Agriculture Reference
In-Depth Information
3.8 cm long. In the fruit-ripening stage, a 4- to 13-cm long, 1- to 2-cm wide, unwinged, leguminous
fruit develops. There is a ridge along the length of the fruit. The husk is very hairy and carries up
to 7 seeds. The seeds are flattened uniform ellipsoids, 1 to 1.9 cm long, 0.8 to 1.3 cm wide, and 4 to
6.5 cm thick. The hilium, the base of the
funiculus
(connection between placenta and plant seeds),
is surrounded by a significant arillus (fleshy seed shell). It bears white, lavender, or purple flowers.
Its seed pods are about 10 cm long and are covered in loose orange hairs that cause a severe itch if
they come in contact with skin. The seeds are shiny black or brown drift seeds.
Habitat and Distribution —
It is found occurring naturally in tropical parts of Africa, Asia,
and Caribbean.
Ethnomedicinal Uses —
Mucuna seeds are used in traditional medicine mainly for the treat-
ment of diabetes and male sexual dysfunction and as a soup thickener for general weakness. The
pod hairs mixed with syrup, molasses, or honey are taken as an anthelminthic and anti-inflamma-
tory. Boiled seeds are occasionally eaten as a pulse and boiled immature pods and young leaves as
vegetables. It enjoys a reputation as a potent aphrodisiac and source of vitamins and minerals.
Constituents —
Mucuna pruriens
seeds contain protein (15-30%), amino acids, fixed oils (8%),
calcium, fiber, and vitamins. Two important nonprotein amino acids are found in the seed and
in smaller amounts in the stems and leaves: L-dopa (L-3.4-dihydroxyphenylalanine), from which
dopamine, an important medicine to relieve the effects of Parkinson's disease, is prepared, and
DMP (N-dimethyltryptamine), which has hallucinogenic properties. The L-dopa content varies
from 1.6% to 3.3% and is sufficiently high both as a phytomedicinal and for commercial extraction
of the active constituent. The seed also contains a number of alkaloids, the most important of which
are mucunaine, prurienine, and serotine. The stinging hairs of velvet bean, used as an anthelmintic,
contain a pruritogenic, proteolytic enzyme and granular matter, tannic acid, and resin.
1140
The con-
centration of L-dopa in the defatted
Mucuna
meal was greatly increased when extracted by super-
critical carbon dioxide, performed in a laboratory-scale unit at 40°C and 60°C over the pressure
range 150 to 250 bar. A constant flow rate of CO
2
close to 3 ml/min was maintained. This finding is
industrially useful in the production of L-dopa from
Mucuna
without the problem associated with
residual solvent after extraction of plant materials for clinical use.
807
Pharmacological Studies —
The chemical compounds responsible for the itch are the protein
mucunain and serotonin. The seed powder of
Mucuna pruriens
has been clinically assessed in
several studies for its application in the treatment of Parkinson's disease.
808,809
The clinical effects
of
Mucuna
seed powder and levodopa (L-dopa) pharmacokinetics were evaluated following two
different doses of mucuna preparation and were compared with standard L-dopa/carbidopa (LD/
CD). In the study, 8 patients with Parkinson's disease with a short duration L-dopa response and
on period dyskinesias completed a randomized, controlled, double-blind, crossover trial. Patients
were challenged with single doses of 200/50 mg LD/CD and 15 and 30 g of mucuna preparation in
randomized order at weekly intervals. L-dopa pharmacokinetics were determined, and the Unified
Parkinson's Disease Rating Scale and tapping speed were obtained at baseline and repeatedly dur-
ing the 4 h following drug ingestion. Dyskinesias were assessed using modified AIMS and Goetz
scales. The 30-g mucuna preparation when compared with standard LD/CD, led to a considerably
faster onset of effect (34.6 vs. 68.5 min;
p
= 0.021), reflected in shorter latencies to peak L-dopa
plasma concentrations. Mean on time was 21.9% (37 min) longer with 30 g mucuna than with LD/
CD (
p
= 0.021); peak L-dopa plasma concentrations were 110% higher, and the area under the
plasma concentration-versus-time curve (area under curve) was 165.3% larger (
p
= 0.012). No sig-
nificant differences in dyskinesias or tolerability occurred. These findings suggest that the rapid
onset of action and longer on time without concomitant increase in dyskinesias on mucuna seed
powder formulation indicate that this natural source of L-dopa might possess advantages over con-
ventional L-dopa preparations in the long-term management of Parkinson's disease.
808
The antidiabetic activity has been established in a rat model. Chronic administration of the
alcoholic extract of
Mucuna pruriens
seeds resulted in a significant dose-dependent reduction in
