for table listing potential phytochemicals from the Griffin collection.
Legumes: Natures Medicine
Chest By Sean
December 11, 1996
Winged bean, jack bean, velvet bean, snout bean, ringworm bush,
and fish poison bean: These arent exactly household names even among
farmers, but theyre all sources of agricultural products that could lead
to future drugs.
These plants also are part of a special legume collection
maintained by the Agricultural Research Service. The collection contains more
than 4,000 accessions that scientists describe as an unopened medicine
chest. These legumes are a central source of experimental plant material
for public and private researchers worldwide.
Winged bean, for example, has high levels of proteins called
lectins, which are used as diagnostic tools in medical research because they
bind to certain blood cells. Winged beans also contain erucic acid (an
antitumor medication) and polyunsaturated fatty acids that can be used to treat
acne and eczema.
Another legume in the collection, kudzu, is best known as a
prolific but unwanted roadside weed. But its also a source of a number of
chemicals including daidzein (an anti-inflammatory and antimicrobial), daidzin
(a cancer preventive) and genistein (an antileukemic).
Velvet bean is a source of dopa, which the brain converts into the
neurotransmitter dopamine. Reductions in dopamine have been associated with
Parkinsons disease, which occurs when dopamine-producing brain cells are
destroyed. Velvet bean also contains serotonin, another brain neurotransmitter
that may be involved in learning, sleep, and control of moods.
Along with their pharmaceutical potential, these legumes also
fix nitrogen--transforming atmospheric nitrogen into a form plants
can use for growth--enriching the soil and making them ideal candidate crops
for sustainable agriculture. Some legumes can add up to 500 kilograms of
nitrogen per hectare to the soil, alleviating the need for fertilizer and
lessening the chance of water pollution.
A feature article about this research appears in the November 1996 issue
of ARS Agricultural Research magazine. The article is on
Scientific contact: Brad Morris, USDA-ARS Plant Genetic
Conservation Resources Unit, Griffin, Ga., phone (770) 229-3253,