The effects of fexofenadine on eosinophilia and systemic anaphylaxis in mice infected with Trichinella spiralis

Abstract Background : The effects of the non-impairing, H 1 -receptor antagonist fexofenadine were investigated in in vivo mouse models of eosinophilia and systemic anaphylaxis. Methods : Eosinophilia was investigated in C57BL/6 mice ( n =5 per group) infected with Trichinella spiralis , with and without administration of fexofenadine HCl (5, 10 and 20 mg/kg/day). Eosinophilia was also studied, with and without fexofenadine administration, in mice with a congenital mast-cell deficiency (W/W v ) and controls (+/+). The effect of fexofenadine HCl (20 mg/kg/day) on IL-5 and eotaxin blood levels was also investigated in C57BL/6 mice. In a separate model, systemic anaphylaxis was induced in C57BL/6 mice using T. spiralis antigen. Fexofenadine HCl (5, 10 and 20 mg/kg) or vehicle was administered 20 min before antigen challenge ( n =5 per group). The effect of fexofenadine on systemic anaphylaxis caused by IgE and anti-IgE was also examined in CBF1 mice injected with serum from NC/Nga mice with high IgE levels. Rectal temperature was measured as an indicator of anaphylaxis. Results : In C57BL/6 mice, repetitive oral administration of fexofenadine HCl (5, 10 and 20 mg/kg/day) resulted in dose-dependent suppression of eosinophilia ( p v mice. In addition, single oral administration of fexofenadine HCl (10 and 20 mg/kg) significantly suppressed the decrease in rectal temperature ( p p p Conclusion : These results indicate that fexofenadine suppresses both eosinophilia and systemic anaphylaxis, both of which are fundamental reactions in allergic diseases.