Agriculture Reference
In-Depth Information
African Names —
Arabic: fasolia; Hausa: wake; Igbo: akidi, okwe; Swahili: haragwe, haragi;
Yo r u b a : aw uj e
Description —
It is a twining annual herb, erect or recumbent, with short stems, climbing up a
length of 5 m. The leaves are trifoliate, opposite, oval pinnate, and acuminate. It produces whitish
flowers with yellow or purple spots. The pods are narrow with a beak at the end and contain seeds
of various colors.
Habitat and Distribution —
It is a cultivated crop grown in most parts of the world. It does not grow
well in an atmosphere with high humidity and in lowland areas, where it is frequently attacked by pests.
Ethnomedicinal Uses —
The leaves of the plant are used in the preparations of lotions for
external use in the treatment of a variety of skin conditions; a paste made with the crushed bean
cake has been applied to cutaneous leishmanial lesions. The bean is eaten as a nutrient during con-
valescence. Duke
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listed the plant as used as a carminative, depurative, acne application, digestive,
diuretic, emmenagogue, febrifuge, and cardiotonic, among several other uses.
Constituents —
The beans are rich in protein and are recognized as a cheap source of proteins.
They also contain starch, cyanogenetic glycoside, and a hemaglutin, phaseolitin. The leaves, pods,
and beans yield several vitamins and minerals, and enormous variation exists in the ratio of these
nutrients in plants from different parts of the world and among different hybrids. The fresh beans
have been found to contain estrone, estriol, and 17α-estradiol.
851
Pharmacological Studies —
Phaseolin isolated from the beans has fungicidal activity.
227
Aqueous extracts depress the isolated intestine of the rabbit and guinea pig.
852
Toxicity —
The plant contains up to 0.008% toxic HCN and the tumor-enhancing phytogluti-
nin; both constituents are, however, destroyed during cooking. The seeds also contain trypsin and
chymotrypsin inhibitors.
378
PHYSOSTIGMA VENENOSUM
Botanical Name —
Physostigma venenosum
Balfour
Synonym —
Physostigma venonum
Balf.
Family —
Leguminosae
Common Names —
Calabar bean, African ordeal bean, fève de Calabar (F)
African Names —
Arabic: shagar lubiyar kalabar; Efik: esere: Igbo: akpi; Yoruba: iso
Description —
The plant is a subligneous creeper with smooth climbing stalks, with twining
branches climbing to a great height. The leaves are trifoliate, 6 × 10 cm. The pink or purple flowers
are borne in axillary racemes. The pods are up to 15 cm long, oblong in shape, and contain a few
ellipsoid seeds 3 cm long. The seeds are dark brown in color, extremely hard, and testa smooth in
the neighborhood of the grooved hilium, which runs the whole length of the convex side and around
one end; where somewhat wrinkled, on the other side of the groove is a well-marked ridge; in the
groove are the grayish, papery remains of the funiculus.
9,28
Habitat and Distribution —
It is found in the dense rainforest areas of the continent and dis-
tributed from Senegal to Zaire.
Ethnomedicinal Uses —
The drug is used with other herbs by the Barkwiris in the local treat-
ment of articular rheumatism. An extract of the seeds or a mixture of the seed in palm oil is used
for eradicating lice and bugs. In the Ivory Coast, a weak decoction of the seeds is used for edemas.
Constituents —
The seeds contain the alkaloids physostigmine (eserine), eseridine, eseramine,
physovenine, phytosterol, and starch. They also yield an albumin.
Pharmacological Studies —
Physostigmine is used in the treatment of glaucoma as an eye-
drop. The compound is a powerful and reversible acetylcholine esterase inhibitor and therefore
allows acetylcholine to exert maximal effect on the smooth muscles, glands, and heart. It therefore
effectively increases the concentration of acetylcholine at the sites of cholinergic transmission. It
