Laburnum.—Laburnum.
Related entry: Scoparius (U. S. P.)—Scoparius
The seeds of Cytisus Laburnum, Linné.
Nat. Ord.—Leguminosae.
COMMON NAMES: Bean-trefoil, Golden chain.
ILLUSTRATION: Botanical Magazine, Plate 176.
Botanical Source and History.—Laburnum is an unarmed shrub or small tree, native of the mountainous portions of southern Europe, and frequently found in cultivation, especially in Great Britain. The leaves are petiolate and trifoliate, with ovate lanceolate leaflets, pubescent underneath. The golden-yellow flowers, which appear from May to June, are very showy, and are disposed in loose, pendulous racemes. The calyx is campanulate and two-lipped; the upper lip is entire, the lower one three-toothed. The corolla is papilionaceous, with a large vexillum. The fruit is a brown legume, containing many seeds, and is attenuate at the base. The genus Cytisus is almost exclusively European, and there is no indigenous species in the United States. Cytisus Scoparius, Link, or "common broom," a very abundant shrub in Great Britain, is extensively used as a diuretic.
Chemical Composition.—The ripe seeds of Cytisus Laburnum, as well as other species of Cytisus, contain an alkaloid cytisine, discovered and obtained pure in 1864, by Husemann and Marmé. It also occurs in other genera of plants, and was established by A. Partheil (Archiv der Pharm., 1892, p. 470), to be identical with ulexin, discovered by A. W. Gerrard (Pharm. Jour. Trans., 1886, Vol. XVIII, p. 101), in the seeds of Ulex europaeus. More recently, K. Gorter (Archiv der Pharm., 1897, p. 321), proved its identity with baptitoxine, the alkaloid of the root of Baptisia tinctoria (which see). Prof. Plugge (1891) also believes it to be the same substance as sophorin, from Sophora tomentosa. Cytisine (Ulexine, Baptitoxine) has the formula C11H14N2O (Partheil, 1892; Gorter, 1897), and when pure crystallizes in large colorless prisms, soluble in water, alcohol, chloroform, and acetic ether; less soluble in benzol, amyl alcohol, and acetone; insoluble in petroleum ether, carbon disulphide, and absolute ether. It melts at 152° to 153° C. (305.6° to 307.4° F.), and can be sublimed by heating in vacuo. It is a dyad base, forming two series of salts with acids. The nitrate (C11H14N2O.HNO3+H2O) forms large crystals. Partheil obtained 1.5 per cent of cytisine from laburnum. In the mother liquors he observed the presence of cholin.
Action, Medical Uses, and Dosage.—Administered to certain animals, as the dog, cat, etc., even in small doses, M. Chevallier found laburnum to occasion emesis, muscular debility, increased pulse, accelerated respiration, somnolence, spasms, and finally death. With man, according to Dr. T.S. Gray, Popham, Clout, and others, the bark, the flowers, or the seeds, in large doses, produce a sense of indisposition, drowsiness, followed by vomiting, vertigo, cold sweats, dryness and constriction of the throat, gastric pain, pallor, purging, accelerated respiration, strong contraction of the features, dilatation of the pupils, muscular contractions, quick and agitated pulse, and other symptoms of narcotism. Recovery from these symptoms occurs more or less speedily, and no case is recorded in which death was the result. In cases of poisoning by laburnum, Dr. Gray has advised the use of charcoal, though in many severe cases, persons who have suffered severely from the symptoms named, have promptly recovered without the aid of any antidote. Chevallier, who, having taken 6 or 8 grains of cytisine, found himself threatened with severe symptoms, drank quite freely of lemonade, and thereby checked their further progress. In medicinal doses, Dr. Gray recommends the use of the active principles of laburnum in the treatment of dyspepsia attended with vomitings of bile-matters and alternate attacks of diarrhoea and constipation; likewise to cheek the vomiting of children who eject their food soon after its ingestion; to relieve bronchial cough, and mitigate the severity of the paroxysms of pertussis and asthma, and to prevent the sympathetic vomiting of pregnancy; however, these recommendations have not been supported by subsequent trials. Prof. J. M. Scudder (Spec. Med.), suggests the small dose (teaspoonful of the solution of 10 drops of a tincture of the recent bark, made with 98 per cent alcohol, in 4 ounces of water), every 1 to 3 hours in irritation of mucous tissues occurring in nervous dyspepsia, in the restlessness and uneasiness which follows mental overwork, and in the excitation of the gastric and hepatic nerves giving rise to frequent and easily excited vomiting. The dose of a decoction, of sp. gr. 1.034, is from 2 to 30 minims; of cytisine, from 1/8 grain to 2 grains (hypodermatically 1/10 to 1/8 grain); of laburnine, from 2 to 10 grains. In a case where poisoning occurs, the best course to pursue is to remove the contents of the stomach as speedily as possible by means of an emetic well diluted with warm water, and then to administer ammonia, whiskey, or other diffusible stimulants.
