"The leaves of Barosma betulina (Thunberg), Bartling et Wendland, and Barosma crenulata (Linné), Hooker"—(U. S. P).
COMMON NAME: Buchu.
ILLUSTRATIONS: Bentley and Trimen, Med. Plants, 45, 46.
The synonymy of the official plants yielding buchu is somewhat uncertain. The following are generally recognized:
I. Barosma betulina, Bartling (Diosma crenata, De Candolle and others; Diosma betulina, Thunberg).
II. Barosma crenulata, Hooker (Barosma crenata, Kunze; Diosma crenulata, Linné; Diosma crenata, Linné; Diosma odorata, De Candolle).
Botanical Source.—The official buchu leaves are derived from plants which are chiefly differentiated from each other by their leaves. They are both slender, smooth, perennial shrubs, having twiggy, somewhat angular branches, of a purplish-brown color, and reach a height of from 2 to 3 feet. The flowers are white or pinkish. The leaves are opposite, or nearly so, and are almost sessile, or, at best, having but a very short petiole. Five upright carpels, each containing a single oblong, shining black seed, comprise the fruit. The leaves are conspicuously marked with oil glands appearing as pellucid spots. The leaves of other species also appear in commerce, conspicuous among which are those of the Barosma serratifolia, Willdenow).
History.—The plants yielding buchu are indigenous to Southern Africa, occupying a limited extent of territory. According to Burchell they are odoriferous, and are, when powdered, used by the Hottentots under the name of Bookoo or Buku, for anointing their bodies. They likewise prepare a buchu brandy by distilling the leaves with wine, and which they employ as an efficient remedy in all affections of the stomach, bowels, and bladder; they also apply a decoction of the leaves to wounds. Buchu is said to have been introduced into medicine by a London drug firm (Reece & Co., in 1821), to whom a supply had been sent by Cape Colonists, who learned its uses from the Hottentots (Pharmacographia). Buchu leaves have a strong odor, resembling somewhat that of pennyroyal, and a corresponding taste. When held up to the light translucent dots may be observed, owing to the fact that the under surface of the leaves is beset with scattered glandular oil-points. If buchu leaves be preserved with ordinary care, their odor will remain for some years. The long variety of buchu is occasionally adulterated with leaves of Empleurum serrulatum, Aiton (Rutaceae), a shrub growing in the same locality with buchu. They have a different odor from buchu, a bitter taste, are narrower than buchu leaves, and the oil-gland at the apex, present in B. serratifolia, is absent. Moreover, the adulterant has leaves with an acute apex, while those of long buchu are truncate. The leaves of another species of the same order, the B. Eckloniana, Berg, has also been imported with true buchu. They are markedly crenate, have a rounded base, and are grown on pubescent twigs (Pharmacographia).
Description.—Buchu is described in the U. S. P. as follows: "About 15 Mm. (½ inch) long, roundish-obovate, with a rather wedge-shaped base, or varying between oval and obovate, obtuse, crenate or serrate, with a gland at the base of each tooth, dull yellowish-green, thickish, pellucid-punctate; odor and taste strongly aromatic, somewhat mint-like, pungent and bitterish "—(U. S. P.). The two official species of buchu constitute the short (round) buchu of commerce. The leaves of the B. betulina compose the greater amount of this grade. They range from ½ to ¾ inch in length, and possess more rigidity than the second 'species. These leaves are obovate and wedge-shaped toward the petiole, and usually have the apex curved backward. The margins are bordered with sharp serratures, an oil-gland being set at the base of each serrature. This variety varies somewhat in size and shape. The second species, B. crenulata, has longer leaves (from ¾ to 1 ½ inch), which have a crenately serrulate margin, each indenture having an oil-gland situated at the bottom of it. They may be oval, oblong, or obovate, and are narrower than the preceding variety. The longer and large leaves constitute the commercial intermediate buchu. This species presents but little variation in the size and shape of its leaves. The long buchu of commerce is that derived from the Barosma serratifolia, Willdenow (Diosma serratifolia, Curtis), official in the U. S. P., of 1880. These leaves differ considerably from the preceding, having a lance-linear form, irregularly narrowing towards each extremity, and have a truncate apex furnished with an oil-gland. They range from 1 to 1 ½ inch in length, and have a sharply serrulate margin, each serrature containing an oil-cell.
Chemical Composition.—Buchu leaves have been analyzed by Brandes and Cadet de Gassicourt, and later by Flückiger, Hanbury, and P. W. Bedford. Gassicourt found them to contain volatile oil (0.665 per cent), gum, extractive, chlorophyll, resin, lignin, etc. The leaves also contain mucilage. Their virtues are chiefly due to the volatile oil and extractive, which they yield to alcohol, or water. The oil has a powerful penetrating odor, somewhat like that of peppermint. Different amounts of the volatile oil were obtained by the above-named investigators, that derived from the long buchu being of lesser quantity than that from the short leaves. According to Schimmel & Co. (Semi-Annual Report, Oct., 1893), the percentage yield from B. betulina is 2 per cent, and from B. serratifolia 1 per cent. On subjecting this volatile oil to a low temperature, a stearopten, known as diosphenol (C14H22O3), or barosma camphor separates, which may be recrystallized from alcohol in needles. When pure they are colorless, and, according to Flückiger, have a nearly pure peppermint odor. They dissolve freely in carbon disulphide. Barosma camphor is present only in a small amount in the B. serratifolia, while the B. betulina is very rich in diosphenol. The specific gravity of the oil from the last variety (B. betulina) is 0.944, at 15° C. (59° F.), while that from the B. serratifolia, after elimination of diosphenol, which separates at ordinary temperature, is 0.969, at 15° C. (59° F.) (Schimmel's Report). Diosphenol can not be distilled without decomposition. Both Brand and Landerer had observed bodies to which they gave the name diosmin. That of the former was a bitterish body, while that of the latter was probably the stearopten diosphenol, as he observed it in a tincture of buchu, which had been made for some length of time. Prof. E. F. Wayne obtained salicylic acid by distilling the leaves. Others have failed to find it. The ash of buchu leaves contains considerable manganese. Barosma crenulata was examined by Spica, who found an oil differing somewhat from that of the other observers, and the diosphenol obtained he regarded as an oxycamphor. From the greenish-yellow mint-like oil he obtained a body, the odor of which resembled thymol. To this body he applied the name dioscamphor. From the residue after the extraction of the oil he obtained, by means of alcohol, a substance to which he gave the name diosmin (Ph. J. Tr., 1885).
Action, Medical Uses, and Dosage.—Buchu is an aromatic stimulant and tonic. It promotes the appetite, relieves nausea and flatulence, and acts as a diuretic and diaphoretic. In favoring the urinary secretion it augments both the solid and watery constituents. On the other hand, when the kidneys are excessively active, their action is restrained by buchu. It is principally used in chronic diseases of the urino-genital organs, as in cases of chronic inflammation of the mucous membrane of the bladder, irritable conditions of the urethra, in urinary discharges with increased deposit of uric acid, and in incontinence connected with diseased prostate. Profuse muco, or muco-puruluent discharges, with vesico-renal irritation, point to its use. It is a remedy where irritation depends upon altered secretions from the urethral glands. Acid urine, with continual desire to urinate and when but little relief is experienced from the effort, calls for buchu. Catarrh of the bladder, from the extension of gonorrhoea, from irritant injections, or due to gleet, is relieved by it. For this use, as well as for long-standing cystic irritability, the patient having difficulty in restraining his urine, administer the following: Rx Specific barosma, fl℥iiiss; tinct. chloride of iron, fl℥ss. Mix. Sig. A teaspoonful 4 times a day in a wine-glassful of infusion of hops or in sweetened water. Upon the prostate gland it is said to resemble thuja in its action, though it is less powerful than the latter. Some have found it beneficial in dyspeptic, cutaneous, and rheumatic affections. I do not, however, think it equal to many of our indigenous remedies, which are sadly neglected by the profession, in their eagerness for something at a distance from home. Were our native plants more closely investigated, there would be but little use for foreign, and consequently expensive agents (Prof. King). Under favorable circumstances a warm infusion of buchu leaves will cause diaphoresis. Dose of the powder, from 20 to 30 grains, 2 or 3 times a day; of the infusion, 2 to 4 fluid ounces, 3 or 4 times a day; of the tincture, 1 to 2 fluid drachms; specific barosma, 10 to 60 drops, well diluted, from 3 to 6 times a day.
Specific Indications and Uses.—Abnormally acid urine, with constant desire to urinate, with but little relief from micturition; vesico-renal irritation; copious mucous, or muco-purulent discharges; cystorrhoea.