Previously, Dr. Dexter's team has demonstrated that neurodegeneration in Parkinson's disease (PD) is associated with a process called oxidative stress. Oxidative stress is caused by either an increase in the production of highly reactive molecules called free radicals or a deficiency in antioxidants that the body normally uses to neutralize free radicals. These highly reactive free radicals can damage many cellular components. Consequently, trying to stop the damaging effects of these free radicals may be of potential benefit to Parkinson's disease patients. Current therapies to treat Parkinson's disease primarily reduce the clinical symptoms of the disease but do not stop or prevent the neuronal loss. Polyphenols are naturally occurring chemicals that are widely found in fruits, vegetables, seeds, tea, wine etc. Such chemicals have been shown to have antioxidant properties by scavenging the free radicals, binding free iron (levels of which are increased in the Parkinsonian substantia nigra) that can stimulate free radical formation, and boost the bodies own antioxidant defence mechanisms. Recently, we have demonstrated that one such citrus polyphenol, tangeretin (found in tangerines), was found in high concentrations in the brain after oral administration and it was also shown to have neuroprotective effects in an animal model of Parkinson's disease (i.e. protected the dopaminergic nerves against a toxin). This project aims to investigate further the neuroprotective effects of tangeretin and identify how it is producing such effects. Such data may support a clinical trial of tangeretin or other polyphenols in Parkinson's disease.