Montelukast protects against renal ischemia/reperfusion injury in rats

The renoprotective potential of montelukast: a scoping review

Introduction

Kidney damage can result from various factors, leading to structural and functional changes in the kidney. Acute kidney injury (AKI) refers to a sudden decline in kidney function, while chronic kidney disease involves a gradual deterioration lasting more than 3 months. Mechanisms of renal injury include impaired microcirculation, inflammation, and oxidative stress. Cysteinyl-leukotrienes (CysLTs) are inflammatory substances contributing to tissue damage. Montelukast, a leukotriene receptor antagonist, has shown potential renoprotective effects in experimental models of kidney injury.

Methods

The authors conducted a scoping review using PubMed, Scopus, and Web of Science databases to identify relevant studies investigating the impact of montelukast on renal diseases. Articles published until 2022 were included and evaluated for quality. Data extraction and analysis were performed based on predetermined inclusion criteria.

Results

The scoping review included 30 studies from 8 countries. Montelukast demonstrated therapeutic effects in various experimental models of nephrotoxicity and AKI induced by agents such as cisplatin, lipopolysaccharide, diclofenac, amikacin, Escherichia coli, cyclosporine, methotrexate, cobalt-60 gamma radiation, doxorubicin, and cadmium. Studies involving human subjects with nephrotic syndrome, pyelonephritis, and other renal diseases also reported positive outcomes with montelukast treatment. Montelukast exhibited anti-inflammatory, anti-apoptotic, antioxidant, and neutrophil-inhibiting properties, leading to improved kidney function and histopathological changes.

Conclusions

Montelukast shows promise as a renoprotective medication, particularly in early-stage kidney injury. Its ability to mitigate inflammation, oxidative stress, and neutrophil infiltration contributes to its therapeutic effects. Further research is needed to explore the clinical applications and mechanisms underlying the renoprotective action of montelukast.

Montelukast Influence on Lung in Experimental Diabetes

Background and Objectives: The influence of montelukast (MK), an antagonist of cysLT1 leukotriene receptors, on lung lesions caused by experimental diabetes was studied. Materials and Methods: The study was conducted on four groups of six adult male Wistar rats. Diabetes was produced by administration of streptozotocin 65 mg/kg ip. in a single dose. Before the administration of streptozotocin, after 72 h, and after 8 weeks, the serum values of glucose, SOD, MDA, and total antioxidant capacity (TAS) were determined. After 8 weeks, the animals were anesthetized and sacrificed, and the lungs were harvested and examined by optical microscopy. Pulmonary fibrosis, the extent of lung lesions, and the lung wet-weight/dry-weight ratio were evaluated. Results: The obtained results showed that MK significantly reduced pulmonary fibrosis (3.34 ± 0.41 in the STZ group vs. 1.73 ± 0.24 in the STZ+MK group p < 0.01) and lung lesion scores and also decreased the lung wet-weight/dry-weight (W/D) ratio. SOD and TAS values increased significantly when MK was administered to animals with diabetes (77.2 ± 11 U/mL in the STZ group vs. 95.7 ± 13.3 U/mL in the STZ+MK group, p < 0.05, and 25.52 ± 2.09 Trolox units in the STZ group vs. 33.29 ± 1.64 Trolox units in the STZ+MK group, respectively, p < 0.01), and MDA values decreased. MK administered alone did not significantly alter any of these parameters in normal animals. Conclusions: The obtained data showed that by blocking the action of peptide leukotrienes on cysLT1 receptors, montelukast significantly reduced the lung lesions caused by diabetes. The involvement of these leukotrienes in the pathogenesis of fibrosis and other lung diabetic lesions was also demonstrated.

Montelukast, an available and safe anti-asthmatic drug, prevents maladaptive remodelling and maintains cardiac functionality following myocardial infarction

Preclinical and clinical data indicate that the 5-lipoxygenase pathway becomes activated in cardiovascular diseases suggesting an important role of CysLTs in atherosclerosis and in its ischemic complications. This study aims to investigate the effects of montelukast, a CysLTR-1 antagonist, in a mouse model of myocardial infarction (MI). C57BL/6N female mice were subjected to coronary artery ligation and received montelukast (10 mg/kg/day, intraperitoneal) or vehicle. Montelukast exerted beneficial effects in the infarcted area, decreasing mRNA expression of inflammatory genes, such Il1β and Ccl2 (p < 0.05), at 48 h after MI, and reducing infarct size and preventing ischemic wall thinning (p < 0.05) at 4 weeks. Furthermore, montelukast counteracted maladaptive remodelling of whole heart. Indeed, montelukast reduced LV mass (p < 0.05) and remote wall thickening (p < 0.05), and improved cardiac pumping function, as evidenced by increased global ejection fraction (p < 0.01), and regional contractility in infarcted (p < 0.05) and in remote non-infarcted (p < 0.05) myocardium. Finally, montelukast prevented cardiomyocytes hypertrophy (p < 0.05) in remote myocardium, reducing the phosphorylation of GSK3β, a regulator of hypertrophic pathway (p < 0.05). Our data strongly demonstrate the ability of montelukast to contrast the MI-induced maladaptive conditions, thus sustaining cardiac contractility. The results provide evidences for montelukast "repurposing" in cardiovascular diseases and in particular in myocardial infarction.

The role of non-protein-coding RNAs in ischemic acute kidney injury

Acute kidney injury (AKI) is a condition characterized by a rapid decline in kidney function within a span of 48 hours. It is influenced by various factors including inflammation, oxidative stress, excessive calcium levels within cells, activation of the renin-angiotensin system, and dysfunction in microcirculation. Ischemia-reperfusion injury (IRI) is recognized as a major cause of AKI; however, the precise mechanisms behind this process are not yet fully understood and effective treatments are still needed. To enhance the accuracy of diagnosing AKI during its early stages, the utilization of innovative markers is crucial. Numerous studies suggest that certain noncoding RNAs (ncRNAs), such as long noncoding RNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs), play a central role in regulating gene expression and protein synthesis. These ncRNAs are closely associated with the development and recovery of AKI and have been detected in both kidney tissue and bodily fluids. Furthermore, specific ncRNAs may serve as diagnostic markers and potential targets for therapeutic interventions in AKI. This review aims to summarize the functional roles and changes observed in noncoding RNAs during ischemic AKI, as well as explore their therapeutic potential.

Zafirlukast protects against hepatic ischemia-reperfusion injury in rats via modulating Bcl-2/Bax and NF-κB/SMAD-4 pathways

Hepatic ischemia/reperfusion injury (IRI) is a clinical problem commonly during liver transplantation and other liver surgery. This study aimed to evaluate the protective effect of zafirlukast (ZFK) on IR-induced hepatic injury and investigate its relevant protective mechanism. Thirty-two male Wistar albino rats were randomly allocated to four groups: sham, IRI, ZFK, and ZFK + IR groups. ZFK was administered orally in a dose of 80 mg/kg/day for 10 consecutive days. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBL) levels, and gamma glutamyl transferase (GGT) activity were estimated. Liver tissues were used to assess oxidative stress biomarkers including malondialdehyde (MDA), myeloperoxidase (MPO), nitric oxide (NOx), and reduced glutathione (GSH) contents. Inflammatory cytokines, tumor necrosis factor alpha (TNF-α) and interleukin-33 (IL-33), in addition to apoptosis biomarkers, BCL2 associated X protein (Bax), B-cell lymphoma 2 (Bcl2) and galactine-9 (GAL9) proteins were also assessed. Western blot analysis was performed for vascular endothelial growth factor (VEGF) and fibrinogen expressions. Immunohistochemical analysis for hepatic nuclear factor-kappa B (NF-κB) and SMAD-4 was done in addition to histopathological examination. Our study revealed that ZFK pre-treatment resulted in liver function restoration and oxidative stress correction. Moreover, inflammatory cytokines were significantly reduced and a remarkable reduction of apoptosis, angiogenesis, and clotting formation has been indicated. Additionally, a significant reduction in SMAD-4 and NF-kB protein expressions was observed. These results were supported by hepatic architecture improvement. Our findings revealed that ZFK possesses a potential protective effect against liver IR possibly through its antioxidant, anti-inflammatory and anti-apoptotic properties.

NHWD-870 protects the kidney from ischemia/reperfusion injury by upregulating the PI3K/AKT signaling pathway (experimental study)

Renal ischemia-reperfusion injury is a critical clinical condition with a potentially fatal prognosis if not adequately managed. NHWD-870, a known Brd4 inhibitor with anti-cancer properties, exhibits additional attributes such as antioxidant, anti-inflammatory, and anti-apoptotic effects, suggesting its potential to preserve renal tissue and mitigate damage during ischemic insults. We aimed to assess the potential nephroprotective effect of NHWD-870 by investigating its anti-apoptotic, anti-inflammatory, and antioxidant properties in a rat model of renal ischemia-reperfusion injury. Male Wistar Albino rats (n=24) were randomly assigned to four groups: sham, control, vehicle, and NHWD-870. The control group experienced bilateral renal ischemia for 30 minutes, followed by 2 hours of reperfusion, while the sham group underwent a laparotomy without ischemia-reperfusion induction. The vehicle group received a DMSO injection, and the NHWD-870 group was administered 3mg/kg NHWD-870 orally 24 hours before repeating the control group protocol. Blood samples were collected after reperfusion for blood urea nitrogen (BUN) and serum creatinine (SCr) analysis. ELISA method was used to assess IL-1B, BCL-2, PGF-2, and PI3K/AKT signaling pathways in renal tissue. Tubular injury severity was evaluated through histopathological analysis. NHWD-870 treatment improved renal function and histological preservation compared to the control and vehicle groups. BUN, sCR, IL-1B, BCL-2, and PGF-2 levels in renal tissue were significantly improved in the NHWD-870 group (p<0.05). Furthermore, the PI3K/AKT signaling pathway was significantly upregulated (p<0.01), and tubular injury severity was reduced in the NHWD-870 group. NHWD-870 demonstrated substantial nephroprotective effects in reducing renal damage induced by ischemia-reperfusion injury in rats. These effects may be attributed to the anti-apoptotic properties, as indicated by increased levels of the anti-apoptotic protein Bcl-2, and the reduction in oxidative stress marker PGF-2 through upregulation of the PI3K/AKT signaling pathway, along with the decrease in the inflammatory marker IL-1B.

The effect of JQ1 systemic administration on oxidative stress and apoptotic markers in renal ischemic reperfusion injury in a rat model

This study aimed to investigate the effects of JQ1 in a renal ischemia-reperfusion (IR) rat model. Twenty-four adult male Wistar Albino rats were randomly divided into four equal groups. The sham group underwent laparotomy without ischemia-reperfusion induction. The control group experienced bilateral renal ischemia for 30 minutes, followed by a 2-hour reperfusion period. The vehicle group (IR group + DMSO) and JQ1 group (same as in control IR + 25 mg/kg JQ1). Kidney and blood samples were collected 2 hours after reperfusion. Blood samples were used to analyze serum creatinine and blood urea nitrogen levels. Renal tissue was assessed for TNF-alpha, caspase-3, FOXO4, PI3K/AKT signaling pathway, and histological analysis. The control group exhibited significantly higher serum creatinine, blood urea nitrogen, caspase-3, TNF-alpha, and FOXO4 levels in renal tissue compared to the sham group. Additionally, the PI3K/AKT signaling pathway was significantly decreased in the control group. Histopathological examination revealed severe kidney damage in the control group compared to the sham group. In rats treated with JQ1, serum creatinine, BUN, caspase-3, TNF-alpha, and FOXO4 levels in renal tissue significantly improved. The PI3K/AKT signaling pathway was substantially increased (p-value 0.01) compared to the Vehicle and Control groups. The tubular severity score was also significantly reduced in the JQ1-treated groups compared to the Control and Vehicle groups. In conclusion, JQ1 significantly ameliorated renal ischemia-reperfusion injury in rats by suppressing apoptosis and inflammatory pathways.

Atorvastatin-mediated downregulation of VCAM-1 and XO/UA/caspase 3 signaling averts oxidative damage and apoptosis induced by ovarian ischaemia/reperfusion injury

Background

Oxidative damage is critical in the pathogenesis of ovarian ischaemia/reperfusion (I/R) injury, and statins have been reported to exert antioxidant activity. However, the role of VCAM-1 and xanthine oxidase (XO)/uric acid (UA) in ovarian I/R injury is not known. Also, whether or not atorvastatin exerts antioxidant activity like other statins is unclear.

Objectives

This study investigated the involvement of VCAM-1 and XO/UA in ovarian I/R injury and the likely protective role of atorvastatin.

Methods

Forty female Wistar rats were randomized into sham-operated, ischaemia, ischaemia/reperfusion (I/R), ischaemia and atorvastatin, and I/R and atorvastatin.

Results

In comparison with the sham-operated group, atorvastatin blunted ischaemia and I/R-induced distortion of ovarian histoarchitecture and follicular degeneration. Also, atorvastatin alleviated ischaemia and I/R-induced rise in XO, UA, and malondialdehyde, which was accompanied by inhibition of ischaemia and I/R-induced reductions in reduced glutathione level, enzymatic antioxidant activities and increase in myeloperoxidase activity and TNF-α and IL-6 levels by atorvastatin treatment. Additionally, atorvastatin blocked ischaemia and I/R-induced increase in VCAM-1 expression, caspase 3 activity, 8-hydroxydeoxyguanosine level and ovarian DNA fragmentation index.

Conclusion

For the first time, this study revealed that atorvastatin-mediated downregulation of VCAM-1 and XO/UA/caspase 3 signaling averts oxidative injury, inflammation, and apoptosis induced by ovarian ischaemia/reperfusion injury.

Prophylactic Treatment with Hydrogen Sulphide Can Prevent Renal Ischemia-Reperfusion Injury in L-NAME Induced Hypertensive Rats with Cisplatin-Induced Acute Renal Failure

(Background and Objectives): Renal ischemia perfusion injury is one of the major issues in kidney transplant. The aim of the study was to investigate the hypothesis that prophylactic treatment-with a hydrogen sulphide donor to an acute renal failure case of hypertensive rats-can minimize the ischemia reperfusion injury of the kidney which is beneficial for kidney transplant. To check this hypothesis, the present study was designed to investigate the effect of chronic administration of a hydrogen sulphide (H2S) donor and sodium hydrosulfide (NaHS) on nuclear factor kappa B (NF-kB) and inter cellular adhesion molecule-1 (ICAM-1) concentration in non-renal failure (NRF) and acute renal failure (ARF) rats in the ischemia-reperfusion injury (IRI) model of the kidney in both normotensive WKY and hypertensive rats (L-nitro arginine methyl ester (L-NAME-induced); (Materials and Methods): A total number of 48 Sprague-Dawley rats were recruited into eight groups each consisting of six animals. Each of these eight groups was used to measure systemic and renal parameters, H2S, antioxidant parameters in plasma, plasma concentration of NF-kB and ICAM-1 and renal cortical blood pressure. ARF was induced by single intraperitoneal (i.p.) cisplatin injection (5 mg/kg). Hypertension was induced by oral administration of L-NAME in drinking water for four weeks at 40 mg/kg/day. NaHS was administered (i.p) at 56 µmol/kg for five weeks while dL-propargylglycine (PAG), a H2S generation inhibitor, was administered as a single intra-peritoneal injection (50 mg/kg). An acute surgical experiment was performed for the induction of renal ischemia for 30 min by renal artery clamping followed by reperfusion for three hours; (Results): Chronic administration of NaHS attenuated the severity of ARF in both normotensive and hypertensive animals (L-NAME) along with lowering the blood pressure in hypertensive groups. NaHS improved the oxidative stress parameters such as total superoxide dismutase (T-SOD), glutathione (GSH) and reduced the malondialdehyde (MDA) concentration along with reduction of NF-kB and ICAM-1 following renal IRI; Conclusions: These findings demonstrate that H2S not only reduced the severity of cisplatin induced ARF but also reduced the severity of renal IRI by upregulating antioxidants along with decreased concentrations of NF-kB and ICAM-1 in normotensive and L-NAME induced hypertensive rats.

Montelukast and Acute Coronary Syndrome: The Endowed Drug

Acute coronary syndrome (ACS) is a set of signs and symptoms caused by a reduction of coronary blood flow with subsequent myocardial ischemia. ACS is associated with activation of the leukotriene (LT) pathway with subsequent releases of various LTs, including LTB4, LTC4, and LTD4, which cause inflammatory changes and induction of immunothrombosis. LTs through cysteine leukotriene (CysLT) induce activation of platelets and clotting factors with succeeding coronary thrombosis. CysLT receptor (CysLTR) antagonists such as montelukast (MK) may reduce the risk of the development of ACS and associated complications through suppression of the activation of platelet and clotting factors. Thus, this critical review aimed to elucidate the possible protective role of MK in the management of ACS. The LT pathway is implicated in the pathogenesis of atherosclerosis, cardiac hypertrophy, and heart failure. Inhibition of the LT pathway and CysL1TR by MK might be effective in preventing cardiovascular complications. MK could be an effective novel therapy in the management of ACS through inhibition of pro-inflammatory CysLT1R and modulation of inflammatory signaling pathways. MK can attenuate thrombotic events by inhibiting platelet activation and clotting factors that are activated during the development of ACS. In conclusion, MK could be an effective agent in reducing the severity of ACS and associated complications. Experimental, preclinical, and clinical studies are recommended to confirm the potential therapeutic of MK in the management of ACS.

Leukotriene Inhibitors with dexamethasone show promise in the prevention of death in COVID-19 patients with low oxygen saturations

Introduction

COVID-19 is a major health threat around the world causing hundreds of millions of infections and millions of deaths. There is a pressing global need for effective therapies. We hypothesized that leukotriene inhibitors (LTIs), that have been shown to lower IL6 and IL8 levels, may have a protective effect in patients with COVID-19.

Methods

In this retrospective controlled cohort study, we compared death rates in COVID-19 patients who were taking a LTI with those who were not taking an LTI. We used the Department of Veterans Affairs (VA) Corporate Data Warehouse (CDW) to create a cohort of COVID-19-positive patients and tracked their use of LTIs between November 1, 2019 and November 11, 2021.

Results

Of the 1,677,595 cohort of patients tested for COVID-19, 189,195 patients tested positive for COVID-19. Forty thousand seven hundred one were admitted. 38,184 had an oxygen requirement and 1214 were taking an LTI. The use of dexamethasone plus a LTI in hospital showed a survival advantage of 13.5% (CI: 0.23%-26.7%; p < 0.01) in patients presenting with a minimal O₂Sat of 50% or less. For patients with an O₂Sat of <60 and <50% if they were on LTIs as outpatients, continuing the LTI led to a 14.4% and 22.25 survival advantage if they were continued on the medication as inpatients.

Conclusions

When combined dexamethasone and LTIs provided a mortality benefit in COVID-19 patients presenting with an O₂ saturations <50%. The LTI cohort had lower markers of inflammation and cytokine storm.

Vincamine Modulates the Effect of Pantoprazole in Renal Ischemia/Reperfusion Injury by Attenuating MAPK and Apoptosis Signaling Pathways

Pantoprazole has an antioxidant function against reactive oxygen species (ROS). Vincamine, a herbal candidate, is an indole alkaloid of clinical use against brain sclerosis. The aim of the present experiment is to evaluate, on a molecular level for the first time, the value of vincamine in addition to pantoprazole in treating experimentally induced renal ischemia/reperfusion injury (IRI). One-hundred-and-twenty-eight healthy male Wistar albino rats were included. Serum creatinine, blood urea nitrogen, and malondialdehyde levels were assessed. ELISA was used to estimate the pro-inflammatory cytokines. The expression of Bcl-2 and Bax genes was assessed by quantitative real-time PCR. ERK1/2, JNK1/2, p38, cleaved caspase-3, and NF-κB proteins expressions were estimated using western blot assay. The kidneys were also histopathologically studied. The IRI resulted in impaired cellular functions with increased creatinine, urea nitrogen, malondialdehyde, TNF-α, IL-6, and IL-1β serum levels, and up-regulated NF-ĸB, JNK1/2, ERK1/2, p38, and cleaved caspase-3 proteins. Furthermore, it down-regulated the expression of the Bcl-2 gene and upregulated the Bax gene. The treatment with vincamine, in addition to pantoprazole multiple doses, significantly alleviated the biochemical and histopathological changes more than pantoprazole or vincamine alone, whether the dose is single or multiple, declaring their synergistic effect. In conclusion, vincamine with pantoprazole multiple doses mitigated the renal IRI through the inhibition of apoptosis, attenuation of the extracellular signaling pathways through proinflammatory cytokines’ levels, and suppression of the MAPK (ERK1/2, JNK, p38)–NF-κB intracellular signaling pathway.

A high dose of estrogen can improve renal ischemia-reperfusion-induced pulmonary injury in ovariectomized female rats

Renal ischemia-reperfusion injury (RIRI) as a pathological process induces remote organ injury such as lung complications and it is regulated in a hormone-dependent manner. This study investigates the effect of estrogen on RIR-induced pulmonary injury in ovariectomized (OV) rats. A total of 60 female Wistar rats were divided into six groups: (i) intact sham, (ii) OV sham, (iii) OV sham + estradiol valerate (E), (iv) intact ischemia, (v) OV ischemia, and (vi) OV ischemia + E. Bilateral ischemia was performed for 45 min in all groups except sham. Before the ischemia, OV groups received an intramuscular (i.m.) injection of E. After reperfusion, blood samples were collected for serum analysis and kidney and lung tissue were separated for pathological experiment and malondialdehyde (MDA) and nitrite measurement. The left lung was weighed to measure pulmonary edema. Estrogen deficiency caused a greater increase in blood urea nitrogen and creatinine levels during IRI. Ischemia reduced nitrite of serum and lung tissue. The increased level of MDA during ischemia, returned to normal levels via estrogen injection. The severity of renal and lung damage in ischemic groups increased significantly, and estrogen improved this injury. Estrogen as an antioxidant agent can reduce oxidative stress and may improve renal function and ameliorating lung damage caused by RIR.

Hydrogen Sulphide Treatment Prevents Renal Ischemia-Reperfusion Injury by Inhibiting the Expression of ICAM-1 and NF-kB Concentration in Normotensive and Hypertensive Rats

Our main objective was to investigate the effect of chronic administration of hydrogen sulphide donor (sodium hydrosulphide) on the expression of intercellular adhesion molecule-1 (ICAM-1) and concentration of nuclear factor-kappa B (NF-kB) in a renal ischemia-reperfusion injury (IRI) model of WKY and L-nitro-arginine-methyl-ester (L-NAME)-induced hypertensive rats. Sodium hydrosulphide (NaHS) was administered intraperitoneally (i.p.) for 35 days while cystathionine gamma lyase (CSE) inhibitor dL-propargylglycine (PAG) was administered at a single dose of 50 mg/kg. Animals were anesthetised using sodium pentobarbitone (60 mg/kg) and then prepared to induce renal ischemia by clamping the left renal artery for 30 min followed by 3 h of reperfusion. Pre-treatment with NaHS improved the renal functional parameters in both WKY and L-NAME-induced hypertensive rats along with reduction of blood pressure in hypertensive groups. Oxidative stress markers like malondialdehyde (MDA), total superoxide dismutase (T-SOD) and glutathione (GSH) were also improved by NaHS treatment following renal IRI. Levels of ICAM-1 and NF-kB concentration were reduced by chronic treatment with NaHS and increased by PAG administration after renal IRI in plasma and kidney. Treatment with NaHS improved tubular morphology and glomerulus hypertrophy. Pre-treatment with NaHS reduced the degree of renal IRI by potentiating its antioxidant and anti-inflammatory mechanism, as evidenced by decreased NF-kB concentration and downregulation of ICAM-1 expression.

Pantoprazole Attenuates MAPK (ERK1/2, JNK, p38)-NF-κB and Apoptosis Signaling Pathways after Renal Ischemia/Reperfusion Injury in Rats

Ischemia/reperfusion injury (IRI) in the kidney is the most common cause of acute renal dysfunction through different cell damage mechanisms. This study aimed to investigate, on molecular basics for the first time, the effect of pantoprazole on renal IRI in rats. Different biochemical parameters and oxidative stress markers were assessed. ELISA was used to estimate proinflammatory cytokines. qRT-PCR and western blot were used to investigate the gene and protein expression. Renal histopathological examination was also performed. IRI resulted in tissue damage, elevation of serum levels of creatinine, urea nitrogen, malondialdehyde, TNF-α, IL-6, IL-1β, up-regulation of NF-κB, JNK1/2, ERK1/2, p38, and cleaved caspase-3 proteins. Furthermore, it up-regulated the expression of the Bax gene and down-regulated the expression of the Bcl-2 gene. Treatment of the injured rats with pantoprazole, either single dose or multiple doses, significantly alleviated IRI-induced biochemical and histopathological changes, attenuated the levels of proinflammatory cytokines, down-regulated the expression of NF-κB, JNK1/2, ERK1/2, p38, and cleaved caspase-3 proteins, and the Bax gene, and up-regulated Bcl-2 gene expression. Moreover, treatment with pantoprazole multiple doses has an ameliorative effect that is greater than pantoprazole single-dose. In conclusion, pantoprazole diminished renal IRI via suppression of apoptosis, attenuation of the pro-inflammatory cytokines’ levels, and inhibition of the intracellular signaling pathway MAPK (ERK1/2, JNK, p38)–NF-κB.

Assessment of the Nephroprotective Properties of the Erythropoietin Mimetic Peptide and Infliximab in Kidney Ischemia-Reperfusion Injury in Rats

Chronic kidney disease (CKD) or acute kidney injury (AKI) causes impaired kidney function, leading to cognitive impairment, neuropathy, and cerebrovascular disease. Due to kidney damage, toxins stay in the blood rather than leaving the body through the urine, and brain function is affected by kidney-brain interaction. The present study aimed to investigate the protective effects of erythropoietin mimetic peptide (pHBSP) and infliximab on ischemic renal reperfusion injury. The experiment was performed on 70 white male Wistar laboratory rats which received recombinant erythropoietin, pHBSP, and infliximab. Under anesthesia, traumatic vascular clamps were applied to the left renal pedicle for 40 min, and nephrectomy was performed on the right. Functional tests and laboratory tests were performed 5 min and 24 h after the reperfusion.  Thereafter, 24 h after the surgery, the plasma creatinine and urea levels in the sham-operated animals were obtained at 45.9±0.8 mmol/L and 6.7±0.2 mmol/L, respectively. Plasma creatinine and urea levels in the control group animals were 102.63±3.6 mmol/L and 21.80±1.29 mmol/L, respectively. The administration of pHBSP and infliximab to the animals with ischemia-reperfusion kidney injury has a pronounced nephroprotective effect, as compared to erythropoietin. There was a significant decrease in blood levels of creatinine and urea, improvement of microcirculation in the kidney, normalization of glomerular filtration rate, and fractional sodium excretion. The results of the study demonstrated pointed to the prospects of pHBSP and infliximab administration in ischemia-reperfusion kidney injury and justified the feasibility of further research in this field.

Role of leukotriene pathway and montelukast in pulmonary and extrapulmonary manifestations of Covid-19: The enigmatic entity

Severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2), the responsible agent for the coronavirus disease 2019 (Covid-19), has its entry point through interaction with angiotensin converting enzyme 2 (ACE2) receptors, highly expressed in lung type II alveolar cells and other tissues, like heart, pancreas, brain, and vascular endothelium. This review aimed to elucidate the potential role of leukotrienes (LTs) in the pathogenesis and clinical presentation of SARS-CoV-2 infection, and to reveal the critical role of LT pathway receptor antagonists and inhibitors in Covid-19 management. A literature search was done in PubMed, Scopus, Web of Science and Google Scholar databases to find the potential role of montelukast and other LT inhibitors in the management of pulmonary and extra-pulmonary manifestations triggered by SARS-CoV-2. Data obtained so far underline that pulmonary and extra-pulmonary manifestations in Covid-19 are attributed to a direct effect of SARS-CoV-2 in expressed ACE2 receptors or indirectly through NF-κB dependent induction of a cytokine storm. Montelukast can ameliorate extra-pulmonary manifestations in Covid-19 either directly through blocking of Cys-LTRs in different organs or indirectly through inhibition of the NF-κB signaling pathway.

Mechanistic insight on the role of leukotriene receptors in ischemic-reperfusion injury

Leukotrienes (LT) are a class of inflammatory mediators produced by the 5-lipoxygenase (5-LO) enzyme from arachidonic acid (AA). We discussed the various LT inhibitors and downstream pathway modulators, such as Mitogen-Activated Protein Kinases (MAPK), Phosphatidylinositol 3-Kinase/Protein Kinase B (PI3K/Akt), 5'-Adenosine Monophosphate-Activated Protein Kinase (AMPK), Protein Kinase C (PKC), Nitric Oxide (NO), Bradykinin, Early Growth Response-1 (Egr-1), Nuclear Factor-κB (NF-κB), and Tumor Necrosis Factor-Alpha (TNF-α), which in turn regulate various metabolic and physiological processes involving I/R injury. A systematic literature review of Bentham, Scopus, PubMed, Medline, and EMBASE (Elsevier) databases was carried out to understand the nature and mechanistic interventions of the leukotriene receptor modulations in ischemic injury. In the pathophysiology of I/R injuries, LT has been found to play an important role. I/R injury affects most of the vital organs and is characterized by inflammation, oxidative stress, cell death, and apoptosis leading to morbidity and mortality. sThis present review focuses on the various LT receptors, i.e., CysLT, LTC4, LTD4, and LTE4, involved in developing I/R injury in organs, such as the brain, spinal cord, heart, kidney, liver, and intestine.

The examination of the nephroprotective effect of montelukast sodium and N-acetylcysteine ın renal ıschemia with dimercaptosuccinic acid imaging in a placebo-controlled rat model

Purpose

To determine the nephroprotective effect of NAC and Montelukast Sodium administration against the development of renal damage associated with long warm renal ischemia.

Methods

Twenty-seven rats were randomly divided into 3 study groups, which received NAC, montelukast and placebo, and 3 rats were included in the sham-treated control group. Medications were given 3 days before the procedure. DMSA renal scintigraphy was performed before and after surgery. The right renal pedicle was occluded for 45 min to induce ischemia and then subjected to reperfusion for 6 h (I/R groups).

Results

On pathological examination, the mean pathological scores of the montelukast and NAC groups were significantly lower than those of the placebo group. (p <0.05). In biochemical examination, significant differences were found in all parameter levels between the placebo group and the montelukast and NAC groups. (p <0.05) When postoperative DMSA renal scintigraphy measurements and renal function levels were compared, significant differences were found between the montelukast and NAC groups and the placebo and sham groups.

Conclusion

The administration of NAC and montelukast sodium was seen to have a nephroprotective effect against the development of renal damage associated with warm renal ischemia.

Protective effect of dapsone against renal ischemia-reperfusion injury in rat

Background: Ischemia/reperfusion can cause injury to tissues and compromise functionality of organs due to inflammatory processes. Significantly, development of these effects in kidney tissue has been a challenging issue that leads to acute renal injury. In this study, anti-inflammatory, anti-oxidative, and protective features of dapsone on kidney ischemia/reperfusion injury were investigated.Material and methods: Renal ischemia was induced in rats by bilateral renal arteries clamping for 45 min followed by 24 h reperfusion phase. The effects of different doses of dapsone (1, 3, 10 mg/kg) on ischemia/reperfusion injury in kidney tissue were investigated by targeting BUN, Creatinine, LDH, MDA, MPO, IL-1β, TNF-α, and NFκB. In addition histopathological examination was performed by H&E staining method.Results and discussion: Comparing the findings of this study showed significant reduction in BUN and LDH in 10 mg/kg dapsone received groups, and Cr, MDA, and MPO in 3 mg/kg dapsone received groups. The serum level of TNF-α was significantly decreased with both doses of 3 and 10 mg/kg dapsone. The same results were observed in the serum level of IL-1β and NFκB. Besides, remarkable improvement in histological damages was also observed with dapsone treatment.Conclusion: These results support the hypothesis that the positive effects of dapsone on the renal ischemia/reperfusion injury are mediated by modulating inflammatory cascades.

Montelukast for Medical Delay in Flap Surgery

BACKGROUND

Delay phenomenon can be used for better blood supply of the flap in plastic surgery. Effects of Montelukast have been observed to reduce ischemia/reperfusion injury in various organs due to angiogenic and anti-oxidant effects. The present study aimed to determine the role of Montelukast as medical delay of the flaps.

METHODS

In this experimental study, 42 Wistar rats were divided into 3 equal groups. These groups were Surgical Delay Group (SDG), Medical Delay Group (MDG) and Control Group (CG). In SDG, 8×3 cm rectangular randomized random skin flap was first surgically delayed at rats' back. The MDG received 10 mg/kg oral Montelukast via orogastric tube for 5 days as medical delay. In MDG and SDG flap, harvesting was undertaken after a delayed period, but there was not any delayed period in CG. After delayed period, a segment of the skin flap was biopsied for assessing angiogenesis. After 14th days, the photos were taken and the size of the necrotic area of the flap was measured.

RESULTS

A significant difference was observed between the mean survival and angiogenesis (p=0.002). The same performance was reported between MDG and SDG, which were alike regarding survival and angiogenesis (p>0.05); while there was a significant difference between the control and surgical groups, as well as control and medical groups (p<0.05). Finally, the inflammation showed no significant difference (p>0.05).

CONCLUSION

Regarding positive effects of Montelukast on survival and angiogenesis, it is recommended to be used as a medication for larger studies.

Therapeutic and protective effects of montelukast against doxorubicin-induced acute kidney damage in rats

Objective(s):

The current study was designed to investigate the therapeutic and protective effects of montelukast (ML) against doxorubicin (DOX)-induced acute kidney damage in rats.

Materials and Methods:

Thirty-five Wistar albino female rats were randomly divided into 5 groups as follows: Group I: Control; Group II: Control+ML; Group III: DOX; Group IV: DOX+ML; Group V: ML+DOX. At the end of the experiment, the kidney tissues of rats were collected. Thiobarbituric acid reactive substance (TBARS), reduced glutathione, superoxide dismutase (SOD), and catalase levels were determined from the kidney tissues. In addition, the kidney tissues were examined histologically.

Results:

DOX induced a significant increase in the kidney TBARS levels, whereas SOD contents significantly decreased when compared with the control group. On the other hand, ML administration before and after DOX injection caused significant decreases in TBARS production and also increases in SOD levels. Histologically, the most remarkable damage was glomerulosclerosis and tubular changes in the DOX group. Moreover, marked tubular necrosis and swelling in tubular epithelial cells were observed in this group. Contrarily, although glomerulosclerosis was recognized as alleviated also in both DOX+ML and ML+DOX groups, the lesions did not completely ameliorate. However, treatment with ML after DOX injection was more effective than treatment with ML before DOX injection with respect to the protection of tubular structures.

Conclusion:

It was determined that ML treatment after DOX injection caused therapeutic effects against DOX-induced kidney damage. Thence, ML treatment is of some clinical properties for oxidative stress damage in kidney tissues.

Zafirlukast Is a Dual Modulator of Human Soluble Epoxide Hydrolase and Peroxisome Proliferator-Activated Receptor γ

Cysteinyl leukotriene receptor 1 antagonists (CysLT1RA) are frequently used as add-on medication for the treatment of asthma. Recently, these compounds have shown protective effects in cardiovascular diseases. This prompted us to investigate their influence on soluble epoxide hydrolase (sEH) and peroxisome proliferator activated receptor (PPAR) activities, two targets known to play an important role in CVD and the metabolic syndrome. Montelukast, pranlukast and zafirlukast inhibited human sEH with IC₅₀ values of 1.9, 14.1, and 0.8 μM, respectively. In contrast, only montelukast and zafirlukast activated PPARγ in the reporter gene assay with EC₅₀ values of 1.17 μM (21.9% max. activation) and 2.49 μM (148% max. activation), respectively. PPARα and δ were not affected by any of the compounds. The activation of PPARγ was further investigated in 3T3-L1 adipocytes. Analysis of lipid accumulation, mRNA and protein expression of target genes as well as PPARγ phosphorylation revealed that montelukast was not able to induce adipocyte differentiation. In contrast, zafirlukast triggered moderate lipid accumulation compared to rosiglitazone and upregulated PPARγ target genes. In addition, we found that montelukast and zafirlukast display antagonistic activities concerning recruitment of the PPARγ cofactor CBP upon ligand binding suggesting that both compounds act as PPARγ modulators. In addition, zafirlukast impaired the TNFα triggered phosphorylation of PPARγ2 on serine 273. Thus, zafirlukast is a novel dual sEH/PPARγ modulator representing an excellent starting point for the further development of this compound class.

Leukotrienes and kidney diseases

Purpose of review

This review will critically highlight the role of leukotrienes as mediators of renal diseases and drug nephrotoxicity. It will also discuss the recently identified mechanism of cysteinyl leukotrienes induction and action, and will propose clinical implementation of these findings.

Recent findings

Since last reviewed in 1994, leukotrienes were shown to mediate drug-associated nephrotoxicity, transplant rejection and morbidity in several models of renal diseases. Although leukotrienes may be released by various infiltrating leukocytes, a recent study demonstrated that cytotoxic agents trigger production of leukotriene C₄ (LTC₄) in mouse kidney cells by activating a biosynthetic pathway based on microsomal glutathione-S-transferase 2 (MGST2). LTC₄ then elicits nuclear accumulation of hydrogen peroxide-generating NADPH oxidase 4, leading to oxidative DNA damage and cell death. LTC₄ inhibitors, commonly used as systemic asthma drugs, alleviated drug-associated damage to proximal tubular cells and attenuated mouse morbidity.

Summary

Cysteinyl leukotrienes released by mast cells trigger the symptoms of asthma, including bronchoconstriction and vasoconstriction. Therefore, effective leukotriene inhibitors were approved as orally administered asthma drugs. The findings that leukotrienes mediate the cytotoxicity of nephrotoxic drugs, and are involved in numerous renal diseases, suggest that such asthma drugs may ameliorate drug-induced nephrotoxicity, as well as some renal diseases.

Montelukast inhibits inflammatory response in rheumatoid arthritis fibroblast-like synoviocytes

Montelukast, a potent selective antagonist of cysteinyl leukotriene (cysLT) receptors, has displayed its important anti-oxidative and anti-inflammatory effects in various tissues and organs. Rheumatoid arthritis (RA) is an immune disease defined by hyperplastic synovitis and joint destruction. Fibroblast-like synoviocytes in RA (RA-FLSs) are the main cell component of the hyperplastic synovium. Whether montelukast can protect against the inflammatory milieu of RA remains unclear. Here, it is shown that cysLT1R is present in FLSs and unregulated in RA-FLSs. Montelukast has an inhibitory effect on the inflammatory microenvironment of RA by decreasing the secretion of IL-6, IL-8, MMP-3 and MMP-13 in FLSs induced by IL-1β. Notably, treatment with montelukast attenuated IL-1β-induced phosphorylation of IκBα, IκBα degradation, nuclear translocation of p65 and NF-κB activity to express a luciferase reporter gene in FLSs. The findings of the current study provide evidence for a novel therapeutic strategy for RA using montelukast.

Zileuton alleviates acute cisplatin nephrotoxicity: Inhibition of lipoxygenase pathway favorably modulates the renal oxidative/inflammatory/caspase-3 axis

OBJECTIVE

The current study investigated for the first time the possible beneficial effect of zileuton, a selective 5-lipoxygenase inhibitor (5-LOX), against cisplatin-induced acute renal failure.

METHODOLOGY

Male Sprague-Dawley rats (180-200 g) were administered cisplatin once (5 mg/kg, i.p.) alone or combined with oral zileuton (10 mg/kg, given twice; 1 h before and 12 h after cisplatin).

RESULTS

Compared with control rats, acute cisplatin administration caused significant increases of BUN (33.76 ± 7.74 vs 61.88 ± 11.35 mg/dl), serum creatinine (0.61 ± 0.21 vs 1.56 ± 0.28 mg/dl), renal levels of MDA (6.40 ± 1.04 vs 20.52 ± 2.18 nmol/g tissue), NOx (3.45 ± 1.20 vs 17.70 ± 2.27 nmol/g tissue), TNF-α (6.71 ± 0.66 vs 23.71 ± 3.41 pg/g tissue), MPO (0.87 ± 0.09 vs 3.12 ± 0.41 U/mg tissue protein) and renal caspase-3 activity (2.81 ± 0.37 vs 12.70 ± 2.94 U/mg tissue protein). Whereas, total SOD activity (1.99 ± 0.53 vs 0.79 ± 0.06 U/mg tissue protein) and IL-10 (110.98 ± 19.70 vs 62.34 ± 14.42 pg/g tissue) were significantly decreased. Cisplatin-induced nephrotoxicity was further confirmed histopathologically (tubular necrosis, cystic dilatation of renal tubules, vacuolar degeneration of renal tubular epithelium with perivascular oedema, and interstitial fibrosis). These changes were accompanied by alteration in 5-LOX pathway manifested as elevated renal levels of 5-LOX, LTD4 and LTB4. Simultaneous administration of zileuton to the cisplatin-treated rats reversed the deleterious renal insults and restored the measured parameters near to control values.

CONCLUSIONS

These data establish the first experimental evidence that zileuton abrogates cisplatin nephrotoxicity in rats probably via the inhibition of detrimental actions of 5-LOX products, thus favorably affecting renal oxidative/inflammatory/caspase-3 axis. Based on current findings, the therapeutic prospect of zileuton for this purpose is recommended.

Bone marrow-derived cPLA2α contributes to renal fibrosis progression

The group IVA calcium-dependent cytosolic phospholipase A2 (cPLA2α) enzyme directs a complex "eicosanoid storm" that accompanies the tissue response to injury. cPLA2α and its downstream eicosanoid mediators are also implicated in the pathogenesis of fibrosis in many organs, including the kidney. We aimed to determine the role of cPLA2α in bone marrow-derived cells in a murine model of renal fibrosis, unilateral ureteral obstruction (UUO). WT C57BL/6J mice were irradiated and engrafted with donor bone marrow from either WT mice [WT-bone marrow transplant (BMT)] or mice deficient in cPLA2α (KO-BMT). After full engraftment, mice underwent UUO and kidneys were collected 3, 7, and 14 days after injury. Using picrosirius red, collagen-3, and smooth muscle α actin staining, we determined that renal fibrosis was significantly attenuated in KO-BMT animals as compared with WT-BMT animals. Lipidomic analysis of homogenized kidneys demonstrated a time-dependent upregulation of pro-inflammatory eicosanoids after UUO; KO-BMT animals had lower levels of many of these eicosanoids. KO-BMT animals also had fewer infiltrating pro-inflammatory CD45+CD11b+Ly6C^hi macrophages and reduced message levels of pro-inflammatory cytokines. Our results indicate that cPLA2α and/or its downstream mediators, produced by bone marrow-derived cells, play a major role in eicosanoid production after renal injury and in renal fibrinogenesis.

Resveratrol and Montelukast Alleviate Paraquat-Induced Hepatic Injury in Mice: Modulation of Oxidative Stress, Inflammation, and Apoptosis

Paraquat (PQ) is one of the most used herbicide worldwide. Its cytotoxicity is attributed to reactive radical generation. Resveratrol (Res) and montelukast (MK) have anti-inflammatory and antioxidant properties. The protective effects of Res, MK, or their combination against PQ-induced acute liver injury have not been investigated before. Therefore, we explored the protective potential of Res and/or MK against PQ hepatic toxicity in a mouse model. Mice were randomly assigned to five groups: group I served as the normal control and group II received a single dose of PQ (50 mg/kg, i.p.). Groups III, IV, and V received PQ plus oral Res (5 mg/kg/day), MK (10 mg/kg/day), and Res/MK combination, respectively. Res and/or MK reduced PQ-induced liver injury, evidenced by normalization of serum total protein, ALT, and AST. Res and/or MK significantly reversed PQ-induced oxidative stress markers glutathione and malondialdehyde. Res and/or MK significantly reduced PQ-induced inflammation reflected in TNF-α levels. Furthermore, Res and/or MK reversed PQ-induced apoptosis assessed by differential expression of p53, Bax, and Bcl-2. Histopathologic examination supported the biochemical findings. Although Res and MK displayed antioxidative, anti-inflammatory, and antiapoptotic activities, their combination was not always synergistic.

The leukotriene receptor antagonist montelukast and its possible role in the cardiovascular field

BACKGROUND

Cysteinyl leukotrienes (LTC4, LTD4, and LTE4) are pro-inflammatory mediators of the 5-lipooxygenase (5-LO) pathway, that play an important role in bronchoconstriction, but can also enhance endothelial cell permeability and myocardial contractility, and are involved in many other inflammatory conditions. In the late 1990s, leukotriene receptor antagonists (LTRAs) were introduced in therapy for asthma and later on, approved for the relief of the symptoms of allergic rhinitis, chronic obstructive pulmonary disease, and urticaria. In addition, it has been shown that LTRAs may have a potential role in preventing atherosclerosis progression.

PURPOSE

The aims of this short review are to delineate the potential cardiovascular protective role of a LTRA, montelukast, beyond its traditional use, and to foster the design of appropriate clinical trials to test this hypothesis.

RESULTS AND CONCLUSIONS

What it is known about leukotriene receptor antagonists? •Leukotriene receptor antagonist, such as montelukast and zafirlukast, is used in asthma, COPD, and allergic rhinitis. • Montelukast is the most prescribed CysLT₁ antagonist used in asthmatic patients. • Different in vivo animal studies have shown that leukotriene receptor antagonists can prevent the atherosclerosis progression, and have a protective role after cerebral ischemia. What we still need to know? • Today, there is a need for conducting clinical trials to assess the role of montelukast in reducing cardiovascular risk and to further understand the mechanism of action behind this effect.

Medical perspective in testicular ischemia-reperfusion injury

Testicular torsion or torsion of the spermatic cord is one of the most serious urological conditions. It causes testicular injury, which potentially leads to male subfertility. The turning of the spermatic cord and spermatic structures around themselves results in biochemical and histological changes; however, following testicular detorsion, tissues undergo reperfusion that causes more severe damage than that induced by ischemia. Since the primary causes of testicular damage are reactive oxygen species production, an increase in intra-mitochondrial calcium concentration and an increased rate of cellular apoptosis, different medications may potentially be effective. It seems that several medications, experimentally and sometimes clinically, serve an adjuvant role in the cellular damage that occurs following ischemia-reperfusion. Antioxidants, calcium channel blockers, phytotherapeutical medicinals, anaesthetics, hormones and platelet inhibitors may potentially create a solid basis for an adjuvant restoring therapy and ameliorate testicular function following torsion. The current study aimed to review the relevant literature and discuss the actions of a number of molecules that may protect the testes during ischemia/reperfusion injury.

Influence of melatonin on IL-1Ra gene and IL-1 expression in rats with liver ischemia reperfusion injury

The aim of the present study was to explore the influence of melatonin (MT) on rats with liver ischemia reperfusion injury (IRI) and its mechanism. A total of 66 male Sprague-Dawley rats were randomly divided into 3 groups: i) Normal control group, ii) ischemia reperfusion group (IR group) and iii) melatonin treatment group (MT group). Rats in the MT group were administered an intraperitoneal injection of MT (10 mg/kg, 1 ml) at 70 and 35 min before ischemia, early reperfusion, and 1 and 2 h after reperfusion, respectively. Blood was removed at the normal time-point (prior to any processes), 35 min before ischemia, 2, 4, 8 and 24 h after reperfusion. Subsequently the rats were sacrificed. The pathological changes of liver tissues, interleukin-1 receptor antagonist (IL-1Ra) gene and IL-1 expression levels were detected. There were no evident differences between the immediate reperfusion and 2 h IR group and MT group. The liver structure injury of the 4, 8 and 24 h MT groups were improved to various differences compared to the corresponding IR group; liver IL-1β of the MT group at 35 min after ischemia, and 2, 4, 8 and 24 h after reperfusion was evidently lower than that of the IR group (P<0.05); IL-1Ra mRNA expression in the 2 h MT group was higher compared to the 2 h IR group by 4.85-fold; and IL-1Ra mRNA expression in the 4 h MT group was higher compared to the 4 h IR group by 9.34-fold. Differences between two groups at other time-points were <2-fold. In conclusion, MT can upregulate IL-1Ra gene expression by reducing generation of IL-1 thus reducing IRI.

Beneficial effects montelukast, cysteinyl-leukotriene receptor antagonist, on renal damage after unilateral ureteral obstruction in rats

Introductıon

Ureteral obstruction is a common pathology and caused kidney fibrosis and dysfunction at late period. In this present, we investigated the antifibrotic and antiinflammatory effects of montelukast which is cysteinyl leukotriene receptor antagonist, on kidney damage after unilateral ureteral obstruction(UUO) in rats.

Mateirıals and Methods

32 rats divided four groups. Group 1 was control, group 2 was sham, group 3 was rats with UUO and group 4 was rats with UUO which were given montelukast sodium (oral 10 mg/kg/day). After 14 days, rats were killed and their kidneys were taken and blood analysis was performed. Tubular necrosis, mononuclear cell infiltration and interstitial fibrosis scoring were determined histopathologically in a part of kidneys; nitric oxide(NO), malondialdehyde(MDA) and reduced glutathione(GSH) levels were determined in the other part of kidneys. Urea-creatinine levels were investigated at blood analysis. Statistical analyses were made by the Chi-square test and one-way analysis of variance (ANOVA).

Results

There was no difference significantly for urea-creatinine levels between groups. Pathologically, there was serious tubular necrosis and fibrosis in group 3 and there was significantly decreasing for tubular necrosis and fibrosis in group 4(p<0.005). Also, there was significantly increasing for NO and MDA levels; decreasing for GSH levels in group 3 compared the other groups(p<0.005).

Conclusıon

We can say that montelukast prevent kidney damage with antioxidant effect, independently of NO.

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.

Montelukast attenuates lipopolysaccharide-induced cardiac injury in rats

This study investigates the possible protective effects of montelukast (MNT) against lipopolysaccharide (LPS)-induced cardiac injury, in comparison to dexamethasone (DEX), a standard anti-inflammatory. Male Sprague Dawley rats (160–180 g) were assigned to five groups ( n = 8/group): (1) control; (2) LPS (10 mg/kg, intraperitoneal (i.p.)); (3) LPS + MNT (10 mg/kg, per os (p.o.)); (4) LPS + MNT (20 mg/kg, p.o.); and (5) LPS + DEX (1 mg/kg, i.p.). Twenty-four hours after LPS injection, heart/body weight (BW) ratio and percent survival of rats were determined. Serum total protein, creatine kinase muscle/brain (CK-MB), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) activities were measured. Heart samples were taken for histological assessment and for determination of malondialdehyde (MDA) and glutathione (GSH) contents. Cardiac tumor necrosis factor α (TNF-α) expression was evaluated immunohistochemically. LPS significantly increased heart/BW ratio, serum CK-MB, ALP, and LDH activities and decreased percent survival and serum total protein levels. MDA content increased in heart tissues with a concomitant reduction in GSH content. Immunohistochemical staining of heart specimens from LPS-treated rats revealed high expression of TNF-α. MNT significantly reduced percent mortality and suppressed the release of inflammatory and oxidative stress markers when compared with LPS group. Additionally, MNT effectively preserved tissue morphology as evidenced by histological evaluation. MNT (20 mg/kg) was more effective in alleviating LPS-induced heart injury when compared with both MNT (10 mg/kg) and DEX (1 mg/kg), as evidenced by decrease in positive staining by TNF-α immunohistochemically, decrease MDA, and increase GSH content in heart tissue. This study demonstrates that MNT might have cardioprotective effects against the inflammatory process during endotoxemia. This effect can be attributed to its antioxidant and/or anti-inflammatory properties.

Renal ischemia/reperfusion injury; from pathophysiology to treatment

Ischemia/reperfusion injury (IRI) is caused by a sudden temporary impairment of the blood flow to the particular organ. IRI usually is associated with a robust inflammatory and oxidative stress response to hypoxia and reperfusion which disturbs the organ function. Renal IR induced acute kidney injury (AKI) contributes to high morbidity and mortality rate in a wide range of injuries. Although the pathophysiology of IRI is not completely understood, several important mechanisms resulting in kidney failure have been mentioned. In ischemic kidney and subsequent of re-oxygenation, generation of reactive oxygen species (ROS) at reperfusion phase initiates a cascade of deleterious cellular responses leading to inflammation, cell death, and acute kidney failure. Better understanding of the cellular pathophysiological mechanisms underlying kidney injury will hopefully result in the design of more targeted therapies to prevent and treatment the injury. In this review, we summarize some important potential mechanisms and therapeutic approaches in renal IRI.

5-Lypoxygenase products are involved in renal tubulointerstitial injury induced by albumin overload in proximal tubules in mice

The role of albumin overload in proximal tubules (PT) in the development of tubulointerstitial injury and, consequently, in the progression of renal disease has become more relevant in recent years. Despite the importance of leukotrienes (LTs) in renal disease, little is known about their role in tubulointerstitial injury. The aim of the present work was to investigate the possible role of LTs on tubulointerstitial injury induced by albumin overload. An animal model of tubulointerstitial injury challenged by bovine serum albumin was developed in SV129 mice (wild-type) and 5-lipoxygenase-deficient mice (5-LO^–/–). The changes in glomerular morphology and nestin expression observed in wild-type mice subjected to kidney insult were also observed in 5-LO^–/– mice. The levels of urinary protein observed in the 5-LO^–/– mice subjected or not to kidney insult were lower than those observed in respective wild-type mice. Furthermore, the increase in lactate dehydrogenase activity, a marker of tubule damage, observed in wild-type mice subjected to kidney insult did not occur in 5-LO^–/– mice. LTB₄ and LTD₄, 5-LO products, decreased the uptake of albumin in LLC-PK1 cells, a well-characterized porcine PT cell line. This effect correlated with activation of protein kinase C and inhibition of protein kinase B. The level of proinflammatory cytokines, tumor necrosis factor-α and interleukin (IL)-6, increased in mice subjected to kidney insult but this effect was not modified in 5-LO^–/– mice. However, 5-LO^–/– mice subjected to kidney insult presented lower macrophage infiltration and higher levels of IL-10 than wild-type mice. Our results reveal that LTs have an important role in tubulointerstitial disease induced by albumin overload.

Aerosolized montelukast polymeric particles-an alternative to oral montelukast-alleviate symptoms of asthma in a rodent model

PURPOSE

Cysteinyl leukotrienes (CysLTs) propagate inflammatory reactions that result from allergen exposure in asthma. Montelukast, a CysLT type-1 receptor antagonist, disrupts mediator-receptor interactions and minimizes inflammatory response. In this study, we have evaluated anti-asthmatic efficacy of inhalable montelukast-loaded large porous particulate formulations in ovalbumin-induced rat airway inflammation model that mimics asthma.

METHODS

The anti-inflammatory effects of a montelukast-loaded formulation were investigated in rats by measuring the total protein content, levels of injury markers and number of inflammatory cells in the bronchoalveolar lavage fluid (BALF). The histopathological studies assessed the morphological and structural changes that occur in asthmatic lungs. Animals were also challenged with methacholine to examine the airway hyper-reactivity.

RESULTS

Compared with healthy animals, asthmatic animals showed a 3.8- and 4.77-fold increase in the protein content and number of inflammatory cells in BALF, respectively. Intratracheal montelukast particles reduced the protein content by 3.3-fold and the number of inflammatory cells by 2.62-fold. Also, montelukast particles reduced the lactate dehydrogenase (LDH) and myeloperoxidase (MPO) levels by a 4.87- and 6.8-fold in BALF, respectively. Montelukast particles reduced the airway wall thickness by 2.5-fold compared with untreated asthmatic lungs. Further, particulate formulation protected the lungs against methacholine-induced bronchial provocation (p < 0.05).

CONCLUSIONS

Respirable large porous particles containing montelukast alleviated allergen-induced inflammatory response in an animal model and prevented histological changes associated with asthma. Thus montelukast-loaded large porous polylactic acid (PLA) particles could be an aerosolized delivery approach for administration of currently available oral montelukast.

Montelukast attenuates neuropathic pain through inhibiting p38 mitogen-activated protein kinase and nuclear factor-kappa B in a rat model of chronic constriction injury

BACKGROUND

Cysteinyl leukotrienes and their receptors have been shown to be involved in the generation of neuropathic pain. We performed this study to determine the antagonistic effect of montelukast, a cysteinyl leukotrienes receptor antagonist, on neuropathic pain and its underlying mechanism.

METHODS

Neuropathic pain was induced by chronic constriction injury (CCI) of the sciatic nerve in rats. After CCI, rats were repeatedly administered montelukast (0.5, 1.0, and 2.0 mg/kg intraperitoneal, once daily) for a period of 14 days. Mechanical withdrawal threshold and thermal withdrawal latency were assessed before surgery and on days 1, 3, 5, 7, and 14 after CCI. The levels of interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α in the spinal cord were determined by enzyme-linked immunosorbent assay. The phosphorylation of p38 mitogen-activated protein kinase (MAPK) and activation of nuclear factor-kappaB (NF-κB) were assessed by Western blot. The expression of astrocyte marker glial fibrillary acidic protein and microglia marker Iba-1 and the coexpression of p-p38MAPK and Iba-1 or NF-κB and Iba-1 were observed by immunofluorescent staining.

RESULTS

The CCI group displayed significantly decreased mechanical withdrawal threshold and thermal withdrawal latency on days 1, 3, 5, 7 and 14 compared with sham groups (P <0.05, P < 0.0001), which were markedly increased by montelukast (P < 0.05, P < 0.01, P <0.0001). After administration with montelukast for 14 days, as biological markers of inflammation, the levels of IL-1β (P < 0.0001), IL-6 (P = 0.001 for low dosage, P < 0.0001 for middle and high dosages), and TNF-α (P =0.002, 0.001, < 0.0001 for low, middle, and high dosage, respectively) in the spinal cord were lower than those in the CCI group. Western blot analysis demonstrated that montelukast reduced the elevated expression of p-p38 MAPK (P =0.006, 0.015, < 0.0001 for low, middle, and high dosage, respectively) and NF-κB (P < 0.0001) in the spinal cord induced by CCI. Immunofluorescent staining showed that montelukast could inhibit CCI-induced activation of microglia but not astrocytes in the spinal cord. In addition, montelukast (2.0 mg/kg) significantly decreased the number of p38MAPK and Iba-1 or NF-κBp65 and Iba-1 double-positive cells.

CONCLUSIONS

These results suggest that montelukast could effectively attenuate neuropathic pain in CCI rats by inhibiting the activation of p38MAPK and NF-κB signaling pathways in spinal microglia.

The effects of montelukast on random pattern skin flap survival: An experimental study in rats

BACKGROUND

A variety of methods to improve skin flap survival, including the use of pharmacologic agents, have been intensively investigated. Decreasing neutrophil-mediated inflammation and tissue injury has been reported to be effective in improving flap survival. Montelukast is a selective reversible cysteinyl leukotriene receptor-1 antagonist that has been found to have protective effects against renal ischemia reperfusion injury and burn-induced oxidative injury of the skin in rats. However, its effects on skin flap survival have not been previously reported.

OBJECTIVE

The aim of this study was to investigate the effects of montelukast on neutrophil-mediated random pattern skin flap survival.

METHODS

Male Sprague-Dawley rats weighing 230 to 250 g were randomly divided into 2 groups-the montelukast-treated group and the control group. Caudally based rectangular random pattern skin flaps 3 × 9 cm were elevated on the backs of the rats. The flaps were sutured into their original places. In the montelukast group, 1 mL of solution containing 10 mg/kg montelukast was administered intraperitoneally (IP) 30 minutes before surgery and then daily for 6 days. In the control group, 1 mL of saline was administered IP 30 minutes before surgery and then daily for 6 days. To observe the effects of montelukast, myeloperoxidase (MPO) activity, an index of tissue neutrophil infiltration, was measured from extracted skin tissue 12 hours after flap elevation. Flap viability was evaluated 7 days after surgery by measuring necrotic flap area and total flap area.

RESULTS

Sixteen rats (mean [SD] weight, 240.6 [6.6] g) were equally divided between the 2 groups. All rats survived throughout the study period. Mean (SD) MPO activity in flap tissue was significantly lower in the montelukast group than in the control group (14.57 [2.33] vs 21.28 [4.86] U/g protein; P = 0.005). The percentage of necrotic flap area was significantly lower in the montelukast group than in the control group (17.17 [7.95] vs 37.51 [10.72]; P = 0.001).

CONCLUSION

This small, experimental, in vivo animal study found that montelukast was associated with both lower MPO activity and a lower percentage of necrotic random pattern skin flap area. Future studies are needed to clarify these findings.

Renoprotective effects of montelukast, a cysteinyl leukotriene receptor antagonist, against methotrexate-induced kidney damage in rats

Methotrexate (MTX) is a cytotoxic chemotherapeutic agent used for treatment of several cancers. Nephrotoxicity, an adverse side effect of high-dose MTX, is attributed to abnormal production of reactive oxygen species (ROS), inflammatory mediators, and neutrophil infiltration. Montelukast (MON) is a cysteinyl leukotriene receptor antagonist. Recently, it has gained a considerable interest as a ROS scavenger and inflammatory modulator. In this study, we investigated the effect of MON against MTX-induced nephrotoxicity. Rats were divided into four groups: control group, MON group (10 mg/kg, orally), MTX group (20 mg/kg, i.p., single injection), and MON + MTX group (MON was administered 5 days before and 5 days after MTX administration). At the end of the experiment, serum was collected for analysis of blood urea nitrogen (BUN) and creatinine. Glutathione (GSH), lipid peroxides (malondialdehyde), tumor necrosis factor alpha (TNF-α) levels, superoxide dismutase, myeloperoxidase activities, and nuclear factor kappa beta (NF-κB) protein expression were determined in renal tissues. In addition, kidney tissues were examined histopathologically and immunohistochemically for NF-κB. MTX administration produced acute renal damage as indicated from severe elevation in BUN and serum creatinine. The role of oxidative stress and inflammatory mechanisms in MTX-induced nephrotoxicity was evidenced from the unbalance in tissue oxidative parameters, increased TNF-α levels, and NF-κB expression in renal tissues. On the other hand, MON significantly reduced the toxic effects of MTX as indicted from normalization of kidney-specific parameters, oxidative stress, and inflammatory mediators. This data was further supported by histopathological studies. Thus, co-administration of MON may be promising in alleviating the systemic side effects of MTX.

Montelukast prevents ischaemia/reperfusion-induced ovarian damage in rats

OBJECTIVE

To investigate the efficacy of montelukast for prevention of ischaemia/reperfusion (I/R) injury in rat ovary.

STUDY DESIGN

Twenty-four female adult rats were included in the study. I/R injury was induced by CO2 pneumoperitoneum in a laparoscopic rat model. The rats were divided at random into three groups: the sham group was subjected to catheter insertion but was not subjected to pneumoperitoneum; the saline group was subjected to 60 min of pneumoperitoneum and 30 min of reperfusion, with 1 mg/kg physiological saline administered 10 min before pneumoperitoneum; and the montelukast group was subjected to 60 min of pneumoperitoneum and 30 min of reperfusion, with 20mg/kg montelukast administered 10 min before pneumoperitoneum. Damage to ovarian tissue was scored by histopathological evaluation. Caspase-3 expression was determined immunohistochemically. Ovarian tissue levels of malondialdehyde and glutathione, and plasma total antioxidant capacity were measured biochemically.

RESULTS

In comparison with the sham group, ovarian sections in the montelukast group had higher scores for follicular degeneration and oedema (p<0.001). Montelukast treatment prevented tissue damage in ovaries, and this result was significant. Caspase-3 expression was only observed in ovarian surface epithelium in the saline and montelukast groups. However, the mean caspase-3 expression score was higher in the saline group than the montelukast group (p<0.001). Tissue levels of malondialdehyde were higher in the montelukast group than the sham group, but plasma total antioxidant capacity and tissue levels of glutathione were significantly lower. Pretreatment with montelukast reduced lipid peroxidation (p<0.005) and improved antioxidant status in rats (p<0.001).

CONCLUSION

Montelukast is effective for the prevention of I/R-induced damage in rat ovary.

Oxidative stress and apoptosis in a pig model of brain death (BD) and living donation (LD)

Background

As organ shortage is increasing, the acceptance of marginal donors increases, which might result in poor organ function and patient survival. Mostly, organ damage is caused during brain death (BD), cold ischemic time (CIT) or after reperfusion due to oxidative stress or the induction of apoptosis. The aim of this study was to study a panel of genes involved in oxidative stress and apoptosis and compare these findings with immunohistochemistry from a BD and living donation (LD) pig model and after cold ischemia time (CIT).

Methods

BD was induced in pigs; after 12 h organ retrieval was performed; heart, liver and kidney tissue specimens were collected in the BD (n = 6) and in a LD model (n = 6). PCR analysis for NFKB1, GSS, SOD2, PPAR-alpha, OXSR1, BAX, BCL2L1, and HSP 70.2 was performed and immunohistochemistry used to show apoptosis and nitrosative stress induced cell damage.

Results

In heart tissue of BD BAX, BCL2L1 and HSP 70.2 increased significantly after CIT. Only SOD2 was over-expressed after CIT in BD liver tissue. In kidney tissue, BCL2L1, NFKB, OXSR1, SOD2 and HSP 70.2 expression was significantly elevated in LD. Immunohistochemistry showed a significant increase in activated Caspase 3 and nitrotyrosine positive cells after CIT in BD in liver and in kidney tissue but not in heart tissue.

Conclusion

The up-regulation of protective and apoptotic genes seems to be divergent in the different organs in the BD and LD setting; however, immunohistochemistry revealed more apoptotic and nitrotyrosine positive cells in the BD setting in liver and kidney tissue whereas in heart tissue both BD and LD showed an increase.