Protective effect of 2-hydroxy-4-methoxy benzoic acid on testosterone induced benign prostatic hyperplasia in Wister rats

Quantitative measurements of prostate capsule and gland density and their correlation to prostate size: possible clinical implications in prostate cancer

PURPOSE

To study histo-anatomical imaging features and possible association between prostate volume, capsule thickness and glandular density within the peripheral zone (PZ) of prostates of different sizes.

METHODS

Patients were selected who had undergone radical prostatectomy. Specimen selection was based on two factors: first, easy reconstruction of prostate anatomy by the histological slides; and second, based on prostate size. Specimens were chosen with small (< 35 cc) and also with large size (> 80 cc). A total of 20 patients were selected. None of these patients had undergone previous treatment. Computer-based imaging for quantitative measurements of capsule thickness and glandular density within the PZ were performed. Multiple regression analysis was performed to determine the relationship between these measured parameters and the clinical characteristics of these patients.

RESULTS

Multiple regression analysis revealed a strong, positive association between prostate size and average capsule thickness; on the contrary, we found a negative correlation between prostate volume and average glandular density. Fibrotic thickness of the capsule was associated with gland atrophy and decreased gland density within the PZ.

CONCLUSIONS

The results suggest that BPH may be associated with the development of fibrosis and gland atrophy within the peripheral zone. As 80% of prostate cancer originates from the glandular epithelium within the peripheral zone, this observed phenomenon may explain the inverse relationship between BPH and incidence of prostate cancer well documented in the literature.

Protective effect of black mulberry (Morus nigra L.) fruit hydroalcoholic extract against testosterone-induced benign prostatic hyperplasia in rats

BACKGROUND

Finding new agents for prevention and/or treatment of benign prostatic hyperplasia (BPH) especially from natural sources is a demanding field.

OBJECTIVES

This study aimed to evaluate the effect of black mulberry (BM) (Morus nigra) fruit hydroalcoholic extract on the establishment of BPH in rats.

MATERIALS AND METHODS

Forty-nine adult male rats were randomly assigned into 7 equal groups: I: Sham control (SC), a sham surgery was performed. II: positive control (PC), rats were castrated and received testosterone propionate, at 10mg/kg/day S.C. for BPH induction. III: comparative control (CC), BPH was induced and the rats received finasteride at 5mg/kg/day P.O. IV-VII: (T1-T4): BPH was induced and the rats received BM extract at 25, 50, 100 and 200mg/kg/day P.O. for 4 consecutive weeks.

RESULTS

Finasteride and/or BM extract especially at the two higher dosages, significantly affected prostate weight, prostatic index, percent of inhibition, serum and prostatic levels of dihydrotestosterone (DHT), serum prostate-specific antigen (PSA), antioxidant parameters of prostatic tissue as well as histopathological and histomorphometric parameters (epithelial thickness and acinar area) of prostate.

CONCLUSIONS

BM extract has protective effects against experimentally-induced BPH in rats with regard to histopathological and biochemical parameters which may be related to its antioxidant as well as DHT reducing properties in prostatic tissue.

Protective role of diosmin against testosterone propionate-induced prostatic hyperplasia in Wistar rats: Plausible role of oxidative stress and inflammation

Benign prostatic hyperplasia (BPH) is an important key health concern for aging men. Polyphenolic compounds have been found to possess important roles in the inhibition of numerous ailments that involve reactive oxygen species and inflammation. Diosmin is a citrus flavone that possesses antioxidant, anti-inflammatory, antiproliferative, and anticancer activities, so based on these properties of diosmin, we decided to evaluate its effect on testosterone propionate (TP)-induced BPH. A total of 30 Wistar rats were randomly assigned to five groups having six animals in each. This study was of 28 days in which TP (5 mg kg−1) was administered to induce BPH in the last 10 days of the study. It was found that diosmin at the doses of 20 and 40 mg kg−1significantly reduced malondialdehyde and xanthine oxidase formation in a dose-dependent manner; however, it replenished catalase, glutathione (GSH), and GSH-dependent enzymes, that is, glutathione peroxidase, glutathione reductase, and glutathione- S-transferase significantly against TP-induced BPH. Further, immunohistochemical study showed that diosmin alleviated inflammatory markers (nuclear factor kappa-light-chain-enhancer of activated B cells, cyclooxygenase-2, and interleukin-6). It was also found that diosmin downregulated the expression of androgen receptor and decreased the prostate-specific antigen concentration dose-dependently, significantly against TP-induced BPH. Diosmin also restored histoarchitecture of the prostate in a dose-dependent manner. Findings from the present study revealed the protective role of diosmin against TP-induced BPH in Wistar rats.

Potential repositioning of GV1001 as a therapeutic agent for testosterone‑induced benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is one of the leading causes of male reproductive disorders. Therapeutic agents currently in use have severe side effects; therefore, alternative drugs that exhibit improved therapeutic activity without side effects are required. The present study investigated the protective effect of GV1001 against testosterone‑induced BPH in rats. BPH in castrated rats was established via daily subcutaneous (s.c.) injections of testosterone propionate (TP, 3 mg/kg) dissolved in corn oil for 4 weeks. GV1001 (0.01, 0.1 and 1 mg/kg, s.c.) was administered 3 times per week for 4 weeks, together with TP (3 mg/kg) injection. The rats were sacrificed on the last day of treatment, and their prostates were excised and weighed for biochemical and histological studies. Serum levels of testosterone and dihydrotestosterone (DHT) were also measured. In rats with TP‑induced BPH, a significant increase in prostate weight (PW) and prostatic index (PI), accompanied by a decrease in antioxidant enzyme activity, was observed. Histological studies revealed clearly enlarged glandular cavities in rats with BPH. GV1001 (0.01 and 0.1 mg/kg) treatment significantly decreased PW and PI in rats with TP‑induced BPH. In addition, GV1001 demonstrated a potent inhibitory effect on 5α‑reductase in prostate. The present data suggest that the protective role of GV1001 against testosterone‑induced BPH is closely associated with its antioxidant potential. Additional studies are required to identify the mechanisms by which GV1001 protects against BPH to determine its clinical application.

Identification of reference genes and miRNAs for RT-qPCR in testosterone propionate-induced benign prostatic hyperplasia in rats

Testosterone propionate-induced benign prostatic hyperplasia in rats is a common model that is widely used in studies of the effects and molecular mechanisms of drugs designed to treat benign prostatic hyperplasia. RT-qPCR is a widely used technique in gene expression studies. Proper normalisation is critical for accurate expression analysis. Currently, no validated reference genes are available for RT-qPCR in rat benign prostatic hyperplasia. Given that microRNAs regulate mRNA expression at the post-transcriptional level, they are usually studied together. Here, the expression stability of 21 putative reference genes including 8 mRNAs and 13 miRNAs was evaluated in benign prostatic hyperplasia in rats. Relative expression levels of each gene were detected in rats from a model group and a normal group using SYBR RT-qPCR. Expression stability was evaluated by geNorm and NormFinder. The commonly used reference genes, such as ACTB, B2M and mir-16, were less stable, and let-7a was eliminated due to a large Ct value, most likely indicating a relatively low expression level. Therefore, to obtain reliable results, mir-26a was recommended as a suitable reference for miRNA expression analysis and EF-1a as a suitable reference for mRNA analysis in testosterone propionate-induced benign prostatic hyperplasia in rats.

Iodine prevents the increase of testosterone-induced oxidative stress in a model of rat prostatic hyperplasia

Oxidative stress and inflammation are involved in the development and/or progression of benign prostatic hyperplasia (BPH). Molecular iodine (I₂) induces antiproliferative and apoptotic effects in prostate cancer cells, but it is unknown if I₂ regulates oxidative stress in the normal and/or tumoral prostate. The purpose of this study was to analyze the effects of I₂ and celecoxib (Cxb) on oxidative stress and inflammation in a model of prostatic hyperplasia. Cxb was used as positive control of cyclooxygenase-2 (COX-2) inhibition. Prostatic hyperplasia was induced in male Wistar rats (170g) with testosterone (5mg/kg/week, for three weeks). One week before hyperplasia induction, I₂ (25mg/day/rat) or Cxb (1.25mg/day/rat) was supplied for four weeks in the drinking water. Prostatic hyperplasia was evaluated by histological analysis, DNA content, and/or proliferating cell nuclear antigen (PCNA) expression. Lipoperoxidation (malondialdehyde) and nitrite (NO2^-) levels were analyzed by colorimetric methods, while nitric oxide synthase (NOS), COX, and myeloperoxidase (MPO) enzymes were analyzed using RT-PCR, immunoblotting, and/or enzymatic assays. Levels of 15-F2t-isoprostanes, prostaglandins (PGE₂), leukotrienes (LTB₄), and tumor necrosis factor alpha (TNFα) were measured by ELISA. Control testosterone-treated animals exhibited hyperplasia in the dorsolateral prostate, as well as increments in almost all oxidative parameters except for COX-1, TNFα, or MPO. I₂ and Cxb prevented epithelial hyperplasia (DNA content) and oxidative stress induction generated by testosterone in almost the same intensity, and the minimum I₂ dose required was 2.5mg/rat. The antioxidant capacity of I₂ was also analyzed in a cell-free system, showing that this element inhibited the conversion of nitrate (NO₃^-) to NO₂^-. I₂ did not modify the prostatic oxidative state in testosterone untreated rats. In summary, our data showed that antiproliferative and antioxidant effects of I₂ involve the inhibition of NOS and the COX-2 pathway. Further studies are necessary to analyze the therapeutic and/or adjuvant effects of I₂ with first-line medications used to treat 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.

Potential ameliorative effects of grape seed-derived polyphenols against cadmium induced prostatic deficits

Grape (Vitis vinifera) is consumed as fruit and wine for people. In this study, rat model of prostatic deficits was induced by orally receiving 60mg/L cadmium chlorine (CdCl₂) through drinking water for 20 weeks. Grape seed-derived polyphenols extract (GSP) was orally given for 20 weeks. Finally, the prostatic levels of E-cadherin, fibronectin, and α-smooth muscle actin were measured by immunohistochemical and qPCR analysis. The oxidative stress was measured by detecting the levels of malondialdehyde, nitric oxide, reduced glutathione/oxidized glutathione and enzymatic antioxidant status. Additionally, the prostatic expressions of transforming growth factor-β1 (TGF-β1), type I TGF-β receptor (TGF-βRI), Smad3, phosphorylation-Smad3 (p-Smad3), Smad7, nuclear related factor-2 (Nrf-2), heme oxygenase-1 (HO-1) and γ-glutamate cysteine ligase catalytic subunit (γ-GCLC) were measured by western blot. The levels of microRNA (miR)-133a/b were measured by qPCR. It was observed that GSP ameliorated the prostatic oxidative stress and fibrosis induced by CdCl₂. GSP also inhibited the over-generation of TGF-β1 and p-Smad3, as well as enhanced the levels of Smad7, Nrf-2, HO-1, γ-GCLC and miR-133a/b. These results showed that GSP could attenuate Cd-induced prostatic deficits.

The anti-hyperplasia, anti-oxidative and anti-inflammatory properties of Qing Ye Dan and swertiamarin in testosterone-induced benign prostatic hyperplasia in rats

Qing Ye Dan (QYD) is the whole plant of Swertia mileensis and used in Chinese folk medicine for the treatment of prostatitis, benign prostatic hyperplasia (BPH) and so on. This study was to investigate the effects of QYD and its main component swertiamarin on BPH induced by testosterone in rats. The prostatic expressions of vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), basic fibroblast growth factor (βFGF) and proliferating cell nuclear antigen (PCNA) were detected by immunohistochemistry assay. Prostatic levels of oxidative stress and inflammatory-related factors were also analyzed. Additionally, the prostatic expressions of androgen receptor (AR), estrogen receptor (ER)-α, ER-β, hypoxia-inducible factor (HIF)-1α, B-cell CLL/lymphoma (Bcl)-2 and Bcl-2-associated X protein (Bax) were measured by western blot. The epithelial-mesenchymal transition (EMT) associated factors were evaluated by quantitative RT-PCR. It showed that QYD and swertiamarin ameliorated the testosterone-induced prostatic hyperplasia and collagen deposition, attenuated the over-expressions of HIF-1α, VEGF, EGF, βFGF, PCNA, AR and ER-α, reduced the ratio of Bcl-2/Bax, enhanced the expression of ER-β, inhibited the oxidative stress and local inflammation, as well as relieved prostatic EMT. It suggested that QYD and swertiamarin had prostatic protective potential against BPH.

Oxidative stress in prostate hyperplasia and carcinogenesis

Prostatic hyperplasia (PH) is a common urologic disease that affects mostly elderly men. PH can be classified as benign prostatic hyperplasia (BPH), or prostate cancer (PCa) based on its severity. Oxidative stress (OS) is known to influence the activities of inflammatory mediators and other cellular processes involved in the initiation, promotion and progression of human neoplasms including prostate cancer. Scientific evidence also suggests that micronutrient supplementation may restore the antioxidant status and hence improve the clinical outcomes for patients with BPH and PCa. This review highlights the recent studies on prostate hyperplasia and carcinogenesis, and examines the role of OS on the molecular pathology of prostate cancer progression and treatment.

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.

Finasteride Has Regionally Different Effects on Brain Oxidative Stress and Acetylcholinesterase Activity in Acute Thioacetamide-Induced Hepatic Encephalopathy in Rats

Finasteride (FIN) inhibits neurosteroid synthesis and potentially improves the course of hepatic encephalopathy (HE). This study aimed to investigate the effects of FIN on brain oxidative stress and acetylcholinesterase (AchE) activity in acute thioacetamide-induced HE in rats. Male Wistar rats were divided into groups: 1. control; 2. thioacetamide-treated group (TAA; 900 mg/kg); 3. finasteride-treated group (FIN; 150 mg/kg); 4. group treated with FIN and TAA (FIN+TAA). Daily doses of FIN (50 mg/kg) and TAA (300 mg/kg) were administered intraperitoneally during three days and in FIN+TAA group FIN was administered 2h before every dose of TAA. FIN pretreatment prevented TAA-induced rise in malondialdehyde level in the cortex due to restoration of catalase activity and increased expression of superoxide dismutase 1 (SOD1) and induced an increase in malondialdehyde level in the thalamus due to reduction of glutathione peroxidase (GPx) and glutathione reductase (GR) activity. Although FIN pretreatment did not affect malondialdehyde level in hippocampus and caudate nucleus, hippocampal SOD1 expression was higher (p<0.05) and GR activity lower in FIN+TAA vs. TAA group (p<0.05). GPx activity was lower in caudate nucleus in FIN+TAA vs. TAA group (p<0.01). FIN pretreatment prevented TAA-induced rise in AchE activity in the thalamus and caudate nucleus and AchE activity correlates inversely in the thalamus (p<0.05) and positively in caudate nucleus (p<0.01) with malondialdehyde level. FIN has regionally selective effects on oxidative stress and AchE activity in the brain in acute TAA-induced HE in rats. The prooxidant role of FIN in the thalamus may be causally linked with inhibition of AchE.

Modulatory effect of silymarin on inflammatory mediators in experimentally induced benign prostatic hyperplasia: emphasis on PTEN, HIF-1α, and NF-κB

The current study aimed to investigate the potential role of the anti-inflammatory effects of silymarin (SIL) in inhibiting experimentally induced benign prostatic hyperplasia (BPH) in rats. Rats were injected testosterone (3 mg/kg/day, subcutaneously (s.c.)) for 2 weeks. In the treatment group, SIL (50 mg/kg, per orally (p.o.)) was administered daily to rats concomitantly with testosterone. Rats were killed 72 h after the last testosterone injection. Then, prostate tissues were dissected out, weighed, and subjected to histological, immunohistochemical, and biochemical examinations. Rats treated with testosterone showed marked increase in prostate weight and prostate weight/body weight with histopathological picture of inflammation and hyperplasia as well as increased collagen deposition. Co-treatment with SIL significantly alleviated these pathological changes. Further, SIL attenuated testosterone-induced nuclear factor-kappa B (NF-κB), cyclooxygenase-II (COX-II), and inducible nitric oxide synthase (iNOS) upregulation, and blunted testosterone-mediated increase in nitric oxide level and messenger RNA (mRNA) expression of interleukin-6 (IL-6) and IL-8. Testosterone-induced downregulation of phosphatase and tensin homolog (PTEN) and upregulation of hypoxia-inducible factor 1α (HIF-1α) were alleviated by SIL. Our findings highlight the anti-inflammatory properties of SIL as a crucial mechanism of its preventive actions against experimental BPH. This can be attributed to, at least partly, attenuating the expression of NF-kB and the subsequent inflammatory cascade, ameliorating the expression of PTEN, and mitigating that of HIF-1α. These data warrant further investigations for the potential use of SIL in the management of BPH.