One-electron reduction of aminochrome. The one-electron reduction of aminochrome is catalyzed by flavoenzymes that utilize NADH as an electron donor, generating leukoaminochrome o-semiquinone radical. This radical is extremely reactive with oxygen and autoxidizes by reducing molecular oxygen to superoxide radicals. This redox cycling induces oxidative stress and depletes the NADH required for the generation of energy (ATP) in the mitochondria. Redox cycling can also be catalyzed by flavoenzymes that utilize NADPH as an electron donor, depleting the NADPH required for the reduction of oxidized glutathione.
