Methods: Female BALB/c mice were sensitized with seven i.p. injections of 1 mg/kg (taken in protein equivalents) of G6-extract and later on were challenged with eight intranasal applications (IA) of G6 in concentration of 10 mg/ml. Between sensitization and IA periods different groups of mice were treated with s.c. injections of Timpol in total doses: 4, 40 400, and 4000 μg/kg. Two control groups obtained ASIT with either G6 (total dose 19.7 mg/kg) or saline only. The levels of serum anti-G6 IgE/IgG antibodies (Ab) were detected by ELISA. After IA lungs were taken for histological examination, bronchial hyper-reactivity to metacholine was assessed by non-invasive pneumography and cell composition in bronchoalveolar lavage (BAL) was evaluated by microscopy.
Results: Anti-G6 IgE Ab were elevated in all groups in the beginning of ASIT and slightly decreased at the end of treatment. After IA the levels of anti-G6 IgE in groups treated with G6 and Timpol (doses 40 and 400 µg/kg) were similar to that of control group (saline). Anti-G6 IgG Ab have been increasing during ASIT in all groups. The highest level of anti-G6 IgG was noticed after IA in groups treated with Timpol (doses 4 and 40 µg/kg). All groups of mice treated with Timpol demonstrated reduction of allergic inflammation in lungs in comparison to the control group (saline). ASIT with Timpol in doses 4 and 40 µg/kg reduced eosinophil and inflammatory cell count in BAL. ASIT with Timpol in doses 4, 40 and 400 µg/kg demonstrated improvement of lung function assessed by pneumography.
Conclusions: Data obtained support the conception that ASIT with Timpol especially in dose 40 µg/kg may be effective approach for treatment of mild asthma in humans.