In 5×FAD mice, cinnamaldehyde treatment (i.p. administered) led to an improvement in AD symptoms by reducing β-site APP Cleaving Enzyme 1 (BACE1) levels through the activation of the Silent information regulator 1 (SIRT1)-peroxisome proliferator-activated receptor γ (PPARγ) coactivator 1α (PGC1α)-PPARγ pathway, suggesting that it might be a useful therapeutic approach for AD patients [54]. Here, BACE1 is linked to Alzheimer disease.