Bryoniae Radix. Bryony Root.
Bryony root is obtained from Bryonia dioica, Jacq. (N.O. Cucurbitaceae), a climbing plant, with perennial root, common in the South of England. The root is collected in the autumn, and used both in the fresh and dried states. It is usually of large size (5 to 10 centimetres in diameter) and nearly cylindrical shape, tapering gradually towards the tip. It is usually simple, but sometimes branches into two. The fresh root is externally of a yellowish-white colour, and marked with transverse corky ridges, which give to it a wrinkled appearance; internally it is whitish and fleshy, and the broken surface exudes a juice, which appears milky from the presence of numerous minute starch grains. The transverse section exhibits a narrow bark, separated by a fine line from the large fleshy wood. The wood contains small groups of vessels, radially arranged, and extending from the centre to the bark. The odour of the fresh root is unpleasant, the taste nauseous, bitter, and acrid. The dried root occurs in rounded slices, obtained by cutting the root transversely. The slices vary in size, averaging about 5 centimetres in diameter. They have a thin yellowish-grey cork, and a whitish wood, marked with concentric rings, and radially arranged vessels. The dried root has a bitter, acrid taste. This drug should be distinguished from black bryony (Tamus communis, L.).
Constituents.—The chief constituents of bryony root are an amorphous, brownish-yellow, bitter alkaloidal principle, and a dark-brown viscid resin, of which the dried root contains about 2 per cent., and from which can be isolated a phytosterol, a dihydric alcohol (bryonol), and a mixture of fatty acids. Other constituents are an essential oil, an amorphous, bitter, glucosidic product which yields a brown resin and a sugar on hydrolysis, a crystalline neutral substance, and an enzyme which slowly hydrolyses the glucosidic constituent, and also effects the hydrolysis of amygdalin and salicin.
Action and Uses.—The alkaloidal and resinous principles in bryony root have a similar action to the resinous constituents of jalap and colocynth, large doses of the tincture being cathartic and diuretic. Small doses are given to relieve the pain and cough of pleurisy. An infusion (1 in 10) has been recommended as a styptic. In cases of poisoning the stomach must be evacuated and demulcent drinks given; the body temperature must be maintained by the use of blankets and hot bottles.
PREPARATION.
- Tinctura Bryoniae, B.P.C.—TINCTURE OF BRYONY. 1 in 10.
- Small doses of tincture of bryony are used to allay cough in pleurisy and phthisis. The dose of 6 decimils (0.6 milliliters) (10 minims) is sometimes exceeded; large doses are cathartic and diuretic. Dose.—½ to 6 decimils (0.05 to 0.6 milliliters) (1 to 10 minims).
