A synopsis of drugs currently in preclinical and early clinical development for the treatment of benign prostatic hyperplasia

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.

Modulatory Effect of Silymarin on Apoptosis in Testosterone -Induced Benign Prostatic Hyperplasia in Rats

Benign prostatic hyperplasia (BPH) is considered a normal part of the aging process in men, and is characterized by an imbalance between cell proliferation and apoptosis. Our study aimed to investigate the potential protective role of silymarin (SIL) against testosterone-induced BPH in rats and to elucidate the molecular mechanisms underlying SIL pro-apoptotic and anti-proliferative effects. Forty adult male Wistar rats were divided equally into four groups: control group, BPH group (3 mg/kg testosterone propionate, s.c. for 14 days, SIL group (50 mg/kg SIL, orally, once daily concomitantly with 3 mg/kg testosterone propionate s.c.) and inhibitor group (50 mg/kg SIL orally concomitantly with 3 mg/kg testosterone, s.c. and 0.5 mg/rat Z-VAD-FMK, i.p.). Silymarin induced caspase-dependent apoptosis in BPH as SIL significantly reduced prostatic Bcl-2 protein and increased Bax protein concentration. Also, SIL down-regulated survivin (Inhibitor of apoptosis protein (IAPs) gene expression in rat prostate assisting mainly caspase-dependent pathway. Silymarin significantly decreased cytochrome-c cytosolic concentration and increased caspase 3 activity compared to BPH group. Silymarin significantly increased the content of p27/^kip1 (Cyclin dependent kinase inhibitor (CDKIs) promoting cell cycle arrest. The histological features of BPH such as hypertrophy, papillary projections formation, improved in SIL group. Silymarin showed a significant anti-proliferative and pro-apoptotic role in BPH and accordingly it could be effectively and safely used as a treatment tool in cases of BPH or prostatic disorders.

A phytosterol-enriched saw palmetto supercritical CO2 extract ameliorates testosterone-induced benign prostatic hyperplasia by regulating the inflammatory and apoptotic proteins in a rat model

BACKGROUND

Benign prostatic hyperplasia (BPH) is a pathological condition affecting older men. BPH complications often lead to deterioration in the quality of life. Serenoa repens (Saw Palmetto) is used for treating lower urinary tract infections in traditional medicine.

METHODS

This study was performed to compare the efficacy of β-sitosterol enriched saw palmetto oil (VISPO) and conventional saw palmetto oil (SPO) extracted using supercritical fluid extraction, in alleviating the BPH complications using testosterone-induced BPH model rats. The animals received testosterone (5 mg/kg s.c.) with or without SPO and VISPO (200 and 400 mg/kg b.w.) or Finasteride (1 mg/kg b.w.) p.o. for 28 days. At the end of the experiment, overnight fasted animals were euthanized, blood samples collected for serum analysis of testosterone. Prostate tissue histomorphology was examined by hematoxylin and eosin (H&E) staining. Western blot analysis was performed using prostate tissue homogenates.

RESULTS

VISPO exhibited superior efficacy compared to SPO as evident from the significant decrease in prostate weight to body weight ratio, serum testosterone level and increase in growth inhibition of prostate tissue compared to BPH group (p < 0.001). Histological examination of prostate tissue samples showed that VISPO treatment was comparatively better than SPO in improving the hyperplastic patterns. Further, VISPO significantly regulated the expression of inflammatory and apoptotic marker proteins in BPH rats.

CONCLUSION

Our data provide experimental evidence that β-sitosterol enriched saw palmetto oil could be higher efficacious in treating the BPH complications compared to the conventional saw palmetto oil preparations.

Potential Therapeutic Effects of Underground Parts of Kalanchoe gastonis-bonnieri on Benign Prostatic Hyperplasia

Benign Prostatic Hyperplasia (BPH) affects mainly older men. It is estimated to affect 50% of 51-60-year-old men and 70% of 61-70-year-old men. BPH is a nonmalignant proliferation of epithelial and stromal cells of the prostate gland regions. Despite the use of conventional pharmacological therapy, herbal medicines are used in BPH therapy, and several mechanisms of action have been suggested based on their complex chemical composition. Considering the ethnomedicinal uses of Kalanchoe gastonis-bonnieri (KGB), we evaluated the inhibitory effects on the proliferation of stromal cells from primary benign prostatic hyperplasia (BPH) of four different aqueous extracts from this plant: underground parts from specimens in flower (T1 treatment), leaves from specimens in flower (T2 treatment), and flowers (T3 treatment) and leaves from specimens not in flower (T4 treatment). T1, T2, T3, and T4 treatments at 250 μg/ml for 72 hours inhibited BPH cells by 56.7%, 29.2%, 39.4%, and 13.5%, respectively, showing that the KGB underground parts extract (T1 treatment) was the most active. Our findings show that the extract of the KGB underground parts (150 and 250 μg/ml) stimulates important changes in the BPH cells, modulating crucial processes such as proliferation, viability, and apoptosis. HPLC-DAD-MS/MS analysis provided a tentative identification of glycosylated syringic acid derivatives, glycosylated forms of volatile compounds, and lignans in this extract. Finally, these results suggest that there is a potential therapeutic use for KGB in BPH, which could improve the clinical management of the disease.

Understanding patient and physician perceptions of benign prostatic hyperplasia in Asia Pacific, Latin America and the Commonwealth of Independent States: the Prostate Research on Behaviour and Education (PROBE) II survey

AIM

To assess attitudes and beliefs towards benign prostatic hyperplasia (BPH)/ lower urinary tract symptoms (LUTS) and its treatment among patients and physicians in Latin America, Asia Pacific and the Commonwealth of Independent States (CIS).

METHODS

Cross-sectional, quantitative study conducted between December 2014 and September 2015. Separate questionnaires were administered to BPH/LUTS patients receiving drug treatment for their condition and to practising physicians who treat patients with BPH/LUTS.

RESULTS

In total, 1094 patients and 202 physicians completed a questionnaire. Most patients (61%) felt very/fairly well informed about BPH/LUTS, and 60% of physicians perceived patients to be very/somewhat informed. Overall, 70% of physicians felt that it would be valuable to raise awareness of BPH/LUTS and encourage men to consult a physician. The first symptoms most commonly noticed by patients were need to urinate more frequently, slower/weaker stream and nocturia. At first consultation, 71% of patients recalled providing a urine sample, 57% having a blood test for prostate-specific antigen and 56% a digital rectal examination being performed. Over two thirds of patients (69%) were satisfied with their current medication; highest satisfaction rates (among both patients and physicians) were reported for alpha blockers and 5ARIs, either as monotherapies or used in combination. Patients were prepared to wait longer for symptom relief in order to have a reduced risk of surgery. Most physicians (90%) thought that at least some patients believe BPH/LUTS to be a progressive condition. Most physicians thought that patients were very/fairly concerned about BPH surgery (92%) and acute urinary retention (72%); 52% of physicians thought treatment adherence was "extremely" important.

CONCLUSIONS

This study provides valuable insights into the attitudes and beliefs of patients and physicians in Asia Pacific, Latin America and CIS about BPH/LUTS and its management. It also highlights areas of discordance between patient/physician perceptions and beliefs about BPH/LUTS, and potential areas of focus to improve the experience of affected patients.

Drug interactions between antiretrovirals and drugs used to treat benign prostatic hyperplasia/lower urinary tract symptoms

INTRODUCTION

Significant advances in antiretroviral (ARV) therapy have transformed HIV into a chronic manageable disease. Co-morbidities associated with aging, such as benign prostatic hyperplasia (BPH), are becoming increasingly prevalent in the HIV-infected population. The pharmacological treatment of BPH involves medications mainly metabolized by CYP 450 enzymes, while many ARVs have inducing or inhibiting effects on the CYP 450 system. Consequently, there is potential for significant pharmacokinetic (PK) interactions between these two classes of medications.

AREAS COVERED

This article reviews the pharmacology and metabolism of selected BPH drug therapies and ARVs, in addition to highlighting potential interactions between these two drug categories. The authors also present PK evidence of interactions from available clinical trials, product monographs and international conference abstracts. Potentially significant drug interactions are summarized and strategies for management are discussed.

EXPERT OPINION

Drugs most likely to interact with BPH medications include protease inhibitors, the non-nucleoside reverse transcriptase inhibitors efavirenz, nevirapine, etravirine, and the cobicistat-boosted integrase inhibitor elvitegravir. Clinically significant PK interactions with BPH medications and dolutegravir, raltegravir, rilpivirine, or the investigational agent doravirine do not appear to exist. Clinicians working with HIV-infected individuals need to recognize the potential for interactions involving BPH and ARV treatments to ensure effective and safe drug therapy use.

Advancing a Comprehensive Approach to the Study of Lower Urinary Tract Symptoms

PURPOSE

Lower urinary tract symptoms are common in the United States population, leading to significant economic, quality of life and public health issues. The burden will increase as the population ages, and risk factors for lower urinary tract symptoms, including diabetes and obesity, remain highly prevalent. Improving clinical management and establishing the knowledge base to prevent lower urinary tract symptoms will require a comprehensive research approach that examines factors beyond the lower urinary tract. While the study of extra-lower urinary tract factors has increased recently, current urological research does not systematically account for the broad set of potential contributing factors spanning biological, behavioral, psychological/executive function and sociocultural factors. A comprehensive assessment of potential contributors to risk, treatment response and progression is necessary to reduce the burden of this condition in the United States.

MATERIALS AND METHODS

We considered challenges to continuing the predominantly lower urinary tract dysfunction centric approach that has dominated previous research of lower urinary tract symptoms.

RESULTS

We developed a new, comprehensive framework for urology research that includes a broader set of potential factors contributing to lower urinary tract symptoms. This framework aims to broaden research to consider a comprehensive set of potential contributing factors and to engage a broad range of researchers in the investigation of as many extra-lower urinary tract factors as possible, with the goal of improving clinical care and prevention.

CONCLUSIONS

We propose a new framework for future urology research, which should help to reduce the medical and economic burden of lower urinary tract symptoms in the United States population.