Quercetin, as the typical representative of flavonoids, could effectively alleviate AD symptoms and AD-like lesions by combating OS and inflammation through stimulating the Nrf2/HO-1 signal and ARE depended-gene expression in AD, as well as inactivating ERK1/2 and NF-κB pathways [42, 137]; at the same time, quercetin had excellent abilities to AD improvement through suppressing the release of high mobility group box 1, receptor for advanced glycation end products, NF-κB and inflammatory cytokines (like IL-4, IL-1 and TNF-α) [137]. Here, IL4 is linked to Alzheimer disease.