Low-dose tadenan protects the rabbit bladder from bilateral ischemia/ reperfusion-induced contractile dysfunction

The African cherry: A review of the botany, traditional uses, phytochemistry, and biological activities of Prunus africana (Hook.f.) Kalkman

ETHNOPHARMACOLOGICAL RELEVANCE

Prunus africana (Hook.f.) Kalkman (Rosaceae), commonly known as "Pygeum" or "African cherry", occurs in mainland montane forests scattered across sub-Saharan Africa, Madagascar, and some surrounding islands. Traditionally, decoctions of the stem-bark are taken orally for the treatment of a wide variety of conditions, such as benign prostatic hyperplasia (BPH), stomach ache, chest pain, malaria, heart conditions, and gonorrhoea, as well as urinary and kidney diseases. The timber is used to make axe handles and for other household needs. The dense wood is also sawn for timber.

AIM

The fragmented information available on the ethnobotany, phytochemistry, and biological activities of the medicinally important P. africana was collated, organised, and analysed in this review, to highlight knowledge voids that can be addressed through future research.

MATERIALS AND METHODS

A bibliometric analysis of research output on P. africana was conducted on literature retrieved, using the Scopus® database. The trend in the publications over time was assessed and a network analysis of collaborations between countries and authors was carried out. Furthermore, a detailed review of the literature over the period 1971 to 2021, acquired through Scopus, ScienceDirect, SciFinder, Pubmed, Scirp, DOAJ and Google Scholar, was conducted. All relevant abstracts, full-text articles and various book chapters on the botanical and ethnopharmacological aspects of P. africana, written in English and German, were consulted.

RESULTS

A total of 455 documents published from 1971 to 2021, were retrieved using the Scopus search. Analysis of the data showed that the majority of these documents were original research articles, followed by reviews and lastly a miscellaneous group comprising conference papers, book chapters, short surveys, editorials and letters. Data were analysed for annual output and areas of intense research focus, and countries with high research output, productive institutions and authors, and collaborative networks were identified. Prunus africana is reported to exhibit anti-inflammatory, analgesic, antimicrobial, anti-oxidant, antiviral, antimutagenic, anti-asthmatic, anti-androgenic, antiproliferative and apoptotic activities amongst others. Phytosterols and other secondary metabolites such as phenols, triterpenes, fatty acids, and linear alcohols have been the focus of phytochemical investigations. The biological activity has largely been ascribed to the phytosterols (mainly 3-β-sitosterol, 3-β-sitostenone, and 3-β-sitosterol-glucoside), which inhibit the production of prostaglandins in the prostate, thereby suppressing the inflammatory symptoms associated with BPH and chronic prostatitis.

CONCLUSIONS

Many of the ethnobotanical assertions for the biological activity of P. africana have been confirmed through in vitro and in vivo studies. However, a disparity exists between the biological activity of the whole extract and that of single compounds isolated from the extract, which were reported to be less effective. This finding suggests that a different approach to biological activity studies should be encouraged that takes all secondary metabolites present into consideration. A robust technique, such as multivariate biochemometric data analysis, which allows for a holistic intervention to study the biological activity of a species is suggested. Furthermore, there is a need to develop rapid and efficient quality control methods for both raw materials and products to replace the time-consuming and laborious methods currently in use.

Treatment of Benign Prostatic Hyperplasia by Natural Drugs

Benign prostatic hyperplasia (BPH) is one of the most common urinary diseases affecting men, generally after the age of 50. The prevalence of this multifactorial disease increases with age. With aging, the plasma level of testosterone decreases, as well as the testosterone/estrogen ratio, resulting in increased estrogen activity, which may facilitate the hyperplasia of the prostate cells. Another theory focuses on dihydrotestosterone (DHT) and the activity of the enzyme 5α-reductase, which converts testosterone to DHT. In older men, the activity of this enzyme increases, leading to a decreased testosterone/DHT ratio. DHT may promote prostate cell growth, resulting in hyperplasia. Some medicinal plants and their compounds act by modulating this enzyme, and have the above-mentioned targets. This review focuses on herbal drugs that are most widely used in the treatment of BPH, including pumpkin seed, willow herb, tomato, maritime pine bark, Pygeum africanum bark, rye pollen, saw palmetto fruit, and nettle root, highlighting the latest results of preclinical and clinical studies, as well as safety issues. In addition, the pharmaceutical care and other therapeutic options of BPH, including pharmacotherapy and surgical options, are discussed, summarizing and comparing the advantages and disadvantages of each therapy.

Kidney, skeletal muscle and myocardium as potential target sites of Pygeum africanum toxicity in Wistar rats

OBJECTIVE

Extract of Pygeum africanum (PAE) is commonly used herbal medication in the treatment of benign prostatic hyperplasia. In Montenegro and neighboring countries, PAE is primarily advertised as dietary supplement in the treatment of erectile dysfunction. The purpose of this study was to broaden the current cognition concerning its safety profile.

MATERIAL AND METHODS

Twenty-four adult male Wistar rats were used. The first control group (O) received water and second control group (OO) received olive oil for 30 days. The third and fourth groups (PA5 and PA10) were treated with PAE dissolved in olive oil (50 and 100mg/kg p.o. daily). The behavior of animals was observed continuously, bodyweight gain (BWG) was calculated weekly and the weight of selected organs was measured at the end of experiment. Total protein and glutathione content of the liver were analyzed. Standard biochemical analyses were also performed.

RESULTS

BWG was higher in PA5 compared to both controls at all measuring intervals. Liver weight/body weight ratio was significantly higher in PA10 in comparison with O. Prostate weight/body weight ratio was lower in both PA5 and PA10 compared to OO, achieving statistical significance in PA5. The value of creatinine was higher in PA5 and PA10 compared to both control groups, but achieving statistical significance in PA10 only. LDH was also increased in PA5 and PA10 compared to both controls.

CONCLUSIONS

Both dosage regimens of PAE, particularly PA10, caused some toxicological effects in Wistar rats after one month of application. Kidney, skeletal muscle and/or myocardium are suspected as target sites of PA toxicity most likely. In order to provide more reliable conclusion it is necessary to conduct an additional research on the basis of these findings.

Effects of Ganoderma Lucidum shell-broken spore on oxidative stress of the rabbit urinary bladder using an in vivo model of ischemia/reperfusion

Oxidative stress plays an important role in specific disease pathophysiology and the aging process. In the history of human kind, many herbs were utilized for disease prevention and anti-aging treatment. However, there are few direct evidences provided by modern laboratory technology. The current study was designed to evaluate Ganoderma Lucidum's (GL) ability to reduce the damage from in vivo ischemia/reperfusion (I/R) using a rabbit model of I/R that has been effectively utilized to prove the effects of drugs and supplements to reduce oxidative stress. Urinary bladder dysfunction secondary to benign prostatic hyperplasia (BPH) is a major affliction of aging men. One of the major etiologies of obstructive bladder dysfunction (OBD) is oxidative stress induced by I/R. Pharmaceutical studies and clinical research have proven that GL is useful in helping to prevent certain types of pathology and also helpful in prolonging human life in part by acting as an antioxidant. Using an in vivo model of I/R, we have investigated the ability of GL to protect bladder function from oxidative damage mediated by I/R. Our studies demonstrated that ischemia followed by reperfusion resulted in a significant decrease in bladder compliance and decreases in the contractile responses to a variety of forms of contractile stimulation. Pretreatment of rabbits with Ganoderma Lucidum prior to subjecting the rabbits to I/R completely inhibited the negative effects of I/R on both the compliance and contractile responses. These results demonstrate that Ganoderma provides excellent protection of bladder function following I/R (oxidative stress).

Coenzyme Q10 protect against ischemia/reperfusion induced biochemical and functional changes in rabbit urinary bladder

PURPOSE

Ischemia, reperfusion, and free radical generation have been recently implicated in the progressive bladder dysfunction. Coenzyme Q10 (CoQ10) is a pro-vitamin like substance that appears to be efficient for treatment of neurodegenerative disorders and ischemic heart disease. Our goal was to investigate the potential protective effect of CoQ10 in a rabbit model of in vivo bilateral ischemia and ischemia/reperfusion (I/R).

MATERIAL AND METHODS

Six groups of four male New Zealand White rabbits each were treated with CoQ10 (3 mg/kg body weight/day-dissolved in peanut oil) (groups 1-3) or vehicle (peanut oil) (groups 4-6). Groups 1 and 4 (ischemia-alone groups) had clamped bilateral vesical arteries for 2 h; in groups 2 and 5 (I/R groups), bilateral ischemia was similarly induced and the rabbits were allowed to recover for 2 weeks. Groups 3 and 6 were controls (shams) and were exposed to sham surgery. The effects on contractile responses to various stimulations and biochemical studies such as citrate synthase (CS), choline acetyltransferase (ChAT), superoxide dismutase (SOD), and catalase (CAT) were evaluated. The protein peroxidation indicator, carbonyl group, and nitrotyrosine contents were analyzed by Western blotting.

RESULTS

Ischemia resulted in significant reductions in the contractile responses to all forms of stimulation in vehicle-fed rabbits, whereas there were no reductions in CoQ10-treated rabbits. Contractile responses were significantly reduced in vehicle-treated I/R groups, but significantly improved in CoQ10-treated rabbits. Protein carbonylation and nitration increased significantly in ischemia-alone and I/R bladders; CoQ10 treatment significantly attenuated protein carbonylation and nitration. CoQ10 up-regulated SOD and CAT activities in control animals; the few differences in CoQ10-treated animal in SOD and CAT after ischemia and in general increase CAT activities following I/R.

CONCLUSIONS

CoQ10 supplementation provides bladder protection against I/R injury. This protection effect improves mitochondrial function during I/R by repleting mitochondrial CoQ10 stores and potentiating their antioxidant properties.

The role of free radicals and nitric oxide in the ischemia–reperfusion injury mediated by acute bladder outlet obstruction

Free-radical generation and nitric oxide (NO) generation were detected in the rat bladder following acute bladder outlet obstruction (BOO), and the results were compared with those for vascular ischemia and reperfusion (I-R). Forty male Sprague Dawley rats were used. In the acute BOO plus I-R group (group 1), rats were catheterized with a 3-Fr catheter and an inflated balloon was positioned at the bladder neck. The bladder was overdistended after administration of Ringer solution and furosemide (12 mg/kg, each) for 60 min, and was then drained to allow reperfusion for 30 min. In the acute BOO plus nerve stimulation group (group 2), the pelvic nerve was stimulated in the distended bladder for 60 min (5 s every 5 min, 10 V/0.1 ms, 20 Hz). Pelvic nerve stimulation was performed in nonobstructed animals in group 3. In the I-R group (group 4), the distal aorta was occluded for 60 min followed by reperfusion for 30 min. Sham-operated animals served as the control group (group 5). At the end of the protocols, the levels of hydroxyl and superoxide radicals and NO levels were measured in the bladder tissues with luminol- and lucigenin-enhanced chemiluminescence methods. The results were compared by a one-way analysis of variance test. The levels of hydroxyl radicals were not significantly different between the study groups. In contrast, superoxide radicals and NO levels were significantly increased in both group 1 and group 4 compared with those in control animals (P<0.05 for all comparisons). Superoxide radical generation in group 2 was comparable to the levels in group 1 (P>0.05), whereas NO levels were substantially lower than in group 1 (P=0.06). In summary, vascular I-R causes significant oxidative damage to the bladder. Acute BOO with overdistension of the bladder mimics the effects of true vascular I-R injury. The NO pathway has possibly a major role in I-R-induced bladder damage. Prolonged BOO may therefore significantly enhance the oxidative damage to the bladder and further accentuate the effects of generalized atherosclerotic processes in the elderly adult.

Nonclinical vehicle use in studies by multiple routes in multiple species

The laboratory toxicologist is frequently faced with the challenge of selecting appropriate vehicles or developing utilitarian formulations for use in in vivo nonclinical safety assessment studies. Although there are many vehicles available that may meet physical and chemical requirements for chemical or pharmaceutical formulation, there are wide differences in species and route of administration specific to tolerances to these vehicles. In current practice, these differences are largely approached on a basis of individual experience as there is only scattered literature on individual vehicles and no comprehensive treatment or information source. This approach leads to excessive animal use and unplanned delays in testing and development. To address this need, a consulting firm and three contract research organizations conducted a rigorous data mining operation of control (vehicle) data from studies dating from 1991 to present. The results identified 65 single component vehicles used in 368 studies across multiple species (dog, primate, rat, mouse, rabbit, guinea pig, minipig, chick embryo, and cat) by multiple routes. Reported here are the results of this effort, including maximum tolerated use levels by species, route, and duration of study, with accompanying dose limiting toxicity. Also included are basic chemical information and a review of available literature on each vehicle, as well as guidance on volume limits and pH by route and some basic guidance on nonclinical formulation development.

Pygeum africanum extract inhibits proliferation of human cultured prostatic fibroblasts and myofibroblasts

OBJECTIVE

To investigate the effect of Pygeum africanum (PA) extract on the proliferation of cultured human prostatic myofibroblasts and fibroblasts; this extract is used for treating urinary disorders associated with benign prostatic hyperplasia (BPH).

MATERIALS AND METHODS

Primary cultures of prostatic stromal cells were obtained from histologically confirmed human BPH by enzymatic digestion. Cell proliferation was measured by 5-bromo2'-deoxy-uridine (BrdU) incorporation assays, and cytotoxicity by luminescent quantification of adenylate kinase activity.

RESULTS

Cultured cells were labelled by an anti-vimentin antibody, and most of them by an alpha-smooth-muscle-actin antibody, revealing the presence of fibroblasts and myofibroblasts. BrdU incorporation tests showed that proliferation of cultured human stromal cells, stimulated by fetal calf serum, by basic fibroblast growth factor and by epidermal growth factor, was dose-dependently inhibited by PA extract (5-100 microg/mL). Except at 100 microg/mL, no acute cytotoxicity of the extract was detected after 24 h of culture. Similarly, the extract dose-dependently inhibited the proliferation of Madin-Darby canine kidney epithelial cells, but to a lesser extent; whatever the dose of extract, no acute toxicity was evident on this cell line.

CONCLUSION

PA extract inhibits the proliferation of cultured human prostatic myofibroblasts and fibroblasts. We propose that cultured human prostatic cells offer a reliable model for preclinical screening of therapeutic agents, and to study the mechanisms underlying the inhibition of proliferation.

Effect of maturation and aging on response of rabbit bladder to bilateral in vivo ischemia/reperfusion

OBJECTIVES

To evaluate the impact of maturation and aging on the effect of bilateral in vivo ischemia/reperfusion on bladder function.

METHODS

Male rabbits were separated into three groups by age: immature, mature, and aged rabbits; and each group was subdivided into five subgroups. Each rabbit was subjected to 2 hours of bilateral ischemia. After ischemia, the rabbits in subgroup 1 were killed immediately; the other subgroups were allowed to recover for 1, 7, or 14 days. Separate control (sham-operated) subgroups were not subjected to ischemia. At the end of the experimental period, the bladder was excised, body and base separated, and two strips were prepared from each and mounted in individual baths. The contractile responses to field stimulation and carbachol, adenosine triphosphate, and potassium chloride were determined for the body. The responses to field stimulation alone were determined for the base.

RESULTS

The rabbit body and bladder weights of the mature and aged rabbits were significantly greater than that of the young rabbits, but not different from each other. The mature rabbits were significantly more sensitive to ischemia/reperfusion than were the young rabbits. Finally, the aged rabbits were slightly more sensitive to ischemia/reperfusion than the mature rabbits.

CONCLUSIONS

The results of our study have shown that the sensitivity of the bladder to ischemia/reperfusion injury increases with age. A very significant increase was found in the sensitivity between young and mature rabbits, with a significantly smaller increase in sensitivity between mature and old rabbits.

Protective effects of grape suspension on in vivo ischaemia/reperfusion of the rabbit bladder

OBJECTIVE

To investigate the potential protective effect of a grape suspension in a rabbit model of in vivo bilateral ischaemia/reperfusion (I/R), which is a causal factor in obstructive bladder dysfunction.

MATERIALS AND METHODS

Six groups of four New Zealand White rabbits were treated by twice-daily gavage with aqueous grape suspension (groups 1-3) or sugar-water vehicle (groups 4-6) for 3 weeks. Groups 1 and 4 then received bilateral ischaemia for 2 h, and groups 2 and 5 received bilateral ischaemia for 2 h and reperfusion (recovery) for 1 week. Groups 3 and 6 were controls (sham-operated). The effects on cystometry, in vitro contractile responses, and morphology were evaluated.

RESULTS

Ischaemia resulted in significant reductions in the contractile responses to all forms of stimulation in vehicle-fed rabbits, whereas there were no reductions in grape-fed rabbits. Contractile responses were significantly reduced in both I/R groups, but significantly more in vehicle-fed than in grape-fed rabbits. Immunohistochemical studies showed less hypoxia in the bladders of grape-fed rabbits than in vehicle-fed rabbits for both ischaemia-only and I/R groups.

CONCLUSIONS

Feeding rabbits with grape suspension provided significant protection against the hypoxic effects of bilateral ischaemia and I/R.