Abstract: A transgenic fly whose genome is modified to express enhanced levels of glutamate-cysteine ligase (GCL) gene is provided. The fly displays phenotypes associated with Alzheimer's disease (AD). Further, a method for diagnosing AD is provided, which includes assessing enzymatic activities in mitochondrial enzymes. Glutathione pathway are investigated by creating Alzheimer's model Drosophila with over-expression of the GCLc gene, inducing redox stress through sleep deprivation, and analyzing mitochondrial electron transport chain (ETC) using colorimetric enzymatic assays. For prevention of AD, it is proposed that the epigenetic approaches be used to increase glutathione levels in vivo before the onset of AD. For treatment of AD, it is proposed that the glutathione levels be increased by GCLc modulation.