Metformin Attenuates Testosterone-Induced Prostatic Hyperplasia in Rats: A Pharmacological Perspective

Metformin: A promising clinical therapeutical approach for BPH treatment via inhibiting dysregulated steroid hormones-induced prostatic epithelial cells proliferation

The occurrence of benign prostate hyperplasia (BPH) was related to disrupted sex steroid hormones, and metformin (Met) had a clinical response to sex steroid hormone-related gynaecological disease. However, whether Met exerts an antiproliferative effect on BPH via sex steroid hormones remains unclear. Here, our clinical study showed that along with prostatic epithelial cell (PEC) proliferation, sex steroid hormones were dysregulated in the serum and prostate of BPH patients. As the major contributor to dysregulated sex steroid hormones, elevated dihydrotestosterone (DHT) had a significant positive relationship with the clinical characteristics of BPH patients. Activation of adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) by Met restored dysregulated sex steroid hormone homeostasis and exerted antiproliferative effects against DHT-induced proliferation by inhibiting the formation of androgen receptor (AR)-mediated Yes-associated protein (YAP1)-TEA domain transcription factor (TEAD4) heterodimers. Met's anti-proliferative effects were blocked by AMPK inhibitor or YAP1 overexpression in DHT-cultured BPH-1 cells. Our findings indicated that Met would be a promising clinical therapeutic approach for BPH by inhibiting dysregulated steroid hormone-induced PEC proliferation.

The Effects of 16-HETE Enantiomers on Hypertrophic Markers in Human Fetal Ventricular Cardiomyocytes, RL-14 Cells

BACKGROUND

Cytochrome P450 (CYP) metabolizes arachidonic acid to produce bioactive metabolites such as EETs and HETEs: mid-chain, subterminal, and terminal HETEs. Recent studies have revealed the role of CYP1B1 and its associated cardiotoxic mid-chain HETE metabolites in developing cardiac hypertrophy and heart failure. Subterminal HETEs have also been involved in various physiological and pathophysiological processes; however, their role in cardiac hypertrophy has not been fully defined.

OBJECTIVE

The objective of the current study is to determine the possible effect of subterminal HETEs, R and S enantiomers of 16-HETE, on CYP1B1 expression in vitro using human cardiomyocytes RL-14 cells.

METHODS

In the study, RL14 cell line was treated with vehicle and either of the 16-HETE enantiomers for 24 h. Subsequently, the following markers were assessed: cell viability, cellular size, hypertrophic markers, CYP1B1 gene expression (at mRNA, protein, and activity levels), luciferase activity, and CYP1B1 mRNA and protein half-lives.

RESULTS

The results of the study showed that 16-HETE enantiomers significantly increased hypertrophic markers and upregulated CYP1B1 mRNA and protein expressions in RL-14 cell line. The upregulation of CYP1B1 by 16-HETE enantiomers occurs via a transcriptional mechanism as evidenced by transcriptional induction and luciferase reporter assay. Furthermore, neither post-transcriptional nor post-translational modification was involved in such modulation since there was no change in CYP1B1 mRNA and protein stabilities upon treatment with 16-HETE enantiomers.

CONCLUSION

The current study provides the first evidence that 16R-HETE and 16S-HETE increase CYP1B1 gene expression through a transcriptional mechanism.

Effect of C-Type Natriuretic Peptide (CNP) on Spermatozoa Maturation in Adult Rat Epididymis

C-type natriuretic peptide (CNP) is highly expressed in male reproductive tissues, such as the epididymis. The aim of this study is to explore the role of CNP in the maturation of rat epididymal spermatozoa. First, the expression levels of CNP and its specific natriuretic peptide receptor-B (NPR-B) were detected in various tissues of rats and epididymis at different stages after birth. Then a castrated rat model was established to analyze the relationship between testosterone and CNP/NPR-B expression in the epididymis. Finally, CNP and different inhibitors (NPR-B inhibitors, cGMP inhibitors) were used to incubate epididymal sperm in vitro to examine sperm mobility and expression of sperm maturation-related factors. The results showed CNP/NPR-B mRNAs were expressed in all tissues of rats, but were extremely highly expressed in male genital ducts (seminal vesicle, prostate and epididymis). The expression of CNP/NPR-B in epididymis was the highest at birth and the fifth week after birth. In the epididymis, CNP/NPR-B were highly expressed in the caput and located in the epididymal epithelial cells. After castration, the expression of CNP/NPR-B decreased sharply and was restored quickly after testosterone supplementation. In vitro, CNP could significantly promote the acquisition of epididymal sperm motility through the NPR-B/cGMP pathway and induce the expression of sperm maturation-related factors (such as Bin1b, Catsper 1, Dnah17, Fertilin). This study shows that CNP plays a role in epididymal sperm maturation. The mechanism of CNP is to promote the acquisition of epididymal sperm fluidity through the NPR-B/cGMP signaling pathway and also to regulate sperm maturation-related genes. Moreover, the expression of CNP/NPR-B was regulated by testosterone.

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.

Established and emerging treatments for diabetes-associated lower urinary tract dysfunction

Dysfunction of the lower urinary tract (LUT) including urinary bladder and urethra (and prostate in men) is one of the most frequent complications of diabetes and can manifest as overactive bladder, underactive bladder, urinary incontinence, and as aggravated symptoms of benign prostate hyperplasia. We have performed a selective literature search to review existing evidence on efficacy of classic medications for the treatment of LUT dysfunction in diabetic patients and animals, i.e., α1-adrenoceptor and muscarinic receptor antagonists, β3-adrenoceptor agonists, and phosphodiesterase type 5 inhibitors. Generally, these agents appear to have comparable efficacy in patients and/or animals with and without diabetes. We also review effects of antidiabetic medications on LUT function. Such studies have largely been performed in animal models. In the streptozotocin-induced models of type 1 diabetes, insulin can prevent and reverse alterations of morphology, function, and gene expression patterns in bladder and prostate. Typical medications for the treatment of type 2 diabetes have been studied less often, and the reported findings are not yet sufficient to derive robust conclusions. Thereafter, we review animal studies with emerging medications perhaps targeting diabetes-associated LUT dysfunction. Data with myoinositol, daidzein, and with compounds that target oxidative stress, inflammation, Rac1, nerve growth factor, angiotensin II receptor, serotonin receptor, adenosine receptor, and soluble guanylyl cyclase are not conclusive yet, but some hold promise as potential treatments. Finally, we review nonpharmacological interventions in diabetic bladder dysfunction. These approaches are relatively new and give promising results in preclinical studies. In conclusion, the insulin data in rodent models of type 1 diabetes suggest that diabetes-associated LUT function can be mostly or partially reversed. However, we propose that considerable additional experimental and clinical studies are needed to target diabetes itself or pathophysiological changes induced by chronic hyperglycemia for the treatment of diabetic uropathy.

Icariin ameliorates metabolic syndrome-induced benign prostatic hyperplasia in rats

Metabolic syndrome (MetS) is an immense health issue that causes serious complications in aging males including BPH. Icariin (ICA) is a flavonol glycoside that exerts a plethora of pharmacological effects. The present investigation tested the potential of ICA to ameliorate benign prostatic hyperplasia (BPH) induced by MetS in rats. Animals were allocated to 5 groups in which the first and second groups were kept on water and regular food pellets. MetS was induced in the third, fourth, and fifth groups by keeping the animals on high fructose and salt diets for twelve consecutive weeks. These groups were given vehicle, ICA (25 mg/kg), and ICA (50 mg/kg), respectively. MetS was confirmed by an increase in rats' weight, accumulation of visceral fat, insulin resistance, and dyslipidemia. This was accompanied by manifestation of BPH including increased prostate weight, prostate index, and histopathological alterations. Treating the animals with both doses of ICA significantly ameliorated the increase in weight and index of the prostate as well as altered prostate histopathology. In addition, ICA significantly decreased cyclin D1 expression, upregulated Bax, and downregulated Bcl2 mRNA expression. ICA prevented lipid peroxidation, reduced glutathione depletion, and catalase exhaustion, which further lowered markers of prostate inflammation such as interleukin-6 and tumor necrosis factor-α. Moreover, ICA prevented the decrease in prostate content of phosphorylated 5'-adenosine monophosphate (AMP)-activated protein kinase (pAMPK). In conclusion, ICA protects against MetS-induced BPH. This is due to its antiproliferative, proapoptotic, antioxidant, and anti-inflammatory activities as well as the activation of AMPK.

BPA-induced prostatic hyperplasia in vitro is correlated with the unbalanced gene expression of AR and ER in the epithelium and stroma

As a typical environmental endocrine disruptor (EED), bisphenol A (BPA) can induce pathological hyperplasia of the prostatic epithelium and stroma. This study concentrates mainly on the effect and underlying mechanisms of BPA on prostatic hyperplasia, which is based on the culture of primary human prostate epithelial cells (HPEpiC) and human prostate fibroblasts (HPrF). In an effect to screen the optimal pro-survival BPA levels, HPEpiC and HPrF were, respectively, exposed to concentration gradients of BPA (10^-12 M-10^-4 M) solution diluted with two corresponding medium and incubated for 72 h at 37°C. CCK-8 assay showed that 10^-9 M-10^-5 M BPA could facilitate the proliferation of HPEpiC, while similar proliferative effect of HPrF only needed 10^-11 M-10^-7 M BPA. HPrF were more sensitive to BPA than HPEpiC. The qualification of PCNA gene expression measured using quantitative real-time polymerase chain reaction (qRT-PCR) also mirrored the BPA-induced cell proliferation. Additionally, our results considered that androgen receptor (AR), estrogen receptor (ERα, ERβ), and NFKB1 gene expressions exhibited up-regulation in HPEpiC treated with 10^-9 M BPA for 72 h. However, in HPrF, the identical BPA treatment could activate ERα, ERβ, and NFKB1 gene expressions and down-regulated the expression of AR levels. It is further confirmed that low-dose BPA can indeed promote the proliferation of human prostate cells in vitro, and the mechanisms of BPA for prostatic epithelial and stromal hyperplasia may not be consistent.

In-silico and in-vivo evaluation of sesamol and its derivatives for benign prostatic hypertrophy

Pharmacological treatment for BPH includes 5-α reductase inhibitors as Finasteride and Dutasteride as a monotherapy or in combination with antimuscarinic drugs, alpha-blockers, 5-phosphodiesterase inhibitor drugs. Androgen receptor inhibitors revealed several adverse events as decreased libido, erectile dysfunction, ejaculatory dysfunction, and gynecomastia. Hence, the emergence of complementary and alternative medications having safety profile—preferably, edible natural products—would be highly desirable. In-silico studies based on Maestro Molecular Modelling platform (version 10.5) by Schrӧdinger, LLC was used to identify the lead molecules. The in-vivo activity studied on rats gave the positive results. The findings based on experiments as antioxidant parameters showed the potential to quench the free radicals. The significant results were also seen in prostatic index and histopathological studies supported the above findings. Based on these data, sesamol and derivative have proven efficacy in protecting against testosterone induced BPH.

The Effect of Metformin on Male Reproductive Function and Prostate: An Updated Review

Metformin is the first-line oral antidiabetic drug that shows multiple pleiotropic effects of anti-inflamation, anti-cancer, anti-aging, anti-microbia, anti-atherosclerosis, and immune modulation. Metformin's effects on men's related health are reviewed here, focusing on reproductive health under subtitles of erectile dysfunction (ED), steroidogenesis and spermatogenesis; and on prostate-related health under subtitles of prostate specific antigen (PSA), prostatitis, benign prostate hyperplasia (BPH), and prostate cancer (PCa). Updated literature suggests a potential role of metformin on arteriogenic ED but controversial and contradictory effects (either protective or harmful) on testicular functions of testosterone synthesis and spermatogenesis. With regards to prostate-related health, metformin use may be associated with lower levels of PSA in humans, but its clinical implications require more research. Although there is a lack of research on metform's effect on prostatitis, it may have potential benefits through its anti-microbial and anti-inflammatory properties. Metformin may reduce the risk of BPH by inhibiting the insulin-like growth factor 1 pathway and some but not all studies suggest a protective role of metformin on the risk of PCa. Many clinical trials are being conducted to investigate the use of metformin as an adjuvant therapy for PCa but results currently available are not conclusive. While some trials suggest a benefit in reducing the metastasis and recurrence of PCa, others do not show any benefit. More research works are warranted to illuminate the potential usefulness of metformin in the promotion of men's health.

Is the beta estradiol receptor receiving enough attention for its metabolic importance in postmenopause?

The relationship between menopause and the development of metabolic diseases is well established. In postmenopause women, there is an expansion of visceral white adipose tissue (WATv), which highly contributes to the rise of circulating lipids. Meanwhile, muscle glucose uptake decreases and hepatic glucose production increases. Consequently, in the pancreas, lipotoxicity and glycotoxicity lead to deficient insulin production. These factors initiate an energy imbalance and enhance the probability of developing cardiovascular and metabolic diseases. Although the activation of estradiol receptors (ER) has been shown to be beneficial for the WAT stock pattern, leading to the insulin-sensitive phenotype, authors have described the risk of these receptors' activation, contributing to neoplasia development. The selective activation of beta-type ER (ERβ) seems to be a promising strategy in the treatment of energy imbalance, acting on several tissues of metabolic importance and allowing an intervention with less risk for the development of estrogen-dependent neoplasia. However, the literature on the risks and benefits of selective ERβ activation still needs to increase. In this review, several aspects related to ERβ were considered, such as its physiological role in tissues of energy importance, beneficial effects, and risks of its stimulation during menopause. PubMed, SciELO, Cochrane, and Medline/Bireme databases were used in this study.

Correlation Between Testosterone Replacement Treatment and Lower Urinary Tract Symptoms

Lower urinary tract symptoms (LUTS) are a cluster of voiding symptoms, such as weak stream, hesitancy, intermittency, urinary frequency, urgency, and nocturia. LUTS are frequent in elderly men and it considered the ultimate clinical symptoms of benign prostatic hyperplasia. With aging, male hypogonadism is increased which is defined as decreased ability of the testes to produce sperm and sex steroids because of a pituitary/hypothalamic, or testicular deficiency. In academic andrology associations, the term "male hypogonadism" is commonly used to categorize testosterone deficiency. Testosterone deficiency syndrome (TDS) is defined as a decrease in serum testosterone accompanied by symptoms such as libido decrease, depressive disorder, erectile dysfunction, and fatigue. Although the mechanism about testosterone-replacement therapy (TRT) effects on men with hypogonadism is not yet identified, TRT has been shown to effectively relieve the symptoms of TDS as well as LUTS by several studies. Although the present review demonstrates the effectiveness and safety of TRT in men with TDS by prior studies, future large scale of clinical trials should be conducted to present more high-quality evidence to clinicians and patients.

Amelioration of testosterone-induced benign prostatic hyperplasia using febuxostat in rats: The role of VEGF/TGFβ and iNOS/COX-2

Benign prostatic hyperplasia (BPH) is a common male disorder. Febuxostat is a non-purine, selective inhibitor of xanthine oxidase (XO), which has a strong antioxidant capacity and pleiotropic pharmacological properties. This study's objective was to explore the potential ameliorative effects of febuxostat against testosterone-induced BPH in rats. Febuxostat (10 mg/kg/day, per os [p.o.]) prevented increased prostate index levels, serum levels of prostate-specific antigen (PSA), and testosterone levels compared to animals treated with testosterone alone, when administered for 28 days. Histological examination indicated that febuxostat dramatically ameliorated pathological changes in the prostate architecture compared to the testosterone group. Similarly, febuxostat markedly improved testosterone-induced oxidative stress by inhibiting the increase in lipid peroxide and nitrite content, and by reducing the level of depletion of reduced glutathione (GSH) and superoxide dismutase (SOD) activity, which significantly reduced the prostate content of pro-inflammatory cytokines, including tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6). Furthermore, febuxostat significantly reduced the prostatic content, both in terms of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) messenger ribonucleic acid (mRNA) levels, and of protein levels. Moreover, compared to the testosterone group, febuxostat's beneficial effects prevented the increase in growth factors, comprising vascular endothelial cell growth factor A (VEGF-A) and transforming growth factor beta (TGF-β) protein levels. Its ameliorating effects were equal to those of finasteride, which is the most widely used remedy for BPH. In conclusion, this study provides novel evidence that febuxostat experimentally attenuates testosterone-induced BPH in rats, at least in part by inhibiting iNOS/COX-2 and VEGF/TGF-β pathways.

Febuxostat attenuates testosterone-induced benign prostatic hyperplasia in rats via inhibiting JAK/STAT axis

AIM

To investigate the possible modulatory effect of febuxostat in testosterone-induced benign prostatic hyperplasia (BPH) in rats with emphasis on xanthine oxidase (XO)/Janus Kinases (JAK)/signal transducer and activator of transcription (STAT) axis.

MAIN METHODS

Male Wistar rats were treated with testosterone with/out febuxostat. Effect of febuxostat on BPH was assessed at the structural level by histopathology and determination of prostate weight/index. Cyclin D1 protein expression was assessed immunohistochemically and the ratio of Bax/Bcl-2 mRNA expression was determined by real time polymerase chain reaction analysis (RT-PCR). Besides, uric acid serum level was determined colorimetrically. Prostatic XO activity, as well as oxidative stress and inflammatory markers were evaluated. Additionally, western blot analysis was performed for determination of JAK-1 and phosphorylated form of STAT-3 expression in tissues.

KEY FINDINGS

Results revealed that febuxostat inhibited the increase in prostatic weight and index compared to testosterone-treated group. Additionally, febuxostat ameliorated testosterone-induced histopathological changes, prevented the rise in cyclin D1 expression and enhanced Bax/Bcl2 ratio. Febuxostat suppressed testosterone induced- increase in XO activity in prostates and serum level of uric acid. Moreover, it regulated oxidative stress markers including; malondialdehyde (MDA), superoxide dismutase (SOD) activity and glutathione (GSH) content. Also, it inhibited the increase in prostate contents of interleukin-6 (IL-6), interleukin-1β (IL-1 β), tumor necrosis factor (TNF-α) and nuclear factor (NF-κB). Interestingly, febuxostat markedly reduced JAK-1 and subsequent phosphorylation of STAT-3 protein expression.

SIGNIFICANCE

Febuxostat ameliorates testosterone-induced BPH via suppressing XO/JAK/STAT axis. This may help to re-purpose the use of XO inhibitors.

The modulatory effects of cinnamaldehyde on uric acid level and IL-6/JAK1/STAT3 signaling as a promising therapeutic strategy against benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is a widespread disorder in elderly men. Cinnamaldehyde, which is a major constituent in the essential oil of cinnamon, has been previously reported to reduce xanthine oxidase activity, in addition to its anti-inflammatory, anti-oxidant, and anti-proliferative activities. Our study was designed to investigate the potential modulatory effects of cinnamaldehyde on testosterone model of BPH in rats through reduction of uric acid level, and suppression of IL-6/JAK1/STAT3 signaling pathway. Cinnamaldehyde (40 and 75 mg/kg) was orally administered to male Wistar rats for 3 weeks, and concurrently with testosterone (3 mg/kg, s.c.) from the second week. Cinnamaldehyde ameliorated the elevation in prostatic weight and index compared to rats treated with testosterone only, that was also confirmed by alleviation of histopathological changes in prostate architecture. The protective mechanisms of cinnamaldehyde were elucidated through inhibition of xanthine oxidase activity and reduced uric acid level. That was accompanied by reduction of the pro-inflammatory cytokines; interleukin-6 (IL-6), IL-1β, tumor necrosis factor-alpha (TNF-α), and the nuclear translocation of the transcription factor NF-κB p65, that could be attributed also to the enhanced anti-oxidant defense by cinnamaldehyde. The protein expression of JAK1, which is IL-6 receptor linked protein, was reduced with subsequently reduced activation of STAT3 protein. That eventually suppressed the formation of the proliferation protein cyclin D1, while elevated Bax/Bcl2 ratio. It can be concluded that reducing uric acid level through xanthine oxidase inhibition and suppression of the inflammatory signaling cascade; IL-6/JAK1/STAT3; by cinnamaldehyde could be a novel and promising therapeutic approach against BPH.

Roles of estrogen receptor α and β in the regulation of proliferation in endometrial carcinoma

Endometrial carcinoma (EC), an estrogen-dependent gynecological malignancy, is prevalent worldwide. Estrogen receptor α (ERα) and estrogen receptor β (ERβ) are two main estrogen receptor isoforms, which mediate estrogen-induced proliferation in EC. However, the dynamic changes of ERα and ERβ subtype expression and their functions on proliferation in EC remain elusive. In this study, we aimed to investigate the expression of ERα and ERβ in para-tumor eutopic endometrium, endometrial atypical hyperplasia and EC by immunohistochemistry and then analyse their clinical significance. Subsequently, Ishikawa cells with ERα or ERβ knockdown by lentivirus transfection were used to explore the relationship between ERα/ERβ and cell proliferation, and preliminarily evaluate whether metformin's inhibitory effect on estrogen-induced cell proliferation was mediated by ERα and ERβ. We found that the expression of ERα and ERβ were markedly changed in endometrial hyperplasia and EC compared with that in para-tumor eutopic endometrium and exhibited different expression trends. Through further analysis, we discovered that ERα presented higher expression in endometrial atypical hyperplasia and early stage of EC than that in para-tumor eutopic endometrium, while the expression of ERβ gradually decreased from para-tumor eutopic endometrium to EC. Additionally, the cell cycle-related protein, CyclinD1 was gradually increased but p21 decreased. Furthermore, knockdown of ERα and ERβ severally in Ishikawa cells either inhibited or promoted estrogen-induced cell proliferation through regulating CyclinD1 and p21 expression. Meanwhile, the inhibitory effect of metformin on estrogen-induced cell proliferation was respectively blunted or partly reversed by knockdown of ERα or ERβ. Altogether, ERα and ERβ have different expression patterns in the progression of EC either facilitating or suppressing cell proliferation through regulating the expression of CyclinD1 and p21 in EC cells, and may also mediate the inhibitory effect of metformin on estrogen-induced EC cells proliferation.

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.

The Oleo-Gum-Resin of Commiphora myrrha Ameliorates Male Reproductive Dysfunctions in Streptozotocin-Induced Hyperglycemic Rats

Background: The oleo-gum-resin of Commiphora myrrha (myrrh) has a long history of therapeutic use in traditional medicine. The aim of this study was to seek for the scientific evidence to determine whether the ethanolic extract of myrrh (EEM) has any beneficial effects on Streptozotocin (STZ) induced testicular impairments, and explore the possible mechanisms underlying such actions. Methods: Forty-eight severe and complicated diabetic rats (fasting blood glucose above 350 mg/dL), randomly were divided into six equal groups (n=8). Besides, eight healthy rats allocated as a normal control group and only treated with vehicle solution. The diabetic animals orally received the extract (100, 200, 300, and 500 mg/kg), metformin (500 mg/kg) or vehicle solution for 28 days. As a final point, plasma glucose and insulin, circulatory sex hormones, sperm parameters including sperm concentration, motility and viability and also testicular malondialdehyde (MDA) levels were assessed. Furthermore, quantitative histological evaluation of seminiferous tubules area and determination of germinal cells apoptosis were performed. Results: None of the studied doses of EEM showed anti-diabetic effects. However, the extract mainly at the maximum dose (500 mg/kg) exhibited beneficial effects on reproductive impairments. The EEM treated rats mainly at 500 mg/kg had significantly higher sperm concentration, sperm motility, sperm viability, sex hormones and lower testicular MDA and germ cell apoptosis index than untreated diabetic rats. Conclusion: These results indicated that EEM may have beneficial effects against reproductive dysfunction induced by diabetes. The mechanisms behind the effects might be associated with the EEM sex hormone booster potential, antioxidant and anti-apoptotic properties.

Can Botulinum Toxin A Still Have a Role in Treatment of Lower Urinary Tract Symptoms/Benign Prostatic Hyperplasia Through Inhibition of Chronic Prostatic Inflammation?

Patients with benign prostatic hyperplasia (BPH) can exhibit various lower urinary tract symptoms (LUTS) owing to bladder outlet obstruction (BOO), prostatic inflammation, and bladder response to BOO. The pathogenesis of BPH involves an imbalance of internal hormones and chronic prostatic inflammation, possibly triggered by prostatic infection, autoimmune responses, neurogenic inflammation, oxidative stress, and autonomic dysfunction. Botulinum toxin A (BoNT-A) is well recognized for its ability to block acetylcholine release at the neuromuscular junction by cleaving synaptosomal-associated proteins. Although current large clinical trials have shown no clinical benefits of BoNT-A for the management of LUTS due to BPH, BoNT-A has demonstrated beneficial effects in certain subsets of BPH patients with LUTS, especially in males with concomitant chronic prostatitis/chronic pelvic pain syndrome and smaller prostate. We conducted a review of published literature in Pubmed, using Botulinum toxin, BPH, BOO, inflammation, LUTS, and prostatitis as the key words. This article reviewed the mechanisms of BPH pathogenesis and anti-inflammatory effects of BoNT-A. The results suggested that to achieve effectiveness, the treatment of BPH with BoNT-A should be tailored according to more detailed clinical information and reliable biomarkers.

The preventive effect of metformin on progression of benign prostate hyperplasia: A nationwide population-based cohort study in Korea

Metformin, a first-line treatment for type 2 diabetes mellitus (T2DM), has recently been recognized for its pleotropic anti-proliferative, anti-cancer, and anti-aging effects. Contrary to the studies characterizing metformin effects in prostate cancer, little is known about these effects in BPH progression. With the Sample Cohort DB data during 2007 and 2017 from the Health Insurance Review and Assessment Service (HIRA) in South Korea, we investigated the preventative effect of metformin on BPH progression. The study population consisted of 211,648 BPH naïve patients that were diagnosed with BPH in 2009 and a follow-up occurrence of prostatectomy until 2017 that was defined as progression of BPH. These patients were divided into three treatment groups: without T2DM, T2DM without metformin, and T2DM with metformin. The hazard ratio in the T2DM with metformin group was 0.86 for prostatectomy compared to the group without T2DM (CI = 0.77-0.96, P value = 0.007) after adjusting for confounding factors such as age, comorbidity, residential area, level of hospital, and category of BPH medications. The T2DM with high-dose metformin group had a significantly lower risk of prostatectomy with hazard ratio of 0.76 (CI = 0.62-0.92, P value = 0.005) in stratified analysis. Our results suggest that metformin may improve BPH progression based on the reduced risk of prostatectomy, although T2DM effects on BPH were unclear. Future observational studies and prospective trials are needed to confirm the effects of metformin on BPH progression.

Metformin induces human esophageal carcinoma cell pyroptosis by targeting the miR-497/PELP1 axis

Evasion of apoptosis is a major contributing factor to the development of chemo- and radiotherapy resistance. Therefore, activation of non-apoptotic programmed cell death (PCD) could be an effective alternative against apoptosis-resistant cancers. In this study, we demonstrated in vitro and in vivo that metformin can induce pyroptosis, a non-apoptotic PCD, in esophageal squamous cell carcinoma (ESCC), a commonly known chemo-refractory cancer, especially at its advanced stages. Proline-, glutamic acid- and leucine-rich protein-1 (PELP1) is a scaffolding oncogene and upregulated PELP1 in advanced stages of ESCC is highly associated with cancer progression and patient outcomes. Intriguingly, metformin treatment leads to gasdermin D (GSDMD)-mediated pyroptosis, which is abrogated by forced expression of PELP1. Mechanistically, metformin induces pyroptosis of ESCC by targeting miR-497/PELP1 axis. Our findings suggest that metformin and any other pyroptosis-inducing reagents could serve as alternative treatments for chemo- and radiotherapy refractory ESCC or other cancers sharing the same pyroptosis mechanisms.

Pathophysiology of Benign Prostatic Hyperplasia and Benign Prostatic Enlargement: A Mini-Review

Benign prostatic hyperplasia (BPH), benign prostatic enlargement (BPE) and lower urinary tract symptoms (LUTS) belong to the most frequent diseases in ageing men. Beyond the 6th decade of life, more than 30% of men suffer from moderate to severe LUTS requiring intervention. The pathophysiology of BPH/BPE is still incompletely understood. The dominant role of the androgen system and the androgen receptor is well defined. Androgen receptors are expressed in BPH tissue in which they are activated by the potent androgen dihydrotestosterone. Synthesis of dihydrotestosterone is under control of the 5α-reductase enzyme, activity of which is antagonized by finasteride and dutasteride. More recently, the impact of prostatic inflammation and metabolic parameters particularly for the development of BPE and LUTS has increasingly been recognized. A better understanding of the pathophysiology is a prerequisite for the development of novel, more effective medical treatment options.

The effect of metformin therapy on incidence and prognosis in prostate cancer: A systematic review and meta-analysis

The relationship between metformin and prostate cancer (PCa) remains controversial. To clarify this association, the PubMed, Embase and Cochrane library databases were systematically searched from their inception dates to May 23, 2018, using the keywords “metformin” and “prostate cancer” to identify the related studies. The results included incidence, overall survival (OS), PCa-specific survival (CSS) and recurrence-free survival (RFS), which were measured as hazard ratios (HR) with a 95% confidence interval (95% CI) using Review Manager 5.3 software. A total of 30 cohort studies, including 1,660,795 patients were included in this study. Our study revealed that metformin treatment improves OS, CSS and RFS in PCa (HR = 0.72, 95% CI: 0.59–0.88, P = 0.001; HR = 0.78, 95% CI: 0.64–0.94, P = 0.009; and HR = 0.60, 95% CI: 0.42–0.87 P = 0.006, respectively) compared with non-metformin treatment. However, metformin usage did not reduce the incidence of PCa (HR = 0.86, 95% CI: 0.55–1.34, P = 0.51). In conclusion, compared with non-metformin treatment, metformin therapy can significantly improve OS, CSS and RFS in PCa patients. No association was noted between metformin therapy and PCa incidence. This study indicates a useful direction for the clinical treatment of PCa.

Anti-Proliferative Effects of HBX-5 on Progression of Benign Prostatic Hyperplasia

Benign prostatic hyperplasia (BPH), an age-dependent disorder with a prevalence percentage of 60% in the 60s, has been found to involve an androgenic hormone imbalance that causes confusion between cell apoptosis and proliferation. Because general medications for BPH treatment have undesirable side effects, the development of effective alternative medicines has been considered. HBX-5 is a newly developed formula with the aim of improving BPH, and is composed of nine medicinal herbs. BPH was induced in the rats by intramuscular injection of testosterone propionate after castration. Rats were divided into six groups, and the efficacy of HBX-5 on testosterone-induced BPH in rats was estimated. In addition, RWPE-1 and WPMY-1 cells were used to demonstrate the effect of HBX-5 on BPH in vitro model. Compared with the control group, HBX-5 administration group suppressed BPH manifestations, such as excessive development of prostate, and increase of serum dihydrotestosterone and 5α-reductase concentrations. Furthermore, immunohistochemistry analysis revealed that HBX-5 significantly decreased the expression of androgen receptor (AR) and proliferating cell nuclear antigen (PCNA). In addition, results of RWPE-1 and WPMY-1 cells showed that HBX-5 inhibited the over-expression of AR and PSA in DHT-induced prostate hyperplastic microenvironments.

Effect of sorghum ethyl-acetate extract on benign prostatic hyperplasia induced by testosterone in Sprague-Dawley rats

Benign prostatic hyperplasia (BPH) is commonly observed in men > 50 years worldwide. Phytotherapy is one of the many treatment options. Sorghum (Sorghum bicolor L.) contains various health-improving phytochemicals with antioxidant and inhibitory activities on cell proliferation, both in vitro and in vivo. To confirm the effects of Donganme sorghum ethyl-acetate extract (DSEE) on BPH, we induced BPH in Spragye-Dawley rats using exogenous testosterone. We measured prostate weight, examined prostrates histopathologically, and analyzed mRNAs associated with male hormones and proteins associated with cell proliferation in the prostate. DSEE inhibited weight gain of the prostate; decreased mRNA expressions of androgen receptor and 5α-reductase II; and improved histopathological symptoms, the protein-expressed ratio of Bax/Bcl-2, and the oxidative status of BPH induced by testosterone in SD rats. Therefore, DSEE may have potential as a preventive or therapeutic agent against BPH.

Metformin: an antiproliferative agent and methylation regulator in treating prostatic disease?

Existing drugs that have been used in clinical practice for other purposes can prove useful for reutilization, since much of the safety profile and pharmacokinetics have been completed. Therefore, the drugs can enter clinical practice for a variety of causes with less regulatory burden. Metformin may prove to be such a drug; it may have a role in other diseases, besides the management of diabetes. In this perspective, we provide our findings and understanding of metformin as an alternative way to treat urological abnormal proliferation. We propose the potential mechanisms into two hallmarks: direct antiproliferative function via insulin-like growth factor (IGF) signaling pathway and epigenetic modulating via adjusting DNA methylation. These specific hallmarks may ultimately contribute to a better understanding of metformin in treating prostatic diseases.

Effects of metformin on prostatic tissue of rats with metabolic syndrome and benign prostatic hyperplasia

OBJECTIVES

To investigate the efficacy of insulin sensitizer on prostatic tissue in animal model with benign prostatic hyperplasia (BPH) secondary to metabolic syndrome (MetS).

METHODS

Models were established by providing Sprague-Dawley rats with high fat diet (HFD) combined with metformin or not. All objects were killed 40 days later with prostatic tissue being removed, weighed before stained, as well as the expression level of insulin-like growth factor I (IGF-1) and receptor (IGF-1R) being measured, and the level of insulin resistance (IR) has also been evaluated.

RESULTS

Model has been successfully established. Level of prostatic hyperplasia and IR as well as IGF-1 and IGF-1R expressions in the blank and saline control subunits of HFD group was higher than that of normal diet group (P < 0.05). In the subunit of metformin, along with the suppression of IR, the level of prostatic hyperplasia and the expression of IGF-1 pathway have both decreased (P < 0.05).

CONCLUSION

MetS can promote the growth of prostate during the formation of central obesity and IR. IGF-1 pathway may have an important role in the induction of BPH following IR. The application of metformin can suppress the expression of IGF-1 and IGF-1R, thus preventing the promotive effect of IR on prostate tissue in animal model of MetS.

Hyperlipidemia is associated with an increased risk of clinical benign prostatic hyperplasia

BACKGROUND

A high fat diet is associated with risk of benign prostatic hyperplasia (BPH). However, whether hyperlipidemia is associated with BPH remains unclear. This population-based cohort study elucidated whether hyperlipidemia is associated with an increased risk of BPH.

METHODS

We used a new-exposure design and analyzed data retrieved from the Taiwan National Health Insurance Database between January 1, 2000 and December 31, 2013. The cohort of men with newly diagnosed hyperlipidemia and the age- and index-date-matched (1:3) nonhyperlipidemia cohort were tracked for incidence of BPH during a 1- to 14-year follow-up. Diagnosis of BPH using the International Classification of Diseases, Ninth Revision, Clinical Modification codes, and the occurrence of BPH diagnosis plus the use of alpha-blockers or 5-alpha reductase inhibitors or receipt of transurethral resection of the prostate were the primary and secondary endpoints, respectively. The confounders in this study were diabetes mellitus, hypertension, coronary heart disease, obesity, liver cirrhosis, nonsteroidal anti-inflammatory drugs, metformin, aspirin, and number of urologist visits. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using a multivariate Cox proportional hazards regression model adjusted for the propensity score.

RESULTS

A total of 35 860 subjects (aged 40-99 years)-including the hyperlipidemia cohort (n = 8,965) and nonhyperlipidemia cohort (n = 26 895)-were identified. Our data revealed that the hyperlipidemia cohort had significantly higher incidences of developing BPH (24.6% vs 12.3%, P < 0.001) and treated BPH (13% vs 5.7%, P < 0.001) compared with the nonhyperlipidemia cohort. The risk of developing BPH in the hyperlipidemia cohort was significantly higher than that in the nonhyperlipidemia cohort (HR = 1.73, 95% CI = 1.63-1.83, P < 0.001) after adjustment for the propensity score.

CONCLUSIONS

Hyperlipidemia is associated with an increased risk of clinical BPH.

Metabolic syndrome and benign prostatic hyperplasia: An update

Metabolic syndrome (MetS) is a cluster of metabolic abnormalities related to central adiposity and insulin resistance. Its importance is increasingly recognized as it associates with increased risks of metabolic and cardiovascular diseases. These metabolic aberrations of MetS may lead to development of benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS) in men. A 26.5%-55.6% prevalence of MetS in men with LUTS was reported in worldwide studies. Although the exact biological pathway is not clear yet, insulin resistance, increased visceral adiposity, sex hormone alterations and cellular inflammatory reactions played significant roles in the related pathophysiological processes. Clinician should recognize the cardiovascular and metabolic impacts of MetS in men with LUTS, early risk factors optimization and use of appropriate medical therapy may possibly alter or slower the progression of LUTS/BPH, and potentially avoid unnecessary morbidities and mortalities from cardiovascular and metabolic diseases for those men.

A review for clinicians: Prostate cancer and the antineoplastic properties of metformin

OBJECTIVES

Metformin has numerous antineoplastic effects including an AMP-activated protein kinase-dependent mechanism, AMP-activated protein kinase-independent mechanisms, alteration of insulin and insulin-like growth factor signaling pathways, and suppression of androgen signaling pathways that trigger prostate cancer growth and proliferation. In contrast to other malignancies that are associated with increased incidence among patients with obesity and type II diabetes mellitus (T2DM), epidemiological studies suggest that obesity and T2DM may impart a protective effect on prostate cancer incidence by creating a set of metabolic conditions that lower androgen levels.

METHODS AND MATERIALS

The PubMed and Web of Science databases were searched using the terms "prostate cancer," "metformin," "antineoplastic," "antitumorigenic," and "diabetes" up to the first week of August 2016. Articles regarding metformin's antineoplastic properties on prostate cancer were reviewed.

RESULTS

Treating T2DM with metformin may reverse the metabolic conditions that suppress androgen levels, thereby enabling higher levels of androgens to stimulate prostate growth, proliferation, and tumorigenesis. Thus, the antineoplastic properties of metformin may not be appreciable in the early stages of prostate cancer development because metformin corrects for the metabolic conditions of T2DM that impart a protective effect on prostate cancer. These findings, although inconclusive, do not support the use of metformin as a preventive agent for prostate cancer. However, the future appears bright for metformin as either a monotherapy or an adjunct to androgen deprivation therapy, external-beam radiation therapy, prostatectomy, or chemotherapy. Support for this includes meta-analyses that suggest a mortality benefit to patients with prostate cancer on metformin, a clinical trial that demonstrates metformin leads to significant improvement in metabolic syndrome parameters for patients with prostate cancer on androgen deprivation therapy, and a clinical trial that shows metformin has modest activity in the treatment of some patients with asymptomatic or minimally symptomatic metastatic castration-resistant prostate cancer.

CONCLUSIONS

This review summarizes the literature regarding the antineoplastic mechanisms, clinical implications, and future trajectory of clinical research for metformin in prostate cancer.

Endocrine control of benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is the most common benign proliferative disease among aging men. Androgens play a key role in the development and growth of the male genital tract favoring differentiation and proliferation of stromal and epithelial cells of the prostate gland. It is known that growth factors play a crucial role in the cross-talk between stromal cells and epithelial cells. These factors, mainly secreted by stromal cells, act in an autocrine/paracrine manner to maintain prostate cellular homeostasis. A number of experimental studies support the interdependence between growth factors (IGF, FGF, TGF) and the steroid hormone milieu of the prostate. Alterations of these interactions may alter the balance between proliferation and cell death leading to the development of BPH. The onset of BPH is closely related to an inflammatory microenvironment. Chronic inflammation, which generally follows the acute inflammation because of infectious agents, is favored by hormonal or metabolic abnormalities. However, a close correlation between these mechanisms and metabolic or sexual hormones (androgen/estrogen ratio) alteration has been shown suggesting a key role of hypogonadism in the development of prostate inflammation. This review clear shows that the BPH pathogenesis and the subsequent onset of the lower urinary tract symptoms (LUTS) depends from different etio-pathogenetic factors whose mechanism of action remains to be evaluated.