In our body, the antioxidant system is a key protective mechanism that helps us fight off free radical attacks. Free radicals are molecules with unpaired electrons that are constantly produced in the body and can damage cells. To fight off these free radicals, our bodies utilize antioxidant enzymes such as superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), and catalase (CAT) to remove them.
Superoxide dismutase (SOD) is a metalloproteinase that catalyzes the disproportionation reaction of superoxide anion radicals to produce oxygen and hydrogen peroxide. This reaction can reduce the number of superoxide anion radicals, thereby mitigating their damage to cells. Therefore, SOD plays an important role in fighting oxidative stress.
Glutathione peroxidase (GSH-PX) is a selenium-containing enzyme that catalyzes the reduction of hydrogen peroxide and glutathione to remove peroxide. This reaction can reduce the number of peroxide radicals and prevent them from damaging the cells. In addition, GSH-PX further protects the integrity of cell membranes by scavenging hydroxide ions and preventing them from reacting with lipids.
Catalase (CAT) is an inorganic enzyme containing heme that catalyzes the breakdown of hydrogen peroxide into water and oxygen. CAT works by quickly removing hydrogen peroxide, preventing it from accumulating and damaging cells.
Collectively, these three antioxidant enzymes play a key protective role in our body. Together, they form a powerful antioxidant system that helps us fight off free radical attacks and protect our cells from damage. However, with age and environmental factors, the activity of these enzymes may decrease, leading to the accumulation of free radicals and cell damage. Therefore, understanding and maintaining the activity of these enzymes is essential to maintain our health.