The
cytochrome P450 (CYP)
enzymes are a diverse group of
heme monooxygenases that, through the course of their reaction cycle, contribute to cellular
reactive oxygen species (ROS). CYP
enzymes play a crucial role in human physiology and are involved in drug and
xenobiotic metabolism as well as biosynthesis of endogenous molecules and are expressed throughout the human body. However, during the course of the CYP catalytic cycle, ROS can be generated through uncoupling of the enzymatic cycle. ROS is known to modify endogenous molecules, included
lipids,
proteins, and
nucleic acids, which can lead to cell damage and death and contribute to disease development. ROS has been implicated in a wide range of diseases and conditions, including
cancer and ageing, but ROS also play a role in the normal physiological functions in the cell. Here, we discuss specific examples whereby ROS generated by CYPs contribute to or protect against various phenomena, such as hyperoxic
lung injury, oxidative hepatic toxicity, formation of
DNA adducts from lipid peroxidation products. We have also discussed the mechanistic roles of CYP
enzymes belonging to various families, and their effect on cellular ROS production, in relation to normal cellular function as well as disease pathophysiology.