Disturbances in DNA methylation are postulated to result in various central nervous system diseases including Alzheimer's disease (AD). The SH-SY5Y neuronal cell line treated with Aβ1-40 (5 μmol/L) protein is considered to be a model of AD. Hence the aim of this study was to examine the influence of Schizandrol A, a plant extract, on DNA methylation in SH-SY5Y cells exposed to Aβ1-40. Aβ1-40 were incubated with varying concentrations of Sehizandrol A to a final concentration of 1 (low), 3 (intermediate) or 9 μg/ml (high). Exposure of SH-SY5Y with Aβ1-40 reduced viability, and altered cellular morphology and mRNA expression of DNA methyltransferase (DNMT3A) and DNMT3B. Treatment with 1 or 3 μg/ml Sehizandrol A resulted in normal cell morphology as well as elevated cell number, enhanced viability, and increased mRNA expression of DNMT3A and DNMT3B compared to saline. However, an increase in Sehizandrol A to 9 μg/ml produced a fall in cell viability, as well as a decrease in mRNA DNMT3A and DNMT3B expression to control levels. Data demonstrated that Schizandrol A at 1 or 3 μg/ml improved cell morphological appearance and viability of Aβ1-40 injured SH-SY5Y cells by an enhanced DNA methylation pathway.