As shown in Figure 4D, ECH treatment significantly reduced sAPPβ in the brains of 2 × Tg-AD mice relative to the vehicle-treated 2 × Tg-AD mice (P = 0.008), which was consistent with the results of BACE1 protein level and activity, strongly suggesting that ECH decreases Aβ by modulating APP processing through the inhibition of the BACE1-mediated cleavage of APP for the amyloidogenic pathway. Here, APP is linked to Alzheimer disease.