CAT and Parkinson disease: From the literature it is revealed that elevated levels of free radicals [reactive oxygen species (ROS)], protein and lipid oxidation, DNA damage and reduced activities of superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), etc. makes DAergic neurons of patients with PD more prone to oxidative stress (OS).5,6 This respective increased and decreased activity in neurons of substantia nigra parscompacta of patients with PD leads to oxidative stress which ultimately leads to neuroinflammation.