c-Src-deficient cells; cytotoxicity was mainly observed at higher concentrations (>50 μM).

CONCLUSIONS AND IMPLICATIONS

In human prostate, smooth muscle tone and growth are both controlled by an SFK-dependent process, which may explain their common role in bladder outlet obstruction. Targeting prostate smooth muscle tone and prostate growth simultaneously by a single compound may, in principal, be possible.

Design, synthesis, crystal structure, biological evaluation and molecular docking studies of carbazole-arylpiperazine derivatives

Subtype-selective α₁-adrenoceptor (AR) antagonists display optimum therapeutic efficacies for the treatment of benign prostatic hyperplasia (BPH). In this study, we designed and synthesized novel carbazole-arylpiperazines derivatives (1 and 2) on the basis of the proposed pharmacophore model for α₁-AR antagonists. Structural properties were investigated using single-crystal X-ray diffraction analysis. Comparison of crystal structures with ligand-based pharmacophore models revealed that the two agents may possess antagonistic effects on α_1D subtype. Tissue functional assay in vitro showed that compound 2 exerted strong antagonistic activity on α_1B-AR (pA₂ 7.13) with a poor selectivity for α_1A and α_1D subtypes. Compound 1 exhibited enhanced antagonistic effect on α_1D subtype (pA₂ 7.06) and excellent selectivity for α_1D over α_1B (α_1D/α_1B ratio=79.4). To illustrate the relationship between antagonistic activity and chemical structure, molecular docking studies were performed using the homology models of α₁ receptors. Binding mechanism indicated that small hydrophobic substituents attached to the arylpiperazine moiety were essential for rational design of α_1D-selective antagonists.

Effect of tamsulosin on the pharmacokinetics of dutasteride in Chinese male healthy volunteers

The purpose of this study was to evaluate the effect of tamsulosin (0.2 mg) on the pharmacokinetics of dutasteride (0.5 mg) in a group of healthy Chinese male volunteers. This was an open-label, single-sequence, 3-period, drug-drug interaction phase 1 study. Twenty-four healthy Chinese male volunteers were enrolled and administered a single dose of 0.5 mg dutasteride and, following a 28- to 30-day washout period, 0.2 mg tamsulosin once daily for 7 days. On day 5, subjects received 0.2 mg tamsulosin coadministered with 0.5 mg dutasteride. Serum dutasteride and tamsulosin concentrations were monitored. In the presence or absence of tamsulosin, there were no apparent changes in dutasteride AUC and Cmax . Adverse events reported were mild to moderate in intensity and resolved by the end of the study. In healthy Chinese male volunteers, tamsulosin 0.2 mg at steady state had no apparent effect on dutasteride pharmacokinetics. Dutasteride and tamsulosin when administered alone or in combination were well tolerated.

Effect of Selective Prostaglandin E2 EP2 Receptor Agonist CP-533,536 on Voiding Efficiency in Rats with Midodrine-Induced Functional Urethral Obstruction

OBJECTIVES

We investigated the effect of the selective prostaglandin E2 EP2 receptor agonist CP-533,536 on voiding efficiency in rats with midodrine-induced functional urethral obstruction.

METHODS

The effect of CP-533,536 (0.03-0.3 mg/kg, intravenous [i.v.]) on urethral perfusion pressure (UPP) was investigated in anesthetized rats pre-treated with midodrine (1 mg/kg, i.v.), which forms an active metabolite that acts as an α1 -adrenoceptor agonist. The effect of CP-533,536 (0.03-0.3 mg/kg, i.v.) on cystometric parameters was also investigated in anesthetized rats. In addition, the effect of CP-533,536 (0.03-0.3 mg/kg, i.v.) on residual urine volume (RV) and voiding efficiency (VE) was investigated in conscious rats treated with midodrine (1 mg/kg, i.v.).

RESULTS

CP-533,536 dose-dependently decreased UPP elevated by midodrine in anesthetized rats. In contrast, CP-533,536 did not affect maximum voiding pressure, intercontraction interval, or intravesical threshold pressure. In conscious rats, midodrine (1 mg/kg, i.v.) markedly increased RV and reduced VE. CP-533,536 dose-dependently ameliorated increases in RV and decreases in VE induced by midodrine.

CONCLUSIONS

These results suggest that a selective EP2 receptor agonist could ameliorate the elevation of RV and improve the reduction of VE in rats with functional urethral obstruction caused by stimulation of α1 -adrenoceptors. The mechanism of action might be not potentiation of bladder contraction but rather preferential relief of urethral constriction.

X-ray Crystallography, DFT Calculations and Molecular Docking of Indole-Arylpiperazine Derivatives as α1A-Adrenoceptor Antagonists

Indole-arylpiperazine derivatives have exhibited good selectivity for the α_1A-adrenoceptor, but the structure-activity-binding mechanism relationship remains unclear. In the current study, three compounds (1, 2 and 3) were investigated through single-crystal X-ray diffraction analysis, density functional theory (DFT) calculations and molecular docking using a homology model of the α_1A receptor. Compounds 1 and 3 form H-bonds networks to stabilize their three-dimensional structures, while C–H···π interactions play a significant role in the packing of 2. Based on DFT-optimized conformations, the HOMO-LUMO energy gaps and molecular electrostatic potential (MEP) were theoretically calculated at the B3LYP/6-311G (d, p) level of theory. Chemical reactivity increases in the order of 3 < 2 < 1, and the maximum positive region of the MEP maps is mainly localized over the NH group. The binding mechanisms of ligand-α_1A-adrenoceptor complexes were illustrated by molecular docking. Binding to Gln177 of the second extracellular loop region via hydrogen bonds is likely to be essential for α_1A-selective antagonists. The present work sheds light on the studies of structure-activity-binding mechanism and aids in the design of α_1A antagonists with high selectivity.

Alpha-Blocker Treatment Response in Men With Lower Urinary Tract Symptoms Based on Sympathetic Activity: Prospective, Multicenter, Open-Labeled, Observational Study

Purpose:

In this study, we compared the treatment outcomes for an α-blocker between 2 groups of men, one with high sympathetic activity (HSA) and another with low sympathetic activity (LSA) or normal sympathetic activity.

Methods:

A total of 159 men (≥50 years of age) with lower urinary tract symptoms resulting from benign prostatic hyperplasia were analyzed. We assigned patients to groups according to their sympathetic activity, which was evaluated by heart ratevariability measurements. HSA was defined as a low frequency/high frequency ratio greater than 1.6. All patients received 10mg of alfuzosin once a day for 12 weeks. The primary end point was a change in the total International Prostate SymptomScore (IPSS) at 12 weeks from baseline.

Results:

Sixty-seven men were assigned to the HSA group and 92 men were assigned to the LSA group. The baseline characteristics were not significantly different between the 2 groups, and the response to alfuzosin was good in both groups. Themean total IPSS change was not different between the groups. Both groups were not significantly different with respect to the changes in maximal flow rate, IPSS voiding or storage symptom subscores, quality of life, and rates of adverse drug events. TheHSA group showed a similar willingness to continue treatment compared to the LSA group, although their treatment satisfaction rating was lower.

Conclusions:

The therapeutic effects of alfuzosin did not differ in regards to the differences in sympathetic activity, but treatment satisfaction ratings were lower in the HSA group.

Drug treatment patterns for the management of men with lower urinary tract symptoms associated with benign prostatic hyperplasia who have both storage and voiding symptoms: a study using the health improvement network UK primary care data

BACKGROUND

Real-world data on the pharmacological management of men who have lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH) are limited.

OBJECTIVE

To characterize men with LUTS/BPH who had both storage and voiding symptoms and to evaluate treatment patterns in UK primary care.

DESIGN, SETTING AND PARTICIPANTS

This was an observational study of men aged ≥45 years with a diagnosis, symptoms or therapies indicative of LUTS/BPH with both storage and voiding components. These men were identified from the large Health Improvement Network (THIN) database between 1 January 2004 and 30 September 2011.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Drug prescriptions and switching/discontinuation patterns for α₁-blockers and antimuscarinics.

RESULTS AND LIMITATIONS

We identified 8694 men with a median age of 66.0 (interquartile range [IQR], 59.0-74.0) years. Most (7850; 90.3%) received an α₁-blocker, and 2167 (24.9%) received antimuscarinic therapy over a median of 2.1 years. The most commonly prescribed α₁-blocker was tamsulosin (81.8%); most frequent antimuscarinics were tolterodine (41.0%), oxybutynin (37.2%) and solifenacin (35.7%). Concomitant prescription of α1-blocker and antimuscarinic therapy (within 30 days of each other) was received by 1160 men (14.8% of α₁-blocker-treated men). Of α₁-blocker recipients, 3024 (38.5%) discontinued during follow-up, while 1149 (53.0%) discontinued antimuscarinic therapy. Of 2167 men who received an antimuscarinic, 476 (22.0%) switched to another antimuscarinic. Of the three most commonly prescribed antimuscarinics, solifenacin had the lowest proportions of discontinuations (43.0%) and switches (15.3%), and the longest median duration of therapy (90 days, IQR 30-300). General practice consultations accounted for most resource use (5307.9 per 1000 patient-years).

CONCLUSIONS

This study presents real-world management of men with LUTS/BPH who have both storage and voiding symptoms. The low proportion of men who received concomitant α₁-blocker and antimuscarinic therapy suggests that some patients are sub-optimally treated in routine clinical practice.

Effects of Schisandra chinensis extract on the relaxation of isolated human prostate tissue and smooth muscle cell

ETHNOPHARMACOLOGICAL RELEVANCE

Schisandra chinensis has been commonly used as a traditional herbal medicine to treat various diseases including body weakness, dysentery, impotence, enuresis and frequent urination in many countries including Korea, China and Russia. Benign prostate hyperplasia is a common disease for the elderly men and it induces lower urinary tract symptoms which hinder general activity and quality of life. We evaluated the therapeutic potential of Schisandra chinensis extract (SCE) in benign prostate hyperplasia using human prostate tissue.

MATERIALS AND METHODS

Schisandra chinensis fruit was collected and extracted with ethanol. Human prostate tissues were obtained from 14 prostate cancer patients. Macroscopically normal tissue was excised from the transition zone and the periurethral regions. Isolated prostate tissue strips were mounted in an organ-bath system, and the relaxation effect of SCE was evaluated by cumulative addition to prostate strips pre-contracted with 10(-5)M norepinephrine. The effect of tamsulosin was compared, and the additive effect was evaluated. Electrophysiological studies using cultured human prostate smooth muscle cells (HPrSMC) were conducted.

RESULTS

Cumulative dosing of SCE induced concentration-dependent relaxation in contracted prostate tissue (n=18, P<0.05). Simultaneous dosing of SCE and tamsulosin showed an additive relaxation effect. The relaxation effect of SCE was abolished by inhibition of K+ channels by pre-treatment with tetraethylammonium. In HPrSMC, extracellular application of 100 μg/mL SCE significantly increased outward currents, and this effect was significantly attenuated by treatment with 100 nM Iberiotoxin.

CONCLUSIONS

SCE showed a dose dependent relaxation effect on human prostate tissue as well as an additive effect with tamsulosin. The relaxation effects of SCE on HPrSMC were, in part, due to the activation of K+ channels.

Honokiol, a constituent of Magnolia species, inhibits adrenergic contraction of human prostate strips and induces stromal cell death

Purpose

Smooth muscle contraction and prostate growth are important targets for medical therapy of lower urinary tract symptoms (LUTS) in patients with benign prostatic hyperplasia. Honokiol and Magnolol are lignan constituents of Magnolia species, which are used in traditional Asian medicine. Here, we examined effects of honokiol and magnolol on contraction of human prostate tissue and on growth of stromal cells.

Methods

Prostate tissues were obtained from radical prostatectomy. Contraction of prostate strips was examined in organ bath studies. Effects in stromal cells were assessed in cultured immortalized human prostate stromal cells (WPMY-1). Ki-67 mRNA was assessed by reverse transcription-polymerase chain reaction, and proliferation by a fluorescence 5-ethynyl-2′-deoxyuridine assay.

Results

Honokiol (100μM) reduced noradrenaline-induced contractions, which was significant at 10 to 100μM noradrenaline. Honokiol reduced phenylephrine-induced contractions, which was significant at 3 to 100μM phenylephrine. Honokiol reduced electric field stimulation-induced contractions very slightly. In WPMY-1 cells, honokiol (24 hours) induced cell death. Magnolol (100μM) was without effects on contraction, and cellular viability.

Conclusions

Honokiol inhibits smooth muscle contraction in the human prostate, and induces cell death in cultured stromal cells. Because prostate smooth muscle tone and prostate growth may cause LUTS, it appears possible that honokiol improves voiding symptoms.

Hormonal manipulation of lower urinary tract symptoms secondary to benign prostatic obstruction

Although the etiology of lower urinary tract symptoms (LUTS) is often multifactorial, a significant proportion of men over the age of 50 suffer from benign prostatic obstruction (BPO) secondary to benign prostatic hyperplasia. Prostate, being an androgen responsive organ is dependent on the male sex hormone, testosterone, for growth. Thus, treatment strategies that manipulate the levels of circulating hormones that influence the level of testosterone and/or prostatic growth represent an important potential option for patients suffering with troublesome LUTS due to BPO. Despite this, the only hormonal treatment that is currently used in daily clinical practice is the 5-alpha reductase inhibitor. In this article, we review the current evidence on the use of the 5-alpha reductase inhibitors finasteride and dutasteride. We also discuss new emerging hormonal manipulation strategies for patients with LUTS secondary to BPO.