Tuesday, December 8, 2009

Abrus precatorius

Habitat: Commonly found as twining herb in mixed deciduous forests, in moist shady localities, grow best in fairly dry regions at low elevations.

Distribution: It is native to India, introduced to warmer regions of the world. It is found throughout India, even at altitudes up to 1200 m on the outer Himalayas. It is now naturalized in all tropical countries. It grows in tropical climates such as India, Sri Lanka, Thailand, the Philippine Islands, South China, North America, Tropical Africa and the West Indies. It also grows in all tropical or subtropical areas. It is used as an ornamental plant throughout North America.

Taxonomic description: A beautiful, much-branched, slender, perennial, deciduous, woody, prickly twining herb with cylindrical, wrinkled stem having smooth textured brown colored bark. Leaves stipulate and pinnately compound, leaflets 7-24 pairs, 0.6-2.5 x 0.4-1.2 cm, turgid, oblong, obtuse, truncate at both ends, appressed hairy.

Flowers in axillary racemes, shorter than leaves, fascicled on the swollen nodes, pink or pinkish-white; calyx-lobes short, appressed hairy. Pods 1.5-5.0 x 0.8-1.5 cm, turgid, oblong, appressed hairy, with a sharp deflexed beak, silky-textured, 3 to 5-seeded.

Seeds elliptic to sub-globose, ca 0.5 cm in diam., smooth, glossy, shining red with black blotch around the hilum. Fl. & Fr.: August – January.

Taxonomy of the Plant

Kingdom: Plantae

Division: Magnoliophyta

Class: Magnoliopsida

Order: Fabales

Family: Fabaceae

Genus: Abrus

Species: precatorius

Botanical name: Abrus precatorius

Common names: Indian liquorice, Rosary pea, Crab’s eye, Jequerity, Precatory bean, Tento muido, Graines Reglisse, Gunchi, Liane Reglisse, Ma Liao Tou, Paratella, Paternoster, Peonia, Reglisse, Rakat.

Chemical Components: Seeds are poisonous and contain abrin, a poisonous principle. The sweet principle glycirrhizin is same as that of liquorice.

Abrine, Abraline, Abrasine, Abricin, Abrin, Abrusgenic-acid, Abrusgenic-acid-methyl-ester, Abruslactone, Abrussic-acid, Anthocyanins, Ash, Calcium, Campesterol, Choline, Cycloartenol, Delphinidin, Gallic-acid,, Glycyrrhizin, Hypaphorine, N,n-dimethyl-tryptophan, N,n-dimethyl-tryptophan-metho-cation-methyl-ester, P-coumaroylgalloyl-glucodelphinidin, Pectin, Pentosans, Phosphorus, Delphinidin, Gallic-acid,, Glycyrrhizin, Hypaphorine, N,n-dimethyl-tryptophan, N,n-dimethyl-tryptophan-metho-cation-methyl-ester, P-coumaroylgalloyl-glucodelphinidin, Pectin, Pentosans, Phosphorus, Picatorine, Polygalacturonic-acids, Precasine, Precatorine and Protein Trigonelline determined in the plant.

Medicinal Importance: The seeds are considered abortifacient, anodyne, aphrodisiac, antimicrobial, diuretic, emetic, expectorant, emollient, febrifuge, laxative, purgative, refrigerant, sedative, vermifuge, antidote and used in various ailments to cure headache, snakebite, cancer, cold, conjunctivitis, convulsion, cough, diarrhea, fever, gastritis, gonorrhea, jaundice, malaria, night-blindness, ophthalmia and rheumatism. The seeds are also used to treat diabetes and chronic nephritis.

Leaves, roots and seeds are used for medicinal purposes. The plant is used in some traditional medicine to treat scratches and sores and wounds caused by dogs, cats and mice, and is also used with other ingredients to treat leucoderma. The leaves are ground with lime and applied on acne sores, boils and abscesses. The plant is also traditionally used to treat tetanus, and to prevent rabies. Various African tribes use powdered seeds as oral contraceptives.

Paste of roots is administered to cure abdominal pains and tumors. The paste with fresh rhizome of ‘Haldi’ (Curcuma longa) is applied on wounds. This paste is also taken orally as a single dose once only for abortion. Grinded roots of Abrus precatorius is taken with pure clarified butter thrice a day for four days to cure cough. For graying of hair, a paste of leaves and seeds is made and juice is extracted. This juice is applied on hair as oil once a day one hour before taking bath. Dry seeds of Abrus precatorius are powdered and taken one teaspoonful once a day for two days to cure worm infection.

The seeds are highly toxic due to presence of Abrin, a protein. It may be fatal if eaten. The primary symptoms include nausea, vomiting, severe abdominal pain and diarrhea, burning in throat; later ulcerative lesions of mouth and oesophagus. Ingested seeds can affect the gastrointestinal tract, the liver, spleen, kidney, and the lymphatic system. Infusion of seed extracts can cause eye damage, conjunctivitis and even blindness after contact. The major symptoms of poisoning are acute gastroenteritis with nausea, vomiting and diarrhoea leading to dehydration, convulsions, and shock. Dehydration, as well as direct toxicity on the kidneys, could result in oliguria that might progress to death in uraemia.

Abrin, which consists of abrus agglutinin, and toxic lectins abrins a, b, c and d are the five toxic glycoproteins found in the seeds. Abrin is a ribosome – inactivating protein which blocks protein synthesis and is one of the most deadly plant toxins known. The toxin is released only after broking of seeds.

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