Pulmonary function changes and immunomodulation of cytokine expression by zafirlukast after sensitization and allergen challenge in brown Norway rats

Innate immunity response of zafirlukast treated-tilapia during foreign body inflammation

There is limited knowledge regarding the blockade of cysteinyl leukotriene receptors (CysLTRs) and their effects in teleost fish. The present study investigated the effects of Zafirlukast, antagonist of CysLTR1 receptor, on the foreign body inflammatory reaction in Nile tilapia (Oreochromis niloticus). Zafirlukast-treated tilapia demonstrated a decrease in the formation of multinucleated foreign body giant cells and Langhans cells on the round glass coverslips implanted in the subcutaneous tissue, along with a significant reduction in white blood cell counts and decreased production of reactive oxygen species. There was an increase in serum levels of α2-macroglobulins, as well as a decrease in ceruloplasmin and haptoglobin. Zafirlukast treatment led to a significant decrease in the area of splenic melanomacrophage centers and a reduction in the presence of lipofuscin. These findings highlight the potential anti-inflammatory effects of zafirlukast treatment in tilapia and indicate its action on CysLTR1 receptor, modulating the innate immune response of tilapia during the foreign body reaction. The comprehension of chronic inflammation mechanisms in fish has become increasingly relevant, especially concerning the utilization of biomaterials for vaccine and drug delivery.

Montelukast abrogates rhabdomyolysis-induced acute renal failure via rectifying detrimental changes in antioxidant profile and systemic cytokines and apoptotic factors production

In addition to antiasthmatic effect, the cysteinyl leukotriene receptor 1 (CysLT₁) antagonist montelukast shows renoprotective effect during ischemia/reperfusion and cyclosporine-induced renal damage. Here, we proposed that montelukast protects against rhabdomyolysis-induced acute renal failure. Compared with saline-treated rats, at 48 h following the induction of rhabdomyolysis using intramuscular glycerol (10 ml 50% glycerol/kg), significant elevations in serum levels of urea, creatinine, phosphate and acute renal tubular necrosis were observed. This was associated with elevations in serum Fas, interleukin-10, tumor necrotic factor-alpha, and transforming growth factor-beta1 and renal malondialdehyde and nitrite and detrimental reductions in renal catalase and superoxide dismutase activities. The effects of rhabdomyolysis on renal functional, biochemical and structural integrity and the associated changes in cytokines and Fas levels were abolished upon concurrent administration of montelukast (10 mg/kg i.p.) for 3 days (1 day before and 2 days after induction of rhabdomyolysis). Alternatively, administration of the anti-oxidant, α-tocopherol (400 mg/kg i.m.) for 3 days, succeeded in alleviating renal oxidative stress, but had no significant effect on the circulating levels of most cytokines and partially restored kidney functional and structural damage. Serum level of interleukin-6 was not altered by rhabdomyolysis but showed significant elevations in rats treated with montelukast or α-tocopherol. Collectively, motelukast abrogated functional and structural renal damage induced by rhabdomyolysis via ameliorating renal oxidative stress and modulation of systemic cytokines and apoptotic factors production. The results of this work are expected to open new avenues for early prevention of rhabdomyolysis-induced acute renal failure using selective CysLT₁ antagonists such as montelukast.

Effect of erythromycin on bronchial hyperreactivity and inflammation in ovalbumin-sensitized brown Norway rats

To evaluate the effect of erythromycin on bronchial hyperreactivity, inflammation, and T-cell related cytokine mRNA expression in rats sensitized to ovalbumin, three experimental groups of 10 brown Norway rats each were sensitized by breathing aerosolized ovalbumin. From day 1 to day 15, one group was given oral erythromycin 80 mg/kg/day, another group oral erythromycin 20mg/kg/day, and the third group oral saline only. A fourth control group of 10 rats breathed aerosolized saline. After sensitization, the three experimental groups were provoked by breathing ovalbumin, with the controls again breathing saline. The rats were then anesthetized and paralyzed, and pulmonary function tests were performed at baseline and after varying doses of acetylcholine. Bronchoalveolar lavage (BAL) fluid and lung tissues were examined for expression of mRNA for T-cell cytokines. Our results showed that erythromycin had no beneficial effects on pulmonary function and lung inflammation in the two erythromycin-treated experimental groups compared with the saline experimental group. Th2-related cytokines and their mRNA expression in the three experimental groups were higher than in controls but did not differ among the experimental groups. In conclusion, erythromycin does not prevent bronchial hyperreactivity or an inflammatory response in ovalbumin-sensitized rats.

The effect of treatment with montelukast on in vitro interleukin-10 production of mononuclear cells of children with asthma

BACKGROUND

The effects of leukotriene modifiers on IL-10 production have not been studied in children with asthma.

OBJECTIVE

The primary objective of this study was to determine the changes in IL-10 concentrations, clinical efficacy and peripheral blood eosinophil counts after treatment with montelukast.

METHODS

The study was conducted on 27 patients: 13 patients monoallergic to grass pollen during the pollen season (GPs group) and out of the pollen season (GPos group), and on 14 patients monoallergic to house dust mite (HDM) from May to September (HDM group). Main outcome measures were changes in concentrations of IL-10 in the supernatant after a 4-week treatment with montelukast. Measurements of asthma severity score, forced expiratory volume in 1 s (FEV1) and peripheral blood eosinophil counts were the secondary end-points.

RESULTS

Montelukast resulted in a within-group significant increase in IL-10 concentration in the supernatant in the GPs (54.0 vs. 125.5 pg/mL) and in the HDM (51.2 vs. 77.1 pg/mL) group. Montelukast had no effect on changes of IL-10 concentration in the supernatant from peripheral blood mononuclear cell (PBMC) culture after non-sensitizing allergen stimulation. Montelukast significantly improved asthma control and FEV1, and significantly decreased eosinophil blood count in the GPs and in the HDM group after a 4-week treatment. Montelukast did not lead to changes of all measured parameters within the GPos group.

CONCLUSION

Montelukast increased IL-10 concentration in supernatants from sensitizing allergen-stimulated PBMC culture obtained from children with asthma monoallergic to grass pollen during the pollen season, and from children with asthma monoallergic to HDM.

Effect of MX-68 on airway inflammation and hyperresponsiveness in mice and guinea-pigs

MX-68 is a newly synthesized antifolate, which is a derivative of methotrexate (MTX). In this paper, the effect of MX-68 on allergic airway responses in mice and guinea-pigs was studied. In the first experiment, antigen-induced airway inflammation and airway hyperresponsiveness (AHR) to acetylcholine in mice were examined and compared with the effects of classical antifolate methotrexate and prednisolone. Mice were sensitized with ovalbumin as an antigen and challenged with ovalbumin inhalation three times. After the last inhalation, AHR and airway inflammation were observed. An increase in Th2 cytokines (IL-4 and IL-5) and a decrease in a Th1 cytokine (IFN-gamma) in the bronchoalveolar lavage fluid (BALF), as well as an elevation of the immunoglobulin level in serum, were observed in sensitized mice. Oral administration of MX-68 had no effect on changes of body weight, but prednisolone reduced body weight during the experiment. The antigen-induced AHR and increases in the number of eosinophils and lymphocytes in BALF were significantly inhibited by MX-68. MX-68 interfered with the elevation of IL-4 and IL-5 levels in BALF, but had no effect on the decrease in IFN-gamma. Moreover, MX-68 significantly inhibited the elevation of serum IgE and IgG levels. In the guinea-pig model for bronchial asthma, biphasic increases in airway resistance (immediate asthmatic response, IAR, and late asthmatic response, LAR), as well as accumulated inflammatory cells in BALF, were observed after repeated antigen challenge. These asthmatic responses and inflammatory signs were significantly decreased by administration of MX-68. These results suggest that MX-68 obviously has an anti-inflammatory effect in an animal model of asthma and would be useful clinically for the treatment of bronchial asthma.

Leukotriene receptor antagonism in experimental acute pancreatitis in rats

OBJECTIVES

Acute pancreatitis is a multifactorial disease caused by activation of several inflammatory mediators. Leukotrienes, beside other mediators, may be involved in acute pancreatitis. The aim of this study was to investigate the effects of 'zafirlukast', a leukotriene receptor antagonist, in acute pancreatitis and its relation with prostaglandin synthesis.

METHODS

Eighty rats were randomly divided into eight groups. Acute pancreatitis was induced by subcutaneous injection of cerulein (20 microg/kg), four times at 1-h intervals. Zafirlukast (20 mg/kg) was applied intraperitoneally as a pretreatment. Prostaglandin synthesis was inhibited by low-dose indomethacin (5 mg/kg subcutaneously). Pancreatic histopathology, serum amylase activity and pancreatic myeloperoxidase activity were determined to assess the severity of pancreatitis.

RESULTS

Zafirlukast pretreatment alone did not induce any inflammation and fatty necrosis in pancreatic tissue. However, it increased the histopathological score from 3.70 +/- 0.57 to 6.62 +/- 0.53 in rats with acute pancreatitis (P < 0.001). Fatty necrosis was especially prominent in the zafirlukast-treated acute pancreatitis group compared with the untreated group (2.62 +/- 0.26 versus 0.40 +/- 0.22, respectively; P < 0.001). Inhibition of prostaglandin synthesis by indomethacin partially suppressed the harmful effects of zafirlukast in acute pancreatitis. It decreased the pathological score (4.62 +/- 0.73) and fatty necrosis (1.50 +/- 0.32) in that group.

CONCLUSION

Interestingly, leukotriene receptor antagonism by zafirlukast increased the pancreatic histopathological score and fatty necrosis in rats with acute pancreatitis. Blocking of cysteinyl leukotriene receptors might cause an induction of mediator synthesis via other pathways. Effects of leukotriene receptor antagonism on the pancreas must be evaluated extensively in further studies.