Monoamine oxidase B (MAO-B) inhibitors have an established role in the treatment of
Parkinson's disease as monotherapy or adjuvant to levodopa. Two major recognitions
were required for their introduction into this therapeutic field. The first was the
elucidation of the novel pharmacological properties of selegiline as a selective MAO-B
inhibitor by Knoll and Magyar and the original idea of Riederer and Youdim, supported
by Birkmayer, to explore its effect in parkinsonian patients with on-off phases. In
the 1960s, MAO inhibitors were mainly studied as potential antidepressants, but Birkmayer
found that combined use of levodopa and various MAO inhibitors improved akinesia in
Parkinson's disease. However, the serious side effects of the first non-selective
MAO inhibitors prevented their further use. Later studies demonstrated that MAO-B,
mainly located in glial cells, is important for dopamine metabolism in the brain.
Recently, cell and molecular studies revealed interesting properties of selegiline
opening new possibilities for neuroprotective mechanisms and a disease-modifying effect
of MAO-B inhibitors.
