L-Dopa from the beans Vicia faba and Mucuna pruriens as an Active Substance against Parkinson's Disease

Levodopa (L-dopa) was isolated and first structurally elucidated in detail from the beans of Vicia faba, the broad bean, by Markus Guggenheim in 1913, followed by the development of a chemical synthesis or this compound. The therapeutical potential of L-dopa for the treatment of Parkinson's disease as a precursor of the neurotransmitter dopamine was realized in the 1960s, when first trials with patients were conducted. Later on, the efficacy of L-dopa was further increased by the concomitant application of a peripheral decarboxylase inhibitor. Due to long-term complications of synthetic L-dopa, especially dyskinesia and a decrease of efficacy with time, several research groups looked for alternative treatments with fewer side effects. The beans of Mucuna pruriens, the cowhage or velvet bean, known from ancient Indian Ayurvedic medicine, have been identified as a rich source of L- dopa. The seeds of M. pruriens contain even more L-dopa than the bean of V. faba. M. pruriens extracts showed high antiparkinsonian activities with fewer side effects than synthetic L-dopa in animals and in first studies with humans. Also, neuroprotective properties in vitro were reported which are attributed to tetrahydroisoquinoline derivatives also present in the seeds. Today, an M. pruriens preparation is approved in India. M. pruriens extracts might also become a valuable remedy for the treatment of Parkinson's disease in Europe, but more clinical trials with high numbers of patients are urgently needed prior to an approval in order to further demonstrate the efficacy and safety. Copyright © 2010 S. Karger AG.