The approach to the treatment of Parkinson's disease is slowly but steadily moving away from symptomatic treatment to neuroprotective therapy. To understand the concept of neuroprotection, it is imperative to understand the mechanism of neuronal death in Parkinson's disease.
Biochemical abnormalities presumed to play a role in degeneration of nigral neurons include loss of mitochondrial complex I, accumulation of iron in the substantia nigra, and possible increase in oxygen free radical formation. In addition, the existence of a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-type neurotoxin cannot be excluded.
Neuroprotective agents which may be potentially useful in Parkinson's disease include monoamine oxidase B inhibitors, iron chelators, dopamine transporter blockers, antioxidants, N-methyl-D-aspartate (NMDA) receptor antagonists, and neurotrophic factors. Although most of these agents are still in the experimental stage, there is initial evidence that some may be of use as future neuroprotective therapies.