Generation of reactive oxygen species and their impact on the health related parameters: A critical review
By: Muhammad Usman Khan, Nuareen Aziz Qurashi, Muhammad Saleem Khan, Farhat Jabeen, Ali Umar, Junaid Yaqoob, Muhammad Wajid
Key Words: Reactive oxygen species, Oxidative stress, Sources, Impact, Health disorders.
Int. J. Biosci. 9(1), 303-323, July 2016.
Reactive oxygen species (ROS) are highly reactive molecules produced during cellular metabolism and due to some environmental factors. These species have ability to induce damage in vital molecules. The body has several antioxidant systems to cope with but imbalance of oxidants and antioxidants creates a condition commonly known as oxidative stress. The excess production of ROS is the main cause of oxidative stress. In last forty years, oxidative stress was considered as major factors for pathological disorders and ageing. In body, ROS have dual role either beneficial or harmful in the biological systems. They either act as beneficial (NO•) in the form of signaling or harmful producing the health disorders. Mitochondrion is the major site for ROS production. The other sources include peroxisomes, endoplasmic reticulum, membrane and cytosol. ROS are studying for their pathogenesis of obesity, diabetes, cancer, inflammation, cardiovascular disease, neurodegenerative disorders and aging. In this review, sources, causes and consequences of superoxide radical, singlet oxygen, ozone, hydrogen peroxide, hydroxyl radical, peroxynitrite, peroxyl and alkoyl radicals and reactive nitrogen species are critically analyzed and discussed in details