© Thomas Brendler
Cajanus cajan (L.) Millsp., Leguminosae
Vernacular names: Pigeon pea, Dhal, Gandul, Red gram, Congo pea, Gungo pea, Gungs pea, Alverja, No eye pea, Pigeon pea bush, Puerto Rico pea (English); Ambrevade; Pois d’Angole; Pois d’Ambrevade; Pois du Congo; Pois pigeon (French).
Geographical distribution: Cultivated throughout the tropics; in Africa, mainly in Kenya, Malawi, Nigeria, Uganda and Tanzania.
Description: Perennial woody shrub, stems strong, woody, to 4 m tall, freely branching; leaves spirally arranged on the stem, alternate, pinnately trifoliolate, stipulate; stipels to 15 cm long and 6 cm wide. Inflorescence in terminal or axillary racemes in the upper branches of the bush. Flowers in terminal or axillary racemes, are 2-3 cm long, multi-colored with yellow predominant. Pods compressed, 2–9-seeded, not shattering in the field. Seeds lenticular to ovoid, to 8 mm in diameter.
Chemical constituents: Extracts of roots and leaves of C. cajan yielded betulinic acid, biochanin A, cajanol, genistein and 2 -hydroxygenistein, longistylin A and C and pinostrobin. Protocatechuic, p-hydroxybenzoic, vanillic, caffeic, p-coumaric and ferulic acids were identified and quantified in bark, stem and leaf.
Medicinal uses: Leaves are prepared in an infusion for anaemia, hepatitis, diabetes, urinary infections and yellow fever. Flowers are also prepared in an infusion for dysentery, and menstrual disorders; and the seeds are infused to use as a diuretic. It is useful in the swelling of internal organs. Fresh seeds are claimed to help incontinence in males. Seeds are also used in sickle cell anaemia preparations. Extracts are used for the management of diabetes, hepatitis, and dysentery.
Known biological activities: Antisickling for seed extractss, cytotoxic effects for leaf extracts, while longistylin A and C, and betulinic acid from roots and leaves exhibited a moderately high in vitro activity against chloroquine-sensitive Plasmodium falciparum.