Intraprostatic Botulinum Neurotoxin Type A Injection for Benign Prostatic Hyperplasia-A Spotlight in Reality

Bladder Dysfunction in Older Adults: The Botulinum Toxin Option

Bladder dysfunction, which involves inadequacies of urine storage or emptying, increases with age. Conventional medications may have insufficient efficacy for patients with refractory lower urinary tract symptoms, and their concomitant adverse events (AEs) may be intolerable for the older adult population. For decades, the botulinum toxin type A (BoNT-A) injection has been an option for managing urine frequency, urge incontinence, and voiding dysfunction in the general population refractory to conventional management. This review focuses on studies of BoNT-A application in the management of bladder dysfunction in older adult patients aged ≥ 65 years. In this target population, intravesical BoNT-A injections provide similar efficacy in idiopathic overactive bladder to that in younger adults. Good clinical response has also been demonstrated in older adult patients presenting with storage dysfunction and with various concomitant underlying neurological diseases. However, caution must be taken for the AEs that occur after intravesical BoNT-A injection, including increased post-void residual urine, acute urine retention, and urinary tract infection. Most evidence shows that age is not a major determinant of AEs after adjusting for other factors. In contrast to its application in storage dysfunction, evidence for voiding dysfunction in older adults is scarce. In general, BoNT-A may be a reasonable option for older adult patients with refractory storage dysfunction because of its promising clinical response without significant systemic AEs. Overall, clinicians should be aware of the balance between the therapeutic efficacy of BoNT-A and local AEs in vulnerable members of this population.

The Mechanisms of Action of Botulinum Toxin Type A in Nociceptive and Neuropathic Pathways in Cancer Pain

BACKGROUND

Botulinum toxin type A (BoNT-A) is widely employed for cosmetic purposes and in the treatment of certain diseases such as strabismus, hemifacial spasm and focal dystonia among others. BoNT-A effect mainly acts at the muscular level by inhibiting the release of acetylcholine at presynaptic levels consequently blocking the action potential in the neuromuscular junction. Despite the great progress in approval and pharmaceutical usage, improvement in displacing BoNT-A to other pathologies has remained very limited. Patients under diagnosis of several types of cancer experience pain in a myriad of ways; it can be experienced as hyperalgesia or allodynia, and the severity of the pain depends, to some degree, on the place where the tumor is located. Pain relief in patients diagnosed with cancer is not always optimal, and as the disease progresses, transition to more aggressive drugs, like opioids is sometimes unavoidable. In recent years BoNT-A employment in cancer has been explored, as well as an antinociceptive drug; experiments in neuropathic, inflammatory and acute pain have been carried out in animal models and humans. Although its mechanism has not been fully known, evidence has shown that BoNT-A inhibits the secretion of pain mediators (substance P, Glutamate, and calcitonin gene related protein) from the nerve endings and dorsal root ganglion, impacting directly on the nociceptive transmission through the anterolateral and trigeminothalamic systems.

AIM

The study aimed to collect available literature regarding molecular, physiological and neurobiological evidence of BoNT-A in cancer patients suffering from acute, neuropathic and inflammatory pain in order to identify possible mechanisms of action in which the BoNT-A could impact positively in pain treatment.

CONCLUSION

BoNT-A could be an important neo-adjuvant and coadjuvant in the treatment of several types of cancer, to diminish pro-tumor activity and secondary pain.

Transperineal intraprostatic injection of botulinum neurotoxin A vs transurethral resection of prostate for management of lower urinary tract symptoms secondary to benign prostate hyperplasia: A prospective randomised study

Objectives: To evaluate transperineal intraprostatic injection of botulinum neurotoxin A (BoNT-A) in patients with lower urinary tract symptoms (LUTS) secondary to benign prostate hyperplasia (BPH) who failed to respond to 6-month medical treatment compared with transurethral resection of the prostate (TURP).

Patients and methods: In all, 92 men were divided into TURP and BoNT-A groups after being evaluated using the International Prostate Symptom Score (IPSS) and five-item version of the International Index of Erectile Function, estimation of serum total prostate-specific antigen (tPSA), ultrasonographic estimation of prostatic volume (PV), and uroflowmetry determination of voiding volume (VV), maximum urinary flow rate (Q_max) and post-void residual urine volume (PVR). BoNT-A (200 U diluted in 3 mL saline) was injected, using a 22-G spinal needle under transrectal ultrasonography guidance, with 1-mL in each lobe. Patients were assessed 3-monthly for 12 months.

Results: The IPSS significantly decreased in all patients with a non-significant difference between the groups. The mean VV and Q_max increased, whilst PVR, PV and serum tPSA significantly decreased. Patients who showed deterioration at 12 months were re-evaluated and underwent TURP. BoNT-A injection significantly maintained erectile function compared with TURP.

Conclusion: Intraprostatic BoNT-A injection reduced PV with subsequent increases in VV and Q_max, and decreases in PVR and serum tPSA level. Intraprostatic BoNT-A injection allowed surgery sparing in >70% and preserved erectile function in 91.3% of patients.

Abbreviations: BoNT-A: botulinum neurotoxin A; HRQOL: health-related quality of life; IIEF-5: five-item version of the International Index of Erectile Function; PV: prostatic volume; PVR: post-void residual urine volume; Q_max: maximum urinary flow rate; tPSA: total PSA; VV: voided volume

Promise and the Pharmacological Mechanism of Botulinum Toxin A in Chronic Prostatitis Syndrome

Chronic prostatitis/chronic pelvic pain syndrome (CP/ CPPS) has a negative impact on the quality of life, and its etiology still remains unknown. Although many treatment protocols have been evaluated in CP/CPPS, the outcomes have usually been disappointing. Botulinum neurotoxin A (BoNT-A), produced from Clostridium botulinum, has been widely used to lower urinary tract dysfunctions such as detrusor sphincter dyssynergia, refractory overactive bladder, interstitial cystitis/bladder pain syndromes, benign prostatic hyperplasia, and CP/ CPPS in urology. Here, we review the published evidence from animal models to clinical studies for inferring the mechanism of action underlying the therapeutic efficacy of BoNT in CP/CPPS. Animal studies demonstrated that BoNT-A, a potent inhibitor of neuroexocytosis, impacts the release of sensory neurotransmitters and inflammatory mediators. This pharmacological action of BoNT-A showed promise of relieving the pain of CP/CPPS in placebo-controlled and open-label BoNT-A and has the potential to serve as an adjunct treatment for achieving better treatment outcomes in CP/CPPS patients.

Efficacy and safety of fexapotide triflutate in outpatient medical treatment of male lower urinary tract symptoms associated with benign prostatic hyperplasia

Male lower urinary tract symptoms (LUTS) is an increasingly important problem for the majority of late middle aged and elderly men. Fexapotide triflutate (FT) is a first in-class compound given by local injection via the transrectal intraprostatic route under ultrasound guidance. Data from >1700 FT and control injections in prospective randomized blinded controlled multicenter trials are reviewed and discussed in relation to current developments in the field of treatments for LUTS associated with benign prostatic hyperplasia (BPH). Long-term studies of FT in the United States have shown statistically significant improvement in BPH symptoms and objective outcomes including significant reduction in both spontaneous acute urinary retention as well as the subsequent incidence of BPH surgery. FT has been shown to be well tolerated with an excellent safety profile, and is an efficacious clinic-based treatment for BPH involving an intraprostatic injection that requires only a few minutes to administer, with no catheter nor anesthesia requirements.

Anti-cancer Potential of Captopril and Botulinum Toxin Type-A and Associated p53 Gene Apototic Stimulating Activity

Mutational inactivation of p53 is a key player in the development of human cancer. Thus, retrieving the tumor suppressor activity of p53 gene is considered a novel strategy in cancer therapy. Current study aimed to investigate the anti-cancer potentials of botulinum toxin type-A (BTX-A) and captopril as a trial to shed light on effective anti-cancer therapy with lower side effects. Cytotoxic effect of captopril and BTX-A was determined using MTT assay against colon (HCT116) and prostate cancer (DU145) cells compared to their effect on normal vero cells. Anti-proliferation assay and anti-metastatic effect were carried out using trypan blue exclusion method and wound scratch migration test, respectively. The ability of test drugs to induce apoptosis in cancer cells was examined using real time PCR. Recorded data revealed that captopril exhibited a statistically significant cytotoxicity (P < 0.05) to cancer cells (IC50 values of 1.5 and 1.2 mg/mL) with much lower toxicity to normal cells. At the same time, IC50 values post BTX-A treatment were 7.2 and 6.4 U/mL for HCT116 and DU145 cells, respectively without any toxicity to vero cells. Both drugs showed inhibitory potentials on cellular proliferation and the ability of cancer cells to migrate in scratched monolayers was obviously inhibited along with increasing their concentrations. P53 expression levels in captopril and BTX-A treated DU145 cells were elevated by 4 and 2.5 folds, respectively, while lower level of apoptosis induction in HCT116 cells was observed. Accordingly, BTX-A and captopril could present potential anti-cancer candidates through triggering cancer cells towards self-destruction.

Botulinum toxin and benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is a clinical condition where lower urinary tract symptoms are caused by both a physically obstructing prostate as well as tight smooth muscles around the bladder outlet. Treatment of this condition with botulinum toxin has been used since 2003, but this interest has somewhat died down after two large randomized controlled trials (RCTs) showing equivalence of results between their treatment and placebo arms. However, with review of animal studies and unexplained exaggerated effect of the placebo arms of the two RCTs, together with recent data of sustained benefits after 18 months of treatment, the place of botulinum toxin in the BPH field is probably still present.

Evaluation of botulinum toxin type A effectiveness in preventing postoperative intraperitoneal adhesions

Purpose

Postoperative intraperitoneal adhesions (PIAs) are one of the most important problems surgeons have to face after laparotomies. In this study, we aimed to evaluate the effectiveness of local application of botulinum toxin type A (BoNT-A) in various dosages on the prevention of intra-abdominal adhesions in rats with experimental intra-abdominal adhesions.

Methods

Forty Wistar Albino female rats were randomly separated into 4 groups. The 4 groups were determined as follows: Control (group 1, n = 10); Sham (group 2, n = 10); 10-µg/kg low-dose BoNT-A (group 3, n = 10) and 30-µg/kg high-dose BoNT-A (group 4, n = 10). Subserosal injuries were created on the caecum of all rats. Laparotomy was performed on the fifth day. Adhesion scores, histopathological examination, and E-cadherin expression levels were evaluated.

Results

General adhesion scores for groups 1 and 2 were determined to be significantly high when compared to group 4 (P < 0.001). A significant difference was also determined between groups 3 and 4 in terms of general adhesion scores (P < 0.05). In pair comparisons, a significant decrease in high-dose BoNT-A group (group 4) when compared to groups 1 and 2 in terms of neovascularization, fibroblast density, collagen deposition and inflammatory cell count was determined (P < 0.05).

Conclusion

A significant decrease was observed only in postoperative PIAs in the high-dose BoNT-A group between all 4 rat-groups with experimentally created postoperative PIAs. In this study, high-dose BoNT-A is determined to be an effective agent in preventing postoperative PIAs.

Update on minimally invasive surgery and benign prostatic hyperplasia

Transurethral resection of the prostate (TURP) became the gold standard surgical treatment for benign prostatic obstruction without undergoing randomized controlled trials against the predecessor standard in open suprapubic prostatectomy. TURP has historically been associated with significant morbidity and this has fuelled the development of minimally invasive surgical treatment options. Improvements in perioperative morbidity for TURP has been creating an ever increasing standard that must be met by any new technologies that are to be compared to this gold standard. Over recent years, there has been the emergence of novel minimally invasive treatments such as the prostatic urethral lift (PUL; UroLift System), convective WAter Vapor Energy (WAVE; Rezum System), Aquablation (AQUABEAM System), Histotripsy (Vortx Rx System) and temporary implantable nitinol device (TIND). Intraprostatic injections (NX-1207, PRX-302, botulinum toxin A, ethanol) have mostly been used with limited efficacy, but may be suitable for selected patients. This review evaluates these novel minimally invasive surgical options with special reference to the literature published in the past 5 years.

Effect of mesenchymal stem cells on induced skeletal muscle chemodenervation atrophy in adult male albino rats

The present research was conducted to evaluate the effect of bone marrow derived mesenchymal stem cells (BM-MSCs) as a potential therapeutic tool for improvement of skeletal muscle recovery after induced chemodenervation atrophy by repeated local injection of botulinum toxin-A in the right tibialis anterior muscle of adult male albino rats. Forty five adult Wistar male albino rats were classified into control and experimental groups. Experimental group was further subdivided into 3 equal subgroups; induced atrophy, BM-MSCs treated and recovery groups. Biochemical analysis of serum LDH, CK and Real-time PCR for Bcl-2, caspase 3 and caspase 9 was measured. Skeletal muscle sections were stained with H and E, Mallory trichrome, and Immunohistochemical reaction for Bax and CD34. Improvement in the skeletal muscle histological structure was noticed in BM-MSCs treated group, however, in the recovery group, some sections showed apparent transverse striations and others still affected. Immunohistochemical reaction of Bax protein showed strong positive immunoreaction in the cytoplasm of muscle fibers in the induced atrophy group. BM-MSCs treated group showed weak positive reaction while the recovery group showed moderate reaction in the cytoplasm of muscle fibers. Immunohistochemical reaction for CD34 revealed occasional positive CD34 stained cells in the induced atrophy group. In BM-MSCs treated group, multiple positive CD34 stained cells were detected. However, recovery group showed some positive CD34 stained cells at the periphery of the muscle fibers. Marked improvement in the regenerative capacity of skeletal muscles after BM-MSCs therapy. Hence, stem cell therapy provides a new hope for patients suffering from myopathies and severe injuries.