Emerging drug therapies for benign prostatic hyperplasia

Evaluation of efficacy of cholecalciferol and silymarin in improving lower urinary tract symptoms of benign prostatic hyperplasia: A double-blind, randomized, controlled trial

INTRODUCTION

Benign prostatic hyperplasia (BPH) mainly leads to lower urinary tract symptoms (LUTS) in aging men. The present study investigates the role of cholecalciferol, Silymarin, and their combined administration in patients with BPH suffering from LUTS.

METHODS

This double-blind, randomized, controlled trial enrolled 80 participants (50-80 years) diagnosed with BPH, from March 2019 to March 2020. Based on serum 25-(OH) vitamin D levels we formed subgroups, each receiving specific interventions. Measurements of International Prostate Symptom Score (IPSS), Maximal Urinary Flow Rate (Q-max), Prostate Volume (PV), Post-Void Residual (PVR), and Prostate-Specific Antigen (PSA) were recorded at baseline and following 3 months of follow-up.

RESULTS

Participants with serum concentration of 25-(OH) vitamin D below 20 ng/ml simultaneously received cholecalciferol and Silymarin that significantly improved IPSS, irritation, obstruction, PV, and PVR. In those with concentrations ⩾20 ng/ml, a single use of Silymarin significantly reduced IPSS, irritation, obstruction, and PVR. Adjustment of confounding variables revealed independent and significant effects of both cholecalciferol and Silymarin on PVR, IPSS, and obstruction. Cholecalciferol also improved irritation, while Silymarin reduced prostate volume. These findings highlight potential therapeutic benefits for BPH-associated LUTS, encouraging further exploration and clinical consideration.

CONCLUSIONS

In this investigation, combination therapy with cholecalciferol at 50,000 IU/w for 8 weeks and Silymarin at a dosage of 480 mg for 3 months resulted in a notable improvement in the IPSS score, PV, and PVR, as well as both irritative and obstructive symptoms. However, the total PSA and free PSA amounts did not reach a significant difference.

Effects of Taraxaci Herba (Dandelion) on Testosterone Propionate-Induced Benign Prostatic Hyperplasia in Rats

Benign prostatic hyperplasia (BPH) is the non-malignant enlargement of the prostate, associated with lower urinary tract symptoms (LUTSs). Taraxaci Herba (TH), commonly known as dandelion, has traditionally been utilized in East Asia to treat symptoms related to LUTSs. Based on this traditional use, our study aimed to explore the inhibitory effects of TH on BPH progression using a testosterone propionate-induced rat model. To induce BPH, male Sprague Dawley rats were castrated and injected subcutaneously with testosterone propionate (3 mg/kg/day) for 28 days. Concurrently, TH extract was administered orally at doses of 100 and 300 mg/kg/day throughout the four-week period of testosterone propionate injections. The TH extract significantly reduced both the absolute and relative weights of the prostate, along with histopathological changes in the gland. Moreover, it lowered serum levels of testosterone and dihydrotestosterone and reduced the expression of the androgen receptor in the prostate. Additionally, the TH extract modulated the protein expressions of Bax and Bcl-2, which are key regulators of apoptosis in prostate cells. Collectively, our findings suggest that TH inhibits BPH development partially by modulating androgen signaling and inducing apoptosis within the prostate.

Cinnamomum cassia and Rosa laevigata Mixture Improves Benign Prostatic Hyperplasia in Rats by Regulating Androgen Receptor Signaling and Apoptosis

Benign prostatic hyperplasia (BPH) is the most common condition in elderly men that is characterized by an increase in the size of the prostate gland. Cinnamomum cassia and Rosa laevigata have been reported to treat the symptoms associated with BPH. The aim of this study was to evaluate the effects of HT080, an herbal extract of C. cassia and R. laevigata, on a testosterone propionate (TP)-induced BPH rat model. The rats received a daily subcutaneous injection of TP (3 mg/kg) for 4 weeks to induce BPH. Rats were divided into four groups: group 1 (sham), group 2 (BPH, TP alone), group 3 (Fina, TP + finasteride 1 mg/kg/day), and group 4 (HT080, TP + HT080 200 mg/kg/day). At the end of the experiment, all rats were sacrificed, and their prostate glands were removed, weighed, and subjected to histopathological examination and western blot analyses. Serum testosterone and dihydrotestosterone (DHT) levels were determined. In addition, serum alanine and aspartate aminotransferase levels were measured to evaluate the toxicity in the liver. The Hershberger bioassay was also conducted to investigate the effects of HT080 on androgenic and antiandrogenic activities. In the BPH model, the prostate weight, prostate index, prostate epithelial thickness, and serum testosterone and DHT levels in the HT080 group were significantly reduced compared to the BPH group. Histological studies showed that HT080 reduced prostatic hyperplasia. The protein expression of androgen receptor from the HT080 group was significantly reduced in comparison with the BPH group (p < 0.05). HT080 also induced apoptosis by regulating Bcl-2 and Bax expression. In addition, HT080 showed no toxicity in the liver and did not exhibit androgenic and antiandrogenic activities. Our finding revealed that HT080 can be a potential candidate for the treatment of BPH by regulating androgen receptor signaling and apoptosis.

Frozen-Thawed Sperm Analysis of Benign Prostatic Hyperplasia Dogs Treated With Finasteride

Benign Prostatic Hyperplasia (BPH) is a pathological condition that directly interferes with the reproductive potential of senile dogs, by leading to prostate enlargement and sperm injury, which in turn may compromise sperm freezeability. Moreover, albeit finasteride treatment reduces prostatic volume and blood supply and maintains seminal quality and testicular integrity, the effects of sperm samples submitted to cryopreservation after the finasteride treatment are still unknown. Thus, the aim of this study was to evaluate frozen-thawed semen of BPH dogs, as well as dogs subjected to BPH pharmacological treatment with finasteride. For such purpose, 20 dogs were previously selected and assigned to three experimental groups, according to BPH diagnosis and treatment with finasteride: Control (n = 9), BPH Group (n = 5) and BPH-Finasteride Group (n = 6). Semen was subjected to one-step cryopreservation protocol with tris-fructose-citric acid extender with 5% glycerol and thawed at 37°C for 30 sec. Fresh and post-thaw sperm samples were evaluated for macroscopic parameters, sperm concentration, sperm motility kinetics, sperm mitochondrial activity and potential, oxidative stress, plasmatic and acrosome membrane integrity, sperm DNA fragmentation and sperm binding test on perivitelic membrane of chicken egg yolk. Regarding fresh semen, BPH-Finasteride group had the lowest ejaculate visual aspect (opacity), higher frequency of sperm flagellar beating (BCF) and percentage of sperm with medium velocity. Control group had the highest percentage of sperm DNA integrity compared to BPH group. For the frozen-thawed semen, Control group presented the highest percentage of spermatozoa with high mitochondrial activity. However, the BPH-Finasteride group showed higher number of sperm bound to the perivitelline membrane of chicken egg yolk compared to the BPH Group. Conversely, BPH group had higher percentage of DNA damage. In conclusion, the ejaculate of BPH dogs has higher susceptibility to cryoinjury, whereas finasteride-treated dogs have increased spermatozoa functional performance, suggesting a promising use of BPH dogs as semen donors in sperm cryopreservation programs.

Ethanol Extract of Chaenomeles sinensis Inhibits the Development of Benign Prostatic Hyperplasia by Exhibiting Anti-oxidant and Anti-inflammatory Effects

Chaenomeles sinensis is known to inhibit the development and progression of many age-related diseases, but the underlying molecular mechanisms are largely unclear. In the present study, we observed that the ethanol extract of Chaenomeles sinensis scavenged 2,2’-diphenylpicrylhydrazyl and 2,2’-azinobis diammonium radicals in vitro. The ethanol extract of Chaenomeles sinensis activated antioxidant response element-luciferase activity and induced expression of NRF2 target genes in HaCaT cells. The ethanol extract of Chaenomeles sinensis also suppressed LPS-induced expression of COX-2 and iNOS proteins, and mRNA expression of TNF-α and IL-2 in RAW264.7 cells. Finally, the ethanol extract of Chaenomeles sinensis significantly suppressed testosterone propionate-induced benign prostatic hyperplasia in mice. Together, our study provides the evidence that the ethanol extract of Chaenomeles sinensis inhibits the development of benign prostatic hyperplasia by exhibiting anti-oxidant and anti-inflammatory effects.

Berberine ameliorates testosterone-induced benign prostate hyperplasia in rats

INTRODUCTION

Benign prostatic hyperplasia (BPH) is a major urologic problem that mostly develops in older males. Oxidative stress and inflammation influence the occurrence of BPH. Berberine (BBR) is a natural ingredient that has antioxidant and anti-inflammatory properties. The current research aims at examining the effects of BBR on testosterone-stimulated BPH in rats.

METHODS

Animals were randomly categorized to six groups. In the control group, normal saline and olive oil were injected as the vehicle. BPH group: received testosterone (3 mg/kg, subcutaneous, 28 days), BPH + BBR groups; received BBR (25 and 50 mg/kg, p.o, 28 days), BPH + finasteride groups: received finasteride (1 mg/kg, p.o, 28 days), BBR (50 mg/kg, p.o, alone) was administered for subjects in the BBR group. On the 29th day, after anesthesia, cervical dislocation was used to kill the subjects. Serum concentration of testosterone and dihydrotestosterone was measured and prostate tissues were excised and used for biochemical, inflammation, and histological analysis.

RESULTS

BBR prevented increased serum concentrations of testosterone and dihydrotestosterone. BBR considerably reduced BPH-stimulated oxidative stress and inflammation through preventing the rise in lipid peroxidation and nitrite concentration and declined the accumulations of pro-inflammatory cytokines (e.g. interleukin 1β and tumor necrosis factor α) and declining the depletion rate of GSH and the function of catalase and superoxide dismutase. Histopathological investigations reported that administration of BBR could suppress testosterone-stimulated BPH.

CONCLUSION

This study demonstrated that BBR could significantly prevent the development of BPH in rats.

Effects of larval extracts from identified Protaetia brevitarsis seulensis against benign prostatic hyperplasia induced by testosterone in rats

Protaetia brevitarsis seulensis is an animal-based medicine used traditionally in China, Japan, and Korea to treat hepatic disorders; it has been shown to possess various pharmacological effects such as antibacterial and antioxidant activities. In this study, we investigated the effects of P. brevitarsis on a testosterone-induced benign prostatic hyperplasia (BPH) rat model. To establish the BPH model, the animals were administered a subcutaneous injection of testosterone daily for 28 days. P. brevitarsis was administered by oral gavage at doses of 12.5, 25, and 50 mg/kg for 28 days, along with testosterone injection. P. brevitarsis treatment markedly decreased the absolute and relative prostate weight of BPH animals. The levels of dihydrotestosterone was reduced in P. brevitarsis-treated animals compared to those in the BPH animals. Histological analysis of the prostate showed that P. brevitarsis treatment effectively suppressed the testosterone-induced hyperplasia of prostatic epithelial cells, which was accompanied by reductions in the PCNA and Ki-67 expressions in prostatic tissues. These results indicate that P. brevitarsis effectively suppresses testosterone-induced development of BPH, and thus, is a potential therapeutic agent for BPH.

A metabolomics study of Qianliexin capsule treatment of benign prostatic hyperplasia induced by testosterone propionate in the rat model

A metabolomics investigation of the treatment effect of Qianliexin (QLX) capsules was conducted on rats with benign prostatic hyperplasia (BPH) induced by testosterone propionate. Establishment of the BPH model was confirmed using the prostatic index. Hematoxylin and eosin (HE) staining for TGF-β, EGFR, collagen, IL-1 β, TNF-α was performed and changes in urine volume were measured. Urine and serum samples were collected from three groups, including a control group, a BPH model group and a QLX-treated group and subjected to metabolomics profiling based on ultrahigh-performance liquid chromatography-mass spectrometry. Pharmacodynamics analysis showed that the QLX group had significantly lower histopathological damage, fibrosis damage, and inflammation and higher urine output compared with the model group. Twenty-two potential biomarkers were identified in urine samples and 23 metabolites were identified in plasma samples. Alterations in metabolic patterns were evident in all sample types. The treatment effects of QLX appear to involve various metabolic pathways including lipid metabolism, fatty acid metabolism and purine generation and significantly reduced the pathological symptoms and related biochemical indicators of BPH and improved the level of potential marker metabolites. This comprehensive study suggested that differential markers provided insights into the metabolic pathways involved in BPH and the treatment effects of QLX.

Protective effects of combination of Stauntonia hexaphylla and Cornus officinalis on testosterone-induced benign prostatic hyperplasia through inhibition of 5α- reductase type 2 and induced cell apoptosis

Benign prostatic hyperplasia (BPH) is a progressive pathological condition associated with proliferation of prostatic tissues, prostate enlargement, and lower-urinary tract symptoms. However, the mechanism underlying the pathogenesis of BPH is unclear. The aim of this study was to investigate the protective effects of a combination of Stauntonia hexaphylla and Cornus officinalis (SC extract) on a testosterone propionate (TP)-induced BPH model. The effect of SC extract was examined in a TP-induced human prostate adenocarcinoma cell line. Male Sprague-Dawley rats were randomly divided into 5 groups (n = 6) for in vivo experiments. To induce BPH, all rats, except those in the control group, were administered daily with subcutaneous injections of TP (5 mg/kg) and orally treated with appropriate phosphate buffered saline/drugs (finasteride/saw palmetto/SC extract) for 4 consecutive weeks. SC extract significantly downregulated the androgen receptor (AR), prostate specific antigen (PSA), and 5α-reductase type 2 in TP-induced BPH in vitro. In in vivo experiments, SC extract significantly reduced prostate weight, size, serum testosterone, and dihydrotestosterone (DHT) levels. Histologically, SC extract markedly recovered TP-induced abnormalities and reduced prostatic hyperplasia, thereby improving the histo-architecture of TP-induced BPH rats. SC extract also significantly downregulated AR and PSA expression, as assayed using immunoblotting. Immunostaining revealed that SC extract markedly reduced the 5α-reductase type 2 and significantly downregulated the expression of proliferating cell nuclear antigen. In addition, immunoblotting of B-cell lymphoma 2 (Bcl-2) family proteins indicated that SC extract significantly downregulated anti-apoptotic Bcl-2 and markedly upregulated pro-apoptotic B cell lymphoma-associated X (Bax) expression. Furthermore, SC treatment significantly decreased the Bcl-2/Bax ratio, indicating induced prostate cell apoptosis in TP-induced BPH rats. Thus, our findings demonstrated that SC extract protects against BPH by inhibiting 5α-reductase type 2 and inducing prostate cell apoptosis. Therefore, SC extract might be useful in the clinical treatment of BPH.

Development of Prostate Cancer Organoid Culture Models in Basic Medicine and Translational Research

Prostate cancer (PC) is the most prevalent cancer in men and the second main cause of cancer-related death in Western society. The lack of proper PC models that recapitulate the molecular and genomic landscape of clinical disease has hampered progress toward translational research to understand the disease initiation, progression, and therapeutic responses in each patient. Although several models have been developed, they hardly emulated the complicated PC microenvironment. Precision medicine is an emerging approach predicting appropriate therapies for individual cancer patients by means of various analyses of individual genomic profiling and targeting specific cancer pathways. In PC, precision medicine also has the potential to impose changes in clinical practices. Here, we describe the various PC models with special focus on PC organoids and their values in basic medicine, personalized therapy, and translational researches in vitro and in vivo, which could help to achieve the full transformative power of cancer precision medicine.

Effects of Lespedeza Cuneata aqueous extract on testosterone-induced prostatic hyperplasia

CONTEXT

Lespedeza cuneata G. Don (Fabaceae), has been used as a traditional treatment of various diseases. There is a report L. cuneata effects on hormone replacement therapy for endocrine-related disease. However, studies related to benign prostatic hyperplasia (BPH) have not been investigated.

OBJECTIVE

The effects of L. cuneata aqueous extract (LCW) on testosterone-induced prostatic hyperplasia (TPH) were examined.

MATERIALS AND METHODS

Male Wistar rats (10 weeks, 330-350 g) were randomly divided to 6 groups (n = 6): Control group; TPH group (3 mg/kg, s.c, daily); TPH + LCW (25, 50, 100 mg/kg); TPH + Finasteride 10 mg/kg for 6 weeks. At the end of treatment, histological change of prostate, serum dihydrotestosterone (DHT) level, mRNA expression of 5α-reductase, inflammatory factors, proliferating cell nuclear antigen (PCNA) and fibroblast growth factor-2 (FGF-2) in prostate were examined. Then, LCW was treated with BPH-1, a human BPH cell line, at 25, 50, 100 μg/mL for 24 h and examine mRNA level of androgen receptor (AR) and prostate-specific antigen (PSA). In addition, the content of vicenin-2 was analyzed.

RESULTS

LCW treatment of TPH inhibited serum DHT levels by 54.5, 51.2 and 54.1% and mRNA expression of 5α-reductase were inhibited 54.3, 61.3 and 73.6%, respectively. In addition, mRNA expression of inflammatory factors, PCNA and FGF-2 were decreased in the prostate of rats. Also, LCW attenuated mRNA level of AR and PSA in BPH-1 cell. The content of vicenin-2 in the LCW was analyzed to 0.89 mg/g.

DISCUSSION AND CONCLUSIONS

Based on the results, LCW is a potential pharmacological candidate for the treatment of prostatic hyperplasia.

Aconiti Lateralis Radix Preparata, the Dried Root of Aconitum carmichaelii Debx., Improves Benign Prostatic Hyperplasia via Suppressing 5-Alpha Reductase and Inducing Prostate Cell Apoptosis

Benign prostatic hyperplasia (BPH) is a common disease in elderly men which can be characterized by an abnormal enlargement of the prostate associated with lower urinary symptoms. Current medications available for BPH treatment display several adverse effects; thus, the search for effective treatments with less side effects is still ongoing. In this study, we investigated the effect of Aconiti Lateralis Radix Preparata (dried root of Aconitum carmichaelii Debx.; AL), which is an herb used to treat extremely cold symptoms in traditional Korean medicine, on BPH using a testosterone propionate- (TP-) induced BPH rat model. Eight-week inguinal injection of TP induced BPH in rats, the prostate of which was displaying an abnormal proliferation. The pathological proliferation of the prostate was ameliorated by AL treatment of 4 weeks. Pathohistological changes in the prostate including epithelial thickness and lumen area were restored in AL-treated rats. Furthermore, 5α-reductase (5AR) and androgen receptor (AR), the two main factors in the pathogenesis of BPH, were decreased. In addition, the ratio of BAX and Bcl-2, an indicator of apoptosis, was increased by AL as well. Similar results were observed in AL-treated LNCaP prostate cancer cells. AL treatment suppressed the expression of the 5AR-AR axis and increased the ratio of BAX and Bcl-2. Apoptosis in the testis is considered a crucial side effect of finasteride, a 5AR inhibitor used to treat BPH. Our results showed that AL treatment did not display such effects, while finasteride treatment resulted in loss of spermatogenic cells within the prostate. Overall, these results suggest AL as a potentially safe nature-derived therapeutic agent for BPH treatment.

Effect of gold nanoparticles treatment on the testosterone-induced benign prostatic hyperplasia in rats

Background: Gold nanoparticles (AuNps) are promising agents for prostate cancer therapy. Herein, the in vivo effects of 20 and 50 nm sized AuNps on experimentally induced benign prostatic hyperplasia (BPH) was examined.

Materials and methods: Adult male rats were divided into four groups (n=6–8 each). A negative control group and three groups were injected daily with testosterone (3 mg/kg/subcutaneously) to induce BPH. Animals receiving testosterone were randomized to untreated BPH group and two BPH groups which were treated intraperitoneally with 20 and 50 nm AuNps (5 mg/kg/daily) in addition to testosterone. After three weeks, histopathological changes and serum levels of testosterone and dihydrotestosterone (DHT) were analyzed. In addition, the prostate tissue levels of transforming growth factor-β₁ (TGF-β₁), vascular endothelial growth factor-a (VEGF-A) and interleukin-6 (IL-6) were measured using ELISA.

Results: There were significant increases in the prostate weight/body weight ratio, serum testosterone and DHT and in the prostate tissue content of TGF-β₁, IL-6 and VEGF-A in the untreated BPH group. histological examination showed morphological abnormalities with more proliferation in the glandular epithelial and stromal area and with abundant epithelial papillary folds in the BPH group. Simultaneous administration of 50 nm AuNps with testosterone tended to increase the prostate weight/body weight ratio and increase the tissue level of IL-6 in compared to the BPH group. Conversely, treatment with 20 nm AuNps significantly reduced the elevated tissue content of TGF-β₁, IL-6, and VEGF-A. Histopathological examination also showed that 20 nm but not the 50 nm AuNps administration ameliorates testosterone-induced prostatic hyperplasia.

Conclusions: In experimentally induced BPH, AuNps can inhibit the progression of BPH in a size-dependent manner. while 20 nm AuNps ameliorate BPH by its inhibitory effects on the prostatic cell proliferation, inflammation and angiogenesis, the 50 nm AuNps could potentially exacerbate the development of BPH in rats, mainly through enhancing the inflammatory process.

Triptolide inhibits benign prostatic epithelium viability and migration and induces apoptosis via upregulation of microRNA-218

Benign prostatic hypertrophy (BPH) has become a troublesome disease for elder men. Triptolide (TPL) has been reported to be a potential anticancer agent. However, the potential effects of TPL on BPH have not been shown out. BPH-1 cells were treated with different concentrations of TPL and/or transfected with microRNA-218 (miR-218) inhibitor, pc-survivin, sh-survivin, or their corresponding controls (NC). Thereafter, cell viability was determined by CCK-8 assay. Cell migration was accessed by modified two-chamber migration assay. Cell apoptosis was checked by propidium iodide (PI) and fluorescein isothiocyanate (FITC)-conjugated Annexin V staining. In addition, messenger RNA (mRNA) and protein levels were detected using quantitative real-time polymerase chain reaction (qRT-PCR) and western blot analysis, respectively. BPH-1 cell viability and migration were significantly decreased, while cell apoptosis and expression of miR-218 were statistically enhanced by TPL (P < 0.05 or P < 0.01). However, downregulation of miR-218 increased cell viability and migration, while decreased cell apoptosis compared with the negative control group (P < 0.05 or P < 0.01). Furthermore, the expression of cell cycle–related proteins and cell apoptosis–related proteins were also led to the opposite results with NC. In addition, we found that miR-218 negatively regulated the expression of survivin (P < 0.01) and suppression of survivin significantly enhanced cell apoptosis (P < 0.01). Moreover, the results demonstrated that TPL could inactivate mammalian target of rapamycin (mTOR) pathway, while inhibition of miR-218 alleviated the effects. TPL inhibits viability and migration of BPH-1 cells and induces cell apoptosis and also inactivates mTOR signal pathway via upregulation of miR-218. This study provides evidence for the further studies representing triptolide as a potential agent in the treatment of human BPH.

A two-week, double-blind, placebo-controlled trial of Viola odorata, Echium amoenum and Physalis alkekengi mixture in symptomatic benign prostate hyperplasia (BPH) men

CONTEXT

As an alternative approach, administration of phytotherapeutic agents in management of benign prostate hyperplasia (BPH), is rapidly growing each day. Different authors have indicated effectiveness of Viola odorata L. (Violaceae), Echium amoenum Fisch. & C.A.Mey. (Boraginaceae) and Physalis alkekengi L. (Solanaceae) in treatment of BPH. However, none have reported the beneficial outcomes of the mixture yet.

OBJECTIVE

This study evaluates the therapeutical effects of V. odorata, E. amoenum and P. alkekengi mixture on symptomatic BPH patients.

MATERIALS AND METHODS

Eighty six symptomatic BPH patients with International Prostate Symptom Score (IPSS) of more than 13 and prostate volume of more than 30 cm³ were randomly allocated to receive a two-week course of placebo (control group) or 1 mL of mixed hydro-alcoholic solution of P. alkekengi, E. amoenum and V. odorata extracts (1.5, 1 and 1.5% respectively) (treatment group).

RESULTS

IPSS score of incomplete urination (42.3 ± 2.04%), frequency of urination (20.08 ± 1.02%), intermittency (40.78 ± 2.16%), urgency (60.91 ± 3.14%), weak stream (50.58 ± 2.14%), straining (55.67 ± 2.53%) and nocturia (40.14 ± 1.89%) in treatment group were significantly decreased after treatment compare to placebo receiving group. Furthermore, the prostate volume (16.92 ± 0.89%) and extant urine volume (28.12 ± 1.36%) also significantly decreased in treatment group compared to control group. No significant side effects or abnormalities in biochemical tests and urinalysis were observed throughout the study.

DISCUSSION AND CONCLUSIONS

Based on results, mentioned mixture is safe and effective in improving life quality of patients suffering from BPH.

Establishment of a dog primary prostate cancer organoid using the urine cancer stem cells

Dog spontaneously develop prostate cancer (PC) like humans. Because most dogs with PC have a poor prognosis, they could be used as a translational model for advanced PC in humans. Stem cell‐derived 3‐D organoid culture could recapitulate organ structures and physiology. Using patient tissues, a human PC organoid culture system was established. Recent study has shown that urine cells also possess the characteristic of stem cells. However, urine cell‐derived PC organoids have never been produced. Therefore, we generated PC organoids using the dog urine samples. Urine organoids were successfully generated from each dog with PC. Each organoid showed cystic structures and resembled the epithelial structures of original tissues. Expression of an epithelial cell marker, E‐cadherin, and a myofibloblast marker, α‐SMA, was observed in the urine organoids. The organoids also expressed a basal cell marker, CK5, and a luminal cell marker, CK8. CD49f‐sorted basal cell organoids rapidly grew compared with CD24‐sorted luminal cell organoids. The population of CD44‐positive cells was the highest in both organoids and the original urine cells. Tumors were successfully formed with the injection of the organoids into immunodeficient mice. Treatment with a microtubule inhibitor, docetaxel, but not a cyclooxygenase inhibitor, piroxicam, and an mTOR inhibitor, rapamycin, decreased the cell viability of organoids. Treatment with a Hedgehog signal inhibitor, GANT61, increased the radiosensitivity in the organoids. These findings revealed that PC organoids using urine might become a useful tool for investigating the mechanisms of the pathogenesis and treatment of PC in dogs.

Cynanchum wilfordii Ameliorates Testosterone-Induced Benign Prostatic Hyperplasia by Regulating 5α-Reductase and Androgen Receptor Activities in a Rat Model

Benign prostatic hyperplasia (BPH) is characterized by uncontrolled proliferation of the prostate gland. Cynanchum wilfordii has been reported to improve sexual behavior in male rats. In this study, we investigated the protective effect of an aqueous extract of C. wilfordii (CWW) against BPH development in a testosterone-induced BPH rat model. The rats were divided into the following six groups: sham/vehicle; BPH/vehicle; BPH/finasteride; and three CWW doses (50, 100, and 200 mg/kg). After a 4-week treatment with CWW, the rats were euthanized at scheduled times, and their prostates were weighed, followed by a histopathological examination. Prostate growth inhibition rates in rats administered CWW 50, 100, and 200 mg/kg were 54.5%, 51.8%, and 50.1%, respectively. The BPH/CWW group showed decreased serum testosterone and dihydrotestosterone (DHT) levels compared to the BPH/vehicle group. Furthermore, the BPH/CWW group showed reduced prostate testosterone and DHT levels compared to the BPH/vehicle group. Mechanistically, the reverse transcription-polymerase chain reaction revealed downregulated mRNA expression levels of the androgen receptor, 5α-reductase, and B-cell lymphoma-2 (Bcl-2) in the BPH/CWW200 group compared with those in the testosterone-induced groups. In conclusion, these findings show the effectiveness of CWW in slowing the progression of testosterone-induced BPH in rats.

Quisqualis indica Improves Benign Prostatic Hyperplasia by Regulating Prostate Cell Proliferation and Apoptosis

Quisqualis indica (QI) has been used for treating disorders such as stomach pain, constipation, and digestion problem. This study was aimed to evaluate the therapeutic efficacy of QI extract on treating benign prostatic hyperplasia (BPH) in LNCaP human prostate cancer cell line and a testosterone-induced BPH rat model. LNCaP cells were treated with QI plus testosterone propionate (TP), and androgen receptor (AR) and prostate specific antigen (PSA) expression levels were assessed by Western blotting. To induce BPH, the rats were subjected to a daily subcutaneous injection of TP (3 mg/kg) for 4 weeks. The rats in treatment group were orally gavaged with QI (150 mg/kg) together with the TP injection. In-vitro studies showed that TP-induced increases in AR and PSA expression in LNCaP cells were reduced by QI treatment. In BPH-model rats, the prostate weight, testosterone in serum, dihydrotestosterone (DHT) concentration and 5α-reductase type 2 mRNA expression in prostate tissue were significantly reduced following the treatment with QI. TP-induced prostatic hyperplasia and the expression of proliferating cell nuclear antigen (PCNA) and cyclin D1 were significantly attenuated in QI-treated rats. In addition, QI induced apoptosis by up-regulating caspase-3 and -9 activity and decreasing the B-cell lymphoma 2 (Bcl-2)/Bcl-2-associated X protein (Bax) ratio in prostate tissues of BPH rats. Further investigation showed that TP-induced activation of AKT and glycogen synthase kinase 3β (GSK3β) was reduced by QI administration. Therefore, our findings suggest that QI attenuates the BPH state in rats through anti-proliferative and pro-apoptotic activities and might be useful in the clinical treatment of BPH.

Triptolide reduces prostate size and androgen level on testosterone-induced benign prostatic hyperplasia in Sprague Dawley rats

Benign prostatic hyperplasia (BPH) is an age-related disease of unknown etiology, characterized by prostatic enlargement coincident with distinct alterations in tissue histology. In the present study, we investigated whether triptolide can prevent testosterone-induced prostatic hyperplasia in rats. Castration was performed via the scrotal route after urethane aesthesia. BPH was induced in experimental groups by daily subcutaneous injections of testosterone propionate (TP) for two weeks. Triptolide was administered daily by oral gavage at a dose of 100 and 50 μg·kg^-1 for 2 weeks, along with the TP injections. On day 14, the animals were humanely killed by cervical dislocation after aesthesia. Prostates were excised, weighed, and used for histological studies. Testosterone and dihydrotestosterone (DHT) levels in serum and prostate were measured. The results showed that triptolide significantly reduced the prostate weight, and the testosterone and DHT levels in both the serum and prostate. Histopathological examination also showed that triptolide treatment suppressed TP-induced prostatic hyperplasia. In conclusion, triptolide effectively inhibits the development of BPH induced by testosterone in a rat model.

Effect of kolaviron, a biflavanoid complex from Garcinia kola on some biochemical parameters in experimentally induced benign prostatic hyperplasic rats

BACKGROUND

To determine the effect of kolaviron on some biochemical parameters in benign prostatic hyperplasia (BPH) rats.

METHODS

BPH was induced in rats using a mixture of dihydrotestosterone and estradiol valerate (10:1).

RESULTS

The lethal dose of kolaviron was 3050mg/kg body weight. Body weights, relative heart weight (RHW), relative liver weight (RLW), serum levels of prostate specific antigen, prolactin, estradiol, testosterone, testosterone/estradiol ratio, aspartate transaminase (AST), alanine transaminase (ALT), urea, creatinine and prostatic levels of total proteins in the normal rats administered finasteride (standard drug) or kolaviron were not different (P>0.05) from normal control whereas most of these parameters were altered in the disease control except RHW, RLW, AST and ALT. Finasteride (5mg/70kg) or kolaviron (100 and 200mg/kg) ameliorated most of these parameters compared with disease control except RHW, RLW, prolactin, AST, ALT, urea and creatinine (for kolaviron at 100mg/kg). The normal rats administered finasteride or kolaviron had decreased prostate weights (P<0.05) compared with the normal control which results were corroborated by histological assay that also showed that treatment with kolaviron (200mg/kg) or finasteride reversed the histoarchitecture of the prostates of the BPH rats.

CONCLUSION

Kolaviron could be useful in the management of BPH.

Cinnamomi Cortex (Cinnamomum verum) Suppresses Testosterone-induced Benign Prostatic Hyperplasia by Regulating 5α-reductase

Cinnamomi cortex (dried bark of Cinnamomum verum) is an important drug in Traditional Korean Medicine used to improve blood circulation and Yang Qi. Benign prostatic hyperplasia (BPH) is a common chronic disease in aging men. This study was conducted to determine the effect of Cinnamomi cortex water extract (CC) on BPH. BPH was induced by a pre-4-week daily injection of testosterone propionate (TP). Six weeks of further injection with (a) vehicle, (b) TP, (c) TP + CC, (d) TP + finasteride (Fi) was carried on. As a result, the prostate weight and prostatic index of the CC treatment group were reduced. Histological changes including epithelial thickness and lumen area were recovered as normal by CC treatment. The protein expressions of prostate specific antigen, estrogen receptor α (ERα), androgen receptor (AR), 5α-reductase (5AR), and steroid receptor coactivator 1 were suppressed by treatment of CC. Immunohistochemical assays supported the western blot results, as the expressions of AR and ERα were down-regulated by CC treatment as well. Further in vitro experiments showed CC was able to inhibit proliferation of RWPE-1 cells by suppressing 5AR and AR. These results all together suggest CC as a potential treatment for BPH.

The Wonders of Phosphodiesterase-5 Inhibitors: A Majestic History

The Nobel Prize winning discovery of nitric oxide (NO) in 1986 was the starting point for a new innovation in drug discovery. NO acting as a mediator at different physiological systems is believed to be involved in many physiological and pathological conditions through the formation of the second messenger cyclic guanosine monophosphate (cGMP). cGMP-dependent vasodilation effect of NO is important in regulating pulmonary and systemic pressures, maintaining penis erection, preventing atherosclerosis, preventing platelet aggregation, and protecting and controlling cardiac functions. The main enzyme involved in the termination of cGMP effects is phosphodiesterase enzyme 5 (PDE-5), which is overexpressed in ventricular hypertrophy and heart failure. A milestone in drug discovery was the selective inhibitors of PDE-5 that developed to be a multibillion dollar blockbuster in drug market. PDE-5 inhibitors are approved for the treatment of erectile dysfunctions (EDs), pulmonary hypertension, and benign prostatic hypertrophy. They are also under clinical trials for their cardiac protection against damage induced by ischemia or heart failure. This review article is an update about the pharmacotherapeutics of PDE-5 inhibitors and the majestic history that led to their discovery. The information reported in this review was obtained from the electronic sources of different databases such as PubMed Central, Google Scholar, and Scopus. Keywords used for search included cGMP (mechanisms and functions), EDs (drugs used), nitric oxide, and PDE-5 inhibitors (clinical applications). A total of 165 articles were studied, of which 45 articles were referred to in this review.

Rapatar, a nanoformulation of rapamycin, decreases chemically-induced benign prostate hyperplasia in rats

Benign prostatic hyperplasia (BPH) is the most common age-related disease in men. Here we tested the efficacy of Rapatar, a micellar nanoformulation of rapamycin, in two rat models of BPH: testosterone-induced and sulpiride-induced hyperplasia in ventral lobes and lateral/dorsal lobes, respectively. We found that Rapatar prevented hypertrophic and hyperplastic abnormalities and degenerative alterations in both BPH models. Rapatar normalized weight of the lateral lobes in sulpiride-induced BPH, the most relevant animal model of human BPH. Unlike Finasteride, a standard therapy of BPH, Rapatar reduced inflammation caused by sulpiride. No obvious side effects of Rapatar were detected. Our data provide a rationale for clinical trials of Rapatar in patients suffering from BPH.

Inhibitory effects of Tripterygium wilfordii multiglycoside on benign prostatic hyperplasia in rats

The present study was designed to evaluate the inhibitory effects of Tripterygium wilfordii multiglycoside (GTW) against testosterone-induced benign prostatic hyperplasia (BPH) in rats. A total of 45 rats were randomly divided into five groups: Group I, vehicle control group (sham-operated and treated with vehicle); Group II, BPH group; Group III, BPH rats treated with finasteride at a dose of 5 mg·kg(-1); and Groups IV and V, BPH rats treated with GTW at dose levels of 10 and 20 mg·kg(-1), respectively. The drugs were administered orally once a day for 14 days. Prostate weight, prostatic index, and the testosterone and dihydrotestosterone (DHT) levels in serum and prostate, and the serum prostate specific antigen (PSA) levels were measured; prostate tissues were taken for histopathological examination; and serum biochemical analysis was also performed. The BPH rats displayed an increase in prostate weight, prostatic index with increased testosterone and DHT levels in both the serum and prostate, and increased serum PSA levels. GTW treatment at both doses resulted in significant reductions in prostate weight, prostatic index, testosterone and DHT levels in both the serum and prostate, and serum PSA levels, compared with BPH group. Histopathological examination also indicated that GTW treatment at both doses inhibited testosterone-induced prostatic hyperplasia. Serum biochemical analysis showed that the liver and renal functions were normal. In conclusion, GTW inhibited testosterone-induced prostatic hyperplasia in rats, without host toxicity, providing a basis for the development of GTW as a novel therapy for BPH.

Antiproliferative and Antioxidant Effects of Withania coagulans Extract on Benign Prostatic Hyperplasia in Rats

Background:

Benign prostate hyperplasia (BPH) is a common urological disorder in elderly men. Phytotherapy is frequently used to alleviate the symptoms of this condition.

Objectives:

The present study investigated the effect of Withania coagulans extract (WCE), which is known to have antioxidant, anti-inflammatory, antihyperglycemic, and anti-cancer properties, on testosterone-induced BPH in rats.

Materials and Methods:

Forty Wistar rats were divided into five groups (each n = 8): the control group, the untreated BPH group, and three WCE-treated groups (WCE250, 500, and 1000). BPH was induced with 3 mg/kg subcutaneous injections of testosterone propionate for four weeks. WCE was concomitantly administrated by oral gavage. At the end of the induction schedule, the animals were sacrificed and their prostate glands were dissected, weighed, and fixed for histological examination (H&E and proliferating cell nuclear antigen [PCNA] staining). Half of each sample was prepared for measurement of malondialdehyde (MDA) and total antioxidant capacity (TAC) levels in the prostate.

Results:

The present study revealed that BPH caused elevation of MDA levels, suppression of TAC levels, and increased PCNA expression in the prostate gland. Interestingly, in a dose-dependent manner, WCE caused decreased MDA levels and increased TAC levels in the prostate gland, compared to the untreated BPH group. Histopathological examinations showed a reduction in PCNA expression in the prostate epithelium of the WCE animals.

Conclusions:

W. coagulans inhibits the development of BPH can be useful for the treatment of this condition.

α-Spinasterol from Melandrium firmum attenuates benign prostatic hyperplasia in a rat model

Spinasterol, a biologically active compound, exhibits a number of pharmacological activities, including antitumor, antiulcerogenic and anticarcinogenic activity, and originates from the aerial parts of Aster scaber Thunb (Asteraceae). The present study investigated whether α-spinasterol isolated from Melandrium firmum Rohrbach could prevent benign prostatic hyperplasia (BPH) induced by testosterone propionate (TP) in rats. Male Wistar rats were randomly divided into four groups of eight rats following castration. A negative control group received subcutaneous injections of corn oil. Treatments were administered orally 1 h prior to TP injection. All the rats were sacrificed at the scheduled termination time and their prostates were removed, cleaned and weighed. The prostate size ratio (prostate weight/rat body weight) was then calculated. Additional histopathological examinations were conducted, and the levels of TP and dihydrotestosterone (DHT) in the serum and prostate were measured. TP significantly increased the prostate size ratio (P<0.01), and DHT and testosterone levels in the serum and prostate. The TP-induced increase was significantly inhibited in α-spinasterol-treated rats when compared with the negative controls (P<0.05). In addition, histopathological examination demonstrated that α-spinasterol treatment suppressed TP-induced prostatic hyperplasia. It is concluded that α-spinasterol can prevent TP-induced prostatic hyperplasia and may be beneficial in the management of BPH.

Clinical equipoise and risk-benefit assessment

Clinical equipoise is widely regarded as an ethical requirement for the design and conduct of randomized controlled trials (RCTs). Underlying clinical equipoise is the norm that no patient should be randomized to treatment known (or believed by the expert clinical community) to be inferior to the established standard of care. This implies that patient-subjects should not be exposed to net risks in control groups of randomized trials - risks that are not compensated by the prospect of direct medical benefits from the control intervention. However, proponents of clinical equipoise have no moral objections to permitting net risks for 'nontherapeutic' research procedures employed in clinical trials. This differential assessment makes risk-benefit assessment of randomized trials incoherent. In this article, I examine critically four arguments in defense of clinical equipoise as a requirement for risk-benefit assessment. Each of these arguments fails to support clinical equipoise, leading to the conclusion that we should dispense with this principle in risk-benefit assessment of RCTs.

Inhibitory effect of Yukmijihwang-tang, a traditional herbal formula against testosterone-induced benign prostatic hyperplasia in rats

Background

Yukmijihwang-tang, a traditional herbal formula, has been used for treating disorder, diabetic mellitus and neurosis in China (Liu-wei-di-huang-tang in Chinese), Japan (Lokumijio-to in Japanese) and Korea for many years. In this study, we investigated the effects of Yukmijihwang-tang water extract (YJT) on the development of benign prostatic hyperplasia (BPH) using a rat model of testosterone propionate (TP)-induced BPH.

Methods

A total of 30 rats were divided into five groups. One group was used as a control and the other groups received subcutaneous injections of TP for 4 weeks to induce BPH. YJT (200 or 400 mg/kg) was administered daily for 4 weeks to two groups by oral gavage concurrently with the TP. The animals were euthanized, the prostate and body weights were recorded, and tissues were subjected to hormone assays and histomorphology. In addition, we investigated proliferating cell nuclear antigen (PCNA) expression in the prostate using immunoblotting.

Results

Animals with BPH showed significantly increased absolute and relative prostate weights, increased dihydrotestosterone levels in the serum or prostate and increased PCNA expression in the prostate; however, YJT-treated animals showed significant reductions compared with the animals with TP-induced BPH. Histomorphology also showed that YJT inhibited TP-induced prostatic hyperplasia.

Conclusions

These findings indicate that YJT effectively inhibited the development of BPH and might be a useful drug clinically.

Ursolic acid reduces prostate size and dihydrotestosterone level in a rat model of benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is characterized by hyperplasia of prostatic stromal and epithelial cells, which can lead to lower urinary tract symptoms. The prevalence of BPH increases in an age-dependent manner. We investigated the protective effect of ursolic acid in BPH development using a testosterone-induced BPH rat model. BPH was induced in experimental groups by daily subcutaneous injections of testosterone propionate (TP), for a period of four weeks. Ursolic acid was administrated daily by oral gavage at a dose level of 5mg/kg during the four weeks of TP injections. Animals were sacrificed on the scheduled termination, before prostates were weighed and subjected to histopathological examination. TP and dihydrotestosterone (DHT) levels in the serum and prostate were also measured. BPH-induced animals displayed an increase in prostate weight with increased testosterone and DHT levels in both the serum and prostate. However, ursolic acid treatment resulted in significant reductions in prostate weight and testosterone and DHT levels in both the serum and prostate, compared with BPH-induced animals. Histopathological examination also showed that ursolic acid treatment suppressed TP-induced prostatic hyperplasia. These findings indicate that ursolic acid may effectively inhibit the development of BPH and it may be a useful agent in BPH treatment.

National-wide data on the treatment of BPH in Korea

The healthcare system in Korea provides coverage to all the people who are residing in Korea, so the data of the Korea healthcare system are national-wide and relatively accurate. We obtained the recent 5-year data (2004-2008) on the treatment of BPH from the national health insurance system. We tried to determine the trends or changes of BPH treatments in Korea. Over 3.8 million men visited clinics and were prescribed one or more BPH medications, and more than 44 000 men underwent surgical treatment during 2004-2008. Compared with the year 2004, two times the patients were prescribed BPH medications in 2008. With respect to the surgical treatment, the number of cases was increased 1.6 times in 2006 compared with the previous years. The most commonly used surgical option was TURP before 2006, but laser therapy was carried out as much as TURP in 2006 and in the following years. The relative risk of laser therapy in the 50 s is 1.53 (95% CI is 1.47-1.59). In conclusion, our national-wide data for the Korean BPH patients show that these patients' medical treatment increased during the 5 years from 2004 to 2008. Laser treatment had increased and it might replace TURP in several years.

Reduced levels of 5-α reductase 2 in adult prostate tissue and implications for BPH therapy

BACKGROUND

5-α reductase 2 (5-AR 2) is a key enzyme that is responsible of proper development of prostate tissue. Inhibition of 5-AR 2 has proven to be efficacious for management of urinary symptoms secondary benign prostatic hyperplasia (BPH). However, some patients are resistant to the therapeutic effects of 5-AR 2 inhibitor. We wished to determine why some benign non-cancerous adult human prostates do not express 5-AR 2, and hypothesized that methylation of 5-AR 2 promoter region correlated with low expression of 5-AR 2 protein.

METHODS

The transition zone of 42 human prostate tissues after radical prostatectomy was used for evaluation. Initially, 21 paraffin embedded samples were used to assess immunoreactivity to 5-AR 2 antibody in non-cancerous BPH samples. In the next 21 samples, fresh frozen prostate transition zone samples without cancer were assessed for immunoreactivity and methylation of the 5-AR 2 promoter using methyl-specific PCR.

RESULTS

We show that 6/21 (29%) of benign human prostate samples did not express the 5-AR 2 protein. Moreover, the promoter region of 5-AR 2 contains a CpG island that is methylated in benign prostate epithelial cells in culture and also in 39% (7/18) human prostate tissues. We show a strong correlation between methylation of the 5-AR 2 promoter region and absence of 5-AR 2 protein expression (P = 0.0025, Fisher's exact test).

CONCLUSIONS

Methylation of 5-AR 2 promoter may account for low or absent expression of 5-AR 2 in some human adult prostate tissues.

Benign prostatic hyperplasia: An overview of existing treatment

Benign prostatic hyperplasia (BPH) is the most common condition in aging men, associated with lower urinary tract symptoms (LUTS). A better understanding of the prostate physiology, function, and pathogenesis has led to the development of promising agents, useful in the management of LUTS in men. The specific approach used to treat BPH depends upon number of factors like age, prostrate size, weight, prostate-specific antigen level, and severity of the symptoms. 5α-reductase inhibitors decrease the production of dihydrotestosterone within the prostate, which results in decreased prostate volume, increased peak urinary flow rate, improvement of symptoms, decreased risk of acute urinary retention, and need for surgical intervention. α(1)-adrenergic receptor (α(1)-AR) antagonists decrease LUTS and increase urinary flow rates in men with symptomatic BPH, but do not reduce the long-term risk of urinary retention or need for surgical intervention. Clinical efficacy of either 5α-reductase inhibitor or α(1)-AR antagonist has been further improved by using combination therapy; however, long-term outcomes are still awaited. Many more potential new therapies are under development that may improve the treatment of BPH. This article gives a brief account of rationale and efficacy of different treatment options presently available in the management of BPH.

G protein-coupled receptors, an unexploited animal toxin targets: Exploration of green mamba venom for novel drug candidates active against adrenoceptors

At a time when pharmaceutical companies are having trouble finding new low MW drugs and when biologics are becoming more common, animal venoms could constitute an underexploited source of novel drug candidates. We looked for identifying novel animal toxins active against G protein-coupled receptors (GPCR), the most frequently exploited class of treatment targets, with the aim to develop novel research tools and drug candidates. Screening of green mamba (Dendroaspis angusticeps) venom against adrenoceptors identified two novel venom peptides. ρ-Da1a shown an affinity of 0.35 nM for the α1a-AR while ρ-Da1b displayed affinities between 14 and 73 nM for the three α2-ARs. These two venom peptides have sequences similar to those of muscarinic toxins and belong to the three-finger-fold protein family. α1a-AR is the primary target for the treatment of prostate hypertrophy. In vitro and in vivo tests demonstrated that ρ-Da1a reduced prostatic muscle tone as efficiently as tamsulosin (an antagonist presently used), but with fewer cardiovascular side effects. α2-ARs are the prototype of GPCRs not currently used as treatment targets due to a lack of specific ligands. Blockage of these receptors increases intestinal motility, which may be compromised by abdominal surgery and reduces orthosteric hypotension. In vitro and in vivo tests demonstrated that ρ-Da1b antagonizes α2-ARs in smooth muscles and increased heart rate and blood catecholamine concentrations. These results highlight possible exploitation of ρ-Da1a and ρ-Da1b in important pathologies.

Pharmacological characterization of zinc and copper interaction with the human alpha(1A)-adrenoceptor

Metal ions have a major role in human health, and interact with many classes of receptors including the G-protein coupled receptors. In the peripheral system, zinc mainly accumulates in the soft prostate organ and, with copper, influences prostate disease progression, from normal to hypertrophic or cancerous states. The development of these pathologies may be influenced by the α(1A)-adrenoceptor, the principal regulator of prostate tonicity. There is currently no information on possible interactions between metals and the α(1A)-adrenoceptor. We therefore studied the effects of several mono- and divalent ions on this receptor subtype using binding and functional experiments performed on expressed cloned human α(1A)-adrenoceptor. Regardless of the counter anion used, Zn(2+) and Cu(2+) interact with α(1A)-adrenoceptor with apparent affinities in the low micromolar range. In addition, using specific binding experiments, we established that these ions acted as negative allosteric ligands on prazosin/α(1A)-adrenoceptor interaction, but in a different manner from the allosteric modulator 5-(N-ethyl-N-isopropyl)-amiloride, suggesting distinct mode of interaction. In addition, the presence of Cu(2+) weakly decreased epinephrine affinity, whereas the addition of Zn(2+) shifted to the left the epinephrine binding curve, revealing a positive allosteric effect but only on half of the binding site. Finally, cell-based functional experiments demonstrated that Zn(2+) and Cu(2+) antagonized epinephrine activation in an insurmountable manner, by reducing agonist efficacy without any shift in the epinephrine activation curves. This study shows the interactions between metal ions and the α(1A)-adrenoceptor with affinities compatible with physiological concentrations and suggests that zinc and copper may have a biological role in prostate function.