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.

Eriochloa villosa Alleviates Progression of Benign Prostatic Hyperplasia in vitro and in vivo

Introduction

Benign prostatic hyperplasia (BPH) is a non-neoplastic proliferative disease of the prostate. Eriochloa villosa (EV) reportedly possesses various pharmacological activities, including anti-lipase activity and modulation of various antioxidative enzymes. In this study, we investigate the therapeutic potential of EV against BPH in a testosterone-induced BPH rat model.

Methods

Rats were subjected to a daily subcutaneous injection of testosterone (3 mg kg⁻¹) for 4 weeks to induce BPH. Along with testosterone, rats in the treatment group were administered finasteride (10 mg kg⁻¹) or EV (150 mg kg⁻¹) via oral gavage. Prostatic cancer (LNCaP) cell line was used to examine the effect of EV.

Results

Finasteride and EV significantly decrease the relative prostate weight, serum levels of dihydrotestosterone and testosterone, and prostate epithelial thickness. Testosterone injection induced prostatic hyperplasia and proliferating cell nuclear antigen expression; however, EV treatment significantly attenuated these effects. Moreover, finasteride- and EV-treated rats exhibit an increase in the number of TUNEL-positive cells and reduced Bcl-2 expression in the prostate tissues compared with the testosterone-treated animals. Furthermore, EV suppresses inflammatory cytokines, including interleukin (IL)-6 and IL-8, in the prostate tissues. Meanwhile, the expression of inflammatory mediator cyclooxygenase-2 is consistently upregulated in testosterone-treated rats, whereas EV treatment significantly reverses this effect. Notably, EV treatment suppresses malondialdehyde (MDA) levels and upregulates testosterone-induced catalase (CAT) expression. In addition, EV suppresses expression of androgen receptor (AR) and prostate-specific antigen (PSA) induced by testosterone in LNCaP cells.

Conclusion

The present study results suggest that EV regulates prostatic proliferation, apoptosis, response to inflammation, and oxidative stress in the BPH rat model, and may, therefore, serve as a useful therapeutic agent for BPH.

Protective Role of 4-(4-Hydroxy-3-methoxyphenyl)-2-Butanone on Prostatic Cells Hyperplasia of Rats and Human, 5α-reductase Inhibition Pathway

BACKGROUND

Prostate gland is an exocrine gland that could be affected by various pathological conditions. Benign prostatic hyperplasia (BPH) is an age-dependent medical condition caused by increased activity of 5α-reductase enzyme (5α-R). Medical treatment by finasteride is considered during treatment, but it has unavoidable side effects. Hence, there is an increasing need to use natural ingredients for BPH treatment. Gingerol oil (ginger extract) is transferred by heating into zingerone. Recent studies reported the effect of zingerone on prostate cancer cells.

AIMS AND OBJECTIVES

The aim of the present research is to investigate the protective effect of zingerone against BPH.

MATERIALS AND METHODS

Sixty male Albino Wistar rats were divided into three groups: control group, prostatic hyperplasia group treated with saline, and prostatic hyperplasia group treated with zingerone (PH-Z-G). At day 28, all rats were sacrificed, epididymis and prostate samples were collected for histopathological examination and Western blotting for androgen receptors (ARs) proteins and steroid 5 alpha-reductase 1 (SRD5A1). Human RWPE-1 prostatic cell line was assessed for viability and cycle after treated with zingerone 500 μg/day for 10 days.

RESULTS

PH-S group showed significant (P < 0.05) thickening of connective tissue septa associated with narrowing of acinar lumen. PH-Z group showed regain of the normal histological feature. SRD5A1 and AR expression was significantly (P < 0.05) reduced in PH-Z group in comparison with PH-S group. Cell line proliferation was significantly reduced after application of zingerone with G2/M cell cycle arrest.

CONCLUSION

Our results showed that natural herbal zingerone decreased the prostatic tissue levels of (5α reductase and AR) in rat BPH model, which could be a promising herbal medicine for BPH treatment. Further human clinical trials are required.

Umbelliferone Ameliorates Benign Prostatic Hyperplasia by Inhibiting Cell Proliferation and G1/S Phase Cell Cycle Progression through Regulation of STAT3/E2F1 Axis

Umbelliferone (UMB), also known as 7-hydroxycoumarin, is a derivative of coumarin, which is widely found in many plants such as carrots, coriander, and garden angelica. Although many studies have already revealed the various pharmacological properties of UMB, its effect on benign prostatic hyperplasia (BPH) remains unclear. Therefore, the present study aimed to elucidate the underlying mechanism of the anti-proliferative effect of UMB in a human benign prostatic hyperplasia cell line (BPH-1), as well as its ameliorative effect on BPH in testosterone propionate (TP)-induced rats. The results showed that UMB exerts an anti-proliferative effect in BPH-1 cells by modulating the signal transducer and activator of transcription 3 (STAT3)/E2F transcription factor 1 (E2F1) axis. UMB treatment not only inhibited androgen/androgen receptor (AR) signaling-related markers, but also downregulated the overexpression of G1/S phase cell cycle-related markers. In TP-induced rats, UMB administration demonstrated an anti-BPH effect by significantly reducing prostate size, weight, and epithelial thickness. In addition, UMB suppressed cell proliferation by reducing the expression of proliferating cell nuclear antigen (PCNA) and p-STAT3 (Tyr 705) in prostate tissue following TP injection. These findings suggest that UMB has pharmacological effects against BPH.

Psoralea corylifolia L. extract ameliorates benign prostatic hyperplasia by regulating prostate cell proliferation and apoptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Psoralea corylifolia L. seed (PCL), commonly known as "Poguzhi" or "BuguZhi", has been widely used to treat kidney yang deficiency in traditional Chinese medicine (TCM) where tonifying the yang deficiency is a representative understanding for treatment of hormonal deficiency disorders such as enuresis, oliguria, and prostatic diseases. Although PCL has been commonly used to treat problems of the urinary system, its efficacy against benign prostatic hyperplasia (BPH) has not yet been reported.

AIM OF THE STUDY

In the present study, we aimed to assess the in vitro and in vivo efficacy of PCL against BPH, a condition which negatively impacts quality of life in men.

MATERIALS AND METHODS

Normal human prostate cell lines, RWPE-1 and WPMY-1 cells, were stimulated with 10 nM dihydrotestosterone (DHT) to establish an in vitro BPH model. Subsequently, cells were treated with 100 or 200 μg/ml PCL, which inhibited cell proliferation without cytotoxicity, to evaluate the anti-BPH effect of PCL. Eight-week-old male Wistar rats were castrated, except for those in the control group (Con), and BPH was induced by subcutaneous injection of 10 mg/kg testosterone propionate (TP). Concurrent with daily TP injections, 5 mg/kg of finasteride (Fina) and 50 or 100 mg/kg PCL were orally administrated daily for four weeks, excluding the weekends.

RESULTS

In DHT-stimulated RWPE-1 and WPMY-1 cells, expression of androgen receptor (AR) androgen signaling-related markers such as 5α-reductase 2 (5AR2), AR, and prostate-specific antigen (PSA) was upregulated, whereas 100 or 200 μg/ml of PCL treatment downregulated these markers. Furthermore, PCL significantly reduced the mRNA expression of anti-apoptotic genes and increased the mRNA expression of pro-apoptotic gene. In vivo, administration of PCL reduced prostate size and weight in TP-induced BPH rats. Moreover, histological alterations in epithelium thickness were significantly restored by the administration of PCL. Immunohistochemical analysis revealed increased expression of AR and proliferating cell nuclear antigen (PCNA) in TP-induced BPH prostates; these changes were suppressed by administration of 50 or 100 mg/kg PCL.

CONCLUSIONS

We demonstrated the effect of PCL against BPH, mediated by the regulation of prostate cell proliferation and apoptosis, in DHT-stimulated normal human prostate cell lines and TP-induced BPH rats. These findings suggest that PCL could be a potential therapeutic agent against BPH.

Therapeutic effects of losartan on prostatic hyperplasia in spontaneously hypertensive rats

AIMS

We investigated the therapeutic effects of losartan, an angiotensin II type 1 receptor blocker, on prostatic hyperplasia in spontaneously hypertensive rats (SHRs).

MAIN METHODS

Male SHRs (age, 36 weeks) were perorally treated with losartan (3 or 10 mg·kg^-1) or vehicle once daily for 18 weeks. Age-matched Wistar Kyoto rats (WKYs) were used as vehicle-treated controls (n = 8). The effects of losartan were evaluated by analyzing prostate weight, blood pressure, and prostatic blood flow. The tissue malondialdehyde (MDA), interleukin-6 (IL-6), and basic fibroblast growth factor (bFGF) levels were measured. Histological analysis for the ventral prostate involved hematoxylin and eosin staining and TdT-mediated dUTP nick-end labeling (TUNEL) assay.

KEY FINDINGS

Compared to the vehicle-treated WKYs, the vehicle-treated SHRs had significantly higher prostate weight, prostate weight/body weight ratio (PBR), blood pressure, glandular epithelial area, and tissue MDA, IL-6, and bFGF levels in the ventral prostate and lower prostatic blood flow. Treatment with losartan caused significant recovery of blood flow and decreased PBR and glandular epithelial area as well as tissue MDA, IL-6, and bFGF levels in the SHR ventral prostate without affecting blood pressure. High-dose losartan significantly decreased blood pressure and increased TUNEL-positive cells in the ventral prostate in SHRs.

SIGNIFICANCE

Chronic losartan treatment could ameliorate prostatic hyperplasia via recovery of reduced prostatic blood flow and induction of apoptosis in the ventral prostate in SHRs. Losartan might have therapeutic effects on not only hypertension but also prostatic hyperplasia in humans.

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.

Cranberry Powder Attenuates Benign Prostatic Hyperplasia in Rats

Cranberry powder (CR) is reported to be effective against lower urinary tract symptoms (LUTS) and recurrent urinary tract infections. Benign prostatic hyperplasia (BPH) in men older than 50 years is a common cause of LUTS. Here, we attempted to evaluate if CR is also effective for treating BPH using a BPH-induced rat model, which was orally administered CR. Male Sprague-Dawley rats weighing 200-250 g were randomly divided into the following six groups (n = 9): noncastration group; castration group; BPH group; BPH and cranberry for 8-week (CR8W) group; BPH and cranberry for 4-week (CR4W) group; and BPH and saw palmetto group (saw palmetto). Compared with the BPH group, the CR8W group showed a significant decrease in prostate weight (by 33%), dihydrotestosterone (DHT) levels (by 18% in serum and 28% in prostate), 5-alpha reductase levels (18% reduction of type 1 and 35% of type 2), and histological changes. These results indicate that CR could attenuate BPH by inhibiting 5-alpha reductase and by reducing other biomarkers such as prostate weight and DHT levels. Thus, CR may be an effective candidate for the development of a functional food for BPH treatment. IACUC (USW-IACUC-R-2015-004).

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.

Asteris Radix et Rhizoma suppresses testosterone-induced benign prostatic hyperplasia in rats by regulating apoptosis and inflammation

ETHNOPHARMACOLOGICAL RELEVANCE

Asteris Radix et Rhizoma (AR) refers to the roots and rhizomes of Aster tataricus L., which is widely distributed throughout East Asia. AR has been consumed as a traditional medicine in Korea, Japan and China for the treatment of urologic symptoms. To date, however, the therapeutic effect of AR on benign prostatic hyperplasia (BPH) has not been investigated.

AIM OF THE STUDY

The present study evaluated the therapeutic effects of AR on a testosterone-induced BPH rats.

MATERIALS AND METHODS

We induced BPH to rats by subcutaneous injections (s.c) of testosterone propionate (TP) daily for four weeks. Rats were also administered daily oral gavage of AR (150 mg/kg) or vehicle. After four weeks of induction, all animals were euthanized humanely and their prostate glands were removed, weighed and processed for further analysis, including histopathological examination, real-time PCR, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay and Western blot analysis.

RESULTS

Administration of AR to TP-induced BPH rats considerably reduced prostate weight and concentrations of serum testosterone and prostate dihydrotestosterone (DHT). Epithelial thickness and expression of proliferating cell nuclear antigen (PCNA) were markedly suppressed by AR-treatment in the rats. Furthermore, the expression of the B-cell lymphoma 2 (Bcl-2) were reduced and expression of the Bcl-2-associated X protein (Bax) increased, resulting in significant reduction in Bcl-2/Bax ratio. In addition, AR decreased the level of pro-inflammatory cytokines, including interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). The expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) were reduced by AR treatment in a TP-induced BPH rat model.

CONCLUSIONS

AR alleviates BPH by promoting apoptosis and suppressing inflammation, indicating that AR may be used clinically to treat BPH accompanied by inflammation.