Cellular respiration itself produces, as a by-product, highly reactive oxygen-derived molecules: the superoxide anion, hydrogen peroxide or the hydroxyl radical. In moderate amounts they serve as signals. The problem arises when more build up than the defence systems can neutralise.
Those defences include enzymes (superoxide dismutase, catalase, glutathione peroxidase) and molecules such as glutathione, the main intracellular antioxidant. When they are overwhelmed, reactive species oxidise membrane lipids (including mitochondrial cardiolipin), proteins and DNA.
Oxidative stress appears in ageing and in many diseases, which makes it a frequent target. However, trials with generic antioxidants have been disappointing, and interest has shifted towards strategies aimed at the source, such as the mitochondrion.
A compound being “antioxidant” in a test tube says little. What matters is where it acts, whether it reaches that place in the body and whether it reduces measurable damage.
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Definition for educational and scientific purposes. It is not medical advice or a recommendation for use. NeoPeptidos products are sold labelled for research use only (RUO).