Figure 3.

Sourcesof reactive oxygen species (ROS) that lead to oxidative stress and promote aging. Several endogenous and exogenous factors contribute to excess ROS formation. Any imbalance between the production of free radicals and ROS and their elimination by antioxidant systems can cause oxidative stress that ultimately promotes accelerated aging phenotypes through oxidative macromolecular alterations, such as the exemplary alterations depicted in the bottom right part of the figure.