Figure 1.

Development of oxidative stress. In physiological conditions, ROS remain at low levels by the effect of antioxidants such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSHPx). However, during oxidative stress, ROS levels rise, due to either higher production or impaired antioxidant defense (or both), and this results in the accumulation of damaged biomolecules. Such events are detrimental and either drive or exacerbate diseases such as neurodegenerative disorders.