Parkinson's disease and Mucuna pruriens L.

Qualitative and quantitative determination of L-DOPA in commercial preparations from seeds of Mucuna pruriens L.

Analysis carried out for the study presented as a poster at the LIMPE Congress in November 2014, in Salerno.
Then published on Clinical Neuropharmacology with the title:


Mucuna pruriens in Parkinson's disease: a kinetic-dynamic comparison with levodopa standard formulations

About the authors:


Manuela Contin1-2, PharmD, Giovanna Lopane1, MD, Andrea Passini3, BS, Ferruccio Poli3, ScD, Carmelina Iannello3, PhD, Maria Guarino4, MD.

1IRCCS-ISNB Institute of Neurological Sciences of Bologna; 2Department of Biomedical and Neuromotor Sciences, University of Bologna; 3Department of Pharmacy and Biotechnology, University of Bologna; 4Neurology Unit St.Orsola-Malpighi Hospital, University of Bologna.

The discovery of the healing properties of medicinal herbs accompanies the human being from its origins. The observation of the behaviors of the other animals and the often casual uses led him to use the plants to cure the illnesses he encountered along his path.
In recent decades, herbal medicine has been reassessed considerably, especially at the popular level where people, worried about the side effects of drug therapies or their poor results and conquered by the general tendency of the return to "Nature", prefer to take herbal remedies even if, often, with "do-it-yourself" therapies.
Furthermore, the increasing scientific research has confirmed and clarified many pharmacological properties of plant extracts. Phytotherapy has therefore entered into the official scientific therapies.

However, it must be remembered that medicinal plants today must be considered as potential medicines because the substances contained in them affect biological mechanisms and can interfere with pharmacological therapies. Hence the increasing attention that must be reserved for self-prescribed therapies or advised by unqualified personnel.

The aim of my work was to deepen our knowledge on the effect of food supplements containing Mucuna pruriens L. seed extracts taken from two patients with Parkinson's disease, through a quantitative analysis of L-Dopa contained in the supplement and in seeds from different geographical areas.
Mucuna pruriens L., belonging to the family Fabaceae, is an annual climbing shrub with long tendrils that grows up to 3-18 m long, native to the tropical regions of Africa and southern Asia (India and Sri Lanka), up to the Americas. The leaves are ovate, green-greyish on the underside, with long, silky petioles. They have a heart-shaped appearance, with pointed apexes and at the juvenile stage they are covered with hair on both pages. The flowers, from 6 to 30, are white or purple, hanging in long clusters that take the form of "panicle", 15-32 cm long. Flowering generally begins 45 days after sowing. The fruit, 4-13 cm long, is a pod that contains seeds similar to beans, about 12 mm long, black or brownish with gray variegations. The hairs that cover the pods are colored red-orange and can cause intense irritation to the skin, with the appearance of blisters. Their mucunain and serotonin content causes itching, blisters and dermatitis. Used for centuries in Ayurvedic medicine for the treatment of various disorders, it has gained considerable interest in the West for its content in L-Dopa, a precursor of Dopamine used in the treatment of Parkinson's disease.

Using HPLC, I determined the concentration of L-Dopa in seeds and in commercial preparations of Mucuna pruriens L. that we used for a pharmacodynamic and pharmacokinetic study carried out by Dr.ssa Guarino (Movement Disorders Center - OU Neurology Cirignotta - S. Orsola -Malpighi, Bologna) and Dott.ssa Contin (Laboratory of Clinical Neuropharmacology - Institute of Neurological Sciences, Bologna) with traditional drugs and vegetable capsules in two patients with Parkinson's disease in self-prescribed chronic therapy (3 years) with Mucuna pruriens.

The analyzes carried out at the chemical laboratories of the Botanical Garden of Bologna were able to confirm:

  • the amount of L-Dopa actually taken by patients through the use of the commercial supplement
  • the actual quantity of L-Dopa in the seeds of Mucuna pruriens L. from different geographical areas, finding differences in the characteristics of development and formation of secondary metabolites in plants
  • the effective presence, as was supposed in previous studies, both in the seeds and in the commercial supplement, of synergistic substances with L-Dopa and, in some cases, with a possible role of addiction

In this study, the collaboration between several professional figures has been fundamental, each one able to make their contribution. What has been shown is a vision that now characterizes the current World: a total and unconditional rapprochement with Nature, with modalities that, however, too often hamper the medical activity.
The solution has only one name: cooperation. Not only between professionals, but also between doctor and patient.

With this study we could verify the absence of harmful substances in the plant and in the commercial extract used and the differences in the pharmacokinetic and dynamic characteristics of the same product in different people. Moreover, the patients under examination showed a clear intention to not stop the use of Mucuna pruriens L. They report, in-fact, to feel benefits they do not intend to renounce, including a better management of the motor symptoms in the intervals between a dose and another one of the standard pharmacological formulation of L-Dopa.
Possible side effects due to chronic use of Mucuna extracts do not negatively influence patients' decision, demonstrating one of the typical attitudes of consumers of herbal products. In fact, most people believe that herbal products are absolutely free of side effects, further complicating the management of their health by medical personnel.

So, Nature yes, but with conscience, sensitivity and absence of abuse.