Oxidative stress

Oxidative stress is referred to as a metabolic state in which increased amounts of reactive oxygen compounds are present. These are mainly the superoxide radical O2−, hydrogen peroxide (H2O2) and the hydroxyl radical OH. These radicals are formed during the metabolic processes of the mitochondrial electron transport chain and by cytochrome P450 oxidases. Body cells usually contain so-called antioxidants that act as radical scavengers and can neutralise reducing or oxidising substances. If some or all of these substances are missing, normal repair and detoxification functions in the cell are overburdened and the cell is damaged. This situation is referred to as oxidative stress.

The consequence of oxidative stress is lipid peroxidation, which ultimately leads to cells expending more energy to stabilise the membrane potential. Other consequences are protein oxidation and DNA damage. These processes have a great effect on ageing and life expectancy. The attack of fatty acids by free radicals contributes to the development of arteriosclerosis. It is believed that oxidative stress is also involved in the development of cancer, disorders of the immune system as well as in rheumatic and neurodegenerative diseases. On the other hand, reactive oxygen species are, for example, involved in the elimination and digestion of microorganisms during phagocytosis. During the so-called "oxidative burst", target structures are specifically oxidised and destroyed in the phagolysosomes of macrophages.