The contribution of the WNT pathway to the therapeutic effects of montelukast in experimental murine airway inflammation induced by ovalbumin and lipopolysaccharide.

The wingless/integrase-1 (WNT) pathway involved in the pathogenesis of inflammatory airway diseases has recently generated considerable research interest. Montelukast, a leukotriene receptor antagonist, provides therapeutic benefits in allergic asthma involving eosinophils. We aimed to investigate the role of the WNT pathway in the therapeutic actions of montelukast (MT) in a mixed type of allergic-acute airway inflammation model induced by ovalbumin (OVA) and lipopolysaccharide (LPS) in mice. Female mice were sensitized with intraperitoneal OVA-Al(OH)3 administration in the initiation phase and intranasal OVA followed by LPS administration in the challenge phase. The mice were divided into eight groups: control, asthmatic, and control/asthmatic treated with XAV939 (inhibitor of the canonical WNT pathway), LGK-974 (inhibitor of the secretion of WNT ligands), or MT at different doses. The inhibition of the WNT pathway prevented tracheal 5-HT and bradykinin hyperreactivity, while only the inhibition of the canonical WNT pathway partially reduced 5-HT and bradykinin contractions compared to the inflammation group. Therefore, MT treatment hindered 5-HT and bradykinin hyperreactivity associated with airway inflammation. Furthermore, MT prevented the increases in the phosphorylated GSK-3ß and WNT5A levels, which had been induced by airway inflammation, in a dose-dependent manner. Conversely, the MT application caused a further increase in the fibronectin levels, while there was no significant alteration in the phosphorylation of the Smad-2 levels in the isolated lungs of the mice. The MT treatment reversed the increase in the mRNA expression levels of interleukin-17A. An increase in eosinophil and neutrophil counts was observed in bronchoalveolar lavage fluid samples obtained from the mice in the inflammation group, which was hampered by the MT treatment. The inhibition of the WNT pathway did not alter inflammatory cytokine expression or cell infiltration. The WNT pathway mediated the therapeutic effects of MT due to the inhibition of GSK-3ß phosphorylation as well as the reduction of WNT5A levels in a murine airway inflammation model.

The effect of simvastatin on picrotoxin-induced seizure in mice.

OBJECTIVE: To study the effect of simvastatin on picrotoxin-induce seizures in mice in order to understand the impact of gabaergic system on neuronal cell death. METHODS: The study was held between July and September 2011, at the Karadeniz Technical University in Trabzon, Turkey. Balb/c mice weighting 20-40g were randomly selected and divided into five groups of six each. The first group was designated as control group; and the second as the picrotoxin (10mg/kg; intraperitoneal) alone group. The rest of the groups were administered simvastatin in dozes of 10, 20 and 40mg/kg respectively. Onset, number and duration of seizures, and death time were measured in mice for one hour. At the end of the study, the brain was removed from mice and normal and degenerative pyramidal neurons were counted in hippocampal CA1, CA2, CA3 region by light microscope. Using SPSS 17, Mann=Whitney U and Chi square and student-T tests were performed for statistical analysis. RESULTS: Simvastatin (10mg/kg) significantly decreased the number and duration of picrotoxin-induced seizures in mice. In addition, Simvastatin (10, 20, and 40mg/kg) significantly reduced the total number of abnormal pyramidal cells in CA1 and CA3 hippocampal regions compared to the picrotoxin-alone group. CONCLUSION: The effect of simvastatin on picrotoxin-induced seizures may be the result of increase in gabaergic activity and decrease in glutamatergic activity. More studies are needed to validate these results.