MTOR and Parkinson disease: Although several mechanism studies have proved the protective effect of selenium on PD, for example increasing levels of antioxidant enzyme and GSH [48, 49], reducing dopamine loss [7, 8] and maintaining cellular DNA integrity [9], evidence also indicated that different concentrations of selenium have opposite effects on neuron, high dose of selenium is deemed toxic and will in turn promote oxidative stress, inhibitng mTOR activation, causing p62 and ubiquitin accumulation, eventually promoting autophagy [50].