The Redox Process in Red Blood Cells: Balancing Oxidants and Antioxidants

Red blood cells (RBCs) are a vital component of the body's oxygen supply system. In addition to being pro-oxidants, they are also essential components of the body's antioxidant defense mechanism. RBCs are susceptible to both endogenous and exogenous sources of oxidants. Oxyhemoglobin autoxidation is the primary source of endogenous RBC oxidant production, which produces superoxide radicals and hydrogen peroxide. Potent exogenous oxidants from other blood cells and the surrounding endothelium can also enter RBCs. Both enzymatic (like glutathione peroxidase) and non-enzymatic (like glutathione) mechanisms can neutralize oxidants. These systems are generally referred to as oxidant scavengers or antioxidants, and they work to neutralize these harmful molecules (i.e., oxidants). While their antioxidative capabilities are essential to their physiological functions and delivering oxygen to tissues, their pro-oxidant behavior plays a part in several human pathologies. The redox-related changes in RBCs can have an impact on their function and fate. The balance between pro-oxidants and antioxidants determines the oxidative status of cells, which affects signal transduction, differentiation, and proliferation. When pro-oxidant activity exceeds antioxidative capacity, oxidative stress occurs, leading to cytotoxicity. This type of stress has been linked to various pathologies, including hemolytic anemia. This review compiles the most recent literature investigating the connections between RBC redox biochemistry, antioxidants, and diverse disorders.