Studies found that drinking water containing 100 mg/L berberine exerted a strong neuroprotective effect, improving cognitive deficits, inhibiting the apoptosis of neurons, and promoting the formation of micro-vessels by restoring cerebral blood flow and reducing Aβ accumulation in an APP/tau/PS-1 mouse model of AD (Ye et al., 2021). This evidence concerns the gene MAPT and Alzheimer disease.