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

Medicinal plants and natural products for treating overactive bladder

BACKGROUND

Overactive bladder (OAB) presents a high prevalence of 16-18% worldwide. The pathophysiology of OAB is still poorly understood while effective therapy or countermeasure are very limited. On the other hand, medicinal plants and herbal remedies have been utilized for treating lower urinary tract symptoms (LUTS) in both Eastern and Western cultures since ancient times. In recent years, accumulating progress has also been made in OAB treatment research by using medicinal plants.

METHODS

Relevant literature on the studies of medicinal plants and herbs used to treat OAB was reviewed. The medicinal plants were summarized and categorized into two groups, single-herb medications and herbal formulations.

RESULTS

The present review has summarized current understanding of OAB's pathophysiology, its available treatments and new drug targets. Medicinal plants and natural products which have been used or have shown potential for OAB treatment were updated and comprehensively categorized. Studies on a wide variety of medicinal plants showed promising results, although only a few phytochemicals have been isolated and identified. Until now, none of these herbal compounds have been further developed into clinical therapeutics for OAB.

CONCLUSIONS

This review provides the basis for discovering and designing new phytopharmaceutical candidates with effective and well-tolerated properties to treat OAB. Increasing evidences indicate new strategies with alternative herbal treatment for OAB have high efficacy and safety, showing great promise for their clinical use. Future studies in a rigorously designed controlled manner will be beneficial to further support the eligibility of herbal treatment as OAB therapeutics.

Oxidative Stress: A Putative Link Between Lower Urinary Tract Symptoms and Aging and Major Chronic Diseases

Aging and major chronic diseases are risk factors for lower urinary tract symptoms (LUTS). On the other hand, oxidative stress (OS) is one of the fundamental mechanisms of aging and the development of chronic diseases. Therefore, OS might be a candidate mechanism linking these two clinical entities. This article aims to summarize the studies on the prevalence of LUTS, the role of OS in aging and chronic diseases, and the potential mechanisms supporting the putative link. A comprehensive literature search was performed to identify recent reports investigating LUTS and OS in major chronic diseases. In addition, studies on the impact of OS on the lower urinary tract, including bladder, urethra, and prostate, were collected and summarized. Many studies showed LUTS are prevalent in aging and major chronic diseases, including obesity, metabolic syndrome, diabetes, cardiovascular disease, hypertension, obstructive sleep apnea, autoimmune diseases, Alzheimer’s disease, and Parkinson’s disease. At the same time, OS is a key component in the pathogenesis of those chronic diseases and conditions. Recent studies also provided evidence that exacerbated OS can cause functional and/or structural changes in the bladder, urethra, and prostate, leading to LUTS. The reviewed data support the concept that OS is involved in multiple risk factors-associated LUTS, although further studies are needed to confirm the causative relationship. The specific ROS/RNS and corresponding reactions/pathways involved in chronic diseases and associated LUTS should be identified in the future and could serve as therapeutic targets.

Bladder Hyperactivity Induced by Oxidative Stress and Bladder Ischemia: A Review of Treatment Strategies with Antioxidants

Overactive bladder (OAB) syndrome, including frequency, urgency, nocturia and urgency incontinence, has a significantly negative impact on the quality-of-life scale (QoL) and can cause sufferer withdrawal from social activities. The occurrence of OAB can result from an imbalance between the production of pro-oxidants, such as free radicals and reactive species, and their elimination through protective mechanisms of antioxidant-induced oxidative stress. Several animal models, such as bladder ischemia/reperfusion (I/R), partial bladder outlet obstruction (PBOO) and ovarian hormone deficiency (OHD), have suggested that cyclic I/R during the micturition cycle induces oxidative stress, leading to bladder denervation, bladder afferent pathway sensitization and overexpression of bladder-damaging molecules, and finally resulting in bladder hyperactivity. Based on the results of previous animal experiments, the present review specifically focuses on four issues: (1) oxidative stress and antioxidant defense system; (2) oxidative stress in OAB and biomarkers of OAB; (3) OAB animal model; (4) potential nature/plant antioxidant treatment strategies for urinary dysfunction with OAB. Moreover, we organized the relationships between urinary dysfunction and oxidative stress biomarkers in urine, blood and bladder tissue. Reviewed information also revealed the summary of research findings for the effects of various antioxidants for treatment strategies for OAB.

The profile of urinary biomarkers in overactive bladder

AIMS

In overactive bladder (OAB) research, different biomarkers have been proposed as diagnostic tools and may be used to create individual patient profiles. Assessing the diagnostic performance of biomarkers would better outline their utility. Therefore, our aim was to investigate the diagnostic value of four urinary biomarkers: human brain derived neurotrophic factor (hBDNF), malondialdehyde (MDA), h nerve growth factor (hNGF) and h 8-hydroxydeoxyguanosine in women with OAB. These are neurotrophins/oxidative stress markers that have been linked to lower urinary tract symptoms.

METHODS

A total of 105 women were included in the study and distributed in two groups: a group with OAB (n = 53) and a control group (n = 50). The levels of the biomarkers were determined using enzyme-linked immunosorbent assay technique and they were compared between the groups. If the Mann-Whitney test demonstrated a statistically significant difference, receiver operating curves (ROC) analysis was undertaken.

RESULTS

When normalized to urinary creatinine, hBDNF, MDA, and hNGF showed significantly increased values in women with OAB as compared to controls, whereas 8-OHdG showed no significant difference. The diagnostic performance of these biomarkers was analyzed based on the area under the ROC curve (AUC). MDA had the highest AUC (0.75), followed by hNGF (0.69) and hBDNF (0.67).

CONCLUSIONS

Our findings suggest that MDA, a relatively novel biomarker in OAB research, has a fair performance as a diagnostic tool for OAB. Moreover, urinary neurotrophins (NGF and BDNF) as biomarkers may have a role in the diagnostic pathways of women with OAB symptoms.

The effects of oral administration of the novel muscarinic receptor antagonist DA-8010 on overactive bladder in rat with bladder outlet obstruction

Background

DA-8010 is a novel compound developed for the treatment of overactive bladder (OAB) and urinary incontinence. The aims of this study were to investigate the effects of DA-8010 on OAB in a rat model.

Methods

Study animals were divided into the following five groups of seven animals each: a sham-operated control group, a control group with partial bladder outlet obstruction (BOO) (OAB group), and three DA-8010 (doses of 0.3 mg/kg/day, 1 mg/kg/day, and 3 mg/kg/day, respectively) with partial BOO groups. Oral administration of the drugs was continued for 14 days after 2 weeks of partial BOO. After 4 weeks of partial BOO, cystometrography was performed in all groups. Additionally, pro-inflammatory cytokines, Rho-kinases, and histology of the bladder were analyzed.

Results

There was a significant increase in the contraction interval and a decrease in contraction pressure in the 3 mg/kg/day DA-8010 group versus those in the OAB group. Rho kinase was also significantly decreased in the DA-8010 3 mg/kg/day dosage treatment group. The increased ratio of collagen to smooth muscle after partial BOO was significantly attenuated in the DA-8010 3 mg/kg/day dosage group.

Conclusions

Oral administration of DA-8010 at 3 mg/kg/day improved findings in an OAB rat model induced by partial BOO. Our results suggest that the novel muscarinic receptor antagonist DA-8010 may be a promising drug for treating patients with OAB.

Efficacy of Tadalafil Therapy and Changes in Oxidative Stress Levels in Male Patients with Lower Urinary Tract Symptoms and Overactive Bladder

Objective

To evaluate the effects of tadalafil monotherapy on lower urinary tract symptoms, urodynamic parameters, and oxidative stress levels in male patients.

Methods

This prospective study included 53 male patients with urinary symptoms, who met the criteria for overactive bladder (OAB) (≥ 2 points for Q3 [urgency] in the OAB symptom score [OABSS] assessment and ≥ 3 points for the total score). The patients received 5 mg tadalafil orally once daily, and their symptoms were assessed before and after the 12‐week treatment. The OABSS and international prostate symptom score (IPSS) were used to evaluate the subjective symptoms. The objective findings were assessed using uroflowmetry. Oxidative stress was assessed by determining urinary levels of 8‐hydroxy‐2′‐deoxyguanosine (8‐OHdG) levels with an adjustment for urinary creatinine (CR) concentration.

Results

After tadalafil administration, total and individual indices of the OABSS assessment showed significant improvement. In addition, total storage and voiding symptoms that contributed to the IPSS were also significantly improved. The voided volume was increased, and the maximum flow rate was improved after tadalafil treatment (P = .002 and < 0.001, respectively). Urinary 8‐OHdG/CR decreased from 12.4 ± 9.7 ng/mg CR to 7.6 ± 11.6 ng/mg CR (P < .001). In patients who showed OAB improvement and did not meet the criteria for OAB after the treatment (44 patients, 83.0%), the urinary 8‐OHdG/CR level was significantly decreased from 11.6 ± 8.4 ng/mg CR to 6.4 ± 10.3 ng/mg CR (P < .001).

Conclusions

Tadalafil treatment improves OAB symptoms and urodynamic parameters by decreasing oxidative stress level.

Measuring urinary 8-hydroxy-2'-deoxyguanosine and malondialdehyde levels in women with overactive bladder

Purpose

In this study, we aimed to explain the role of oxidative stress in women with overactive bladder (OAB) by investigating the levels of 8-hydroxy-2′-deoxyguanosine (8-OHdG), a marker of oxidative DNA damage, and malondialdehyde (MDA), an indicator of lipid peroxidation.

Materials and Methods

A total of 90 women were included in the study: 45 female patients diagnosed with OAB at Hopa State Hospital Urology Polyclinic and 45 healthy women without any metabolic or neurologic disease. Levels of MDA and 8-OHdG were measured in 24-hour urine samples for all subjects.

Results

Urinary levels of MDA and 8-OHdG were significantly higher in the OAB group than in the control group (p<0.001). A significant positive correlation (p<0.001) was found between the measurements of 8-OHdG and MDA.

Conclusions

Oxidative stress may be important in the pathophysiology of OAB, because levels of 8-OHdG and MDA are increased. Increased levels of 8-OHdG may be due to damaged nuclear and mitochondrial DNA as a result of oxidative attacks caused by free radicals. Nevertheless, further randomized and prospective studies with larger patient populations are needed.

Improvement of Persistent Detrusor Overactivity through Treatment with a Phytotherapeutic Agent (WSY-1075) after Relief of Bladder Outlet Obstruction

Purpose

Many patients with benign prostatic hyperplasia need treatment for remaining storage symptoms after surgery. Therefore, we evaluated the effect of the phytotherapeutic agent WSY-1075 on persistent detrusor overactivity (DO) after the relief of bladder outlet obstruction (BOO).

Materials and Methods

Rats were assigned to 3 groups: control (n=6), persistent DO (n=6), and persistent DO treated with the phytotherapeutic agent WSY-1075 (n=6). Persistent DO after relief of partial BOO was generated in the rat model, and 6 of the rats with this condition were orally administered WSY-1075. After 4 weeks of administration, cystometry was performed. Additionally, 8-hydroxy-2-deoxyguanosine and superoxide dismutase were measured to evaluate oxidative stress in the bladder. Pro-inflammatory cytokines, such as interleukin-8 and tumor necrosis factor-α, were analyzed, as were the M2 and M3 muscarinic receptors of the bladder.

Results

Significantly increased contraction pressure and a decreased contraction interval were observed in the persistent DO group after relief of BOO. Moreover, oxidative stress, pro-inflammatory cytokines, and M3 muscarinic receptors were significantly increased. After treatment with WSY-1075, significantly reduced DO was observed by cystometry in comparison with the persistent DO group. Additionally, significantly decreased levels of oxidative stress, pro-inflammatory cytokines, and M3 muscarinic receptors in the bladder were observed after treatment with WSY-1075.

Conclusions

Treatment with WSY-1075 improved persistent DO after the relief of BOO mediated by antioxidative and anti-inflammatory effects. Further studies are necessary to identify the exact mechanism of the treatment effect of WSY-1075.

LUTS in pelvic ischemia: a new concept in voiding dysfunction

Lower urinary tract symptoms (LUTS) are a group of voiding symptoms affecting both genders as they age. Traditionally, LUTS in men were commonly attributed to bladder outlet obstruction (BOO) due to benign prostatic enlargement (BPE). It was later shown that, in approximately one-third to more than one-half of cases, LUTS in men are not associated with BOO. Urodynamic changes in the male bladder and symptom scores in aging men were found to be identical to their age-matched female counterparts. These observations suggested that LUTS in the elderly do not necessarily relate to BOO and may result from local changes in bladder muscle, nerves, and blood vessels. However, aging factors predisposing to bladder dysfunction and LUTS remain unknown. Growing evidence suggests that aging-associated pelvic ischemia may be a primary factor in the development of nonobstructed nonneurogenic overactive bladder and LUTS. First identified in experimental models and later in clinical studies, pelvic ischemia has been shown to compromise the lower urinary tract structure and lead to dysfunction. Structural and functional consequences of bladder and prostate ischemia have been documented in animal models. Clinical studies have shown that bladder and prostate blood flow decreases with aging. The severity of LUTS in elderly patients correlates with the degrees of bladder ischemia. LUTS improvement with α blockers has been associated with increased bladder blood flow. Pelvic ischemia may be an independent factor in nonobstructed nonneurogenic bladder instability and LUTS. Further research into the pathophysiology of LUTS in pelvic ischemia may lead to better management of this problem in the elderly population.

Mirodenafil prevents bladder dysfunction induced by chronic bladder ischemia in rats

Purpose:

To investigate the protective effect of mirodenafil on bladder function in a rat model of chronic bladder ischemia (CBI).

Methods:

Twenty-four Sprague-Dawley rats were randomized to three groups: untreated, sham-operated rats (control group); untreated, CBI model rats (CBI group); and CBI rats treated daily with 4 mg/kg mirodenafil (CBI+mirodenafil group). The CBI and CBI+mirodenafil groups underwent endothelial injury to the iliac arteries and were fed a 2% cholesterol diet after injury. Four weeks after surgery, the CBI+mirodenafil group started daily treatment with mirodenafil for four weeks. Eight weeks after surgery, continuous in vivo cystometry and in vivo organ bath studies of detrusor muscle strips were performed.

Results:

in vivo cystometry revealed that the rats in the CBI group had a significantly higher micturition frequency, lower bladder capacity, and lower compliance than the rats in the control and CBI+mirodenafil groups. The detrusor muscle strip study showed that the magnitude of the carbachol-induced contractile response was significantly lower in the CBI group compared to either the control or CBI+mirodenafil group. Addition of daily mirodenafil after induction of CBI decreased the contractile response, compared to untreated CBI rats. CBI induced submucosal fibrosis and degenerative changes in bladder walls, which was reversed by the addition of mirodenafil.

Conclusions:

Daily treatment with mirodenafil showed protective effects against bladder dysfunction resulting from CBI in rats.

Pharmacological treatment of chronic pelvic ischemia

Epidemiological studies have shown that lower urinary tract symptoms, including overactive bladder, commonly occur in both men and women, with an age-related increase in both sexes. Vascular endothelial dysfunction and urological symptoms are common in the metabolic syndrome; they also occur during the human ageing process and are independent risk factors for the development of atherosclerosis and hypertension. Pelvic arterial insufficiency may lead to impaired lower urinary tract perfusion and play an important role in the development of bladder dysfunction such as detrusor overactivity and overactive bladder. It seems reasonable, but has not been definitely established clinically, that chronic ischemia-related bladder dysfunction will progress to bladder underactivity. Studies in experimental models in rabbits and rats have shown that pelvic arterial insufficiency may result in significant bladder ischemia with reduced bladder wall oxygen tension, oxidative stress, increased muscarinic receptor activity, ultrastructural damage, and neurodegeneration. Several types of drug may be able to prevent some of these changes. Even if the α1-adrenoceptor blocker, silodosin, the phosphodiesterase type 5 inhibitor, tadalafil, the β3-α1-adrenoceptor agonist, mirabegron, and the free radical scavenger, melatonin, were unable to prevent the development of neointimal hyperplasia and consequent luminal occlusion in animal models, they all exerted a protecting effect on urodynamic parameters, and on the functional and morphological changes of the bladder demonstrable in vitro. The different mechanisms of action of the drugs suggest that many factors are involved in the pathogenesis of chronic ischemia-induced bladder dysfunction and can be targets for intervention. Since several of the agents tested are used clinically and effectively for relieving lower urinary tract symptoms, the results from animal models of chronic bladder ischemia seem to have translational value. Animal models may be of relevance for designing clinical studies to demonstrate if a certain drug may prevent progression of ischemia-related functional and morphological bladder changes.

Anti-oxidant activity and attenuation of bladder hyperactivity by the flavonoid compound kaempferol

OBJECTIVES

To evaluate the anti-oxidant activity of the flavonoid compound, kaempferol, and to examine its role in the suppression of oxidative stress and attenuation of bladder hyperactivity in a rat model of bladder injury.

METHODS

The anti-oxidative activity of kaempferol was examined in lipopolysaccharide-treated RAW264.7 macrophages by using flow cytometry. For in vivo studies, rats were pretreated with kaempferol or vehicle for 24 h. The rat urothelium was injured by the administration of protamine sulfate for 1.5 h and irritated by the subsequent infusion of potassium chloride for 4 h. Oxidative stress in the bladder tissue was assessed using chemiluminescence assay, and the bladder pressure was determination by cystomertrogram.

RESULTS

Kaempferol significantly suppressed lipopolysaccharide-induced reactive oxygen species production in RAW264.7 rat macrophages. Exposure of the rat bladder to sequential infusion of protamine sulfate and potassium chloride induced bladder hyperactivity. Pretreatment with kaempferol, prevented the formation of reactive oxygen species and prolonged the intercontraction interval.

CONCLUSION

Kaempferol suppresses oxidative stress and attenuates bladder hyperactivity caused by potassium chloride after protamine sulfate-induced bladder injury.

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.

Improvement by phytotherapeutic agent of detrusor overactivity, down-regulation of pharmacological receptors and urinary cytokines in rats with cyclophosphamide induced cystitis

PURPOSE

We characterized pharmacological effects of the phytotherapeutic agent Eviprostat® on urodynamic parameters, bladder muscarinic and purinergic receptors, and urinary cytokines in rats with cyclophosphamide induced cystitis.

MATERIALS AND METHODS

Urodynamic parameters in cyclophosphamide (150 mg/kg intraperitoneally) treated rats were measured by a cystometric method. Muscarinic and purinergic receptors in the bladder and other tissues were measured by radioreceptor assays using [N-methyl-(3)H]scopolamine methyl chloride and [(3)H]αβ-MeATP, respectively. The urinary cytokines interleukin-1β, 6 and 17 were measured with enzyme-linked immunoassay kits. Eviprostat (36 mg/kg per day twice daily for 7 days) was orally administered.

RESULTS

On cystometry the micturition interval and micturition volume were significantly decreased in cyclophosphamide vs sham treated rats, while micturition frequency, basal pressure and post-void residual urine volume were significantly increased. Repeat oral administration of Eviprostat in cyclophosphamide treated rats significantly increased the micturition interval and micturition volume, and decreased micturition frequency, basal pressure and post-void residual urine volume. The maximal number of binding sites for [N-methyl-(3)H]scopolamine methyl chloride and [(3)H]αβ-MeATP was significantly decreased in the bladder of cyclophosphamide vs sham treated rats. Such decreases were significantly attenuated by repeat Eviprostat treatment. Increased urinary cytokine levels in cyclophosphamide treated rats were also effectively attenuated by Eviprostat.

CONCLUSIONS

Repeat Eviprostat treatment significantly improved detrusor overactivity, down-regulated the expression of bladder pharmacological receptors and increased urinary cytokine levels in rats with cyclophosphamide induced cystitis. Therefore, Eviprostat may be a pharmacologically useful phytotherapeutic agent for cystitis.