Mechanisms of Cell Damage and Human Aging

Evidences suggest that one of the links between many different types of cells and tissues demage is
the action of reactive oxygen species (ROS), which are generated as by-products of the essential use
of oxygen by the human body to produce metabolic energy (Martin et al., 1996; von Zglinicki et al.,
2001).
Both oxygen free radicals (ROS) and reactive nitrogen species (RNS) are derived from endogenous
sources (mitochondria, peroxisomes, endoplasmic reticulum, phagocytic cells, etc.) and exogenous
sources such as pollutants, alcohol, tabaco smoke, heavy metals, transition metals, pesticides, certain
medicines such as halotan, paracetamol, and radiation). These substances can adversily affect
various classes of important biological molecules, as nucleic acids, lipids and proteins, altering the
normal redox state increasing oxidative stress (Phaniendra et al., 2015).