SIRT1 regulates intracellular signalling molecules, inhibits apoptosis, regulates inflammation and resists oxidative stress.66, 67 SIRT1 can be involved in regulating the formation of Alzheimer's disease amyloid and maintaining the stability of the neuronal genome.68, 69 Studies have reported that quercetin improve lipid, glucose metabolism and inhibits neurodegeneration through SIRT1 signalling pathway.22, 70 These results suggest SIRT1 might play a pivotal role of quercetin on DE in db/db mice. Here, SIRT1 is linked to Alzheimer disease.