Figure 3: Radiation is interact directly or indirectly with the target, direct effect of radiation on the mitochondria through its interaction directly with DNA leading to deleterious mutations, which in turn, could mediate cancer progression. However, radian could indirectly interact with mitochondrial macromolecules and generate ROS (superoxide anion, hydrogen peroxide, and hydroxyl radicals), which have the ability to damage the mitochondrial DNA, or causing deleterious mutations. This consequently leads to impair in the mitochondrial function or the manifestations of apoptosis, aging, endothelial damage and tissue toxicity without causing a further increase in ROS.