GSR and Parkinson disease: GSH as the most important antioxidant factor plays a critical role to protect neurons from stress disturbances; meanwhile, As and interactions with GSH contents and related enzymes have connected changes with neurodegenerative disorders such as Alzheimer's disease, schizophrenia, and Parkinson's disease [54], because of reduced GPx and glutathione reductase that convert GSH to GSSG form.