The differences were significant in the middle-dose (P < 0.05) and high-dose OMO groups (P < 0.01), suggesting that the OMO treatment can decrease the expression levels of APP, tau, and caspase-3 and increase the SYP protein in the hippocampus of AD rats, especially in the high-dose OMO group. This evidence concerns the gene SYP and Alzheimer disease.