Agriculture Reference
In-Depth Information
Kachenche; Shambala: lufyambo; Sukuma: lufiambo; Swahili: mongaluchi, mtipitipi; Tiwi: damma-
bo, obereku-aniwa; Yoruba: iwere-jeje; Mozambique: cessane, mini-mini, mpanamene, namecolo,
tsangariorio; Swaziland: umphitsi; Zanzibar, Tanzania: matscho ya tipitipi; Afrikaans (Namibia):
mini-minies, minie-minies, paternostertjies; Afrikaans (South Africa): minnie-minnies.
Description —
A woody twining plant with characteristic red and black seeds. The seeds are
pinnate and glabrous, with many leaflets (12 or more) arranged in pairs. The leaflets are oblong,
measuring 2.5 cm long and 1.5 cm wide. The plant bears orange-pink flowers, which occur as
clusters in short racemes, sometimes yellowish or reddish purple in color, and small and typically
pea-like.
Abrus
produces short and stout, brownish pods, which curl back on opening to reveal pen-
dulous red and black seeds (4-6 in each pod).
Habitat and Distribution —
It is found occurring wild in thickets, farms, and secondary clear-
ings and sometimes in hedges. The plant is widely distributed throughout the continent.
Ethnomedicinal Uses —
The leaf decoction is used for treatment of coughs, constipation, colic,
and general pains. The leaves are chewed to relieve hoarseness and bronchial constrictions; the
vapor from crushed leaves boiled with water is used to treat eye inflammation.6
6
The aqueous extract
of the seed is used for the treatment of cancer of the epithelioma and as a vermifuge and an abortifa-
cient. A single dose of the powdered seeds acts as a long-acting contraceptive, with the effect lasting
up to 13 menstrual cycles.
7
The seed infusion has been employed to hasten labor and for treatment of
conjunctivitis granulosa and trachoma.
8
The entire plant is drunk for treatment of venereal disease,
headaches, and snakebites. A poultice prepared from the seeds of
Abrus,
salt, and the unripe fruits
of
Musa paradisica
is applied topically to boils and abscesses.
9
Constituents —
The seeds contains abrin (a highly toxic glycoprotein), hyapaphnorine, preca-
torine, and some other uncharacterized indole alkaloids.
10
Abrin, being a toxalbumin, is inacti-
vated by heat. Trigonelline and other related pyridonium derivatives have been isolated from the
plant. The plant contains phytosterols β-sitosterol and stigmasterol and flavonoids abrecatorin
(6,4′-dimethoxy-7,3′-dihydroxyflavone) and desmethoxycentaureidin-7-O-rutinoside.
11
Two a n t h o -
cyanins have also been identified (xyloglucosyldelphinidin and p-coumarylgalloyl ester of glucosyl-
delphinidin) in the seed coat of pigment of the plant. The free sugars present in the leaves, stems,
roots, and seeds of the plants have been characterized as galactose, arabinose, and xylose.
12
Sweet-
tasting glycosides, the abrusosides, based on the novel cycloartane-type aglycone (abrusogenin),
have been isolated from the leaves of the plant.
13
Pharmacological Studies —
The activity of the seed powder against cancer of the epithelioma
of the hand, skin, and mucosa has been reported.
14
The aqueous extract of the seed elicits a biphasic
response on the field-stimulated guinea pig ileum, being inhibitory at low concentrations but excitatory
at high concentrations. The excitatory exponent contracts most smooth muscles, including the uterus.
Its actions are atropine sensitive. The inhibitory fraction also contracts the uterus but relaxes the other
smooth muscles; it is resistant to common pharmacological blocking agents but is inhibited by indo-
methacin, a prostaglandin synthetase inhibitor.
15
The antifertility activity of the root has been reported.
15
Nwodo had shown that trigonellyl glycoside possesses both nicotinic and muscarinic activity at
the ganglion (i.e., it produces a depressor cum pressor activity on close arterial injection). He main-
tained that while the activity of the isolates of
Abrus
is blocked by indomethacin, these activities were
not essentially due to prostaglandin release.
8
The sweet-tasting glycosides found in the leaves, the
abrusosides, have been shown to be 30-100 times sweeter than sucrose. The glycosides were neither
acutely toxic when tested on mice nor mutagenic to
Salmonella typhimurium
st r a i n T TM677.13
13
A steroidal fraction of extract of the seeds has been shown to cause dose-dependent degenerative
changes in the testicular weights, sperm count, later stages of spermatogenesis, and Leydig cells in
testes of rats.
16
The steroidal fraction also caused a dose-dependent decrease in the enzyme activity
of 3α,3β,17β-hydroxysteroid dehydrogenase, glucose-6-phosphate dehydrogenase, sorbitol dehydro-
genase, and leucine aminopeptidase. A probable mechanism of the alterations in the testes could be
at the pituitary level by a feedback mechanism that may result in decrease in production and release
