This section is from the book "A Treatise On Therapeutics, And Pharmacology Or Materia Medica Vol2", by George B. Wood. Also available from Amazon: Part 1 and Part 2.
Syn. Seneka Snakeroot.
Seneka is the root of Polygala Senega, a small, indigenous,.her-baceous perennial, from nine inches to a foot in height, growing in woods in different parts of the United States, especially the middle and southern sections, on both sides of the Alleghany mountains.
The root is several inches long, tapering, contorted, of about the medium size of a quill, ending at top in an abruptly expanded head, which is rough and irregular from the insertion of the stems of successive years. One of its most striking characters, distinguishing it from all other medicinal roots, is a projecting line or keel, running along its whole length, and having the appearance as if a string were passing from one end to the other, immediately under the bark, shorter than the root, and consequently producing the contorted appearance, which is also characteristic. The colour of the young and fresh roots is yellow; but it darkens and becomes grayish by age and exposure. The colour of the powder is grayish. The root consists of an interior wood, and an outer cortical portion, in the latter of which its sensible properties and medicinal virtues reside. The odour is peculiar, but feeble in the dried root; the taste at first sweetish, but afterwards pungent, acrid, and adhesive. When chewed, the root produces irritation of the throat, excites an increased flow of saliva, and sometimes provokes coughing. its virtues are extracted by water and alcohol, more readily hot than cold. it is injured by long boiling.
Active Principle. The virtues of seneka appear to reside in a peculiar very acrid principle, which, having been ascertained to possess acid properties, has been named polygalic acid, though at first denominated sene-gin. it is a white, pulverulent substance, of little taste at first,, but after a time extremely acrid and irritant to the mouth and fauces. it is slowly soluble in cold and more rapidly in hot water, very soluble in alcohol, and insoluble in ether and the fixed oils. At a boiling temperature, it is said to combine with one or more principles in the root, to form an insoluble compound.
Seneka is locally irritant, in large doses emetic and cathartic, and, in its influence on the system, a general stimulant of the secretions, though with a special direction to the lungs and bronchial mucous membrane. it acts occasionally as a diuretic, diaphoretic, siala-gogue, and emmenagogue. in over-doses, it produces burning heat in the stomach, abdominal pains, and severe vomiting and purging; and sometimes causes, along with increase of the renal secretion, a sense of heat in the urinary passages. There can be little doubt that its active principle is absorbed, and, carrying its irritant properties into the circulation, excites the capillaries more or less everywhere, but particularly in the different emunctories through which it escapes. Senegin or polygalic acid, given to a dog, was found by M. Quevenne to cause vomiting with embarrassed respiration, and to prove fatal in large doses. After death, marks of inflammation were found in the stomach, lungs, and trachea, showing a special tendency, after absorption, to the latter organs. Seneka has little observable influence upon the general circulation; and, when given pretty freely, produces so much nausea, as, in some degree, to counteract its excitant influence upon the ultimate tissue.
Seneka was first brought into notice in the year 1135, by Dr. Tennant, of Virginia, who imagined that it had peculiar virtues in the poison of the rattlesnake, for which it was used by a tribe of Indians. Dr. Tennant also employed it in pectoral diseases. At present no one has any faith in its antidotal powers; but it is among the most highly esteemed expectorants. From its stimulant influence upon the ultimate tissue of the lungs and bronchia, it is not adapted to inflammation of these organs, in its state of highest activity; but in the advanced stages, and in chronic states of the affection, it is often very useful. I believe that it does not operate merely by its expectorant properties, but also through its excitant and alterative influence on the diseased tissue. it is, therefore, peculiarly adapted to those conditions, in which the bronchial mucous membrane is left enfeebled and relaxed by preceding inflammation, and wants the requisite energy to recover its normal state. By combination, however, with tartar emetic or ipecacuanha, its irritant influence over the vessels is modified, so that its expectorant effects may be obtained with less risk of over-excitement of the local circulation; and it may thus be given at an earlier stage than it ought to be ventured on alone. Moreover, as before stated, when given very freely, it produces nausea, and thus induces a sympathetic relaxation of the tissues, which may obviate, in a considerable degree, its direct irritation produced through the circulation.
The complaints in which it has been employed most usefully are pneumonia in its advanced stages, bronchitis after the acute symptoms have subsided, and especially in its chronic states, laryngitis under similar circumstances, and catarrhal croup. I know no one medicine, except mercury, in which I have greater confidence in chronic bronchitis, whether with profuse or scanty expectoration. it has seemed to me to act favourably in cases of this kind, quite independently of any observable influence as an expectorant, and probably by an alterative action on the membrane.
In croup it was very highly recommended by Dr. Archer, of Maryland, and, if given so as to vomit freely, will very generally relieve the spasmodic or catarrhal variety of the disease; but it is probably less efficacious than tartar emetic, and not more so than ipecacuanha. To the cure of pseudomembranous croup it is quite inadequate; but may nevertheless be used conjointly with other measures, in the hope of producing mucous secretion, and thereby loosening the false membrane. To the condition of tracheal and bronchial inflammation which croup frequently leaves behind, it is admirably adapted, especially in combination with other less stimulant expectorants.
In consequence of its occasional diuretic effect, it is said to have been used with success in dropsy; and, in those cases of the disease, not very uncommon, which are associated with chronic bronchitis, it would seem to be indicated, in connection with more certain diuretic medicines.
It is said to have been useful in rheumatism, through its emetic and purgative properties; and its excitant influence on the ultimate tissues places it in the category of alterative medicines, which have been found useful in the chronic forms of that disease, as guaiac, turpentine, etc.
i shall have occasion hereafter to consider the root in relation to its supposed emmenagogue powers.
The dose of powdered seneka is from ten to twenty grains; but it is almost never administered in this state. Decoction, infusion, and syrup are the ordinary forms of exhibition.
1. Decoction of Seneka (Decoctum Senegae, U. S.) is officinally made by boiling a troyounce of the bruised root in a pint of water, for fifteen minutes, straining, and adding enough water, through the strainer, to make the decoction measure a pint. I am not sure, however, that the old plan of boiling the seneka in a pint and a half of water to a pint, is not better; as the solvent power of a larger proportion of water is exerted. This may be improved by the addition of an ounce of bruised liquorice root, which tends, by its demulcent properties, in some degree, to cover the acrimony of the seneka. if a grain of tartar emetic be added, the preparation will be rendered still more efficacious in most cases of bronchial disease. A combination of this kind, with the still further addition of an ounce or more of crystallized sugar, was a favourite remedy of the late Dr. Physick in pectoral diseases, and has been much employed by myself in chronic bronchitis. it has, however, been shown that decoction is not the best method of extracting the virtues of seneka, which are impaired by the continued heat. The dose of the officinal decoction is one or two fluidounces, three or four times a day. The compound decoction referred to, containing tartar emetic, liquorice root, and sugar, besides seneka, may be given in the dose of half a fluidounce or a tablespoonful, every two or three hours.
2. infusion of Seneka (infusum Senegae, Br.) may be made in the same proportions as the decoction, that is, an ounce of the root to a pint of water, and, if duly prepared, is probably more efficient. But, in order that the virtues of the root may be thoroughly extracted, it should be reduced to the state of powder, and then treated upon the plan of percolation. As made, in the British Pharmacopoeia, by simple maceration for an hour, it is probably much feebler. The same additions may be made to this as to the preceding preparation. The dose is the same.
3. Syrup of Seneka (Syrupus Senegae, U. S.) is made by exhausting the root with diluted alcohol, evaporating so as to drive off the alcohol, and then adding sugar to form a syrup. This is an excellent preparation, concentrating the virtues of the medicine in a small bulk, and very convenient of administration. it may be given alone, in the dose of one or two fluidrachms, from two to four times a day.
I have been much in the habit, in the advanced stages of catarrhal disease, and in the chronic forms of it, of employing the following mixture, which often answers a very good purpose, in allaying cough, sustaining expectoration, and modifying favourably the condition of the diseased membrane. Take of syrup of seneka and syrup of squill, each, one fluidounce, antimonial wine and solution of sulphate of morphia, each, half a fluidounce, and mix them together. if deemed advisable, ipecacuanha wine may be substituted for the antimonial. One or two fluidrachms may be taken every four, six, or eight hours.
4. Compound Syrup of Squill (Syrupus Scillae Compositus, U. S.) is an officinal of the U. S. Pharmacopoeia, adopted as a substitute for a preparation long extremely popular under the name of Coxe's hive syrup, originally prepared by Dr. John Redman Coxe, of Philadelphia. it contains the virtues of squill and seneka, with a grain of tartar emetic in each fluidounce. The chief difference between this and the original preparation is that sugar has been substituted for honey. This syrup has been much used in the treatment of our ordinary catarrhal or spasmodic croup, and will, no doubt, generally prove successful, if pushed to emesis. I do not, however, know that it is in any degree more effectual than the antimonial uncombined. it is a good expectorant, applicable to the somewhat advanced stages of pulmonary, bronchial, and laryngeal inflammation, whether in children or adults. The dose it, as an expectorant for an adult, is from twenty minims to a fluidrachm. if given to children with croup, as an emetic, from ten minims to a fluidrachm, according to the age of the child, should be repeated every fifteen or twenty minutes till it vomits