Related entry: Senna pods
"The dried leaflets of Cassia acutifolia Delile, known in commerce as Alexandria Senna, or of Cassia angustifolia Vahl, known in commerce as India Senna (Fam. Leguminosae), without the presence or admixture of more than 10 per cent. of stem tissues, pods, seeds and other impurities." U. S. " Senna Leaves are the dried leaflets of Cassia acutifolia, Delile, and of Cassia angustifolia, Vahl. Known in commerce as Alexandria senna, and Tinnevelly senna." Br.
Sennae Folia, Br.; Senna Leaves; Sene, Fr. Cod.; Feuillea de Sene, Fr.; Folia Senna; P. G.; Sennesblätter, G.; Sena, It.; Sen, Sp.
The plants which yield senna belong to the genus Cassia, of which several species contribute to furnish the drug. These were confounded by Linnaeus and comprised in a single species, which he named Cassia Senna. Since his time the subject has been more thoroughly investigated, especially by Delile, who accompanied the French expedition to Egypt and had an opportunity of examining the plant in its native country. Besides the official species, it is probable that C. lanceolata of Forskhal.and C. aethiopica of Guibourt.contribute towards commercial senna. The leaves of a number of species of Cassia are utilized like senna leaves in the respective countries in which they grow, among which may be mentioned C. marilandica L.; C. cathartica Mart.; C. rugosa Don.; C. splendida Vog.; C. laevigata Willd.; C. multijuga Rich.; C. Chamaecrista L.; and C. montana Hayne. Farwell asserts that Cassia marilandica and other American species of Cassia have been offered in large lots and sold as senna. (M. R., xvii, p. 35.)
Cassia acutifolia is a small undershrub, two or three feet high, with a straight, woody, branching, whitish stem; but, according to Landerer, the senna plant attains the height of eight or ten feet in the African deserts. The leaves are alternate and pinnate, with glandless petioles, and two small narrow pointed stipules at the base. The leaflets, of which from four to six pairs belong to each leaf, are almost sessile, oval-lanceolate, acute, oblique at their base, nerved, from half an inch to an inch long, and of a yellowish-green color. The flowers are yellow, and in axillary spikes. The fruit is a flat, elliptical, obtuse, membranous, smooth, grayish-brown, bivalvular legume, about an inch long and half an inch broad, scarcely if at all curved, and divided into six or seven cells, each containing a hard, heart-shaped, ash-colored seed. C. acutifolia grows wild in great abundance in Upper Egypt, Nubia, Sennaar, and other parts of Africa. This species furnishes the greater part of the variety known in commerce by the name of Alexandria senna.
Cassia angustifolia, as usually grown is annual, but with care it may be made to live through the year, and then assumes the character of an undershrub. It has an erect, smooth stem, and pinnate leaves, with from four to eight pairs of leaflets. These are nearly sessile, lanceolate, obscurely mucronate, oblique at the base, smooth above and somewhat downy beneath, with the veins turned inward so as to form a wavy line immediately within the edge of the leaflet. The most striking character of the leaflet is its length, which varies from 2 to 5 cm. The petioles are without glands; the stipules minute, spreading and semi-hastate. The flowers are bright yellow, and arranged in axillary and terminal racemes rather longer than the leaves. The legume is oblong, membranous, tapering abruptly at the base, rounded at the summit, and 4 to 5 cm. long by about 1.5 cm. broad. This plant is found in Southern Arabia and on the coast of East Africa from Mozambique to the Somali land. It has been said to grow in the interior of India, and is cultivated at Tinnevelly for medicinal use.
Cassia obovata Colladon, possesses a rather shorter stem than that of C. acutifolia, rising to the height of only a foot and a half. The leaves have from five to seven pairs of leaflets, which are obovate, very obtuse, sometimes mucronate. The flowers are in axillary spikes, of which the peduncles are longer than the leaves of the plant. The legumes are very much compressed, curved almost into the kidney form, of a greenish-brown color, and covered with a very short down, which is perceptible only by the aid of a magnifying glass. They contain from eight to ten seeds. This species grows wild in Syria, Egypt, Senegambia, and Jamaica. (P. J., Sept., 1867.) It has been cultivated successfully in Italy, Spain, and the West Indies. It is said to be no longer gathered for senna, although its leaflets and pods have been found in Alexandria senna.
C. lanceolata of Forskhal, found by that author growing in the deserts of Arabia, is admitted by Lindley and others as a distinct species. Some difference of opinion, however, exists upon this point. De Candolle considered it a variety of the C. acutifolia of Delile, from which it differs chiefly in having leaflets with glandular petioles, and, as Forskhal's description preceded that of Delile, he designated the species by the name of C. lanceolata. Forskhal's plant has been supposed by some to be the source of the India or Mocha senna, but the leaflets in this variety are much longer than those of C. lanceolata, from which the plant differs also in having no gland on the petiole. Niebuhr informs us that he found the Alexandria senna growing in the Arabian territory of Abu-Arisch, whence it is taken by the Arabs to Mecca and Jedda. This is probably the C. lanceolata of Forskhal. It is highly probable that this species is the source of a variety of senna which has been brought to this market under the name of Mecca senna.
Cassia aethiopica of Guibourt (C. ovata of Merat), formerly confounded with C. acutifolia, is considered by Lindley to be a distinct species. It grows in Nubia, Fezzan, to the south of Tripoli, and probably, according to Guibourt, throughout Ethiopia. It is from this plant that the Tripoli senna of commerce is derived.
Several varieties of this valuable drug are known in commerce. Of these, four have been received in America—the Alexandria, the Tripoli, the India, and the Mecca senna—but only two are recognized by the Pharmacopoeia, which are officially described as follows:
"Alexandria Senna.—Usually unbroken, occasionally in fragments, leaflets inequilaterally lanceolate or lance-ovate, from 2 to 3.5 cm. in length and from 6 to 10 mm. in breadth, having extremely short, stout petiolules; acutely cuspidate, entire, subcoriaceous, brittle, pale green or grayish-green, sparsely and obscurely hairy, especially beneath, the hairs appressed; odor characteristic, taste somewhat mucilaginous and bitter. Pods few, broadly elliptical, somewhat rent-form, dark green, thin and membranous.
"India Senna.—Leaflets usually unbroken, from 2 to 5 cm. in length and from 6 to 14 mm. in breadth, usually more abruptly pointed than those of Alexandria Senna, yellowish-green and smooth above, paler beneath; in odor and taste closely resembling Alexandria Senna. Pods few, elliptical, more or less reniform and from 4 to 5 cm. in length. Powdered Alexandria Senna is light green; when examined under the microscope it exhibits non-glandular hairs, 1-celled, conical, often curved, from 0.1 to 0.35 mm. in length, walls thick and papillose; calcium oxalate in rosette aggregates, from 0.009 to 0.01 mm. in diameter, and in 4- to 6-sided prisms, about 0.015 mm. in length, usually in crystal fibers; stomata broadly elliptical, about 0.02 mm. in long diameter. In India Senna the powder is slightly darker green than that of Alexandria Senna and the hairs are similar but relatively fewer. Mix 0.5 Gm. of powdered Senna with 10 mils of an alcoholic solution of potassium hydroxide (1 in 10), boil the mixture for about two minutes, dilute it with 10 mils of water and filter. Now acidify the nitrate with hydrochloric acid, shake it with ether; remove the ethereal layer and shake it with 5 mils of ammonia water; the latter is colored pinkish-red or bluish-red. Senna yields not more than 12 per cent. of ash, The yield of ash insoluble in hydrochloric acid is not more than 3 per cent. of the Senna taken." U. S.
"Pale greyish-green or yellowish-green, thin, brittle; usually from two to four centimetres long, the leaflets of Alexandrian senna being usually smaller than those of Tinnevelly senna; lanceolate, or oval-lanceolate, acute, entire, and unequal at the base. Surface finely pubescent or nearly glabrous, veins on the under surface distinct. Epidermis of both surfaces consisting of polygonal cells and bearing one-celled, thick-walled, warty hairs together with stomata, each stoma being enclosed between two cells with their long axes parallel to the ostiole. The powdered Leaves greenish-yellow, exhibiting, in addition to the characteristic epidermis, stomata, and hairs, elongated palisade cells and grouped sclerenchymatous fibres accompanied by prismatic crystals of calcium oxalate. Ash not more than 12 per cent." Br.
1. ALEXANDRIA SENNA.—This variety of senna is gathered in extreme Upper Egypt and the Soudan, and thence sent to Assouan at the First Cataract of the Nile, whence it finds its way into commerce through Cairo, Suakim, Suez and Alexandria. Two crops are produced annually, one in the spring and one in the autumn. The plants are first cut, then dried, and then the stripped-off leaves and pods are packed in crude bales, in which several species of senna are represented in varying proportion, the predominating species being C. acutifolia. Formerly there was an intentional mixture of the product of Cassia acutifolia with the leaflets of C. obovata, brought from other parts of Egypt, and even from Syria, with the leaves of Cynanchum oleaefolium (C. Argel of Delile, Solenastemma Argel Hayne), known commonly by the name of argel or arguel, and sometimes with those of Tephrosia apollinea of De Candolle, a leguminous plant growing in Egypt and Nubia. According to M. Royer, the proportions in which the three chief constituents of this mixture were added together were five parts of C. acutifolia, three of C. obovata, and two of Cynanchum. Thus prepared, the senna was again packed in bales, and transmitted to Alexandria. But at present there is much more uniformity in the constitution of Alexandria senna. This variety of senna is often called in French pharmaceutical works sene de la palthe, a name derived from an impost formerly laid upon it by the Ottoman Porte. A parcel of Alexandria senna, as it was formerly brought to market, consisted of the following ingredients: (1) the leaflets of C. acutifolia, characterized by their acute form, and their length, almost always less than an inch; (2) the leaflets of C. obovata, known by their rounded very obtuse summit, which is sometimes furnished with a small projecting point, and by their gradual diminution in breadth towards their base; (3) the pods, broken leafstalks, flowers, and fine fragments of other parts of one or both of these species; (4) the leaves of Cynanchum oleaefolium, which are distinguishable by their length, almost always more than an inch, their greater thickness and firmness, the absence of any visible lateral nerves on their under surface, their somewhat lighter color, and the regularity of their base. In this last character they strikingly differ from the genuine senna leaflets, which, from whatever species derived, are always marked by obliquity at their base, one side being inserted in the petiole at a point somewhat lower than the other, and at a different angle. Discrimination between this and the other ingredients is of some importance, as the Cynanchum must be considered an adulteration. It is said by the French writers to produce hypercatharsis and much irritation of the bowels, but was found by Christison and Mayer to occasion griping and protracted nausea, with little purgation. The flowers and fruit of the Cynanchum were also often present, the former white and in small corymbs, the latter an ovoid follicle rather larger than an orange-seed. Besides the above constituents of Alexandria senna, it occasionally contained leaflets of genuine senna, much longer than those of the acutifolia or obovata, equalling in this respect the Cynanchum, which they also somewhat resembled in form. They were distinguishable, however, by their greater thinness, the distinctness of their lateral nerves, and the irregularity of their bases. The leaflets and fruit of Tephrosia apollinea, which have been an occasional impurity in this variety of senna, may be distinguished, the former by their downy surface, their obovate-oblong, emarginate shape, their parallel unbranched lateral nerves, and by being usually folded longitudinally; the latter, by its dimensions, being from an inch to an inch and a half long, and only two lines broad. In Europe, Alexandria senna was formerly adulterated with the leaflets of Colutea arborescens L., or bladder senna, and the leaves of Coriaria myrtifolia L., a poisonous plant of Southern Europe..
The leaflets of the Coriaria are ovate-lanceolate, grayish-green with a bluish tint, and are readily known, when not too much broken up, by their strongly-marked midrib and two lateral nerves running from the base nearly to the summit. They are free from hairs and do not contain crystals of calcium oxalate. Another addition to Alexandria senna has been detected by Lacroix of Macon, France, in the leaves of the Globularia Turbith (Globularia Alypum Linn.), which seem to have taken the place of the Colutea arborescens, because more closely resembling the senna leaflet. The leaves of the Globularia are spatulate, much enlarged towards the upper end, rounded at the extremity, but always terminating in a short sharp point. . Besides, they are brown, thick, firm, and hard to the touch, while those of the Colutea are green, very thin, and soft. They have an acrid, very bitter taste, but are without nauseous odor. They are asserted to be cathartic, but milder than senna, and capable of being substituted for it in twice the dose. (J. P. C.,4e ser.,i,413.)
The so-called Aden senna which Holmes states to be active, is composed of small, broad, not very acute, hairy leaves, and is believed to be obtained from C. holosericea Fres. A false senna from Madras has been identified by E. M. Holmes as the product of Cassia montana Hayne. The leaflets are about the size of the Tinnevelly senna, but are distinguishable by obtuse or rounded ends which are with distinct mucronate, the tip is, however, often broken off and absent from individual leaves; by the obtuse angles of the lateral veins and by the presence of a well marked network of veins of the under surface; further, the color of the upper surface is distinctly browner than of the Tinnevelly leaflet. The whole leaves of Cassia montana have from 10 to 15 pairs of leaflets, while the Tinnevelly senna has only from 6 to 8 pairs. In the drug this character can usually be made out by noticing the number of scars on the rachis. For a microscopic description of powder, see H. G-. Greenish, P. J., lvi, 694. In detecting the adulteration of senna, the apothecary may avail himself not only of the general physical characteristics of the leaves, but also of the fact that while the senna leaf, containing no tannic acid, does not precipitate ferric chloride, most leaves used in adulteration do alter the ferric solution. The microscopic characteristics of the false leaves, though varying greatly, are almost always very different from those of senna. In the senna leaflets the epidermis from the upper and under surface is very similar. The stomata are numerous; the epidermal hairs are unicellular and deciduous, leaving, when detached, a base which has the appearance of an annular pad, around which the neighboring cells seem to radiate. The parenchyma of the cell has a thick epidermis, and is divided into three layers, the uppermost and lowest of which consist of palisade tissue, and are separated by a zone of very small, rounded, parenchymatous cells. Rosette aggregate crystals of calcium oxalate are scattered throughout the parenchyma, and prismatic crystals, one in each cell, occur (clustered around the bast tissue of the principal veins.
For a microscopical description of Alexandria senna, see Proc. A. Ph. A., 1882, p. 238.
2. INDIA SENNA.—This variety is in Europe sometimes called Mocha senna, probably because obtained originally from that port. It derives its name of India senna from the route by which it reaches us. Though produced in Arabia, it is brought to this country and Europe from Calcutta, Bombay, and possibly other ports of Hindostan. It consists of the leaflets of Cassia elongata, with some of the leafstalks and pods intermixed. The eye is at once struck by the great length (about two inches) and comparative narrowness of the leaflets, so that the variety may be readily distinguished. The pike-like shape of the leaflet has given rise to the French name of sene de la pique. Many of the leaflets have a yellowish, dark-brown, or blackish color, probably from exposure after collection, and the variety has commonly in mass a characteristic dull tawny hue. It is generally considered inferior in purgative power. Leaflets of a senna resembling the Indian were brought by Livingstone from Southern Africa, where the plant grows abundantly. (P. J., xvii, 499.)
A variety of India senna has reached this country which is a product of Hindostan, being cultivated at Tinnevelly, and probably other places in the south of the Peninsula. The plant was originally raised from seeds obtained, from the Red Sea, and is the same as that from which the common Indian senna is derived. The drug is exported from Madras to England, where it is known by the name of Tinnevelly senna. It is a fine unmixed variety, consisting of unbroken leaflets, from one to two or more inches long, and sometimes half an inch in their greatest breadth, thin, flexible, and of a fine green color. T. B. Groves, however, states as the result of his experiments that Tinnevelly senna contains only two-thirds as much of the active principle as does the Alexandrian. (P. J., Oct., 1868, p. 292.)
Much study has been given to the question of distinguishing the powder of Alexandria and India senna by means of the microscope. (See papers by Sayre, A. J. P., 1896, 1897; Schneider, Am. Drug., 1897; Denniston, Ph. Rev., vol. xvi.) As a result of these studies it is asserted that it is possible to take advantage of the greater hairiness of the Alexandria senna as a practical distinction, it being alleged that a fragment of the epidermis of Alexandria leaf contains twice as many hairs as does a similar sized shred of epidermis from the India senna. It is especially proposed to count the number of epidermal cells between two hairs or their scars, the average distance of the hairs from one another being in the Alexandria senna three epidermal cells, and in the India six cells. Advantage may also be taken of the difference in the neighboring cells of the stomata; in the majority of stomata, in each case, there are two of the neighbor-cells, but in India senna the proportion is one having three neighbor-cells to seven having two, and in the Alexandria the proportion is one having three to two having two.
3. TRIPOLI SENNA.—Genuine Tripoli senna consists in general exclusively of the leaflets of one species of Cassia, formerly considered to be a variety of C. acutifolia, but now admitted to be distinct, and named C. aethiopica. The leaflets, however, are much broken up, and it is probably on this account that the variety is usually less esteemed than the Alexandrian. The aspect given to it by this state of comminution,. and by the uniformity of its constitution, enables the eye at once to distinguish it from the other varieties of senna. The leaflets, moreover, are shorter, less acute, thinner, and more fragile than those of C. acutifolia or Alexandria senna, and their nerves are much less distinct. The general opinion at one time was that it was brought from Sennaar and Nubia to Tripoli in caravans; but, it is reasonably asked by Fee, how could it be afforded at a cheaper price than the Alexandrian, if thus brought on the backs of camels a distance of eight hundred leagues through the desert. It is probably collected at Fezzan, immediately south of Tripoli.
4. MECCA SENNA is still imported under the name of Arabian or Bombay Senna, and is obtained from both wild and cultivated plants of Cassia angustifolia. The best drug is obtained from British India, great care being taken in its garbling. Much of the commercial article is of a dark brown color. The leaflets are oblong-lanceolate, on the average longer and narrower than those of C. acutifolia, and shorter than those of C. elongata. The variety in mass sometimes has a yellowish or tawny hue, more like that of India than like that of Alexandria senna and may be the product of the C. lanceolata of Forskhal. Landerer speaks of a valuable variety of senna, characterized by the large size of the leaflets, and sold under the name of Mecca senna, which he says comes from the interior of Africa.
Commercial senna is prepared for use by garbling, or picking out the leaflets, and rejecting the leafstalks, the impurities, and the leaves of other plants. The pods are also rejected by some apothecaries. (See Senna Fructus.)
The market for senna is gradually changing. For years the drug used in the United States was imported from London or European ports. At the present time, the importations into the United States are largely direct from Egypt. The amount of senna annually exported is about 8000 bales of each of the varieties. Owing to the failure of the crops at certain seasons, the price of senna is very high, and what is known as "broken" senna is found upon the market and sold for the genuine article. This is done with the sanction of the government. In addition, what is known as "senna sittings," which contain large amounts of sand and other foreign matter, have been offered, and these have caused the government inspectors a large amount of trouble. There is considerable difference in the actual constituents of the two sennas, and it would seem advisable for the Pharmacopoeia to restrict the drug to one species or else to include them under two separate titles. This principle has been followed by the German Pharmacopoeia, as well as the Swiss Pharmacopoeia, which restrict the official drug to the Indian senna, or that derived from Cassia angustifolia. Indian senna is known commercially as Tinnevelly senna, and this name should probably have been used in the Pharmacopoeia. Alexandria senna is occasionally admixed with the leaflets of C. obovata Coll. (Bull. Soc. roy. d. pharm. Brux., liii, p. 169). In addition to admixture of senna with the leaflets of Cassia marilandica it is stated that the leaves of Ailanthus glandulosa have been found admixed. A very interesting and characteristic test for genuine senna depends upon the sublimation of its oxymethyl-anthraquinone, which is always a constituent, and this may be further confirmed by testing the sublimed material with a drop of one of the solutions of the alkalies which will show a red-colored test. (Pharm. Prax., v, p. 435.)
Constituents.—The odor of senna is faint and sickly; the taste slightly bitter, sweetish, and nauseous. Water and diluted alcohol extract its active principles. Pure alcohol extracts them but imperfectly. (Bley and Diesel, Ph. Cb., Feb., 1849, p. 126.) The leaves are said to yield about one-third of their weight to boiling water. The infusion is of a deep reddish-brown color, and has the odor and taste of the leaves. When exposed to the air for a short time, it deposits a yellowish insoluble precipitate, supposed to result from the union of extractive matter with oxygen. The nature of this precipitate, however, is not well understood. Decoction also produces some change in the principles of senna, by which its medicinal virtues have been supposed to be impaired, but some experiments of B. Heerlein would seem to show that this opinion is incorrect. An extract prepared by boiling down an infusion, redissolving the residue, and again boiling down to a solid consistence, was found to operate actively in a dose equivalent to a drachm of the leaves. (Ph. Cb., 1851, p. 909.) To diluted alcohol it imparts the same reddish-brown color as to water, but rectified alcohol and ether, digested upon the powdered leaves, become of a deep olive-green.
Lassaigne and Feneulle first isolated a substance to which they gave the name of cathartin, but it proved to be a mixture; Bley and Diesel (Ph. Cb., 1849, p. 126) isolated a yellow coloring matter, which they called chrysoretin, but which Martins identified as chrysophan; Ludwig (A. Pharm. (2), cix, p. 42, and cxc, p. 69) obtained two bitter principles, sennapicrin and sennacrol, the first insoluble, the second soluble in ether; but the active purgative principle was first discovered in 1866 by Dragendorff and Kubly (Viertelj. f. Prakt. Pharm., 16, pp. 96 and 337), who found it to be a glucoside of weak acid character, and named it cathartic acid. Thos. B. Groves, in 1868 (P. J., 1869, p. 196), unaware of Dragendorff and Kubly's discovery, isolated the same principle, and found for it the same reactions. For a method of preparing cathartic acid, by Ralph Stockman, see P. J., 1885, p. 740. Its formula is given as C180H96N2SO82, and by boiling its alcoholic solution with acids it yields cathartogenic acid and sugar. Gensz (A. J. P., 1893, 334), who prepared it later by the method of Kubly and Stockman, gave the formula C30H36NO15. It is amorphous, difficultly soluble in cold water, readily soluble in boiling water. The best solvent is a 30 to 40 per cent. alcohol; ether, benzene, chloroform, and petroleum ether are without solvent action. Alkalies with heat decompose it. It is prepared by partially precipitating with alcohol infusion of senna, concentrating to a syrupy consistence in vacua, filtering, treating the filtrate with a large proportion of absolute alcohol, and repeatedly dissolving in water, and precipitating by alcohol the precipitate thus obtained. It is purified by submitting it (dissolved in moderately strong hydrochloric acid) to dialysis on a diaphragm of parchment paper, cathartic acid having strong colloidal properties. Groves found that ammonium cathartate purged moderately in the dose of three and three-quarters grains, with considerable griping, and that of certain mixed cathartates seven and a half grains purged violently, with much griping and sickness, and continued to act through most of a day. He considers four grains a fair dose. It should be given in connection with an aromatic and a saline cathartic. Magnesium cathartate is soluble. The salts of this acid in aqueous solution are decomposed and rendered inert by long exposure to heat in contact with the air. (Groves, P. J., Oct., 1868, 200-1.) Dragendorff and Kubly also found chrysophanic acid in small proportions, the two substances, sennacrol and sennapicrin, previously mentioned, and a peculiar non-fermentable saccharine principle, with the formula C21H44O19, which they named catharto-mannite. (J. P. C., 4e ser., v.) A. Seidel proposes the name of sennit for catharto-mannite, and gives a process for its preparation in A. J. P., 1885. In 1900 Tschirch and Hiepe made a comprehensive investigation of the chemical constituents of senna in which they found that the active principles belonged to the oxymethylanthraquinone group of glucosides, yielding emodin upon decomposition. From the aqueous percolate they extracted, besides cathartic acid, a crystalline body, giving the same reactions as sennanigrin and having the composition C14H10O5. From the weak ammoniacal percolate they obtained anthraglucosennin, which, however, is composed of several distinct substances, for on treating it with ether, a portion enters solution and another remains undissolved; then the ether-soluble portion, if boiled with toluene and the solution poured on petroleum benzin, precipitates sennaemodin, while sennachrysophanic acid remains in solution and may be obtained on evaporation; the portion insoluble in toluene is a body which the authors have named glucosennin. Its composition agrees with the formula C22H18O8, and it is possibly an emodin glucoside. From the portion of anthraglucosennin insoluble in ether, sennaisoemodin is obtained by treatment with acetone and shaking the resultant solution with petroleum benzin. The acetone solution retains a substance which the authors have named sennarhamnetin. Finally, the portion of anthraglucosennin remaining undissolved after treatment with ether and acetone is a black body which resembles in this and other respects aloenigrin. Sennanigrin, however, yields on treatment with alcoholic potassium hydroxide, sennaemodin and sennachrysophanic acid. (A. Pharm., Aug. 31, 1900, 427, 448.)
Some results of experiments on the properties of senna which more particularly concern the pharmacist are noted in a paper contained in the J. P. C. (Janv., 1874, p. 80), and require to be mentioned here, because they tend to fix certain points which are left undetermined in the above statement. An extract made by evaporating in the air an aqueous infusion of senna possesses but partially the purgative properties of the leaves. If the extract be redissolved in a large quantity of water, and the solution be again evaporated, the extract now obtained will be quite inert. It follows that a prolonged decoction of senna destroys its cathartic powers. The presence of an alkali in the decoction increases the rapidity of the destruction. An infusion of senna in lime water, heated to the boiling point, and then deprived of lime by a stream of carbon dioxide, becomes inert. An infusion of senna, made to boil after the addition of potassium hydroxide, and then neutralized by an acid, is also inert. The mineral acids destroy the purgative powers of senna, but less energetically than the alkalies; the vegetable acids exercise the same power but feebly. Concentrated alcohol does not dissolve the active principle, which is soluble in cold water. It was Heerlein who first determined the complete want of purgative power in the pure alcoholic extract of senna. Nevertheless, this extract possesses in a high degree the odor and taste of senna, and, taken internally, without purging, imparts a deep-yellow color to the urine, which the alkalies change to red. The leaves exhausted by alcohol have all their purgative effect, but lose the power of affecting the urine so that an alkaline solution shall color it red. These facts prove that chrysophanic acid is not the purgative principle of senna. The fact that alcohol removes the odor and taste of senna without affecting its purgative action may sometimes be advantageously applied in cases in which the taste of senna is extremely offensive. L. Siebold, after experimenting with senna leaves washed with alcohol, arrived at the following conclusions: (1) Strong spirit does not remove any of the active principle from senna leaves; (2) the therapeutic action of cathartic acid is assisted by one or more of the constituents yielded by senna to strong alcohol, though these constituents produce no purgative effect when taken alone; (3) senna exhausted by alcohol is a reliable and pleasant purgative, but somewhat weaker in its action than the unexhausted leaves. Tutin reports the analysis of the water soluble portion of an alcoholic extract of Tinnevelly senna as containing (1) salicylic acid, (2) rhein (C15H8O6), (3) kaempferol (1:3:4 trihydroxyflavonol), (4) aloe-emodin (C15H10O5., (5) kaempferin (C23H30O6), a glucoside of kaempferol, (6) glucosides of rhein and aloe-emodin, (7) a magnesium salt of an unidentified organic acid, (8) a sugar. The water insoluble portion contained (1) myricyl alcohol, (2) a phytosterol (C27H46O), (3) a phytosterolin (C33H56O6), (4) palmitic and stearic acids, besides a small amount of essential oil.
Incompatibles.—Many substances produce precipitates with the infusion of senna, but it does not follow that they are all medicinally incompatible, as they may remove only inert ingredients. Cathartic acid is precipitated by infusion of galls and solution of lead sub acetate. Lead acetate and tartar emetic which disturb the infusion, have no effect upon the solution of this substance.
Uses.—Senna was first used as a medicine by the Arabians. It was noticed in their writings as early as the ninth century, and the name itself is Arabic. Like the other cathartics of the anthraquinone series, its action is chiefly upon the lower bowel, and is therefore especially suitable in habitual costiveness. It increases the peristaltic movements of the colon by its local action upon the intestinal wall. The tendency to gripe may be obviated by combining it with aromatics or with a saline laxative. The coloring matter of senna is absorbable, and twenty or thirty minutes after the ingestion of the drug it appears in the urine and may be recognized by a red color on the addition of ammonia. It is asserted also that the milk of nursing women acquires purgative properties after the administration of senna. Under the name of cathartin there is upon the market a mixture of the salts of cathartic acid which may be used in doses of from three to six grains (0.2-0.4 Gm.). Sennax is the name applied to the water-soluble glucoside of senna, and is marketed in tablets each one of which contains 0.075 Gm.
Dose, of senna, one-half to two drachms (2.0-7.7 Gm.).
Off. Prep.—Confectio Sennae, Br., N. F.; Fluidextractum Sennae, U. S.; Infusum Sennae, Br.; Infusum Sennae Compositum, U. S.; Pulvis Glycyrrhizae Compositus, U. S., Br.; Syrupus Sennae (from Fluidextract), U. S., Br.; Tinctura Sennae Composita, Br.; Mistura Sennae Composita (from Infusion), Br.; Syrupus Sarsaparillae Compositus (from Fluidextract), U. S.; Elixir Cascarae Sagradae Compositum (from Fluidextract), N. F.; Elixir Catharticum Compositum (from Fluidextract), N. F.; Species Laxativae, N. F.; Syrupus Ficorum Compositus, N. F.; Syrupus Sennae Aromaticus, N. F.; Syrupus Sennae Compositus, N. F.
The Dispensatory of the United States of America, 1918, was edited by Joseph P. Remington, Horatio C. Wood and others.