Glycosides are substances produced by plants that consist of two components, a sugar part and a non-sugar part, or aglycon. Glycosides are widely distributed in the plant world and can be found in all parts of plants, easily cleaved into a sugar part and an aglycone in the presence of water and enzymes (or enzymes). In glycosides, the nature of the therapeutic properties is mainly due to the aglycone, but the sugar component also exerts therapeutic effects by affecting their solubility and absorption. Glycosides, obtained in pure form usually crystalline substances, easily soluble in water, more difficult in alcohol, often bitter taste, many poisonous and for medicinal purposes are used in small doses. Due to their unstable nature, until recently they were rarely used in pure form for treatment, using more often various extracts. Pure glycosides (strophanthin, erysimine, foxglove glycosides, etc.) are now widely used.). Glycosides are distinguished as cardiac glycosides, bitter glycosides, saponins, anthraglycosides, diaphoretics, etc.
Cardiac glycosides have an effect on the heart muscle and have the greatest medicinal use. Many plants containing cardiac glycosides - Adonis spring, gray jaundice, hemp kendyr, May lily of the valley, sea onion, red foxglove, etc., and others. - have been widely used in folk medicine and are still used today.
Bitter glycosides, or bitters, are substances of plant origin. They have a bitter taste and have a certain physiological effect on the body - increase the secretory activity of the gastrointestinal tract, contribute to the excitement of appetite and improve digestion. Chemically, the bitters have been little studied until recently because of the difficulty of isolating them in pure form. The few bitters isolated in pure form are soluble in water, alcohol and other solvents. The bitter glycosides include absinthine of bitter wormwood, aucubin of veronica medicinalis, eritaurin of goldenseal, etc. Some plants contain non-nitrogenous, non-glycoside bitters. Bitters with known chemical composition include humulone and lupulone, which are contained in the resinous substance of hops and have a sedative effect. Gelenin is found in the roots of elecampane high, which is used as a bitter stomachic remedy. Artemisinin is a bitterness found in common wormwood, and santonin in wormwood santonine.
И. П. Pavlov wrote about such substances as bitters: "Bitters are veterans among the mass of other medicinal substances; their use dates back to the beginning of human history. Already with the Greeks and Romans bitters found their use, and apparently there was reason to use them. In this way the case has continued until our time. But in the last dozen years medicine, and it is the therapeutic department of it in particular, has turned to testing the data of empiricism by experiment. Old drug substances are invited to the laboratory and subjected to examination. Since bitters whet the appetite, t. е. are conducive to the enjoyment of food, then the matter is settled. Bitter substances are substances that promote digestion, improving it, because they excite the appetite, which is the basis of enjoyment of food, and enjoyment is the first real exciter of the secretory nerve centers of the stomach. I think that this conclusion can hardly raise the objection that appetite as the basis of the enjoyment of food is the real exciter of the secretory nerves of the stomach, and, consequently, the bitters that cause it are also exciters, and much better than many of those which, under extremely perverse laboratory conditions, would give some slight separation."
Saponins (from Latin. Sapo - soap) are glycosides that do not contain nitrogen in their composition and are most commonly found in plants. Saponins are well soluble in water and in alcohol. Aqueous solutions of saponins, when shaken, form a stable foam resembling soap foam. Plants that contain saponins are used in medicine as expectorants for respiratory diseases, as well as diuretics, tonic, stimulant and tonic, many of them have a beneficial effect on the cardiovascular system, have a sedative effect and are especially effective in vascular sclerosis (A. Д. Turova, JI. Н. Sokolova, D. В. Pankow).
Recently, it has been revealed that saponins have a favorable effect in the treatment of atherosclerosis of cerebral vessels, atherosclerosis in combination with hypertension and malignant neoplasms (A. М. Zakharov, S. М. Kabanov, 1964).
In small doses of saponins are harmless, but being harmless when taken orally, they are very poisonous when injected subcutaneously and especially when administered intravenously: under the influence of saponins erythrocytes undergo hemolysis.
Glycosides, especially cardiac glycosides, are unstable. Under the action of enzymes in the presence of moisture, as well as in the presence of acids, they are broken down into their constituent parts (sugars and aglycone), which changes the nature of their therapeutic action. Therefore, proper regulations must be carefully followed when harvesting, processing and storing glycoside plants..
