Table 3: Different classes of prooxidants and their common mechanism for development of oxidative stress.

Sl. numberClass ExamplesMechanism

(1)DrugsCommon over-the-counter drug like analgesic (paracetamol) or anticancerous drug (methotrexate)ROS generation leading to alterations in macromolecules which finally can fatally damage the tissues mainly liver and kidney

(2)Transition metalsMagnesium, iron, copper, zinc, and so forthThese metals induce Fenton reaction and Haber-Weiss reaction leading to generation of excessive ROS. Chronic magnesium is a classic prooxidant disease. The other can be hemochromatosis due to high iron levels or Wilson disease due to copper

(3)PesticideBHC, DDT, and so forthStimulation of free radical production, induction of lipid peroxidation, alterations in antioxidant enzymes and the glutathione redox system

(4)Physical exerciseRunning, weight liftingRelaxationcontraction of muscle involves production of ROS. Rigorous exercise leads to excessive ROS

(5)Mental anxietyTension, apprehensionImbalance in the redox system plays a role in neuroinflammation and neurodegeneration, mitochondrial dysfunction, altered neuronal signaling, and inhibition of neurogenesis

(6)PathophysiologyLocal ischemiaGives rise to increased ROS generation

(7)Environmental factorExtreme weather (heat, cold, thunderstorm)During adaptation, mitochondrial membrane fluidity decreases which may disrupt the transfer of electrons, thereby increasing the production of ROS

(8)Antioxidants Ascorbic acid, vitamin E, polyphenolsAct as prooxidant under certain circumstances, for example, heavy metals