“…In addition, decreased antioxidant enzyme activity of enzymes like glutathione peroxidase (GPx) and superoxide dismutase (SOD) causes oxidative stress damage during morphine administration [ 8 ]. In vivo experiments in rats have established that oxidative stress results in neurodegeneration in multiple brain areas, including the hippocampus, nucleus accumbens, and cerebral cortex, related to morphine-induced apoptosis [ 7 , 9 , 10 ].…”