Agriculture Reference
In-Depth Information
Synonyms —
Cyticus cajan
L.,
Cajanus
indicus
Spreng.
Family —
Leguminosae
Common Names —
Pigeon pea, field pea, pois d'Angol, ambrebdade (Comores), pois de pigeon (F).
African Names —
Arabic: bisellat el-Haman; Hausa: waken-masar, waken-turawa; Igbo: fio-
fio; Swahili: mbaazi; Yoruba: otili, otinli
Description —
This is an annual or biennual shrub 2 m high with ribbed, silky pubescent
stems. The stalks and leaves are covered with white down. It has 3 leaflets that are oblong lanceolate
in short stalks. The flowers are brownish-yellow, borne on corymbiform racemes. The fruits occur
as oblong linear pods (over 5 cm long), obliquely constricted between the seeds, which vary from
3 to 4.
28
Habitat and Distribution —
It is pantropic and is cultivated in most parts of the continent. The
plant prefers savanna vegetation and dry forestlands.
Ethnomedicinal Uses —
The leaves are used as a weak decoction for the treatment of measles,
catarrh, and hepatitis. An aqueous infusion of the seeds sometimes mixed with the leaves is dis-
pensed for the management of sickle-cell anemia.
Constituents —
Cajanus
contains amino acids, proteins, fats, carbohydrates, saponins, stil-
benes, flavonoids, and isoflavones.346
346
It also yields minerals, such as calcium, phosphorus, and iron.
The leaves contain the phytoalexins pinostrobin and cajaninstilbene acid and the coumarin caja-
nuslactone (7-hydroxy-5-O-methyl-8-(3-methyl-2-butylene)-4-phenyl-9,10-dihydro-benzopyran-2-
one).
347
Urease has been isolated from pigeon pea. The enzyme is used in diagnostics to determine
the urea present in the blood serum.
Pharmacological Studies —
The seed extract has been shown to possess hypoglycemic and
antimicrobial activities.
348
Later studies of the hypoglycemic activity showed that the extract pro-
duced transient hypoglycemia at a dose of 300 mg/kg. Extracts of the seeds were effective in restor-
ing normal morphology of erythrocytes from blood samples of patients affected by sickle-cell
anemia.
349,350
The aqueous alcohol extract, as well as cajaminose, an amino sugar isolated from it,
prevented the sodium metabisulfite-induced sickling of red blood cells.
351
Phenylalanine has been
isolated as the main constituent of the antisickling fraction of the seed extract and has been sug-
gested as probably responsible for the hematological effect.
352
Viclin, a holoprotein that occurs in seeds, exhibits an unusual stability to the denaturation by
8 M and 6
M guanidine-HCl.
353
The presence of urease in the plant may play some role in its use as
an antisickling agent.
A
Cajanus
flavanone, pinostrobin, inhibits voltage-gated sodium channels of mammalian brain
(IC
50
= 23 µM) based on the ability of this substance to suppress the depolarizing effects of the
sodium channel selective activator veratridine in a synaptoneurosomal preparation from mouse
brain. The resting membrane potential of synaptoneurosomes was unaffected by pinostrobin. The
pharmacological profile of pinostrobin therefore resembles that of depressant drugs that block
sodium channels.
354
Cajanus
has demonstrated antifungal, antioxidant, and hypercholesterolemia
effects in laboratory experiments. Genistein and apigenin from the roots showed remarkable anti-
oxidant properties using the DPPH scavenging activity model.
355
The antidyslipidemic activity of
pigeon pea was evaluated by a high-fat diet (HFD) hamster model, in which the levels of high-
density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), total cho-
lesterol (TC), and total triglycerides (TG) were examined. Pigeon pea administration was found
to promote cholesterol converting to bile acid in HFD-induced hamsters, thereby exerting hypo-
lipidemic activity. It significantly increased hepatic carnitine palmitoyltransferase 1 (CPT-1), LDL
receptor, and cholesterol 7α-hydroxylase (also known as cytochrome P450 7A1, CYP7A1) expres-
sion to attenuate dyslipidemia in HFD-fed hamsters and markedly elevated antioxidant enzymes in
the liver of HFD-induced hamsters, further alleviating lipid peroxidation. This activity was attrib-
uted to a possible role of the large quantity of unsaturated fatty acids (UFAs; C18:2) and phytosterol
(β-sitosterol, campesterol, and stigmasterol) present in pigeon pea.
356
