Figure 1.

Origin of ROS and RNS and oxidative stress in bronchial asthma (BA). Chronic inflammation in BA is characterized by the overproduction of ROS/RNS as a consequence of increased activation of immune and non-immune cells in cellular inflammatory infiltrate. Various exogenous factors promote and amplify the inflammation and also increased the formation of reactive species via many mechanisms (e.g., induction of mitochondrial dysfunction, DNA repair mechanisms damage). Chronic inflammation decreases the capacity of endogenous antioxidant defense mechanisms, which are not able to compensate overproduction of ROS/RNS. This leads to the accumulation of the changes in biomolecules with structural and functional consequences. Abbreviations: NO, nitric oxide; RNS, reactive nitrogen species; ROS, reactive oxygen species.