Glutathione peroxidase (GPx) is a reactive oxygen species (ROS), generated by bodily cells via mitochondrial and enzymatic sources. It is vital that GPx levels are reviewed as it can cause oxidative damage to membrane lipids, proteins and DNA. GPx is an intracellular antioxidant enzyme that enzymatically converts hydrogen peroxide to water (detoxification). Hydrogen peroxidase is vital for the maintenance of normal thiol redox-balance, mitochondrial function, and growth factor-mediated signal transduction. By converting hydrogen peroxidase to water, GPx aids in modulating these processes ¹. GPx also contributes to cell signalling and oxidative protein folding ².

Four of the eight glutathione peroxidases (GPx) are selenoproteins (containing the amino acid form of selenium, Sec) in humans, however, GPx6 is cysteine-containing in rodents, but a selenoprotein in humans, whereas the remaining GPx’s are cysteine containing. Glutathione peroxidase 4 (GPx4) is emerging as one of the most important seleoproteins in mammals and is one of the key regulators of ferroptosis, a form of regulated necrotic cell death ².

GPx displays an inverse correlation with free radicals and consequently oxidative stress (OS). When GPx activity is reduced, antioxidant protection is impaired, resulting in oxidative damage to the membrane fatty acids and functional proteins, resulting in neurotoxic damage. Decreased GPx activity and OS is implicated in the incidence and progression of several health problems, including: cardiovascular disease (CVD), diabetes, atherosclerosis, neurodegenerative disorders and other chronic conditions ³.