Senna Senna alexandrina printed as Cassia acutifolia Click on graphic for larger image

Senna

Botanical: Cassia acutifolia (DELL.)
Family: N.O. Leguminosae

• Description
• Constituents
• Medicinal Action and Uses
• Dosages
• Adulterations and Other Species Uses

C. acutifolia, yielding the finest and most valuable variety of the drug is a small shrub about 2 feet high. The stem is erect, smooth, and pale green, with long, spreading branches, bearing leaflets in four or five pairs, averaging an inch long, lanceolate or obovate, unequally oblique at the base, veins distinct on the under surface, brittle, greyish-green, of a faint, peculiar odour, and mucilaginous, sweetish taste. The form of the base, and freedom from bitterness, distinguish the Senna from the Argel leaves, which are also thicker and stiffer. The flowers are small and yellow. The pods are broadly oblong, about 2 inches long by 7/8 inch broad, and contain about six seeds.

Senna is an Arabian name, and the drug was first brought into use by the Arabian physicians Serapion and Mesue, and Achiarius was the first of the Greeks to notice it.He recommends not the leaves but the fruit, and Mesue also prefers the pods to the leaves, thinking them more powerful, though they are actually less so, but they do not cause griping.

The leaves of C. acutifolia are collected principally in Nubia. Ignatius Pallme, who travelled much in Africa, wrote:

'Senna is found in abundance in many parts of Kardofan, but the leaves are not collected on account of the existing monopoly. The Government draws its supplies from Dongola in Nubia.'

Senna appears to have been cultivated in England about 1640. By keeping the plants in a hot-bed all the summer, they frequently flowered; but rarely perfected their seeds.

Commercial Senna is prepared for use by garbling, or picking out the leaflets and rejecting the lead-stalks, impurities, and leaves of other plants. The amount annually exported is about 8,000 bales of each of the varieties, and the price is high, owing to the failure of the crops at certain seasons. Good Senna may be known by the bright, fresh, yellowishgreen colour of the leaves, with a faint and peculiar odour rather like green tea, and a nauseous, mucilaginous, sweetish, slightly bitter taste. It should be powdered only as wanted, because the powder absorbs moisture, becomes mouldy, and loses its value. Boiling destroys its virtues, unless it be in vacuo, or in a covered vessel.

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---Constituents---Water and diluted alcohol extract the active principles of Senna. Pure alcohol only extracts them imperfectly. The leaves yield about one-third of their weight to boiling water.

The purgative constituents are closely allied to those of Aloes and Rhubarb, the activities of the drug being largely due to anthraquinone derivatives and their glucosides. It contains rhein, aloe-emedin, kaempferol, isormamnetin, both free and as glucosides together with myricyl alcohol, etc. The ash amounts to about 8 per cent, consisting chiefly of earthy and ashy carbonates.

The active purgative principle was discovered in 1866. It is a glucoside of weak acid character, and was named Cathartic Acid. By boiling its alcoholic solution with acids it yields Cathartogenic Acid and sugar. There were also found Chrysophanic Acid, Sennacrol and Sennapicrin, and a peculiar non-fermentable saccharine principle which was named Cathartomannite or Sennit.

The conclusions reached after experimenting with Senna leaves washed with alcohol were as follows:

(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.

Cathartin is the name of a mixture of the salts of cathartic acid which may be used in doses of from 3 to 6 grains.

Sennax is the name applied to the watersoluble glucoside of Senna, marketed in tablets containing 0.75 gram each.

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---Medicinal Action and Uses---Purgative. Its action being chiefly on the lower bowel, it is especially suitable in habitual costiveness. It increases the peristaltic movements of the colon by its local action upon the intestinal wall. Its active principle must pass out of the system in the secretions unaltered, for when Senna is taken by nurses, the suckling infant becomes purged. It acts neither as a sedative nor as a refrigerant, but has a slight, stimulating influence. In addition to the nauseating taste, it is apt to cause sickness, and griping pains, so that few can take it alone; but these characteristics can be overcome or removed, when it is well adapted for children, elderly persons, and delicate women. The colouring matter 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 colour on the addition of ammonia.

The addition of cloves, ginger, cinnamon, or other aromatics are excellent correctives of the nauseous effects. A teaspoonful of cream of tartar to a teacupful of the decoction of infusion of Senna, is a mild and pleasant cathartic, well suited for women if required soon after delivery. Some practitioners add neutral laxative salts, or saccharine and aromatic substances. The purgative effect is increased by the addition of pure bitters; the decoction of guaiacum is said to answer a similar purpose. Senna is contraindicated in an inflammatory condition of the alimentary canal, hemorrhoids, prolapsus, ani, etc. The well-known 'black draught' is a combination of Senna and Gentian, with any aromatic, as cardamom or coriander seeds, or the rind of the Seville orange. The term 'black draught,' it is stated, should never be used, as mistakes have been made in reading the prescriptions, and 'black drop' or vinegar of opium has been given instead, several deaths having been caused in this way.

SENNA PODS, or the dried, ripe fruits, are official in the British Pharmacopceia, though the quantity is restricted, as an adulterant, in the United States Pharmacopoeia.

They are milder in their effects than the leaflets, as the griping is largely due to the resin, and the pods contain none, but have about 25 per cent more cathartie acid and emodin than the leaves, without volatile oil. From 6 to 12 pods for the adult, or from 3 to 6 for the young or very aged, infused in a claret-glass of cold water, act mildly but thoroughly upon the whole intestine.

The fluid extract was formerly treated with alcohol for the removal of the griping principles, but the process was deleted from the United States Pharmacopoeia. The fluid extract is a dark, blackish, thick and somewhat turbid liquid, with a strong flavour of Senna. It is well adapted for exhibition with saline cathartics, such as Epsom salt or cream of tartar. In this ease not more than half the full dose should be given at once. The British Pharmacopoeia 1898 'Liquor Sennae Concentratus' was more like a concentrated infusion than a fluid extraet, but had the same strength as the latter, the menstrum being distilled water; tincture of ginger and alcohol being added.

The infusion of Senna, or Senna Tea, consists of 100 grams of Senna leaves, 5 grams of sliced Ginger, 1,000 millilitres of distilled water, boiling. Infuse in a covered vessel for fifteen minutes, and strain, while hot. The United States Pharmacopoeia prefers coriander to ginger. The infusion deposits, on exposure to air, a yellowish precipitate, so it is advisable to make it in very small quantities, as the deposit aggravates its griping tendency. It is usual to prescribe manna and one of the saline cathartics with it. The cold infusion is said to be less unpleasant in taste, and equal in strength to the hot.

SYRUP OF SENNA is prepared by mixing 8 fluid ounces, 218 minims of fluid extract of Senna, with 81 minims of oil of Coriander and sufficient syrup to make 33 fluid ounces (6 1/2 fluid drachms).

The Aromatic Syrup includes also jalap, rhubarb, cinnamon, clove, nutmeg, oil of lemon, sugar, and diluted alcohol.

The Compound Syrup includes rhubarb, frangula, methyl salicylate, alcohol, and syrup.

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---Dosages---Powdered leaves, 1 drachm. Conct. solution, B.P., 1/2 to 1 drachm. Of compound or aromatic syrup, 2 fluid drachms. Of U.S.P. syrup, for an adult, 1 to 4 fluid drachms. Of B.P. syrup, 1 to 2 fluid drachms. Of Senna, 1/2 to 2 drachms. Of eompound mixture, B.P., 4 to 16 drachms. Of infusion, B.P., 1/2 to 2 fluid ounces. Of fluid extract, for an adult, 1/2 to 2 fluid draehms. Of confection, B.P., 1 to 2 drachms.

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---Adulterations and Other Species Used---Owing to the high price, what is known as 'broken Senna' is found on the market and sold for the genuine article with government sanction in the United States of America. Also, 'Senna siftings,' containing sand and other foreign matter have been offered for sale, causing trouble to government inspectors.

Formerly there was an intentional mixture of 5 parts of C. acutifolia, 3 of C. obovata, and 2 of Cynanchum, but now Alexandrian Senna is more uniform. It is often called in the French Pharmacopoeia séné de la palthe, because of the duty formerly laid upon it by the Ottoman Porte. A parcel of Alexandrian Senna in the market formerly consisted of (1) leaflets of C. acutifolia, (2) leaflets of C. obovata, (3) the pods, broken leaf-stalks, flowers, and fine fragments of either, (4) leaves of Cynanchum oleofolium. The last are larger, thicker, regular at the base, and have no lateral nerves visible on their undersurface. They must be regarded as an adulteration.

C. angustifolia or Tinnevelly Senna, Senna Indica, C. elongata is an annual growing in the Yemen and Hadramaut provinces of Arabia Felix, in Somaliland, Mozambique, Scind, and the Punjab. In Southern India it is cultivated and grows to a larger size. In the German and Swiss Pharmacopoeias, the official drug is restricted to Tinnevelly Senna, and also in the British Pharmacopoeia and the Pharmacopoeia of India. Senna Indica also includes the variety known as Arabian, Mocha, Bombay, or East Indian Senna. Both varieties, as well as Alexandrian Senna, are official in the United States Pharmacopoeia.

There is a certain difference in the qualities and also in the names of the species imported into Britain and America. The fine Tinnevelly Senna goes from Madras or Tuticorin to Britain. The leaflets are unbroken, from 1 to 2 or more inches long, thin, flexible, and green.

It has been stated that it contains only two-thirds as much of the active principle as the Alexandrian.

The other, or Arabian variety, comes via Mocha and Bombay, and is less pure and less carefully prepared. The leaflets are long and narrow, pike-like, so are called in France séné de la pique. Leaflets resembling these were brought by Livingstone from Southeast Africa. Mecca Senna, also known in America as Arabian or Bombay Senna, is obtained from both the wild and the cultivated kinds of C. angustifolia. The best comes from British India. The variety has sometimes a yellowish or tawny colour, more like the Indica than the Alexandrian, and may be the product of C. lanceolata of Forskhal. C. obovata, C. obtusa or Senna obtusa is usually a perennial, found wild in Egypt, Nubia, Abyssinia, Tripoli, Senegal and Benguella, Arabia and India. It was the first kind of Senna known, and being brought by the Moors into Europe, was formerly cultivated in Northern Italy, Spain, and Southern France, and called S. italica. It is official in the British Pharmacopceia and the Pharmacopoeia of India as one of the botanical sources of Alexandrian Senna, but now few of its leaflets are included. It is called by the Arabs S. baladi, i.e. indigenous or wild Senna, to distinguish it from C. acutifolia, S. jebeli, or Mountain Senna. It is common in Jamaica, where its cultivation has been suggested, and where it is called Port Royal Senna or Jamaica Senna.

C. Marilandica or American Senna, Wild Senna, Poinciana pulcherima, formerly Maryland Senna, is a common perennial from New England to Northern Carolina. Its leaves are compressed into oblong cakes like other herbal preparations of the Shakers. It acts like Senna, but is weaker, and should be combined with aromatics. The dose in powder is from 1/2 to 2 1/2 drachms. For the infusion, add 1 ounce of the leaves and 1 drachm of coriander seeds to 1 pint of boiling water. Macerate for an hour in a covered vessel, and strain. Dose: 4 to 5 fluid ounces. These leaves are also found mixed with or substituted for Alexandrian Senna.

C. Chamoecrista, Prairie Senna, Partridge Pea, Dwarf Cassia, or Sensitive Pea, found on the Western Prairies, is an excellent substiture for the above.

C. fistula, or Purging Cassia, C. Stick, Pudding Pipe-Tree, or Alexandrian Purging Cassia, is a tree rising to 40 feet in height, the pulp of the pods being used in the electuary of Senna. It is found in Egypt, the Indies, China, etc.

Colutea arborescens, or Bladder-Senna (see SENNA, BLADDER), Baguenaudier, Séné Indigène, the Sutherlandia frutescens of the Cape, formerly often met with as a substitute, is now usually replaced by Globularia Turbith or Alypum, the leaves of which are milder, so that a double dose may be taken. It is the Wild Senna of Europe.

Coriaria Myrtifolia is a Mediterranean shrub and highly poisonous, so that it should be recognized when present. The leaves are green, very thin, and soft, three veined, ovate-lanceolate, and equal at the base. It grows wild in Southern Europe, and its leaves are used as a black dye. It is also used to adulterate sweet marjoram. Deaths are recorded from eating the small, black berries. A Mexican drug, Tlolocopetale, containing coriarin and coriamurtin, is said to be a product. Other names are Currierts Sumach and Redoul.

Argel leaves (Solenostemma or Cynanchum Argel), from Nubia, are paler in colour, have less conspicuous veins, and an equal base.

Tephrosia leaflets and legumes (Tephrosia Apollinea), from the banks of the Nile, are silky or silvery, equal at the base and usually folded longitudinally on their mid-rib.

Jaborandi Leaflets (Bilocarpus Microphyllus) have been imported under the name of Senna.

Aden Senna is believed to be obtained from C. holosericeae.

C. montana yields a false Senna from Madras, partly resembling the Tinnevelly Senna, though the colour of the upper surface of the leaves is browner.

It must be remembered that the Senna leaf contains no tannic acid and does not alter a ferric solution, while most of those encountered as adulterations precipitate ferric-chloride.

Other varieties used in their native countries, of which little appears to be known, are also:

C. cathartica, C. rugosa, C. splendida, C. leavigata, C. multijuja, Coronilla Emenls or Scorpion Senna, C. obovata or Senegal Senna.

Purchase from Richters Seeds American Senna (Cassia marilandica) Seeds Bladder Senna (Colutea arborescens) Seeds Chinese Senna (Cassia tora) Seeds Indian Senna (Cassia angustifolia) Seeds