Althaea. U. S. Althaea.
"The root of Althaea officinalis Linne (Fam. Malvaceae) deprived of the brown, corky layer and small roots, and carefully dried. Preserve Althaea in tightly-closed containers, adding a few drops of chloroform or carbon tetrachloride from time to time, to prevent attack by insects." U.S.
Radix Hibisci, Radix Bismalvae; Wymote, White Mallow, Mortification root; Racine de Guimauve, Guimauve, Fr.; Radix Althaeae, P. G.; Altheewurzel, Althee, Eibischwurzel; Eibisch, G.; Altea, Malvavischio, It.; Altea, Raiz de Malvavisco, Sp.
Althaea officinalis is an herbaceous perennial, with a perpendicular branching root and erect woolly stems, from two to four feet or more in height, branched and leafy towards the summit. The leaves are described under Folio Althaea, p. 120. The flowers are terminal and axillary, with short peduncles, each bearing one, two, or three flowers. The corolla has five spreading, obcordate petals, of a pale rose color. The fruit consists of numerous capsules united in a compact circular form, each containing a single seed. The plant grows throughout Europe, inhabiting salt marshes, the banks of rivers, and other moist places. It is found also in this country, from New England to New York and westward to Michigan and Arkansas. It is largely cultivated in Europe for medicinal use, particularly in Germany, Belgium and France.
The roots should be collected in autumn from plants at least two years old. They are usually prepared for the market by removing the outer layers. The commercial drug sometimes consists of the unpeeled root, which is sliced transversely and diagonally.
Properties.—Althaea is usually cut into small pieces about 5 mm. in diameter, of a uniform grayish-white color and otherwise having the characters of entire roots; occasionally entire, slenderly tapering, attaining a length of 30 cm. and a thickness of 2 cm., externally whitish, longitudinally furrowed, frequently spirally twisted and covered with the somewhat loosened bast-fibers; fracture of bark fibrous, of wood short and granular; internally yellowish-white; bark 1 to 2 mm. thick, porous, due to mucilage cells, and separated from the slightly radiating wood by a distinct, grayish cambium zone; odor slight; taste sweetish, mucilaginous. The powder is whitish; starch grains numerous, from 0.003 to 0.02 mm. in diameter, usually with a long cleft at the point of origin of growth; sclerenchymatous fibers in groups, the walls being quite thick and more or less lignified; tracheae with scalariform thickenings or with bordered pores; calcium oxalate crystals few, in rosette aggregates from 0.02 mm. to 0.03 mm. in diameter. Add 1 Gm. of Althaea to 10 mils of cold water, allow it to stand with occasional stirring during thirty minutes, and filter through cotton; a pale yellow-colored mucilage is obtained, which is neutral to litmus and is colored a deep yellow on the addition of a few drops of potassium hydroxide T.S. The mucilage does not have a sour or ammoniacal odor. Althaea yields not more than 8 per cent. of ash." U. S.
The abundant mucilage is situated chiefly in special cells, and can be seen to be in layers when alcohol is added. Kraemer (A. J. P., 1898, p. 285) proposed the use of an alcoholic solution of methylene blue for the differentiation of the mucilage. It, with starch and saccharine matter, is taken out by boiling water. The mucilage, without the starch, is extracted by cold water, which thus becomes ropy. A principle was discovered in the root by Bacon, which has been ascertained to be identical with asparagin, C4H8N2O3 + H2O. Boutron-Charland and Pelouze found it to belong to that class of organic principles which are convertible by strong acids, and other agencies, into ammonia and organic acids, and which are designated by the termination amide, being compounds of acid radicals with the group NHa. When such an amide is acted upon by acids, it is decomposed, the acid radical taking OH to form the free acid and the amide group taking H to form ammonia. Thus asparagin, which in this view should be called asparamide, is converted into ammonia and aspartic acid, C4H7NO4, and one molecule of the resulting ammonium aspartate corresponds with one molecule of asparamide and one of water. (J. P. C., xix, 208.) Asparagin, being now recognized aa a derivative of succinic acid, is called amido-succinamide, and the aspartic acid is called amido-succinic acid. It is found in various other plants besides the marshmallow, as in the shoots of asparagus, in vetches grown in the dark, in all the varieties of the potato, and in the roots of the comfrey and licorice plant.
According to Pira, asparagin has acid properties. It has no therapeutic value. Betaine (trimethyl-glycocoll) has been obtained from Althaea by Orlow. (Ph. Z. R., 1898.)
The roots of other Malvaceae are sometimes substituted for that of marshmallow, without disadvantage, as they possess similar properties. Among these are Althaea rosea Cav., or hollyhock, and Malva Alcea L. The dark purple flowers of a variety of A. rosea have been proposed as a test for acids and alkalies. A strong infusion of these flowers imparts to slips of white filtering paper a permanent purplish-blue color, which is reddened by acids, and rendered bluish-green by alkalies.
ALTHAEA or MARSHMALLOW LEAVES, under the title of Folia Althaea, are official in the Swiss, German and Austrian Pharmacopoeias and as Althaea Folia in the National Formulary. The leaves are collected in June or July, while the plant is in flower, and dried. They are described in the N. F. as "the dried leaves of Althaea officinalis Linne (Fam. Malvaceae), without the presence of more than 5 per cent. of stems or other foreign matter." N. F. As seen in commerce they are "gray-green or yellowish gray-green and densely and finely tomentose throughout; petioles one-sixth to one-fifth as long as the blades; blades varying from 5 to 15 cm. in length and from 3 to 10 cm. in breadth, cordate or rhomboidal-ovate in outline, rounded or occasionally nearly truncate at the base, acute at the summit; margin doubly serrate-dentate, the principal teeth from one to three pairs, the lowest almost large enough to be regarded as lobes, the secondary very irregular, triangulate, acute, broader than long, the sinuses acute; two to four occasionally six principal veins originating with the midrib in the petiole, prominent underneath, terete; branches of the midrib arising at a wide angle, nearly straight, each terminating in a marginal tooth. Leaf thin, but appearing thick because of its hairy covering. Odor slight, scarcely characteristic; taste mucilaginous. The powdered drug is grayish to grayish-green and, when examined under the microscope, exhibits numerous unicellular, non-lignified stellate branching hairs, up to 0.6 mm. in length, usually occurring in clusters of two to six; few, short stalked, multicellular glandular hairs; calcium oxalate in rosette aggregates up to 0.025 mm. in diameter; fragments of the epidermal tissue with stomata, the latter about 0.025 mm. in length; few lamellated mucilage cells; usually a few pollen grains, spherical, spiny, up to 0.1 mm. in diameter. Althaea Leaves yield not more than 16 per cent. of ash." N. F.
Uses.—The virtues of marshmallow are exclusively those of a demulcent. The decoction of the root is much used in Europe in irritation and inflammation of the mucous membranes. A syrup of althaea is official in the German Pharmacopoeia, and was introduced into the U. S. Pharmacopoeias of 1880 and 1890 (see U. S. D., 18th edition, p. 1327). Owing to its tendency to ferment rapidly it was not retained in the U. S. P. VIII or IX, but is found in the N. F. IV. (See Syrupus Althaeae.) The roots themselves, as well as the leaves and flowers, boiled and bruised, are sometimes employed as a poultice. In France the powdered root is much used in the preparation of pills and electuaries. It enters, as an ingredient, into one mass and two pills of the U. S. P.
Off. Prep.—Massa Hydrargyri, U. S.; Pilulae Ferri Carbonatis, U. S.; Pilulae Phosphori, U. S., Species Pectorales, N. F.; Syrupus Althaeae, N. F.