Oxidative stress
Oxidative or oxidant stress (or oxidative pressure) is a type of aggression involving the cell’s constituents. It occurs when reactive oxygen species (or free radicals) and/or reactive oxygen species and nitrogen oxidising species penetrate the cell or are formed there. These molecules are unstable and very cytotoxic because they « oxidise » other molecules by subtracting an electron from them, which in turn makes them unstable.