APP and Alzheimer disease: SIRT1 is involved in the regulation of APP processing and the clearance of Aβ and its activation provides neuroprotection [90].SIRT1 modulates tau phosphorylation by deacetylating tau protein and influencing the activity of kinases and phosphatases, such as PP2A activation leading to a decrease in tau phosphorylation [91].SIRT1 regulates neuroinflammation via NF-κB [52,92], highly expressed in AD.SIRT1 promotes mitochondrial biogenesis via activation of mitochondrial PGC-1α gene expression [93], which may lead to a reduction in oxidative stress reported in AD.