Effect of the Phytotherapeutic Agent Eviprostat on Inflammatory Changes and Cytokine Production in a Rat Model of Nonbacterial Prostatitis

Applications of Vertebrate Models in Studying Prostatitis and Inflammation-Associated Prostatic Diseases

It has long been postulated that the inflammatory environment favors cell proliferation, and is conducive to diseases such as cancer. In the prostate gland, clinical data implicate important roles of prostatitis in the progression of both benign prostatic hyperplasia (BPH) and prostate cancer (PCa). However, their causal relationships have not been firmly established yet due to unresolved molecular and cellular mechanisms. By accurately mimicking human disease, vertebrate animals provide essential in vivo models to address this question. Here, we review the vertebrate prostatitis models that have been developed and discuss how they may reveal possible mechanisms by which prostate inflammation promotes BPH and PCa. Recent studies, particularly those involving genetically engineered mouse models (GEMMs), suggest that such mechanisms are multifaceted, which include epithelium barrier disruption, DNA damage and cell proliferation induced by paracrine signals, and expansion of potential cells of origin for cancer. Future research using rodent prostatitis models should aim to distinguish the etiologies of BPH and PCa, and facilitate the development of novel clinical approaches for prostatic disease prevention.

Effects of inflammatory prostatitis on the development and progression of benign prostatic hyperplasia: A literature review

Benign prostatic hyperplasia is a major disease that affects the quality of life of middle-aged and older men. Although >70% of men aged >70 years have pathological benign prostatic hyperplasia, its pathogenesis and progression remain unclear. In this article, we reviewed the scientific literature on this condition and examined the development of lower urinary tract symptoms. Clinically, the weight of the prostate is not always proportional to the severity of the symptoms, and many factors can influence the progression of benign prostatic hyperplasia. Other than androgens, chronic inflammation can play an essential role in its development and the induction of symptoms, especially in symptomatic hyperplasia, because inflammatory cell infiltration is frequently observed in the prostate. Inflammation-induced changes in the prostate environment lead to changes in gene expression and subsequent chronicity of inflammation. It has been suggested that chronic asymptomatic prostatitis might be associated with changes in prostate structure and subsequent symptoms. In animal studies, the administration of anti-inflammatory drugs in rats with chronic prostatitis prevented the infiltration of inflammatory cells and increased the gland-to-stroma ratio. It is hoped that future research on the molecular biology of asymptomatic prostatitis might help to develop new therapeutic strategies for lower urinary tract symptoms associated with symptomatic prostatitis. Our conclusions provide a comprehensive insight into the prevalence and development of benign prostate hyperplasia and the treatment methods that can be used to treat it.

Diagnosis of chronic prostatitis by noninvasive methods in elderly patients with benign prostatic hyperplasia in China

Chronic prostatitis is hard to be identified in BPH patients in clinical works. This study aimed to diagnose chronic prostatitis in BPH patients by noninvasive methods. BPH patients who received transurethral resection of prostate from January 2014 to July 2015 were enrolled in current study. Patients were received examinations of PSA, sex hormones, inflammatory cytokines, metabolic panel and transrectal ultrasonography. According to histological results, patients were divided into two group of BPH with/without prostatitis. Logistic regression was used to find risk factors of chronic prostatitis. As a result, 181 men with an average age of 72.15 ± 8.41 years were enrolled in this study, including 116 patients with prostatitis and 65 patients without prostatitis. The storage sub-score, PSA and IL-2R were significantly higher in patients with prostatitis than those without prostatitis. Based on logistic regression analysis, the above three parameters were also the risk factors of BPH with prostatitis. The diagnostic model was calculated as: 0.317 × storage sub-score + 0.092 × PSA + 0.003 × IL-2R - 4.296. The AUC was 0.725. Histological prostatitis in BPH patients can be diagnosed by the combination of serum IL-2R, PSA and storage sub-score. Identification of chronic prostatitis in BPH patients could more efficiently alleviate urinary symptoms and reduce the risk of disease progression.

A phosphodiesterase 5 inhibitor, tadalafil, suppresses stromal predominance and inflammation in a rat model of nonbacterial prostatitis

BACKGROUND

Chronic inflammation is thought to be a major causative factor for the development of benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS). Tadalafil, a phosphodiesterase type 5 inhibitor (PDE5-I), which has been used for the treatment of BPH-LUTS in daily practice, is known to act at several urinary organs. In this study, focused on the prostate, we examined the effect of tadalafil on the pathological changes and inflammatory factors in a rat nonbacterial prostatitis (NBP) model.

METHODS

Forty ten-month-old male Wistar rats were divided into nonbacterial prostatitis (NBP), NBP with tadalafil treatment (NBP-tadalafil), control, and control treated with tadalafil (control-tadalafil) groups (n = 10 per group). The NBP and NBP-tadalafil groups were castrated and then received daily subcutaneous 17β-estradiol for 30 days. The control-tadalafil and NBP-tadalafil groups were administered daily oral tadalafil for 30 days. All rats were then sacrificed and pathological changes and inflammatory factors were assessed in the prostatic tissues.

RESULTS

In the NBP group, the stroma-to-epithelium (S/E) ratio in the ventral prostate was significantly higher than in the control group (P < 0.001). In the NBP-tadalafil group, the S/E ratio was significantly lower than in the NBP group (P < 0.001). The macrophage levels and the extent of T-cell infiltration in the NBP-tadalafil group were significantly lower than in the NBP group (P < 0.005; P < 0.001, respectively). Compared with the NBP group, tissue concentrations of inflammatory cytokines, such as tumor necrosis factor-α, interleukin-8, and interleukin-1β, were significantly downregulated in the NBP-tadalafil group (P < 0.01; P < 0.05; P < 0.005, respectively).

CONCLUSIONS

Tadalafil suppressed stromal predominance and showed anti-inflammatory effects in a rat NBP model in association with downregulation of inflammatory cytokines.

The influence of asymptomatic inflammatory prostatitis on the onset and progression of lower urinary tract symptoms in men with histologic benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is a condition that greatly affects the quality of life of middle-aged and elderly men. Histopathologically, hyperplastic changes frequently occur in the prostate tissue of elderly men, the incidence of which has been reported to reach approximately 80% in men in their 70s. In clinical practice, approximately 25% of men with histologic BPH are assumed to experience lower urinary tract symptoms (LUTS) and receive some kind of treatment. In other words, there are some men with histologic BPH who do not exhibit LUTS. For that reason, many factors, such as the change in hormonal environment, the immune or autoimmune response, the alteration of gene expression, and so on, are thought to affect the onset and progression of LUTS in men with histologic BPH. One such factor that has long drawn attention is the presence of asymptomatic histological inflammation, which very often accompanies symptomatic BPH. Recent studies have suggested that asymptomatic histological inflammation causes repeated destruction, healing, and regeneration of the prostate tissue, leading to the enlargement of prostatic nodules, while at the same time causing stromal tissue-predominant remodeling of the prostate tissue, which can increase urination resistance and result in the condition changing from asymptomatic BPH to symptomatic BPH. In future, the biomolecular clarification of the significance of asymptomatic histological inflammation in the prostate tissue could help develop new treatment strategies for BPH accompanied by LUTS.

Eviprostat has an identical effect compared to pollen extract (Cernilton) in patients with chronic prostatitis/chronic pelvic pain syndrome: a randomized, prospective study

Background

Previously reported results of a prospective, randomized placebo-controlled study showed that the pollen extract (Cernilton) significantly improved total symptoms, pain, and quality of life in patients with inflammatory prostatitis/chronic pelvic pain syndrome (CP/CPPS) without severe side effects. A phytotherapeutic agent, Eviprostat, is reportedly effective in a rat model of nonbacterial prostatitis. The aim of the present study was to compare the efficacy and safety of Eviprostat to that of the pollen extract in the management of CP/CPPS.

Methods

The patients with category III CP/CPPS were randomized to receive either oral capsules of Eviprostat (two capsules, q 8 h) or the pollen extract (two capsules, q 8 h) for 8 weeks. The primary endpoint of the study was symptomatic improvement in the NIH Chronic Prostatitis Symptom Index (NIH-CPSI). Participants were evaluated using the NIH-CPSI and the International Prostate Symptom Score (IPSS) at baseline and after 4 and 8 weeks.

Results

In the intention-to-treat analysis, 100 men were randomly allocated to Eviprostat (n = 50) or the pollen extract (n = 50). Response (defined as a decrease in the NIH-CPSI total score by at least 25 %) in the Eviprostat group and the pollen extract group was 88.2 and 78.1 %, respectively. There was no significant difference in the total, pain, urinary, and quality of life (QOL) scores of the NIH-CPSI between the two groups at 8 weeks. This was also the case with the total, voiding, and storage symptoms of the IPSS. There were no severe adverse events observed in any patients in this study.

Conclusion

Both the pollen extract and Eviprostat significantly reduced the symptoms of category III CP/CPPS without any adverse events. Eviprostat may have an identical effect on category III CP/CPPS compared the pollen extract.

Trial registration

The study was registered with the University Hospital Medical Information Network Clinical Trials Registry in Japan (UMIN000019618); registration date: 3 November 2015.

Metabolomics strategy reveals therapeutical assessment of limonin on nonbacterial prostatitis

Limonin has been found to possess significant anti-inflammatory properties in animal tests and with, human cells, however, its precise metabolism mechanism has not been well explored. The aim of this study was to investigate the anti-inflammatory effects of limonin in a nonbacterial prostatitis (NBP) animal model. Global metabolite profiling was performed by ultra-high-performance liquid chromatography combined with time-of-flight mass spectrometry (UPLC/ESI-TOFMS) and in conjunction with multivariate data analysis and pathway analysis which were integrated to explore differentiating metabolites and clarify the mechanism of limonin against capsaicin-induced NBP. Limonin has a potential protective function revealed by the metabolic profiling of limonin-treated rats located closer to the normal group. Twenty potential biomarker candidates and several key metabolic pathways contributing to the treatment of NBP were discovered and identified. Among the pathways, the related glycine, serine and threonine metabolism, glycerophospholipid metabolism were acutely perturbed. The changes in metabolites were restored to their base-line levels after limonin treatment, which might be through regulating the perturbed pathways to the normal state. The results indicate that changed biomarkers and pathways may provide evidence and insight into limonin action mechanisms and enable us to increase research productivity toward metabolomics in therapeutical assessment and drug discovery.

Histopathological classification criteria of rat model of chronic prostatitis/chronic pelvic pain syndrome

OBJECTIVE

A variety of murine models of experimental prostatitis that mimic the phenotype of human chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) have been developed. However, there is still a lack of explicit diagnosis criteria about those animal model. Our study is to establish histopathological classification criteria, which will be conducive to evaluate the animal models.

METHODS

We firstly established a rat model of experimental autoimmune prostatitis that is considered a valid model for CP/CPPS. For modelling, male Sprague-Dawley rats were immunized with autologous prostate tissue homogenate supernatant emulsified with complete Freund's adjuvant by subcutaneous injection into abdominal flank and simultaneously immunized with pertussis-diphtheria-tetanus vaccine by intraperitoneal injection. Three immunizations were administered semimonthly. At the 45th day, animals were killed, and prostate tissues were examined for morphology.

RESULTS

Histologically, the prostate tissues were characterized by lymphoproliferation, atrophy of acini, and chronic inflammatory cells infiltration in the stromal connective tissue around the acini or ducts. Finally, we built histopathological classification criteria incorporating inflammation locations (mesenchyme, glands, periglandular tissues), ranges (focal, multifocal, diffuse), and grades (grade I-IV). To verify the effectiveness and practicability of the histopathological classification criteria, we conducted the treatment study with one of the alpha blockers, tamsulosin.

CONCLUSION

The histopathological classification criteria of rat model of CP/CPPS will serve for further research of the pathogenesis and treatment strategies of the disease.

Effect of the phytotherapeutic agent eviprostat on the bladder in a rat model of bladder overdistension/emptying

AIMS

Ischemia-reperfusion injury is an important factor in the development of lower urinary tract symptoms (LUTS) that is partly mediated by the generation of free radicals. We investigate the effect of the phytotherapeutic agent Eviprostat, a treatment for benign prostatic hyperplasia (BPH) that has antioxidant and anti-inflammatory activity, on urinary bladder blood flow (BBF), and function in a rat model of bladder overdistension and emptying (OE).

METHODS

For 8 days before surgery, OE rats received daily oral Eviprostat (36 mg/kg/day) or vehicle, while sham-operated animals received vehicle. The bladder was distended by infusion of saline over a period of 2 hr (overdistension) and then emptied. After 24 hr, BBF was measured with a laser speckle blood flow imager. The oxidative-stress marker malondialdehyde (MDA), proinflammatory cytokines, and myeloperoxidase were determined in the isolated bladder, and histological analysis was performed. Functional contractile responses of bladder strips to electrical field stimulation, carbachol, and KCl were measured.

RESULTS

Twenty-four hours after bladder OE, a significant decrease in BBF and significant increases in bladder weight, malondialdehyde, proinflammatory cytokines, and myeloperoxidase were observed. Eviprostat almost completely prevented these changes. Histological analysis of the bladder of OE rats showed hemorrhage, accumulation of leukocytes, desquamation of epithelium, and edema, and Eviprostat suppressed these changes. The reduction in functional contractile forces in the bladder of OE rats was also prevented by Eviprostat.

CONCLUSION

Eviprostat-mediated suppression of increased bladder oxidative stress and inflammation caused by bladder OE may contribute to the improvement of BBF and bladder function by Eviprostat.

Suppression of bladder overactivity and oxidative stress by the phytotherapeutic agent, Eviprostat, in a rat model of atherosclerosis-induced chronic bladder ischemia

OBJECTIVES

To clarify the mechanism by which chronic bladder ischemia causes bladder functional changes, and to investigate the involvement of oxidative stress and pro-inflammatory cytokines, and the effects of the phytotherapeutic drug, Eviprostat, on these biochemical marker levels and bladder function.

METHODS

Male Sprague-Dawley rats aged 15 weeks were divided into three groups. Arterial injury was experimentally induced by balloon endothelial injury of the iliac arteries, and a 2% cholesterol diet was given for 8 weeks. Rats in the arterial-injury group were given daily oral vehicle or Eviprostat, whereas sham-operated animals on a regular diet (0.09% cholesterol) were given vehicle for the last 2 weeks. Eight weeks after surgery, the levels of bladder pro-inflammatory cytokines, as well as bladder and urinary oxidative-stress markers, were determined. Cystometrograms were carried out without anesthesia or restraint.

RESULTS

Bladder and urinary oxidative-stress markers, and bladder pro-inflammatory cytokine levels were significantly increased in the arterial-injury group, and Eviprostat markedly suppressed these increase. The cystometrograms showed that arterial injury decreased the intermicturition interval without affecting the micturition pressure. This decrease was reversed by Eviprostat treatment.

CONCLUSIONS

Oxidative stress and pro-inflammatory cytokines might be involved in the development of overactive bladder by atherosclerosis-induced chronic bladder ischemia. Eviprostat might provide an attractive treatment option for individuals with bladder dysfunction due to chronic bladder ischemia because of its anti-oxidant and anti-inflammatory properties.