Botanical Source, History, and Description.—The tree furnishing areca nut (Semen arecae) is a handsome palm, probably indigenous to the Malayan group of islands where it is cultivated. It is also cultivated in Ceylon, India, Indo-China, and the Phillipine Islands. Its straight trunk, nearly 2 feet in circumference, shoots upward to a height of 40 or 50 feet. The flowers are borne on a spadix, the male flowers above, the female flowers lowermost. The fruit is ovoid and smooth. It is about as large as a small-sized hen's egg, orange-yellow in color, and consists of a fibrous envelope adherent to a crustaceous endocarp enclosing the single seed. The seeds are hard and heavy, and are cut with difficulty. In shape they are round-conical, and depressed at the base, and at one side of the depressed portion a tuft of fibres is frequently found, showing where the seed was attached to the pericarp. Their color externally is brown, mottled with fawn color, giving it a reticulated appearance. Its internal structure closely resembles that of the common nutmeg, being a brown-red with whitish veins. The odor, when the nut is fresh, is feeble, resembling cheese. The taste is astringent and sub-acrid. Betel nuts have long been employed by the Asiatics as a masticatory, for sweetening the breath and hardening the gums, and are believed by them to improve the digestive powers. They have been given to both dogs and human beings in China and India as a vermifuge (Pharmacographia). They are often chewed with slaked lime and piper betel leaves (see Matico, Related Species).
Chemical Composition.—Areca nuts contain tannin, gallic acid, gum, lignin, volatile and fixed oils, iron peroxide, magnesium phosphate, and other salts. The tannin resembles catechu-tannic acid, is red, and strikes green with ferric salts, quickly changing to brown, and when an alkali is added, a violet coloration ensues. It is not very soluble in either hot or cold water. Pyrocatechin was obtained from it by dry distillation, but no catechin is present in the nut (Pharmacographia). Four alkaloids were isolated by Jahns (Amer. Jour. Pharm., 1889, 1891) from areca nuts. Arecoline (C8H13NO2), a colorless, volatile, and oily, nicotine-like principle, identical with Bombalon's (1885) arekane. The taenifuge properties of the drug are probably due to this principle. It mixes with water, chloroform, alcohol and ether. It yields crystallizable salts, among which the hydrobromide crystallizes best; some of these salts are deliquescent. Arecaine (C7H11NO2+H2O) probably a betaïne-like body, physiologically inert, forms permanent, colorless crystals, insoluble in ether, chloroform, and benzol, almost insoluble in absolute alcohol, but dissolving with ease in diluted alcohol and water. Its salts are crystallizable, acid, and freely dissolve in water. A third alkaloid, areca ïdine (C7H11NO2+H2O), an isomer of arecaine, and non-poisonous, was discovered by Jahns, in 1891. The poisonous arecoline aforementioned is methyl-arecaidine. A fourth alkaloid, discovered by Jahns, and called guvacine (C6H9NO2), is the lower homologue of arecaidine, and non-poisonous.
Action, Medical Uses, and Dosage.—Astringent and taenicide. The chief use of this drug is to expel tapeworms, for which it is said to be efficient in doses of 2 to 6 drachms of the powdered nut, administered in syrup. The smaller dose is generally effectual. A hard charcoal suitable for dentifrices is prepared from the nut. Arecoline is the taenifuge principle, resembling pelletierine, both chemically and in action. Arecaine, the betaïne-like body, has been likened to trigonelline from foenugreek. Experimentation with it upon animals proved it to be inert.
King's American Dispensatory, 1898, was written by Harvey Wickes Felter, M.D., and John Uri Lloyd, Phr. M., Ph. D.