ABSTRACT
Oxidative stress is said to occur when the balance between oxidants and antioxidants shifts in favour of oxidants, as a result of either an excess of oxidants and/or depletion of antioxidants. The lungs are continuously exposed to oxidants generated either endogenously (e.g., released from phagocytes) or exogenously (e.g., air pollutants or cigarette smoke). In addition, intracellular oxidants (e.g., from mitochondrial electron transport) are involved in cellular signalling pathways. The lungs are protected against this oxidative challenge by well-developed enzymatic and non-enzymatic antioxidant systems [1].
