Abrus. Abrus.
Synonyms.—Jequirity; Prayer Beads; Jumble Beads.
Abrus consists of the seeds of Abrus precatorius, Linn. (N.O. Leguminosae), a common Indian and Brazilian shrub. The seeds are characterised by their smooth, glossy surface and bright scarlet colour, with a black patch at the hilum; they are ovoid or sub-globular in shape, and vary from 5 to 8 millimetres in length, and from about 4 to 5 millimetres in breadth.
Constituents.—The chief constituents of the seeds are two poisonous proteins, a vegetable paraglobulin and a phytalbumose, a mixture of the two substances being known as abrin. The activity of the globulin is destroyed at 75° to 80°, and that of the albumose at 85°. Abrus root (Indian liquorice) contains a substance resembling, but not identical with, glycyrrhizin, together with a resin and a trace of alkaloid (abrine); though it is less active, the root possesses poisonous properties similar to those of the seeds, and it should not therefore be employed as a sweetening drug.
Action and Uses.—Abrin resembles snake-venom in its action when absorbed from wounds; it is less poisonous when taken internally. An infusion of abrus seeds has been applied to the eye in granular lids and in opacities of the cornea, but it is a dangerous remedy, as the inflammation which it sets up is difficult to control, and in some instances the sight has been destroyed. A paste of the powdered seeds has been used as an application to lupus, and to tuberculous and syphilitic ulcerations. The dried paste, mounted on sticks, has been used by natives of India for killing cattle. Jequiritol is a standardised preparation of abrin of uniform strength; jequiritol anti-serum is prepared, and is used to neutralise the action of jequiritol.
PREPARATIONS.
- Infusum Abri, B.P.C.—INFUSION OF ABRUS. 1 in 12 ½ .
- The infusion is sometimes diluted with water, from 2 to 20 parts, before use. It should be freshly prepared, for it rapidly decomposes unless a small proportion (about 2 per cent.) of boric acid be added. Its action may be controlled by the use of hot compresses of solution of mercuric chloride (1 in 10,000).
- Pasta Abri, B.P.C.—ABRUS PASTE. 1 in 4.
