Ginsenoside Rb-1's neuroprotective effects on memory and cognitive function in Alzheimer's disease rats were correlated with reduced apoptosis of hippocampal neurons and upregulation of the expression of antioxidant Nrf2, HO-1, and NAD(P)H quinone dehydrogenase-1 (NQO1) genes, increasing the activities of CAT, GSH, and SOD protein enzymes [155]. Here, SOD1 is linked to Alzheimer disease.