Dietary intake of flavonoids and hyperoxia-induced oxidative stress related cough in guinea pigs.

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.