Effects of montelukast and zileuton on testicular torsion/detorsion injury in rats

Pathophysiology and management of testicular ischemia/reperfusion injury: Lessons from animal models

Testicular torsion is a urological emergency that involves the twisting of the spermatic cord along its course. Compelling pieces of evidence have implicated oxidative stress-sensitive signaling in pathogenesis of testicular I/R injury. Although, surgical detorsion is the mainstay management; blockade of the pathways involved in the pathogenesis may improve the surgical outcome. Experimental studies using various testicular I/R models have been reported in a bid to explore the mechanisms associated with testicular I/R and evaluate the benefits of potential therapeutic measures; however, most are limited by their shortcomings. Thus, this review was intended to describe the details of the available testicular I/R models as well as their merits and drawbacks, the pathophysiological basis and consequences of testicular I/R, and the pharmacological agents that have being proposed to confer testicular benefits against testicular I/R. This provides an understanding of the pathophysiological events and available models used in studying testicular I/R. In addition, this research provides evidence-based molecules with therapeutic potentials as well as their mechanisms of action in testicular I/R.

Testicular torsion in vivo models: Mechanisms and treatments

BACKGROUND

Testicular torsion is a condition in which a testis rotates around its longitudinal axis and twists the spermatic cord. This in turn results in a significant decrease in blood flow and perfusion of testicular tissue. During Testicular torsion, the testicular tissue is affected by ischemia, heat stress, hypoxia, and oxidative and nitrosative stress. The testicular torsion should be considered an emergency condition and surgical intervention (testicular detorsion ) as the sole treatment option in viable cases involves counter-rotation on twisted testes associated, when possible, to orchipexy, in order to avoid recurrence. Possible testicular detorsion side-effects occur due to reperfusion and endothelial cells injury, microcirculation disturbances, and intense germ cells loss.

OBJECTIVES

To discuss testicular torsion surgery-based methods, different time frames for testicular torsion induction, and the associated pathophysiology by emphasizing cellular and molecular events as well as different therapeutic agent applications for testicular torsion.

MATERIALS AND METHODS

We reviewed all original research and epidemiological papers related to testicular torsion condition.

RESULTS

Testicular torsion causes germ cell necrosis, arrested spermatogenesis, and diminished testosterone levels, with consequent infertility. Among different involved pathophysiological impacts, testicular torsion/detorsion-induced ischemia seems to play the key role by leading the tissue toward other series of events in testis. Numerous studies have used adjuvant antioxidants, calcium channel blockers, anti-inflammatory agents, or vasodilating agents in order to decrease these effects.

DISCUSSION AND CONCLUSION

To the best of our knowledge, no previously conducted study examined therapeutical agents' beneficial effects post clinical I/R condition in humans. Different agents targeting different pathophysiological conditions were used to ameliorate the ischemia/reperfusion-induced condition in animal models, however, none of the administrated agents were tested in human cases. Although considering testicular detorsion surgery is still the golden method to reverse the testicular torsion condition and the surgical approach is undeniable, the evaluated agents with beneficial effects, need to be investigated furthermore in clinical conditions. Thus, furthermore clinical studies and case reports are required to approve the animal models proposed agents' beneficial impacts.

Investigation of montelukast effect on rosuvastatin induced late puberty in rats

Background:

Puberty is a critical process for the development of sexual organs and reproductive ability. It is triggered and regulated by the hormones. Rosuvastatin can delay the onset of puberty through the inhibition of cholesterol and androgen biosynthesis. On the other hand, montelukast has protective effects against various diseases and against reproductive toxicity induced by other medications, but its effects on puberty have not been studied.

Aims:

Assessment of the protective effect of montelukast against rosuvastatin-induced delayed puberty.

Settings and Design:

At the university.

Materials and Methods:

Eighteen male Wistar rats aged 30 days and weighted 50–60 g were distributed to three groups (six rats per group) and intraperitoneally administered every day for 5 days with 0.2 ml of distilled water as control, 10 mg/kg of rosuvastatin and with rosuvastatin + montelukast (10 mg/kg for each drug). These animals’ groups were euthanised on day 50 of age to assess the effect of rosuvastatin alone and with montelukast on the serum levels of the reproductive hormones and histological manifestations and morphometric measurements of the testes.

Statistical Analysis Used:

One-way analysis of variance and Bonferroni multiple tests were performed to analyse the findings using the GraphPad Prism software.

Results:

Treatment of rats with rosuvastatin showed a significantly decreased level of testosterone and luteinising hormone as well as histopathological and morphometric alterations in the testicular tissues in comparison with the control. Interestingly, co-treatment of rosuvastatin with montelukast could not reverse or mitigate these changes induced late puberty.

Conclusion:

There is no protective effect of montelukast against rosuvastatin-induced delayed puberty.

Acetyl-11-keto-β-boswellic acid prevents testicular torsion/detorsion injury in rats by modulating 5-LOX/LTB4 and p38-MAPK/JNK/Bax/Caspase-3 pathways

AIMS

Testicular torsion/detorsion (T/D) is a critical medical condition that necessitates prompt surgical intervention to avoid testicular atrophy and infertility. The use of natural compounds may protect against the associated detrimental oxidative stress and inflammatory responses. Interestingly, acetyl-11-keto-β-boswellic acid (AKBA), the main active constituent of Boswellia resin, has shown potent inhibitory effect on 5-lipoxygenase enzyme which converts arachidonic acid into inflammatory mediators. Therefore, this study was conducted to assess the protective mechanisms by which AKBA may protect against testicular T/D injury in rats.

MAIN METHODS

Male rats were randomly distributed into five groups: Sham, AKBA (50 mg/kg, p.o.), unilateral testicular T/D, AKBA at two dose levels (25 or 50 mg/kg for 15 successive days) followed by T/D. Histological examination and Johnsen's score were performed to assess testicular injury and perturbations in spermatogenesis. Biochemical parameters included markers of testicular function (serum testosterone), oxidant/antioxidant status (malondialdehyde, glutathione), inflammation (5-lipoxygenase, leukotriene-B4, myeloperoxidase, interleukin-1β, interleukin-6), apoptosis (Bax, Bcl2, caspase-3), DNA integrity (quantitative DNA fragmentation, DNA laddering, PARP-1), energy production (ATP), in addition to p38 MAPK and JNK protein expression.

KEY FINDINGS

In a dose dependent manner, AKBA significantly inhibited testicular T/D-induced upregulation of 5-LOX/LTB4 and p38-MAPK/JNK/Bax pathways and their associated downstream inflammatory and apoptotic cascades. These effects were accompanied with ATP replenishment and DNA preservation, resulting ultimately in salvage of the testis.

SIGNIFICANCE

Unprecedentedly, the present mechanistic study revealed the pathways by which AKBA may inhibit testicular T/D injury and offered a novel protective approach that may attenuate the severity of this condition.

Mechanisms underlying the protective effect of leukotriene receptor antagonist montelukast against doxorubicin induced testicular injury in rats

The obligatory use of cytotoxic drugs to face the malignant tumors results in survivors that suffer from long term health problems. Fertility problems, especially in young boys, exert one of the major consequences of chemotherapy treatment that needs resolution. We investigate the potential effect of the cysteinyl leukotriene receptor antagonist montelukast on doxorubicin-induced testicular damage. Five groups of adult Wistar male rats were subjected to the following treatment; vehicle for the control group, montelukast (20 mg/kg orally daily for 10 days) for the drug control, doxorubicin (12 mg/kg intraperitoneal injection once at 5th day) for the toxic group, montelukast at 10 mg/kg + doxorubicin, montelukast at 20 mg/kg + doxorubicin. The period of the experiment was 10 days administration of montelukast, while doxorubicin was injected at the 5th day. Results of serum testosterone, testicular lipid peroxidation, antioxidant status, and histopathology revealed protection of montelukast against doxorubicin-induced testicular damage. The pro-apoptotic caspase 3 and the pro-inflammatory tumor necrosis factor-alpha were examined immunohistochemically and showed a significant decrease with montelukast treatment as compared to doxorubicin group. Doxorubicin increased gene expression of matrix metalloproteinase 9 and decreased peroxisome proliferator activated receptor gamma. Montelukast treatment restored their expressions to normal values. In conclusion, montelukast administration can ameliorate the testicular damage induced by doxorubicin based on its anti-inflammatory, antioxidant and anti-apoptotic effects as well as by of modulation of important genes expression.

Capsaicin protects against testicular torsion injury through mTOR-dependent mechanism

SCOPE

Testicular torsion and subsequent release of reactive oxygen species (ROS) can cause infertility in adults. Oxidative stress following testicular torsion plays an important role in the ýonset and development of apoptotic cell death through dysregulation of the cellular signaling pathways. Anti-inflammatory and antioxidant properties of capsaicin, a bioactive composition present in red peppers, has already been exploited for treatment of the cancer and pain relief. In present work, we evaluated the role of the mammalian target of rapamycin (mTOR) in antioxidant effect of capsaicin against reperfusion injury following testicular torsion.

METHODS

Male Wistar rats weighing 200-220 g were randomly assigned into four major groups: (i) a sham operated group, (ii) a testicular torsion (TT) group, (iii) three groups treated with different doses of capsaicin (TT + 100, 500 and 1000 μg/ml Cap), and (iv) three groups of healthy rats treated with different doses of capsaicin (100, 500 and 1000 μg/ml). Western blotting assay was used to examine the anti-apoptotic effects of capsaicin in testicular cells following torsion. H&E and TUNEL methods were used to evaluate testicular morphology and apoptosis activity.

RESULTS

Compared to control group, phosphorylation of mTOR was significantly increased in the TT groups. Capsaicin administration remarkably decreased the phosphorylation of mTOR at the highest dose (P < 0.05). Capsaicin decreased apoptosis and preserved tubular morphology in testes.

CONCLUSION

Our results showed that antioxidant properties of capsaicin minimizes cell death and reperfusion injury following testicular torsion.

The protective role of montelukast against intestinal ischemia-reperfusion injury in rats

Several drugs are effective in attenuating intestinal ischemia-reperfusion injury (IRI); however little is known about the effect of montelukast. Fifty rats were randomly assigned to 3 groups: model group (operation with clamping), sham group (operation without clamping), and study group (operation with clamping and 0.2, 2 and 20 mg/kg montelukast pretreatment). Intestinal ischemia-reperfusion was performed by occlusion (clamping) of the arteria mesenterica anterior for 45 min, followed by 24 h reperfusion. Intestinal IRI in the model group led to severe damage of the intestinal mucosa, liver and kidney. The Chiu scores of the intestines from the study group (2 and 20 mg/kg) were lower than that of the model group. Intestinal IRI induced a marked increase in CysLTR1, Caspase-8 and -9 expression in intestine, liver and kidney, which were markedly reduced by preconditioning with 2 mg/kg montelukast. Preconditioning with 2 g/kg montelukast significantly attenuated hepatic tissue injury and kidney damage, and decreased plasma interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) levels in plasma after intestinal IRI. In conclusion, preconditioning with montelukast could attenuate intestinal IRI and the subsequent systemic inflammatory response in rats.

Montelukast prevents testes against ischemia-reperfusion injury through suppression of iNOS expression

OBJECTIVE

To elucidate the mechanism of a possible protective effect of montelukast against testicular ischemia/reperfusion (I/R) injury.

MATERIAL AND METHODS

Fifty-one adult male Wistar-Albino rats were randomly assigned into 6 groups; sham + saline (S), sham + montelukast (M), I/R + S, I/R + S 30', I/R + M and I/R + M 30'. Saline or montelukast (10 mg/kg) was intraperitoneally administered 30 minutes prior to (S 30', M 30') and during detorsion (I/R + S, I/R + M) in the I/R groups. The I/R groups underwent 2 hours of ischemia followed by 4 hours (early-term) of reperfusion in unilateral testes. Half of the rats underwent 24 hours (late-term) of reperfusion to investigate long-term effects. Testicular tissue samples were examined for biochemical and histopathological parameters. Germ cell apoptosis was evaluated using apoptosis-activating factor 1 (Apaf-1). Inducible nitric oxide synthase (iNOS) activity was analyzed in late-term reperfusion groups. Spermatogenic functions were assessed for each testis based on the Johnsen criteria.

RESULTS

Unilateral I/R caused a significant increase in serum TNF-α levels in the early-term group compared to the sham groups. Malondialdehyde levels and myeloperoxidase activity were found to be elevated in the I/R groups and accompanied with a significant decrease in glutathione levels when compared to the sham groups. I/R significantly increased iNOS activity and germ cell apoptosis compared to the sham groups. Montelukast treatment significantly reversed all of these parameters and achieved comparable results with the sham groups. Finally, spermatogenic indices were similar for the bilateral testes between all groups.

CONCLUSION

Montelukast exerts protective effects against testicular I/R injury by inhibiting neutrophil activity, reversing the oxidative stress markers, decreasing iNOS activity and attenuating apoptosis.

Role of cysteinyl leukotriene receptor 1 in intestinal ischemia-reperfusion injury

AIM: To explore the role of cysteinyl leukotriene receptor 1 (CysLTsR1) in intestinal ischemia-reperfusion (I/R) injury.

METHODS: Forty rats were divided into 5 groups: a control group, a model group and low-, medium- and high-dose montelukast groups. After treatment, the water content of the small bowel was determined, and the histological changes in the intestinal tissues were assessed by HE staining. Immunohistochemical assessment of the expression of CysLTR1 and 5-lipoxygenase (5-LOX) was also performed.

RESULTS: Intestinal I/R, small bowel water content (model group 78.13 g ± 1.35 g vs normal group 78.13 g ± 1.35 g, P < 0.05), and CysLTR1 protein and mRNA expression significantly increased in the model group compared with the control group. Application of montelukast decreased intestinal water content (low-, medium-, and high-dose groups 76.47 g ± 1.48 g, 72.67 g ± 5.35 g and 75.39 g ± 3.66 g vs model group 78.13 g ± 1.35 g, P < 0.05), relieved the intestinal tissue injury, and reduced CysLTR1 protein and mRNA expression in intestinal tissues (P < 0.05).

CONCLUSION: CysLTR1 participates in the pathogenesis of intestinal ischemia-reperfusion injury, and may be a target for treatment of I/R injury.

The effects of zileuton and montelukast in reperfusion-induced arrhythmias in anesthetized rats

Background

5-Lipoxygenase is an enzyme involved in the synthesis of leukotriene eicosanoids from arachidonic acid. The therapeutic potential of zileuton, an inhibitor of 5-lipoxygenase, and montelukast, a cysteinyl leukotriene receptor antagonist, for the treatment of ischemia/reperfusion (I/R) injury of the heart has been proposed in a few studies. However, the effects of zileuton and montelukast on I/R-induced arrhythmias have not been determined.

Objective

We assessed the possible protective effects of zileuton and montelukast against I/R-induced arrhythmias.

Methods

Forty-five male Wistar albino rats were divided into 5 groups, each containing 9 rats. Group 1: control, Groups 2 and 3: rats treated with montelukast (10 and 30 mg/kg IP); and Groups 4 and 5: rats treated with zileuton (1 and 3 mg/kg IV) 15 minutes before the induction of ischemia. Ischemia and reperfusion were induced by occluding the left main coronary artery of anesthetized rats for 6 minutes followed by reopening the artery for 6 minutes.

Results

Both doses of zileuton decreased the mean [SE] arrhythmia score (zileuton 1 mg/kg: 1.4 [0.8]; zileuton 3 mg/kg: 1.3 [0.5] vs control: 2.9 [0.3]; P < 0.05), the duration of ventricular tachycardia, and the total length of arrhythmias, but montelukast was not effective to decrease the ventricular arrhythmias during the 6 minutes of reperfusion.

Conclusions

The results indicate for the first time that zileuton exerts an antiarrhythmic effect at different doses and that montelukast is not effective against I/R-induced arrhythmias. These results indicate that zileuton may be a candidate for drug treatment of I/R-induced arrhythmias.