Casc. Sagr. [Rhamnus Purshiana U.S. VIII]
Related entry: Rhamnus
"The dried bark of the trunk and branches of Rhamnus Purshiana De Candolle (Fam. Rhamnaceae)." U. S. "Cascara Sagrada is the dried bark of Rhamnus Purshianus, DC., collected at least one year before being used." Br.
Rhamni Purshiani Cortex, Fr. Cod.; Sacred Bark; Chittem Wood Bark, Dogwood bark, Coffee-berry bark, Pigeon-berry bark, Bear-berry bark. Bitter bark and Yellow bark; Cascara Sagrada, Sp.
A number of species of Rhamnus have been described as growing in California, but according to the best authority there are only four species,—R. alnifolia, L'Her., R. crocea, Nutt., R. Purshiana, DC., and R. californica, Esch. Of these species, R. alnifolia is too rare in the Cascara district to be important; while the spinescent twigs, the very thick oval or roundish leaves, and the small roundish red fruit of R. crocea make it so distinct that it cannot be confounded with the Cascara, whose bark, moreover, it does not resemble. On the other hand, R. californica appears to be very commonly confounded with the official species by collectors, and to have yielded some of the cascara sagrada bark of commerce. R. californica is rare in Northern California, but abundant in the countries lying south and southeasterly, while R. Purshiana is abundant in Northern California, but scarce in the south, so that any bark collected in Northern California is probably genuine. R. californica is chiefly distinguished from the official species by its leaves being thin, and, when not smooth, having a short close pubescence, and the primary veins of the under surface not nearly so numerous, straight, or fine as those of R. Purshiana. Rusby thinks that its leaves are especially distinguished by the channel of the midrib of R. californica being altogether absent, or shallow, or inconspicuous. Nevertheless the species so run into one another that competent botanists believe them identical.
The Rhamnus Purshiana is a small tree, attaining a height of twenty feet. Its leaves are rather thin, elliptic, for the most part briefly acutely pointed, finely serrated, at the base obtuse, somewhat pubescent beneath, from two to seven inches long and from one to three wide. The rather large flowers are in somewhat umbellate cymes; the sepals five; the minute cucullate petals bifid at the apex. The fruit is black, broadly obovoid, four lines long, three-lobed, and three-seeded. The seeds are convex on the back, with a lateral raphe. It is found in California, extending northward to the British territories. For details of manner of collecting the bark see an elaborate and illustrated article by Johnson and Hindman, A. J. P.. 1914, p. 387. The amount of Cascara that is collected annually varies between 3,000,000 and 4,000,000 pounds. Because of the rapid destruction of natural sources of the bark in the Western United States, experiments have been conducted by the Bureau of Plant Industry, U. S. Department of Agriculture, Washington, D. C., to cultivate it.
The Rhamnus californica, or Californian buckthorn or California coffee-tree, yields a bark which is of a dark brown color externally and bright yellow internally, having an intensely bitter taste, with a persistent nauseous aftertaste, and very little odor. It is said to be much more distinctly purgative than that of R. crocea.
It does not seem possible to distinguish with certainty between the barks of the two species by their macroscopic appearance. The bark of R. Purshiana is usually more red than is that of R. californica, but it may be of a distinctly gray color. The microscopic structure of the two barks is, however, different. The medullary rays in R. Purshiana are numerous, thin, for a long distance nearly parallel and straight (according to L. E. Sayre, they converge at their outer ends), run nearly three-quarters of the distance through the bark, and are commonly composed of two rows of cells. In R. californica the medullary rays are much broader, much shorter, and are composed usually of three or more rows of cells; further, they are crooked and not parallel throughout their course. Again, the zone of resin spaces is much broader in R. californica, and the spaces themselves much larger and more numerous than in the official species. For further details and elaborations, see papers by H. H. Rusby, Proc. A. Ph. A., 1890, and by Gathercoal, J. A. Ph. A., 1915, p. 15. According to L. E. Sayre (A. J. P., March, 1897), the powder of the barks can be distinguished by paying attention to the fact that R. Frangula contains no stone cells, while in R. californica and R. Purshiana such cells are abundant, occurring in large, irregular groups below the cork and usually outside the region of the bast: R. Purshiana may also be distinguished from R. californica by color tests. After several days maceration in dilute alcohol the powder of R. Purshiana appears of an orange-yellow color, R. californica of a purplish color; or if 0.2 Gm. of the powdered bark be placed in a small test tube, and there be added 2 mils of potassium hydroxide test solution, R. californica will give a blood-red and R. Purshiana an orange-red color.
The bark of the Rhamnus crocea, the so-called California mountain holly, occurs in slightly curved pieces, externally of a dark brown color, internally of a characteristic red delicately streaked with numerous white veins. The odor is somewhat aromatic, the taste warming and not unpleasantly bitter. It is affirmed to be a tonic and mild laxative.
Properties.—Cascara sagrada occurs in commerce in the form of small broken pieces, often more or less flattened out into a somewhat compressed mass, and also as separated quills of varying length and size. The bark is "Usually in flattened or transversely curved pieces, occasionally in quills; bark from 1 to 5 mm. in thickness; outer surface dark brown or brownish-red, longitudinally ridged, often nearly covered with grayish or whitish lichens, bearing small blackish apothecia, sometimes with numerous lenticels, and occasionally with mosses; inner surface light yellow, light brown, or reddish-brown, longitudinally striate, turning red when moistened with solutions of the alkalies; fracture short, with projections of bast-fibers in the inner bark; in cross section inner bark shows diagonal or curved medullary rays, forming converging groups, the outer bark showing yellowish groups of stone cells which are especially apparent on moistening the freshly cut surface with phloroglucinol T.S. and hydrochloric acid; odor distinct; taste disagreeable, bitter, and slightly acrid. Under the microscope, a transverse section of Cascara Sagrada shows an outer yellowish-brown or reddish-brown corky layer consisting of 10 to 15 or more rows of cells; stone cells in outer bark in tangentially elongated groups of 20 to 50 cells, the walls being very thick and finely lamellated; medullary rays 1 to 4 cells wide, 15 to 25 cells deep, the contents being colored red upon the addition of solutions of the alkalies to the sections; bast-fibers in tangentially elongated groups in the inner bark, the walls being thick and strongly lignified; crystal fibers around the bast-fibers with individual crystals from 0.008 to 0.015 mm. in length; parenchyma with spheroidal starch grains about 0.003 to 0.008 mm. in diameter, or with calcium oxalate either in rosette aggregates or prisms from 0.01 to 0.02 mm. in diameter. Add 0.1 Gm. of powdered Cascara Sagrada to 10 mils of hot water, shake the mixture occasionally until cold, filter it and add sufficient water to make 10 mils; on the addition of 10 mils of ammonia water to this liquid, it is colored an orange-yellow. Macerate 0.1 Gm. of powdered Cascara Sagrada with 10 drops of alcohol, boil the mixture with 10 mils of water, when cold filter it and shake the filtrate with 10 mils of ether; a yellow ethereal solution separates. Shake 3 mils of this ethereal solution with 3 mils of ammonia water; the separated ammoniacal solution still possesses, on diluting with 20 mils of water, a distinct, yellowish-red color. The powder is light brown to olive brown, showing characteristic elongated groups of bast-fibers associated with crystal fibers, the crystals in the latter being in the form of monoclinic prisms from 0.008 to 0.015 mm. in length; stone cells in large groups, the cells having thick and finely porous walls; fragments of parenchyma and medullary ray cells colored red upon the addition of solutions of the alkalies; starch grains either free or in parenchyma cells, the individual grains being somewhat spheroidal, from 0.003 to 0.008 mm. in diameter; calcium oxalate in monoclinic prisms or rosette aggregates from 0.01 to 0.02 mm. in diameter; occasional fragments of reddish-brown cork." U. S.
"In quilled, channelled, or nearly flat pieces from one to two millimetres thick, but varying in length and width. Cork nearly smooth, dark purplish-brown, marked with transversely elongated lenticels, but usually more or less covered with patches of silvery-grey lichen. Inner surface reddish-brown, with faint transverse corrugations and longitudinal striations. Fracture short, but near the inner surface somewhat fibrous. In transverse section, scattered groups of sclerenchymatous cells in both cortex and bast; the parenchymatous cells contain a yellow substance which is colored violet by solution of sodium hydroxide. Odor characteristic but not powerful; taste nauseous, bitter and persistent." Br.
For articles illustrating the pharmacognosy of Cascara bark see Kraemer, A. J. P., 1912, p. 385; Miller, J. A. Ph. A., 1912, p. 1207; and Farwell, J. A. Ph. A., 1914, p. 649. According to the analysis of A. B. Prescott (N. P., Feb., 1879), it contains a very bitter brown resin (which is colored a vivid purple-red by potassium hydroxide); a red resin; a light yellow resin; tannic, malic, and oxalic acids; a neutral crystallizable substance; and a volatile oil. H. F. Meier and J. Le Roy Webber have pointed out in addition the presence of a ferment, glucose, and ammonia. According to these investigators, to the action of the ferment are attributed the unpleasant results attending the administration of "fresh bark"; "seasoned bark"—i.e., such as has been kept a year or two—owes its valuable properties as a laxative, free from griping, to the fact that the ferment has exhausted itself; the laxative properties, they state, reside in the resins, and the tonic effects are due to the crystalline principle. (A. J. P., 1888, 91). Schwabe (A. Pharm., ccxxvi, 569) found emodin, or trioxymethylanthraquinone, which he believes is the active principle. Dohme and Engelhardt (Proc. A. Ph. A., 1897, 193) have shown the analogy of cascara sagrada with Rhamnus Frangula by obtaining a glucoside to which they give the name of purshianin. This decomposes, yielding emodin. and a dextrorotatory non-fermentable sugar, while the frangulin of buckthorn yields emodin and rhamnose as the sugar. Purshianin forms brown-red needles, melting at 237° C. (458.6° F.). Dohme and Engelhardt failed to obtain in a pure form (Proc. A. Ph. A., 1898, 340) the bitter principle of cascara sagrada. Le Prince (C. R. A. S., 1892, 286) claimed to have obtained the active principle of cascara bark in a crystalline form, which he named cascarine; his results are doubted by Jowett who believes that cascarine and purshianin are impure forms of emodin. Jowett (Proc. A. Ph. A., 1904, 288) in an exhaustive paper concludes that the active principle of cascara is contained in that portion of an alcoholic extract which is soluble in water and precipitable by lead subacetate and in that portion of the regenerated lead subacetate precipitate which is soluble in ethyl acetate. Pietsch states that a glucoside from the bark of cascara sagrada which has been named peristaltin has the composition C14H18O8. (Th. M., 1910, No. 1, p. 35.)
Uses.—Cascara sagrada belongs to the group of vegetable cathartics whose activity depends upon the presence of one or more oxides of methylanthraquinone. This group includes aloes, cascara, rhubarb, and senna. In cascara the active principle appears to be emodin, which is trioxymethylanthraquinone, and which appears also to be the purgative principle of aloes. The action of this principle is chiefly to excite peristalsis in the colon, although after large doses there is probably also some effect upon the upper bowel. As the action is chiefly upon the lower intestine it is not to be recommended as a laxative where it is desired to clean out the bowel, but in the treatment of chronic constipation it acts very favorably. It often appears to restore tone to the relaxed bowel and in this way produce a permanent beneficial effect. The bark itself is rarely used, either the extract or fluidextract being eligible preparations.
The addition of belladonna to overcome any tendency to gripe is an advantage. Ordinarily a single dose is given at bedtime but in some cases better results are obtained by exhibiting smaller doses after meals.
Dose, ten to thirty grains (0.6-2.0 Gm.).
Off. Prep.—Extractum Cascarae Sagradae, U. S. (Br.); Fluidextractum Cascarae Sagradae, U. S. (Br.); Fluidextractum Cascarae Sagradae Aromaticum, U. S.; Syrupus Cascarae Aromaticus, Br.; Elixir Cascarae Sagradae (from Aromatic Fluidextract), N. F.; Elixir Cascarae Sagradae Compositum (from Aromatic Fluidextract), N. F., Fluidglyceratum Cascarae Sagradae, N. F.; Fluidglyceratum Cascarae Sagradae Aromaticum, N. F.; Pilulae Aloini, Strychninae et Belladonnae Compositae) (from Extract), N. F.; Syrupus Ficorum Compositus (from Aromatic Fluidglycerate), N. F.
The Dispensatory of the United States of America, 1918, was edited by Joseph P. Remington, Horatio C. Wood and others.