A b s t r a c t Oxidative stress and apoptosis contribute to neuronal degeneration in many neurodegenerative diseases such as Alzheimer's disease. Glutamate is a major excitatory neurotransmitter in the central nervous system (CNS) and is considered responsible for the pathogenesis of many neurological disorders. Reactive oxygen species (ROS) production is thought to be involved in glutamate-induced apoptosis process. In this study, the neuroprotective effects of Citrus aurantium in the glutamate-induced rat's adrenal pheochromocytoma cell line (PC12 cells) were investigated. The cell viability and apoptotic cell death were measured using MTT and propidium iodine (PI)