The study had a double-blind, placebo-controlled, cross-over design, consisted of 2 visits, separated 30 ± 10 days. If during the first visit the drug was used, in the second visit - placebo or vice versa. Before and after procedure, safety measures (arterial blood pressure, heart rate value, and cough scale) were performed. The effect of a possible inhibitor of ROS formation was performed using corticosteroid-naive asthmatic subjects, which are more prone to oxidative stress than healthy non-smoking subjects. The study protocol was approved by the Ethics Committee of Medical University of Lodz (no. RNN/12/08/KE) and written consent was obtained from every subject prior to the study.
EBC was collected using a modification of the method described previously by Doniec et al.2005. The subjects breathed spontaneously through a mouthpiece for 20 min. Each subject wore a nose clip during this procedure. Approximately 2 ml of condensate was collected and immediately stored at -80°C until the procedure of H2O2, NO2- and NO3- measurement.
6 ml of apocynin of total dose 3 mg (0.5 mg/ml) has been nebulized through the mouthpiece with using of a nose clip.
The H2O2 concentration in EBC was measured according to the method applied previously by Nowak et al.2001. Determination of NO2- and NO3- with Griess solution was performed by micromethod, carried out in 96-well plates, according to Griess' method, modified the method described by Dziedzic et al.2003.
