There is many evidence that inhalation of high
oxygen concentration has a toxic influence on pulmonary function and structures.
Hyperoxia-induced oxidative stress is well characterized in rodents and has been used as a valuable model of human
respiratory distress syndrome. We have previously shown that hyperoxic exposure of guinea pigs is associated with suppression of
cough reflex. The goal of this study was to determine the effects of dietary intake of
antioxidant flavonoids (
Flavin7, Vita Crystal Slovakia Ltd., 2 ml/kg b.w.) on
hyperoxia-induced oxidative stress in lung tissue directed on
cough reflex. The experimental group (n = 8) was pretreated with
Flavin7 as a single daily dose for 14 days and subsequently exposed to 100% 02 for 60 h. Hyperoxic group (n = 8) inhaled 100% Oz only. Control group (n = 8) was exposed to normoxia.
Cough was induced by inhalation of
citric acid aerosol at time before and after exposure to
hyperoxia.
Cough was also induced by mechanical stimulation of airways in anaesthetized animals just after the end of
oxygen exposition. When to compare animal groups before and after
hyperoxia, our results have shown a significant decrease 2 (1-6) vs 6 (4-6) p = 0.041 in
citric acid-induced
cough in hyperoxic animals and no significant changes 8 (5.5-8.5) vs 5 (4-6.5) p = 0.055 in animals with
antioxidant therapy. Mechanically-induced
cough after
hyperoxia was not influenced by substitution with
flavonoids. In conclusion, our results indicate that
flavonoids attenuated
hyperoxia-induced down-regulation especially of chemically-induced
cough (Tab. 2, Fig. 2, Ref. 30). Full Text (Free, PDF) www.bmj.sk.