Neuroprotective, anti-apoptotic effects of apomorphine.

There is increasing experimental and clinical evidence that oxidation plays a pivotal role in causing neurodegeneration in general and Parkinson's disease in particular. The protective role of antioxidants in such conditions has not been fully examined, but certain neuroprotective agents that have antioxidant action are now being credited with an ability to prevent oxidation-induced neuronal dysfunction. One such agent is the dopamine agonist apomorphine, which is already in clinical use, providing symptomatic relief in Parkinson's disease patients. Far from having simple antioxidants properties, apomorphine is described as a pluripotent agent that can also afford neuroprotection through mechanisms independent of its antioxidant actions. It can, for example, salvage dopaminergic receptors and terminals, upregulate expression of neurotrophic factors, limit the rate of neuronal loss by interfering with several steps of apoptotic cascades, reduce excitotoxicity by modulating nitric oxide metabolism, and reverse ubiquitine-proteasome dependent pathology. This paper reviews the wide range of apomorphine's neuroprotective benefits, suggesting that it is a promising agent with regards to its potential to prevent, reduce, and retard age-related neurodegeneration.