MAPT and Alzheimer disease: In this study, we demonstrate that Erzhi pills can improve serum levels of oestrogen, regulate the PI3K/AKT signalling pathway in the hippocampus, reduce Aβ deposition in the brain, inhibit the over-phosphorylation of Tau protein, maintain the morphology of hippocampal neurons, and attenuate the apoptosis of hippocampal neurons, thereby improving learning, memory, and cognitive function, in AD rats.